This document discusses virus-host interactions and the genetic modifications that viruses undergo. It covers topics like mutations, interactions between viral genes including genetic recombination and reassortment, and viral interference. It also describes the pathogenesis of viral infections from transmission and spread, to the primary site of replication and clinical manifestations. Additionally, it discusses morphological changes in host cells caused by viruses, the different types of infections that can occur at the cellular level, and the properties and mechanisms of action of interferons.
A picornavirus is a virus belonging to the family Picornaviridae, a family of viruses in the order Picornavirales. Vertebrates, including humans, serve as natural hosts. Picornaviruses are nonenveloped viruses that represent a large family of small, cytoplasmic, plus-strand RNA viruses with a 30-nm icosahedral capsid.
The Paramyxoviridae is a family of single-stranded RNA viruses known to cause different types of infections in vertebrates. Examples of these infections in humans include the measles virus, mumps virus, parainfluenza virus, and respiratory syncytial virus (RSV).
A picornavirus is a virus belonging to the family Picornaviridae, a family of viruses in the order Picornavirales. Vertebrates, including humans, serve as natural hosts. Picornaviruses are nonenveloped viruses that represent a large family of small, cytoplasmic, plus-strand RNA viruses with a 30-nm icosahedral capsid.
The Paramyxoviridae is a family of single-stranded RNA viruses known to cause different types of infections in vertebrates. Examples of these infections in humans include the measles virus, mumps virus, parainfluenza virus, and respiratory syncytial virus (RSV).
This presentation contains 53 power point slides. These slides have description between virus and host cell interactions including concept of permissive and non-permissive infection, latent infection and host immune response to viral infection. Slides are designed for medical students, nurses, academicians who are teaching virology and microbiology in medical universities, schools or college.
herpes simplex virus is a double stranded DNA virus causing many symptoms all over the body. it affects globally all over the world .
neonatal hsv attacks even the baby and made them to a fatal conditions.
This presentation contains 45 slides on general virology comprises of topics on viral classification, transmission, pathogenesis, viral cytopathic effect, stages of viral infections, antiviral drugs and viral vaccines. It also have a slide noting an outline of laboratory diagnosis of viral infection. This power point presentation was designed for medical students, nurses and academicians teaching virology and microbiology in medical universities, schools or colleges.
Largest viruses that infect vertebrates
Can be seen under light microscope
Poxvirus diseases are characterized by skin lesions – localized or generalized
Important diseases caused by poxviruses are-
Smallpox
Monkeypox
Cowpox
Tanapox
Molluscum contagiosum
This presentation contains 53 power point slides. These slides have description between virus and host cell interactions including concept of permissive and non-permissive infection, latent infection and host immune response to viral infection. Slides are designed for medical students, nurses, academicians who are teaching virology and microbiology in medical universities, schools or college.
herpes simplex virus is a double stranded DNA virus causing many symptoms all over the body. it affects globally all over the world .
neonatal hsv attacks even the baby and made them to a fatal conditions.
This presentation contains 45 slides on general virology comprises of topics on viral classification, transmission, pathogenesis, viral cytopathic effect, stages of viral infections, antiviral drugs and viral vaccines. It also have a slide noting an outline of laboratory diagnosis of viral infection. This power point presentation was designed for medical students, nurses and academicians teaching virology and microbiology in medical universities, schools or colleges.
Largest viruses that infect vertebrates
Can be seen under light microscope
Poxvirus diseases are characterized by skin lesions – localized or generalized
Important diseases caused by poxviruses are-
Smallpox
Monkeypox
Cowpox
Tanapox
Molluscum contagiosum
INFECTION, Microbial pathogenicity
Important for MBBS and paramedical students to know about various sources , different types and modes of transmission of infection.
A Very important topic for all healthcare workers.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stockrebeccabio
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stock
Telegram: bmksupplier
signal: +85264872720
threema: TUD4A6YC
You can contact me on Telegram or Threema
Communicate promptly and reply
Free of customs clearance, Double Clearance 100% pass delivery to USA, Canada, Spain, Germany, Netherland, Poland, Italy, Sweden, UK, Czech Republic, Australia, Mexico, Russia, Ukraine, Kazakhstan.Door to door service
Hot Selling Organic intermediates
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Contact us if you are interested:
Email / Skype : kefaya1771@gmail.com
Threema: PXHY5PDH
New BATCH Ku !!! MUCH IN DEMAND FAST SALE EVERY BATCH HAPPY GOOD EFFECT BIG BATCH !
