This study reviewed the immunogenicity and safety of the CYD-TDV dengue vaccine candidate. Researchers collected serum samples and monitored adverse events in vaccine recipients. They found that the vaccine induced neutralizing antibodies against the four dengue virus serotypes. While immune responses varied between individuals, pre-existing flavivirus immunity improved vaccine responses without impacting the balanced response. The first dose primarily induced responses to DENV-2 and DENV-4, while subsequent doses increased responses to all serotypes. However, further studies are still needed to determine safe reactogenicity levels and the immunogenicity required for protection.
The document summarizes key aspects of dengue virus infection and the immune response. It notes that dengue virus is transmitted via mosquito bites and causes fever. The immune response produces IgM and IgG antibodies that help fight the virus. However, secondary infections can be more severe due to antibody-dependent enhancement. There is currently no vaccine or specific treatment, though supportive care and symptom management are used. Research is ongoing into developing antiviral drugs and a safe, effective vaccine against the four dengue virus serotypes.
The document discusses dengue virus (DENV), which is transmitted through mosquitoes and causes dengue fever (DF) and the more severe dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). It summarizes three major hypotheses for the pathogenesis of DHF/DSS: antibody-dependent enhancement, inappropriate T cell response, and viral virulence. It also discusses potential targets for dengue diagnosis, treatment and vaccines.
This document describes the development of reporter Dengue virus (DENV) strains that express green fluorescent protein (GFP) or firefly luciferase (Fluc). The reporter DENV strains were characterized in vitro and in vivo. In vitro, the reporter DENV strains were infectious, sensitive to antiviral compounds and interferons, and allowed screening of a library of interferon-stimulated genes. In vivo bioluminescence imaging in mice revealed that DENV localized predominantly to lymphoid and gut tissues. A mutation (NS4B L52F) was required to confer virulence of the reporter DENV strain in mice. The reporter DENV strains provide a platform for applications such as antiviral discovery and vaccine validation.
Dengue Virus: Genomic Insights, Pathogenic Mechanisms, and Therapeutic Approa...SindhBiotech
This lecture is presented by our volunteer Sajid Ali Shah, he is from Islamabad, Pakistan, and he is covering Dengue Virus: Genomic Insights, Pathogenic Mechanisms, and Therapeutic Approaches
for video: https://youtu.be/whrkkKR-NSY
#denguevirus #virology #virologist #genomics #covid19 #virus #pathogen #pathology #immunology
Retroviruses. Human Immunodeficiency virus (HIV). Diagnostics of HIV & AIDSEneutron
This document discusses human immunodeficiency virus (HIV) and the laboratory diagnosis of HIV infection. It covers:
1. The classification of retroviruses and characteristics of HIV. HIV is a lentivirus that causes AIDS.
2. Methods for laboratory diagnosis of HIV infection including ELISA to detect antibodies and Western blot for confirmation.
3. The stages of HIV infection from acute infection to AIDS. Opportunistic infections are common as the virus progresses.
HIV is a retrovirus that infects and destroys CD4+ immune cells. It has high genetic variability due to a lack of proofreading during replication. There are three main groups of HIV (M, O, N) with group M causing the global epidemic and consisting of nine genetic subtypes. Natural infection progresses from asymptomatic infection to AIDS without treatment over many years. Some individuals are able to control virus levels long-term. Diagnosis involves antibody and viral load testing. While antiretroviral therapy can suppress the virus, developing an effective vaccine has proven difficult due to HIV's ability to mutate and evade the immune system.
Detection of dengue viruses using RT-LAMPRahul Gupta
This is the research paper which i have been choosen for presentation "Detection of Dengue viruses using RT-LAMP", it is a technique use for early detection of Dengue virus.
This study reviewed the immunogenicity and safety of the CYD-TDV dengue vaccine candidate. Researchers collected serum samples and monitored adverse events in vaccine recipients. They found that the vaccine induced neutralizing antibodies against the four dengue virus serotypes. While immune responses varied between individuals, pre-existing flavivirus immunity improved vaccine responses without impacting the balanced response. The first dose primarily induced responses to DENV-2 and DENV-4, while subsequent doses increased responses to all serotypes. However, further studies are still needed to determine safe reactogenicity levels and the immunogenicity required for protection.
The document summarizes key aspects of dengue virus infection and the immune response. It notes that dengue virus is transmitted via mosquito bites and causes fever. The immune response produces IgM and IgG antibodies that help fight the virus. However, secondary infections can be more severe due to antibody-dependent enhancement. There is currently no vaccine or specific treatment, though supportive care and symptom management are used. Research is ongoing into developing antiviral drugs and a safe, effective vaccine against the four dengue virus serotypes.
The document discusses dengue virus (DENV), which is transmitted through mosquitoes and causes dengue fever (DF) and the more severe dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). It summarizes three major hypotheses for the pathogenesis of DHF/DSS: antibody-dependent enhancement, inappropriate T cell response, and viral virulence. It also discusses potential targets for dengue diagnosis, treatment and vaccines.
