This presentation aims to describe the variability present in antibodies.what the Ig superfamily have in common and the various functions it performs.Role of different enzymes imparting diversity to the variable region has been covered.
From studies and predictions such as Dreyer and Bennett's, it shows that the light chains and heavy chains are encoded by separate multigene families on different chromosomes. They are referred to as gene segments and are separated by non-coding regions. The rearrangement and organization of these gene segments during the maturation of B cells produce functional proteins. The entire process of rearrangement and organization of these gene segments is the vital source where our body immune system gets its capabilities to recognize and respond to variety of antigens.
From studies and predictions such as Dreyer and Bennett's, it shows that the light chains and heavy chains are encoded by separate multigene families on different chromosomes. They are referred to as gene segments and are separated by non-coding regions. The rearrangement and organization of these gene segments during the maturation of B cells produce functional proteins. The entire process of rearrangement and organization of these gene segments is the vital source where our body immune system gets its capabilities to recognize and respond to variety of antigens.
I give this lecture on cell adhesion and cell migration in the Cell Biology and Genetics course for first-year veterinary students. The core material comes from Molecular Biology of the Cell, Fifth Edition, but I have added multiple clinical examples and placed the material in the context of the translational medicine component of the course.
T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response and are distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface.
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system.. B cells produce antibody molecules.
In mammals, B cells mature in the bone marrow, which is at the core of most bones. In birds, B cells mature in the bursa of Fabricus.
B cells present antigens (they are also classified as professional antigen-presenting cells (APCs)) and secrete cytokines.
I give this lecture on cell adhesion and cell migration in the Cell Biology and Genetics course for first-year veterinary students. The core material comes from Molecular Biology of the Cell, Fifth Edition, but I have added multiple clinical examples and placed the material in the context of the translational medicine component of the course.
T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response and are distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface.
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system.. B cells produce antibody molecules.
In mammals, B cells mature in the bone marrow, which is at the core of most bones. In birds, B cells mature in the bursa of Fabricus.
B cells present antigens (they are also classified as professional antigen-presenting cells (APCs)) and secrete cytokines.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
3. Fig 1. Schematic representation of some proteins of Ig superfamily.
All members of the superfamily are involved in recognizing other cells/foreign particles. They share basic structural
similarity in the Ig-domain(shades in blue),indicating that the genes encoding these proteins evolved from a common
ancestral gene involved in cell-to-cell recognition.
4. Immunoglobulin superfamily
• The IgSF is a group of cell surface proteins
• characterized by presence of 70–110 amino acid Ig-like domains similar to Ig variable and
constant regions.
• Included are CD2, CD3, CD4, CD7, CD8, CD28, (TCR), MHC class I and MHC class II
molecules, leukocyte function-associated antigen 3 (LFA-3), the IgG receptor etc.
• These molecules share in common with each other an immunoglobulin-like domain, with a
length of approximately 100 amino acid residues and a central disulfide bond that anchors and
stabilizes antiparallel β strands into a folded structure resembling immunoglobulin.
• Members include cell surface antigen receptors, co-receptors and co-stimulatory molecules of the
immune system, molecules involved in antigen presentation to lymphocytes, cell adhesion
molecules, certain cytokine receptors and intracellular muscle proteins.
5. • Over 30 years ago, Kabat and Wu identified sub-regions within
the variable region called complementarity-determining regions
• Hypervariable regions are domains on Ig heavy and light chains
V regions that are in direct contact with antigen and are
frequently mutated to allow diverse antigenic specificities to be
recognized.
• HVR form the antigen-binding site of the antibody molecule.
• Three areas in the V region of light and heavy chains are highly
variable and form distinct loops in the Ig protein structure,
termed as CDR1, CDR2, and CDR3.
• CDRs have different orientations in different antibodies.
• The other areas of the V region are more consistent in amino
acid sequence and they are referred to as the framework
regions.
• Framework regions acts as a scaffold to support these 6 loops.
• The framework sequences between CDRs can be similar or
identical.
CDRs
The division of labor is:
V regions are responsible for epitope
recognition.
C regions are responsible for triggering
a useful response
6. Fig 2(a) Each polypeptide has regions whose amino acid sequences are constant (white and yellow) and
variable (red). The variable regions also contain hypervariable regions. (b) Schematic model of the domain
structure of an antibody molecule.
7. Diversity
• The specificity of a particular antibody, i.e. what the antibody recognises, is determined by the shape of
its variable region ; a particular antibody will bind to a protein that has a region with a complementary
structure to the antibody’s own variable region
• Diversity in the specificity of antibodies is initially generated at the earliest stages of B-cell development.
• While still at the B-cell progenitor stage in the bone marrow, B cells randomly rearrange
their variable (V), diversity (D), and joining (J) genes to form the blueprint for the variable regions of their
antibodies
• Further diversity is added to the variable region genes by an enzyme terminal deoxynucleotidyl
transferase (TdT) that adds extra nucleotides between the V, D and J regions, changing the structure of the
variable regions.
• During the course of an infection, B cells can further alter the specificity of the antibody they produce.
• When a mature B cell meets an antigen that its B-cell receptor recognizes, then the B cell can undergo a
process called somatic hypermutation.
• An enzyme activation-induced cytidine deaminase (AID) makes random mutations in variable region
genes.
• If mutations result in an antibody that more strongly binds to their targets then these B cells will survive and
may differentiate into plasma cells with new specificity.
8. Fig 3.Schematic representation of the rearrangement of variable
region genes
• Human body contains approximately 1010 lymphocytes,
each with a unique combination of gene segments that
specify the variable region.
• process of V(D)J recombination occurs during B
lymphocyte development in bone marrow.
• The role of the B cell is to produce high-affinity
protective antibodies
• To succeed in this function, it attempts to increase the
affinity of its receptors for the immunizing antigen by
mutating its variable-region genes. Mutation of V genes
occurs in the germinal center.
• The human VH locus, as for other antibody gene
segments, is highly polymorphic, and has likely evolved
through the repeated duplication, deletion, and
recombination of DNA.
11. Fig 5. VDJ recombination, affinity maturation and somatic hypermutations
12. • Somatic hypermutation involves introduction of point mutations into V regions of rapidly
proliferating B‐cells in the germinal centers of Lymphoid follicles.
• Antigen‐driven somatic hypermutation of variable immunoglobulin genes can result in an increase
in binding affinity of the B‐cell receptor for its cognate ligand.
• affinity maturation is the process by which B cells produce antibodies with increased affinity for
antigen during the course of an immune response.
• With repeated exposures to the same antigen, a host will produce antibodies of successively
greater affinities.
• Somatic hypermutation occurs at a high rate, thought to be on the order of about 1 × 10−3
mutations per base‐pair per generation, which is approximately 106 times higher than the mutation
rate of cellular housekeeping genes
13. Once activated, B cells may undergo class switch
recombination
In their inactivated state B cells express IgM/IgD but
once activated they may express IgA, IgE, IgG or retain
IgM expression.
they do this by excision of the unwanted isotypes
A master gene, activation-induced deaminase(AID), is
essential for both somatic mutation of variable-region
genes and the switch of the immunoglobulin isotype
from IgM to IgG, IgA, or IgE during the immune
response
Cytokines produced by T cells and other cells are
important in determining what isotype the B cells
express.Fig 6. Class switch recombination. After VDJ recombination,
class switch recombination may occur. Here unwanted Ig genes
are excised so that the desired gene can be expressed. In this
depiction excision occurs and IgE is expressed.