Contact me on Threema or skype to start big business!!
Hot-sale products:
NEW HOT EUTYLONE WHITE CRYSTAL!!
5cl-adba precursor (semi finished )
5cl-adba raw materials
ADBB precursor (semi finished )
ADBB raw materials
APVP powder
5fadb/4f-adb
Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
Payment terms: Western Union,MoneyGram,Bitcoin or USDT.
Deliver Time: Usually 7-15days
Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
2. VIRAL GENETIC MODIFICATIONS
Viruses show genetic modifications by two principal methods—
(1) mutations
(2) interactions between viral genes or their gene products (proteins).
2
3. 1. MUTATION
A mutation is a change that occurs in viral nucleic acid sequence, either due to
mistakes when the viral genome is copied or as the result of environmental factors
Occur during every viral infection, at a frequency of 10-4 to 10-8 mutations per base per generation.
Becomes evident only if it induces some readily observable property or leads to survival or death of the
virus.
Mutants occur spontaneously or may be induced chemically (e.g. 5-fluorouracil) or by physical agents
such as UV light or irradiation.
3
B.1.1.7 –UK Strain
30 and 100 per cent more deadly than
previous strains.
4. TYPES OF MUTATIONS
Conditional lethal mutant can grow only in specific conditions called
permissive conditions, but cannot grow in other conditions.
Temperature sensitive mutant
• Type of conditional lethal mutant that can grow at a low
(permissive)temperature (28-31°C), but not at higher (restrictive)
temperature (37°C).
• ts mutants have been used for preparation of live viral vaccines(e.g. ts
influenza vaccine).
4
5. INTERACTIONS BETWEEN VIRAL GENES
When two or more virus particles infect the same host cell, there occurs a variety
of interactions, both genetic and non-genetic.
5
Genetic Recombination
•Occurs between two different but related viruses of the same family infecting a
host cell simultaneously
•Two viruses exchange segments of nucleic acids between them so that a hybrid
(recombinant virus) results
•Hybrids- possess new genes not found in both the parent viruses, are genetically
stable and able to replicate.
6. REASSORTMENT
Type of recombination seen in segmented RNA viruses such as influenza, rota,
bunya, and arena viruses.
When two strains of influenza virus infect a host cell, gene exchanges take
place between the RNA segments resulting in production of reassortants.
6
7. VIRAL INTERFERENCE
When two viruses infect a host cell or a cell line, sometimes it leads to inhibition of
one of the virus, called viral interference
Interference does not occur with all viral combinations; many viruses may infect and
multiply together in a host cell.
Oral Polio Vaccine (OPV) is a classical example where viral interference is seen.
OPV serotypes interfere with the spread of wild poliovirus, thus played a crucial role
in control of polio outbreaks.
7
8. PATHOGENESIS OF VIRAL INFECTIONS
Transmission (entry into the body)
Primary Viremia
Secondary Viremia
Manifestations of the disease
8
9. TRANSMISSION AND SPREAD OF VIRUSES
9
Mode of transmission Produce Local infection at the portal of
entry
Spread to distant sites from the portal of
entry
Respiratory route
(probably the most common
route)
Produce Respiratory infection-
1. Influenza virus
2. Parainfluenzavirus
3. Respiratory syncytial virus
4. Rhinovirus
5. Adenovirus
6. Coronavirus such as SARS-COV2
7. Herpes simplex virus
Measles virus
Mumps virus
Rubella virus
Varicella-zoster virus
Cytomegalovirus
Parvovirus
Small pox virus
Oral route Produce gastroenteritis
1. Rotavirus
2. Adenovirus-40,41
3. Calicivirus
4. Astrovirus
Poliovirus
Coxsackie virus
Hepatitis Virus – A & E
Cytomegalovirus
Epstein-Barr virus (EBV)