This document describes the development of reporter Dengue virus (DENV) strains that express green fluorescent protein (GFP) or firefly luciferase (Fluc). The reporter DENV strains were characterized in vitro and in vivo. In vitro, the reporter DENV strains were infectious, sensitive to antiviral compounds and interferons, and allowed screening of a library of interferon-stimulated genes. In vivo bioluminescence imaging in mice revealed that DENV localized predominantly to lymphoid and gut tissues. A mutation (NS4B L52F) was required to confer virulence of the reporter DENV strain in mice. The reporter DENV strains provide a platform for applications such as antiviral discovery and vaccine validation.
Dengue Virus: Genomic Insights, Pathogenic Mechanisms, and Therapeutic Approa...SindhBiotech
This lecture is presented by our volunteer Sajid Ali Shah, he is from Islamabad, Pakistan, and he is covering Dengue Virus: Genomic Insights, Pathogenic Mechanisms, and Therapeutic Approaches
for video: https://youtu.be/whrkkKR-NSY
#denguevirus #virology #virologist #genomics #covid19 #virus #pathogen #pathology #immunology
Retroviruses. Human Immunodeficiency virus (HIV). Diagnostics of HIV & AIDSEneutron
This document discusses human immunodeficiency virus (HIV) and the laboratory diagnosis of HIV infection. It covers:
1. The classification of retroviruses and characteristics of HIV. HIV is a lentivirus that causes AIDS.
2. Methods for laboratory diagnosis of HIV infection including ELISA to detect antibodies and Western blot for confirmation.
3. The stages of HIV infection from acute infection to AIDS. Opportunistic infections are common as the virus progresses.
HIV is a retrovirus that infects and destroys CD4+ immune cells. It has high genetic variability due to a lack of proofreading during replication. There are three main groups of HIV (M, O, N) with group M causing the global epidemic and consisting of nine genetic subtypes. Natural infection progresses from asymptomatic infection to AIDS without treatment over many years. Some individuals are able to control virus levels long-term. Diagnosis involves antibody and viral load testing. While antiretroviral therapy can suppress the virus, developing an effective vaccine has proven difficult due to HIV's ability to mutate and evade the immune system.
Detection of dengue viruses using RT-LAMPRahul Gupta
This is the research paper which i have been choosen for presentation "Detection of Dengue viruses using RT-LAMP", it is a technique use for early detection of Dengue virus.
This document summarizes dengue virus, pathogenesis, and laboratory diagnosis. It describes dengue as the most prevalent mosquito-borne viral disease, caused by one of four serotypes. Symptoms range from asymptomatic to severe disease and death. Secondary infection with a different serotype is a risk factor for severe disease. While antibody-dependent enhancement and original antigenic sin may explain some cases, additional factors like host genetics are also involved. Laboratory diagnosis involves serological tests like NS1 antigen detection, IgM ELISA, and molecular tests like RT-PCR. Sensitivity and specificity vary by test but are generally over 95% for validated ELISA kits.
This Power Point presentation deals with the Dengue virus its cause and mechanism. How the virus infects the host and how the host immune cells kill the virus. vaccines against this virus and the recent advances related to these virus.
Dengue- WS on vector borne viral infection 2011javed.khalil
The document discusses dengue virus and the dengue situation in Sri Lanka. It provides details on dengue virus such as its family, serotypes, laboratory diagnosis methods, pathogenesis, and vaccine candidates. It notes that though all four dengue serotypes are circulating in Sri Lanka, serotypes 2 and 3 were predominant before 1989 when the first dengue hemorrhagic fever outbreak occurred, linked to serotype 3 subtype III group B. Genetic analysis showed the strain associated with dengue hemorrhagic fever had genetic changes compared to earlier serotype 3 strains that caused dengue fever. Surveillance data on circulating serotypes from 2006-2011 is also presented.
This document summarizes a study examining the genetic attributes associated with the exceptional sensitivity of an HIV-1 clade C envelope protein to autologous broadly neutralizing plasma antibodies. The researchers identified an envelope that was significantly more sensitive to neutralization by contemporaneous plasma than two other envelopes. Sequence analysis found mutations in the V3/C3 region of the sensitive envelope. Chimeric envelope experiments determined that replacing the V3/C3 region of a resistant envelope with the sensitive envelope conferred enhanced neutralization sensitivity, indicating this region plays a role in exposure of epitopes targeted by plasma antibodies. Fine mapping identified a proline to isoleucine substitution at position 326 in the V3 loop that modulated neutralization susceptibility.
This study examined the genetic attributes associated with the enhanced sensitivity of an HIV-1 clade C envelope protein (HVTR-PG80v2.eJ7) to autologous broadly neutralizing plasma antibodies from an elite neutralizer. The researchers found that mutations in the V3/C3 region of the envelope protein were associated with its increased sensitivity to neutralization by autologous plasma antibodies. Depletion experiments showed that these mutations altered the envelope conformation to better expose epitopes targeted by both neutralizing and non-neutralizing antibodies in the plasma. Therefore, distinct vulnerabilities associated with antibody evasion could be linked to mutations in the V3/C3 region of the HIV envelope.
The document discusses various viral delivery systems for gene therapy. It notes four major problems with current gene therapy: short-lived expression, immune response, issues with viral vectors, and difficulties treating multigene disorders. Common viral vectors discussed include retroviruses, adenoviruses, adeno-associated viruses, and herpes simplex viruses. Each vector type has advantages and limitations for gene delivery applications. Retroviruses can only target dividing cells, while lentiviruses can target both dividing and non-dividing cells. Adenoviral vectors have high transduction efficiency but also elicit strong immune responses. AAV vectors allow long-term expression but have a small cargo capacity.
The Delta variant of SARS-CoV-2 has caused a rise in COVID-19 cases due to its increased transmissibility and immune evasion capabilities. It has mutations in the spike protein that allow it to escape antibodies from both prior infection and vaccination. Additionally, a mutation called P681R enhances the Delta variant's ability to fuse with and enter cells. While the Delta variant can evade most monoclonal antibody treatments and natural immunity, vaccination with two doses provides higher neutralizing antibody levels that are more effective against the variant. Continued research is needed to develop treatments that target the spike protein and its mutations to combat emerging variants.
Vaccine discovery
DNA vaccine, mechanism
methods of delivery
Main concerns: do DNA vaccines cause insertional mutation and elicit anti-DNA antibodies in the body?
completed and ongoing trials.
new strategies: Prime Boost vaccines
Future prospects
1. The document discusses various methods for diagnosing viral infections, including direct fluorescent antibody staining, enzyme immunoassays, viral cell culture, and molecular amplification techniques like PCR.
2. Specific examples of viruses that can be diagnosed using these methods are provided, such as herpes simplex virus, varicella zoster virus, cytomegalovirus, Epstein-Barr virus, and adenovirus.
3. Details are provided on specimen collection and storage, as well as the cytopathic effects and characteristics of each virus in cell culture systems.
This study developed a new method of producing monoclonal antibodies using in vivo RNA transfection rather than peptide vaccination. Mice were transfected with plasmid containing the gene of interest 1, 2, or 3 times. All 5 mice transfected 3 times survived influenza infection, while only 3 of 5 mice survived with peptide vaccination. Analysis found the triple transfected mice produced high levels of stable antibodies of various IgG isotypes. This RNA transfection method stimulated a more effective humoral immune response and higher survival rate compared to peptide vaccination.
1) The study analyzed HIV-1 sequences from 37 patients with high numbers (34 or more) of degenerate base codes in their protease/reverse transcriptase sequences, which can indicate either extensive viral evolution or dual infection. 2) Phylogenetic analysis of envelope and gag sequences from these patients found that 16 (43%) had dual HIV-1 infections, representing 1% of all sequences analyzed. 3) Patients with the highest numbers of degenerate base codes were more likely to have dual infections with different HIV-1 subtypes. The study demonstrates that routine HIV genotyping can help detect undiagnosed dual infections.
This study examined the mechanisms by which HIV-1 clade C escapes neutralization by broadly neutralizing antibodies targeting the N332 glycan site in the envelope protein. The researchers found plasma from an Indian patient that broadly neutralized a panel of HIV strains, and mapped the specificity of these antibodies to the N332 site. When they tested envelope proteins from autologous viruses from the same patient, they found resistance to neutralization despite intact N332 sites. They identified three distinct mechanisms of escape - a mutation replacing N332, longer variable loop 1 lengths hindering antibody access, and additional protective glycans. This highlights how HIV can evolve to evade antibodies targeting a key vulnerability like the N332 site.
Deshpande S et al RETROVIROLOGY_b 2016SHILPA PATIL
1) The study examined the basis for resistance of HIV-1 clade C envelopes (Envs) from an Indian individual to broadly cross-neutralizing autologous plasma antibodies and monoclonal antibodies (mAbs) like PGT121 and PGT128 that target the N332 glycan site.
2) While one Env was resistant due to a N332S mutation, resistance of other Envs was associated with a longer V1 loop length and additional glycans that hindered antibody access to the N332 site.
3) The results show that HIV-1 clade C can escape broadly neutralizing antibodies through distinct mechanisms including mutation, longer variable loops, and added glycans.
A DNA vaccine is a type of vaccine that transfects a specific antigen-coding DNA sequence into the cells of an organism as a mechanism to induce an immune response.
DNA vaccines work by injecting genetically engineered plasmid containing the DNA sequence encoding the antigen(s) against which an immune response is sought, so the cells directly produce the antigen, thus causing a protective immunological response.
This document summarizes key information about HIV/AIDS, including its history, virology, diagnosis, treatment, and prevention. It describes how HIV was first identified in 1981 as the cause of AIDS, belongs to the retrovirus family, and has two types, HIV-1 and HIV-2. Over 30 million people have died of AIDS since 1981, and approximately 2.5 million people are newly infected with HIV each year.
Gene therapy : Types, Gene transfer methods vectors for gene therapy approach...Shivkumar Sammeta
Gene therapy: Types of Gene therapy Gene transfer methods vectors for gene therapy approaches applications advantages and disadvantages. Gene therapy based drugs. Ethical considerations.
1. The document discusses the role of the NS1 antigen in the diagnosis of dengue virus infection. NS1 is a non-structural protein secreted by infected cells in the early febrile phase of infection, making it a useful early marker.
2. Detection of NS1 antigen by ELISA or strip tests has a sensitivity of 63-93% and specificity of 100%, allowing for early diagnosis before antibodies are detectable.
3. The NS1 antigen can be detected in blood during the acute phase of infection, making its detection a valuable tool for rapid diagnosis during the critical initial days of fever.