10. TRANSMISSION AND SPREAD OF VIRUSES (CONT..)
10
Mode of transmission Produce Local infection at the portal of
entry
Spread to distant sites from the portal of
entry
Cutaneous route Produce skin lesions
Herpes simplex virus
Human papilloma virus
Molluscum contagiosum virus
1. Herpes simplex virus
Vector bite - Arboviruses such as-
1. Dengue virus (Aedes)
2. Chikungunya virus(Aedes)
3. Japanese encephalitis virus (Culex)
4. Yellow fever and Zika virus(Aedes)
5. Kyasanur Forest disease virus (Tick)
Animal bite - 1. Rabies virus
11. TRANSMISSION AND SPREAD OF VIRUSES (CONT..)
11
Mode of transmission Produce Local infection at the portal of entry Spread to distant sites from the portal of
entry
Sexual route Produce genital lesions-
1. Herpes simplex virus
2. Human papilloma virus
Hepatitis B, C& rarely D
HIV
Blood transfusion - 1. Hepatitis B, C & rarely D
2. HIV
3. Parvovirus
Injection - Hepatitis B, C & rarely D
HIV
Transplacental
route
Produce congenital manifestations in fetus
1. Rubella virus
2. Cytomegalovirus (CMV)
3. Herpes simplex virus
4. Varicella-zoster virus
5. Parvovirus
Transmitted through placenta to fetus, without congenital
manifestations
1. Measles virus
2. Mumps virus
3. Hepatitis B virus
4. Hepatitis C virus
5. Hepatitis D virus
6. HIV
Conjunctival route 1. Adenovirus
2. Enterovirus70
3. Coxsackie virus A-24
4. Herpes simplex virus
12. PRIMARY SITE OF REPLICATION
Some viruses are restricted to the portal of entry where they multiply and
produce local diseases.
They spread locally over the epithelial surfaces, but there is no viremia
or spread to distant sites.
They have a shorter incubation period and shorter duration of immunity.
12
13. PRIMARY SITE OF REPLICATION (CONT..)
On the other hand, most viruses multiply locally to initiate a silent local
infection which is followed by the spread via lymphatics to regional
lymph nodes (most viruses) or via blood (e.g. polio virus) or via neuronal
spread to reach CNS (e.g. rabies virus).
13
14. MANIFESTATIONS OF VIRAL INFECTIONS
1. lncubation Period:
Time interval between entry of the virus into the body and appearance of first
clinical manifestation.
Depends on the distance between site of entry and the target organ.
Shorter - if the virus produces lesions near to the site of entry e.g. influenza
Longer - if the target organ is much far from the site of entry; e.g. polio virus and
rabies virus
14
Exception- For e.g. Hepatitis B virus, IP 30-180days.
Other factors that depends on the incubation period such as host immune response,
nature of the virus etc.
15. 2. Clinical Manifestations:
Inapparent (subclinical) infection
Apparent (clinical) infection- may be acute, subacute or chronic in nature
depending upon onset of illness.
Respiratory viruses such as influenza and coronaviruses produce upper and lower
respiratory tract infections
Gastroenteritis may be produced by viruses such as Rotavirus and Norwalk virus
Hemorrhagic fever may be a manifestation of viruses such as Dengue, Ebola
virus etc
Neurotropic viruses can produce meningitis (Enteroviruses) or encephalitis
(Rabies, Japanese encephalitis)
15
16. VIRAL PATHOGENESIS AT CELLULAR LEVEL
Three types of infections in a host cell which in turn depends on the nature
of the virus and the cell infected.
16
Types of Infection
1.Failed Infection (Abortive
Infection)
Occurs if the virus infects the host
cells which are non permissive (i.e.
absence of surface receptors or
machineries to support viral
replication)
2. Cell Death (Cytocidal or lytic
Infection)
1. Viruses adopt different mechanisms to induce
host cell death such as:
2. Inhibition of host cell DNA by herpesvirus
3. Inhibition of host cell protein synthesis by
poliovirus
4. Fusion (syncytia formation)
5. Immune mediated lysis
3. Infection without Cell
Death
Steady state infection -
The virus and host cell enter into a
peaceful coexistence, both
replicating independently
1. Latent infection E.g Herpes, HIV,
Slow virus infection
2. Cell Transformation E.g
Oncogenic viruses –HBV, EBV,
HPV
3. Persistent tolerant infection
(Lymphocytic Choriomeningitis
Virus infecting mice)
17. MORPHOLOGICAL CHANGES IN THE HOST CELLS
1. Certain viruses induce characteristic changes in the host cells (e.g. inclusion body), which can be
detected by histopathological staining.