1. The document discusses the role of the NS1 antigen in the diagnosis of dengue virus infection. NS1 is a non-structural protein secreted by infected cells in the early febrile phase of infection, making it a useful early marker.
2. Detection of NS1 antigen by ELISA or strip tests has a sensitivity of 63-93% and specificity of 100%, allowing for early diagnosis before antibodies are detectable.
3. NS1 testing provides advantages over virus culture or PCR for early diagnosis, as it has higher sensitivity than these methods in the first 9 days of symptoms. NS1 along with IgG and IgM testing can also distinguish primary from secondary infections.
Adenoviruses are medium sized, nonenveloped DNA viruses that commonly infect the respiratory, gastrointestinal, and urinary tracts of humans and animals. They cause a variety of clinical manifestations depending on the infected site, including respiratory infections, pneumonia, eye infections, and gastrointestinal illness. Adenoviruses are diagnosed through cell culture, antigen detection, molecular methods like PCR, and serology. Treatment is supportive and prevention relies on good hygiene practices and environmental disinfection. Some adenovirus types were previously used in vaccines but are no longer manufactured.
Dr. X.J. Meng - Designing PRRSV Vaccines for Heterologous ProtectionJohn Blue
1) PRRSV remains a major problem for the global swine industry, causing $664 million in losses annually in the US alone. The emergence of more virulent strains and heterogeneity have complicated vaccine development.
2) DNA shuffling techniques are being used to generate chimeric PRRSV vaccines containing structural genes from multiple heterologous strains, which have shown promise in inducing cross-neutralizing antibodies and protection against diverse strains.
3) Targeting shuffled PRRSV antigens to dendritic cells through DC-SIGN enhances antigen-specific CD4+ and CD8+ T cell immune responses in pigs. These approaches aim to overcome obstacles in developing a broadly protective PRRSV vaccine.
This document summarizes dengue virus, pathogenesis, and laboratory diagnosis. It describes dengue as the most prevalent mosquito-borne viral disease, caused by one of four serotypes. Symptoms range from asymptomatic to severe disease and death. Secondary infection with a different serotype is a risk factor for severe disease. While antibody-dependent enhancement and original antigenic sin may explain some cases, additional factors like host genetics are also involved. Laboratory diagnosis involves serological tests like NS1 antigen detection, IgM ELISA, and molecular tests like RT-PCR. Sensitivity and specificity vary by test but are generally over 95% for validated ELISA kits.
This Power Point presentation deals with the Dengue virus its cause and mechanism. How the virus infects the host and how the host immune cells kill the virus. vaccines against this virus and the recent advances related to these virus.
Dengue- WS on vector borne viral infection 2011javed.khalil
The document discusses dengue virus and the dengue situation in Sri Lanka. It provides details on dengue virus such as its family, serotypes, laboratory diagnosis methods, pathogenesis, and vaccine candidates. It notes that though all four dengue serotypes are circulating in Sri Lanka, serotypes 2 and 3 were predominant before 1989 when the first dengue hemorrhagic fever outbreak occurred, linked to serotype 3 subtype III group B. Genetic analysis showed the strain associated with dengue hemorrhagic fever had genetic changes compared to earlier serotype 3 strains that caused dengue fever. Surveillance data on circulating serotypes from 2006-2011 is also presented.
This document summarizes a study examining the genetic attributes associated with the exceptional sensitivity of an HIV-1 clade C envelope protein to autologous broadly neutralizing plasma antibodies. The researchers identified an envelope that was significantly more sensitive to neutralization by contemporaneous plasma than two other envelopes. Sequence analysis found mutations in the V3/C3 region of the sensitive envelope. Chimeric envelope experiments determined that replacing the V3/C3 region of a resistant envelope with the sensitive envelope conferred enhanced neutralization sensitivity, indicating this region plays a role in exposure of epitopes targeted by plasma antibodies. Fine mapping identified a proline to isoleucine substitution at position 326 in the V3 loop that modulated neutralization susceptibility.
This study examined the genetic attributes associated with the enhanced sensitivity of an HIV-1 clade C envelope protein (HVTR-PG80v2.eJ7) to autologous broadly neutralizing plasma antibodies from an elite neutralizer. The researchers found that mutations in the V3/C3 region of the envelope protein were associated with its increased sensitivity to neutralization by autologous plasma antibodies. Depletion experiments showed that these mutations altered the envelope conformation to better expose epitopes targeted by both neutralizing and non-neutralizing antibodies in the plasma. Therefore, distinct vulnerabilities associated with antibody evasion could be linked to mutations in the V3/C3 region of the HIV envelope.
The document discusses various viral delivery systems for gene therapy. It notes four major problems with current gene therapy: short-lived expression, immune response, issues with viral vectors, and difficulties treating multigene disorders. Common viral vectors discussed include retroviruses, adenoviruses, adeno-associated viruses, and herpes simplex viruses. Each vector type has advantages and limitations for gene delivery applications. Retroviruses can only target dividing cells, while lentiviruses can target both dividing and non-dividing cells. Adenoviral vectors have high transduction efficiency but also elicit strong immune responses. AAV vectors allow long-term expression but have a small cargo capacity.
The Delta variant of SARS-CoV-2 has caused a rise in COVID-19 cases due to its increased transmissibility and immune evasion capabilities. It has mutations in the spike protein that allow it to escape antibodies from both prior infection and vaccination. Additionally, a mutation called P681R enhances the Delta variant's ability to fuse with and enter cells. While the Delta variant can evade most monoclonal antibody treatments and natural immunity, vaccination with two doses provides higher neutralizing antibody levels that are more effective against the variant. Continued research is needed to develop treatments that target the spike protein and its mutations to combat emerging variants.
Vaccine discovery
DNA vaccine, mechanism
methods of delivery
Main concerns: do DNA vaccines cause insertional mutation and elicit anti-DNA antibodies in the body?
completed and ongoing trials.
new strategies: Prime Boost vaccines
Future prospects
1. The document discusses various methods for diagnosing viral infections, including direct fluorescent antibody staining, enzyme immunoassays, viral cell culture, and molecular amplification techniques like PCR.
2. Specific examples of viruses that can be diagnosed using these methods are provided, such as herpes simplex virus, varicella zoster virus, cytomegalovirus, Epstein-Barr virus, and adenovirus.
3. Details are provided on specimen collection and storage, as well as the cytopathic effects and characteristics of each virus in cell culture systems.
This study developed a new method of producing monoclonal antibodies using in vivo RNA transfection rather than peptide vaccination. Mice were transfected with plasmid containing the gene of interest 1, 2, or 3 times. All 5 mice transfected 3 times survived influenza infection, while only 3 of 5 mice survived with peptide vaccination. Analysis found the triple transfected mice produced high levels of stable antibodies of various IgG isotypes. This RNA transfection method stimulated a more effective humoral immune response and higher survival rate compared to peptide vaccination.
1) The study analyzed HIV-1 sequences from 37 patients with high numbers (34 or more) of degenerate base codes in their protease/reverse transcriptase sequences, which can indicate either extensive viral evolution or dual infection. 2) Phylogenetic analysis of envelope and gag sequences from these patients found that 16 (43%) had dual HIV-1 infections, representing 1% of all sequences analyzed. 3) Patients with the highest numbers of degenerate base codes were more likely to have dual infections with different HIV-1 subtypes. The study demonstrates that routine HIV genotyping can help detect undiagnosed dual infections.
This study examined the mechanisms by which HIV-1 clade C escapes neutralization by broadly neutralizing antibodies targeting the N332 glycan site in the envelope protein. The researchers found plasma from an Indian patient that broadly neutralized a panel of HIV strains, and mapped the specificity of these antibodies to the N332 site. When they tested envelope proteins from autologous viruses from the same patient, they found resistance to neutralization despite intact N332 sites. They identified three distinct mechanisms of escape - a mutation replacing N332, longer variable loop 1 lengths hindering antibody access, and additional protective glycans. This highlights how HIV can evolve to evade antibodies targeting a key vulnerability like the N332 site.
Deshpande S et al RETROVIROLOGY_b 2016SHILPA PATIL
1) The study examined the basis for resistance of HIV-1 clade C envelopes (Envs) from an Indian individual to broadly cross-neutralizing autologous plasma antibodies and monoclonal antibodies (mAbs) like PGT121 and PGT128 that target the N332 glycan site.
2) While one Env was resistant due to a N332S mutation, resistance of other Envs was associated with a longer V1 loop length and additional glycans that hindered antibody access to the N332 site.
3) The results show that HIV-1 clade C can escape broadly neutralizing antibodies through distinct mechanisms including mutation, longer variable loops, and added glycans.
A DNA vaccine is a type of vaccine that transfects a specific antigen-coding DNA sequence into the cells of an organism as a mechanism to induce an immune response.
DNA vaccines work by injecting genetically engineered plasmid containing the DNA sequence encoding the antigen(s) against which an immune response is sought, so the cells directly produce the antigen, thus causing a protective immunological response.
This document summarizes key information about HIV/AIDS, including its history, virology, diagnosis, treatment, and prevention. It describes how HIV was first identified in 1981 as the cause of AIDS, belongs to the retrovirus family, and has two types, HIV-1 and HIV-2. Over 30 million people have died of AIDS since 1981, and approximately 2.5 million people are newly infected with HIV each year.
Gene therapy : Types, Gene transfer methods vectors for gene therapy approach...Shivkumar Sammeta
Gene therapy: Types of Gene therapy Gene transfer methods vectors for gene therapy approaches applications advantages and disadvantages. Gene therapy based drugs. Ethical considerations.
1. The document discusses the role of the NS1 antigen in the diagnosis of dengue virus infection. NS1 is a non-structural protein secreted by infected cells in the early febrile phase of infection, making it a useful early marker.
2. Detection of NS1 antigen by ELISA or strip tests has a sensitivity of 63-93% and specificity of 100%, allowing for early diagnosis before antibodies are detectable.
3. The NS1 antigen can be detected in blood during the acute phase of infection, making its detection a valuable tool for rapid diagnosis during the critical initial days of fever.
1. The document discusses the role of the NS1 antigen in the diagnosis of dengue virus infection. NS1 is a non-structural protein secreted by infected cells in the early febrile phase of infection, making it a useful early marker.
2. Detection of NS1 antigen by ELISA or strip tests has a sensitivity of 63-93% and specificity of 100%, allowing for early diagnosis before antibodies are detectable.