2. Aggregates of virions or viral proteins & other products of viral replication that confer altered staining
property to the host cell.
3. Characteristic of specific viral infections.
4. They have distinct size, shape, location and staining properties by which they can be demonstrated in
virus infected cells under the light microscope
17
18. 18
Types of Inclusion Bodies
1. Intracytoplasmic inclusion bodies –
generally acidophilic -pink structures
with Giemsa or Eosin Methylene blue
stains.
2. Intranuclear inclusion bodies are
basophilic
Cowdry type A inclusions are variable
in size and have granular appearance
Cowdry type B inclusions are more
circumscribed and multiple
3. Both intracytoplasmic &
intranuclear inclusions.
Negri bodies –Rabies virus
Paschen body- Variola virus
Guarnieri bodies - Vaccinia virus
Bollinger bodies - Fowl pox virus
Molluscum bodies - Molluscum contagiosum
virus
Perinuclear cytoplasmic body- Reovirus
A)Cowdry type A inclusions
1. Torres body- seen in Yellow fever
2. Lipschultz body - seen in Herpes simplex
B)Cowdry type B inclusions - seen in
1. Poliovirus
2. Adenovirus
Owl’s eye appearance- seen in
Cytomegalovirus
Measles
19. INTERFERONS
The term interferon derives from the ability of these cytokines to interfere with viral replication
Interferons (IFNs) are family of a host coded glycoprotein produced by a variety of host cells on induction by viral or non viral inducers
during cellular transcription and protein synthesis .
Clinical Uses:-
Antiviral – Induces resistance to viral infections, High dose local application shows some benefits in URTI, Herpetic
keratitis, genital warts, imitated use in Hepatitis B, Hepatitis C infection and lymphoma.
Antimicrobial- resistance to intracellular infections e.x Toxoplasma, Malaria and Chlamydia
Cellular effects- a. inhibition of cell growth and proliferation
b. Inhibition of DNA and Protein synthesis
c. increased expression of MHC antigens on cell surface
Immunoregulatory effects- a. incresead cytotoxic activity of Nk cells, K cells and T cells(Tsupressor cell)
b. activation of macrophage cytocidal activity
c. modify the antibody formation
d. Supressive DTH
Research suggests that IFNs may also be beneficial in the treatment of other viral, autoimmune, and neoplastic
conditions of the nervous system like multiple sclerosis
19
20. PROPERTIES OF INTERFERONS
• It is a natural defence mechanism possessed by vertebrate cells against viral infections
• IFN are species specific
• They are not virus specific
• IFN production can be increased by increasing temperature to 40C
• Inhibited by steroids and high oxygen tension
• Inactived by Proteolytic enzyme but not by lipases and nucleases
• Resist heating at 56-60C for one hour
• Mol.wt – 17,000
• Non dialysable, non sedimentable
• Poorly antigenic so no serological test.
•Non toxic, diffusible freely in the body
20
21. 21
Types of Interferons
IFN-I
1. IFN-α (further classified into 13
different subtypes IFN-α1, -α2, -α4, -
α5, -α6, -α7, -α8, -α10, -α13, -α14, -
α16, -α17 and -α21), IFNα- produced
by leukocytes
2. IFN-β. produced by fibroblasts
IFN-II
Only one sub type IFN-γ produced
by lymphocytes
IFN-III
denoted IL-28/29,
Important role in host defense against
viral infections
Biological effects are like IFN-I
22. MECHANISMS OF ACTION
1. IFNs, besides being first line of defence and part of innate immunity against viral infections,
2. Play important roles in immunosurveillance for malignant cells.
3. On exposure to IFN cells produce TIP (Translation Inhibitory Protein) which selectively
inhibits the translation of viral mRNA without affecting cellular mRNA
22
Stimulate resistance to
viral replication in all
cells through cellular
genes activation, with
the consequent
Destruction of the viral
mRNA and
Inhibition of the viral
proteins translation
NK cells mediated lysis
of virus-infected cells
23. QUESTIONS:
Q1. All of the following viruses are transmitted by respiratory
route, except:
a. Influenza virus
b. Rotavirus
c. RSV
d. Rhinovirus
23