3. NS1 testing provides advantages over virus culture or PCR for early diagnosis, as it has higher sensitivity than these methods in the first 9 days of symptoms. NS1 along with IgG and IgM testing can also distinguish primary from secondary infections.
Adenoviruses are medium sized, nonenveloped DNA viruses that commonly infect the respiratory, gastrointestinal, and urinary tracts of humans and animals. They cause a variety of clinical manifestations depending on the infected site, including respiratory infections, pneumonia, eye infections, and gastrointestinal illness. Adenoviruses are diagnosed through cell culture, antigen detection, molecular methods like PCR, and serology. Treatment is supportive and prevention relies on good hygiene practices and environmental disinfection. Some adenovirus types were previously used in vaccines but are no longer manufactured.
Dr. X.J. Meng - Designing PRRSV Vaccines for Heterologous ProtectionJohn Blue
1) PRRSV remains a major problem for the global swine industry, causing $664 million in losses annually in the US alone. The emergence of more virulent strains and heterogeneity have complicated vaccine development.
2) DNA shuffling techniques are being used to generate chimeric PRRSV vaccines containing structural genes from multiple heterologous strains, which have shown promise in inducing cross-neutralizing antibodies and protection against diverse strains.
3) Targeting shuffled PRRSV antigens to dendritic cells through DC-SIGN enhances antigen-specific CD4+ and CD8+ T cell immune responses in pigs. These approaches aim to overcome obstacles in developing a broadly protective PRRSV vaccine.
The best massage spa Ajman is Chandrima Spa Ajman, which was founded in 2023 and is exclusively for men 24 hours a day. As of right now, our parent firm has been providing massage services to over 50,000+ clients in Ajman for the past 10 years. It has about 8+ branches. This demonstrates that Chandrima Spa Ajman is among the most reasonably priced spas in Ajman and the ideal place to unwind and rejuvenate. We provide a wide range of Spa massage treatments, including Indian, Pakistani, Kerala, Malayali, and body-to-body massages. Numerous massage techniques are available, including deep tissue, Swedish, Thai, Russian, and hot stone massages. Our massage therapists produce genuinely unique treatments that generate a revitalized sense of inner serenely by fusing modern techniques, the cleanest natural substances, and traditional holistic therapists.
Can Allopathy and Homeopathy Be Used Together in India.pdfDharma Homoeopathy
This article explores the potential for combining allopathy and homeopathy in India, examining the benefits, challenges, and the emerging field of integrative medicine.
Letter to MREC - application to conduct studyAzreen Aj
Application to conduct study on research title 'Awareness and knowledge of oral cancer and precancer among dental outpatient in Klinik Pergigian Merlimau, Melaka'
Healthy Eating Habits:
Understanding Nutrition Labels: Teaches how to read and interpret food labels, focusing on serving sizes, calorie intake, and nutrients to limit or include.
Tips for Healthy Eating: Offers practical advice such as incorporating a variety of foods, practicing moderation, staying hydrated, and eating mindfully.
Benefits of Regular Exercise:
Physical Benefits: Discusses how exercise aids in weight management, muscle and bone health, cardiovascular health, and flexibility.
Mental Benefits: Explains the psychological advantages, including stress reduction, improved mood, and better sleep.
Tips for Staying Active:
Encourages consistency, variety in exercises, setting realistic goals, and finding enjoyable activities to maintain motivation.
Maintaining a Balanced Lifestyle:
Integrating Nutrition and Exercise: Suggests meal planning and incorporating physical activity into daily routines.
Monitoring Progress: Recommends tracking food intake and exercise, regular health check-ups, and provides tips for achieving balance, such as getting sufficient sleep, managing stress, and staying socially active.
About this webinar: This talk will introduce what cancer rehabilitation is, where it fits into the cancer trajectory, and who can benefit from it. In addition, the current landscape of cancer rehabilitation in Canada will be discussed and the need for advocacy to increase access to this essential component of cancer care.
MBC Support Group for Black Women – Insights in Genetic Testing.pdfbkling
Christina Spears, breast cancer genetic counselor at the Ohio State University Comprehensive Cancer Center, joined us for the MBC Support Group for Black Women to discuss the importance of genetic testing in communities of color and answer pressing questions.
At Apollo Hospital, Lucknow, U.P., we provide specialized care for children experiencing dehydration and other symptoms. We also offer NICU & PICU Ambulance Facility Services. Consult our expert today for the best pediatric emergency care.
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Joker Wigs has been a one-stop-shop for hair products for over 26 years. We provide high-quality hair wigs, hair extensions, hair toppers, hair patch, and more for both men and women.
Chandrima Spa Ajman is one of the leading Massage Center in Ajman, which is open 24 hours exclusively for men. Being one of the most affordable Spa in Ajman, we offer Body to Body massage, Kerala Massage, Malayali Massage, Indian Massage, Pakistani Massage Russian massage, Thai massage, Swedish massage, Hot Stone Massage, Deep Tissue Massage, and many more. Indulge in the ultimate massage experience and book your appointment today. We are confident that you will leave our Massage spa feeling refreshed, rejuvenated, and ready to take on the world.
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This particular slides consist of- what is hypotension,what are it's causes and it's effect on body, risk factors, symptoms,complications, diagnosis and role of physiotherapy in it.
This slide is very helpful for physiotherapy students and also for other medical and healthcare students.
Here is the summary of hypotension:
Hypotension, or low blood pressure, is when the pressure of blood circulating in the body is lower than normal or expected. It's only a problem if it negatively impacts the body and causes symptoms. Normal blood pressure is usually between 90/60 mmHg and 120/80 mmHg, but pressures below 90/60 are generally considered hypotensive.
Exploring the Benefits of Binaural Hearing: Why Two Hearing Aids Are Better T...Ear Solutions (ESPL)
Binaural hearing using two hearing aids instead of one offers numerous advantages, including improved sound localization, enhanced sound quality, better speech understanding in noise, reduced listening effort, and greater overall satisfaction. By leveraging the brain’s natural ability to process sound from both ears, binaural hearing aids provide a more balanced, clear, and comfortable hearing experience. If you or a loved one is considering hearing aids, consult with a hearing care professional at Ear Solutions hearing aid clinic in Mumbai to explore the benefits of binaural hearing and determine the best solution for your hearing needs. Embracing binaural hearing can lead to a richer, more engaging auditory experience and significantly improve your quality of life.
Exploring the Benefits of Binaural Hearing: Why Two Hearing Aids Are Better T...
Adnan, presentation
1. DISECTING THE HUMAN SERUM ANTIBODY RESPONSE
TO SECODARY DENGUE VIRUS INFECTION
MuhammadAdnan
TMID# 536 HOST AND ENVIRONMENTAL DISEASES
MUHAMMAD ADNAN
ID 6038362
MEDICAL ENTOMOLOGY
MAHIDOL UNIVERSITY
BANGKOK, THAILAND
2. INTRODUCTION
• Dengue virus (DENV) is a mosquito-borne flavivirus
• Cause dengue fever and dengue hemorrhagic fever (DHF)
• Th DENV complex consists of 4 viruses designated as serotypes (DENV1-4)
3. • The Ectodomain of E protein is composed of three domains: (EDI, EDII, and EDIII).
• E-protein arranged with icosahedral symmetry with each asymmetric unit containing
portion of three dimers.
• Each DENV particle has 180 monomers of E that are organized into 90 dimers that covers
the entire surface of virus.
INTRODUCTION
4. The DENV envelop (E) protein
which binds to cellular
receptors and mediators viral
entry and fusion, is the main
target of neutralizing and
protective antibodies.
INTRODUCTION
5. • Primary infection by DENV leads to long term protection against the serotype of
infection (Homologous) but not other serotypes.
• Subsequent secondary infection with a new serotype results in serotype cross-
neutralizing antibodies that correlate with durable protection against 2 or more
serotypes.
INTRODUCTION
6. OBJECTIVE
“ To investigate the properties of serum neutralizing antibodies
produced after recovery from secondary DENV infections ”
8. Incubation
Materials and methods
Control With Human
immune sera
Human
immune sera
DENV
U937 DC-
SIGN cells
Control With Human
immune sera
Infected cells
Flow-cytometer
Fluorescent Activated Cell Sorting (FACS) –based
DENV neutralization assay
x 4 DENV serotypes
9. Detection of DENV binding antibodies
Spectrophotometer (405nm)
Materials and methods
ELISAs
10. DENV neutralizing
• Serum incubated to beads coated with purified DENV2
- To remove DENV type2 specific and cross over antibody
- Any reduction in type 1,3, and 4 suggested cross-reactive antibody
• Serum incubated to beads coated with purified DENV1,3, and 4
- To remove DENV type1,3, and 4 specific and cross over antibody
- Any reduction in type 2 suggested cross-reactive antibody
• Bead coated BSA is used as negative control
Materials and methods
11. Result
• Single infection, antibody is unique to serotype
- DENV neutralization titers of the control and depleted samples were not significantly different
(P>0.5, extra sum of squares F test to compare neutralization curve)
• Show type specific antibodies
Fig 1. Neutralization properties of
primary DENV-immune human sera
depleted of DENV-specific antibodies.
12. Result
• Secondary infections
- Cross-reactive and type specific neutralizing
- DT130 strongly neutralized DENV1 and 2 but not in 3 and 4
Fig 2. Neutralization properties of
secondary DENV-immune human sera
depleted of DENV-specific antibodies.
13. • Secondary infections
- Cross reactive antibodies, Both samples got high level of neutralizing antibodies to all 4 types
- When depleted DENV2, the rest 3 subtypes neutralization are significantly loss.
Result
Fig 2. (cont.) Neutralization properties
of secondary DENV-immune human sera
depleted of DENV-specific antibodies
14. • Although primary infections stimulate both DENV serotype-specific and
cross reactive binding antibodies, only the type-specific antibodies have
been linked to durable neutralizing and protective responses.
• Majority of neutralizing antibodies that develop after secondary DENV
infections recognize serotype cross reactive epitopes.
- Some have only DENV serotype cross-reactive and cross-neutralizing
antibodies, while some have mix of cross-reactive and type specific
neutralizing antibodies.
Discussion
15. DT000 and 121 who mainly had cross-reactive neutralizing antibodies are likely to have had
multiple DENV exposures resulting in broad neutralization of all 4 serotypes.
Fig 2. (cont.) Neutralization properties
of secondary DENV-immune human sera
depleted of DENV-specific antibodies
Discussion
16. Fig 2. Neutralization properties of
secondary DENV-immune human sera
depleted of DENV-specific antibodies.
Discussion
DT27 and 130, who had a mixture of type-specific and cross-reactive neutralizing antibodies
are likely to represent people who have been exposed to sequential infections with 2
serotypes only
17. Depletion of DENV binding antibodies from individuals exposed to a
known sequence infection with two different DENV serotypes
3 serum samples with two sequential infection with different serotypes of DENV.
Second infectionFirst infection
Estimate the levels of cross reactive
and type specific neutralizing
antibodies
Beads coated with DENV serotypes of first and second infection
neutralization
assay
Result
19. Recombinant E protein depletion of DENV-specific antibodies from immune sera
DENV2 rE protein
Depletion of DENV recombinant E protein binding antibodies
Result
Control rE conjugated bead
Incubation
+ human sera
Control rE conjugated bead
% rE binding DENV2 neutralizing Abs = 1 −
𝑁𝑒𝑢𝑡50
𝑎𝑓𝑡𝑒𝑟 𝐷𝑉2 𝑟𝐸 𝑑𝑒𝑙𝑒𝑡𝑖𝑜𝑛
𝑁𝑒𝑢𝑡50
𝑎𝑓𝑡𝑒𝑟 𝑐𝑜𝑛𝑡𝑟𝑜𝑙 𝑑𝑒𝑙𝑒𝑡𝑖𝑜𝑛
× 100
20. Fig 3. People exposed to secondary DENV infections develop neutralizing
antibodies that target simple epitopes on recombinant E protein.
Depletion of DENV recombinant E protein binding antibodies
Result
This results indicate that epitopes
displayed on rE protein are a major
target of DENV2 neutralizing antibodies
after secondary infections
22. Cross reactive MBCs induced by primary infection produce cross reactive antibodies
that bind to second infecting serotype with high affinity and undergo somatic hyper
mutation and strongly cross neutralize multiple serotypes
Model of B cell maturation following sequential DENV infections
23. Results in the population of CR MBCs and LLPCs that dominate the neutralizing
antibodies as in the secondary infection
Model of B cell maturation following sequential DENV infections
24. - Increase in affinity and neutralization is shown by increase in color gradient
- TS strongly neutralizing antibodies are maintained through each successive round of
infection and account for small fraction of total neutralizing response
Model of B cell maturation following sequential DENV infections
25. Prior immune status effect on the quality of neutralizing antibodies
DENV naïve individual
Single dose of DENV Vaccine
Immune individual
Tetravalent DENV Vaccine
Serotype specific antibody
Broadly neutralizing antibody
(not towards each serotype)
Tetravalent vaccine efficacy : pre immune individuals > naïve individuals
No DENV immune
With DENV
immune
26. Conclusion
The primary infection provide long term protection against DENV
When secondary, tertiary, quaternary infection occur then cross
neutralization occur
1.
2.
3. Both antibodies and T-cell are responsible for protection against
reinfection by the same serotype
4. To analyze the properties of antibodies from the serum different
tests and titrations with different chemicals were used.
5. For understanding protective responses after natural infections as
well as responses induced by dengue vaccines.
Blood donation was obtain from individuals who had experience a DENV infection during travel to dengue-endemic area
And classified as primary infection if has Neutralizing antibody to only one serotype (mean Neut50 titer is at least 4-fold greater for one serotype)
If The highest titer not 4-fold greater than the 2nd highest titer, It’s mean this classify as secondary infection
Another one is Nicaraguan Pediatric Dengue Cohort Study is an ongoing community-based prospective study of children 2-14 year old
DENV neutralizing activity of human immune sera was assessed by using a flow cytometer-based assay with U937 human monocytic cell
Serially dilute human sera incubate with virus and follow by adding U937 DC-sign cell
Cell were incubate for 2 hr then fixed and stain
Infected cells were quantified by using Flow cytometer
Both confirmation of depletion and assessment of binding activity were conducted by ELISAs with spectrophotometer
For the Depletion of DENV recombinant E protein binding antibodies result
The method that they use is DENV rE protein conjugate with the bead and control bead without DENV rE protein
After incubation with human sera that have DENV rE specific antibody and bind to the rE conjugate bead
So after this the percentage of rE binding DENV2 neutralizing Antibody were calculated using this formulation
And the result
For the primary infection, there are no significant loss of DENV neutralization
So it confirm the important of quaternary structure neutralizing antibody epitope
For the secondary infection, there are significant decrease in DENV neutralizing antibody
This results indicate that epitopes displayed on rE protein are a major target of DENV2 neutralizing antibodies after secondary infections
After primary infection, naïve B cells are activated and give rise to both memory B cell(MBCs) and antibody secreting long lived plasma cells(LLPCs)
Cross reactive antibodies are low affinity, weakly neutralizing
Type specific antibodies strongly neutralize DENV1
Following secondary infection with a new serotype, cross reactive MBCs induced by primary infection produce cross reactive antibodies that bind to second infecting serotype with high affinity and undergo somatic hyper mutation
CR B cells with high affinity for second serotype give rise to cross reactive MBCs and LLPCs that strongly cross neutralize multiple serotypes