Immunology is the branch of biology that deals with the study of the immune system, its mechanism, types, and mode of action.
The immune system is the body’s defense mechanism that triggers response against any foreign particle that has not been previously encountered and helps to combat infections or diseases. The immune system that was present before the birth of a person is called the innate immune system and the system that learns as the person grows and becoming more efficient in recognizing the pathogens as time passes on, is the acquired immune system.
Immune cells have the capacity of the self, non-self discrimination. Tolerance to self-antigen and effector functions against foreign antigen either by the production of antibodies (humoral immunity) or by effector T cells (cell-mediated immunity) is the main function of immune cells.
A personalized vaccines has the potential to create the next golden age in the field of immunization and vaccinology.
Antibody affinity is a quantitative measure of binding strength whereas antibody avidity incorporates the affinity of multiple antigen-binding sites.
Adjuvants are ingredients used in some vaccines to enhance the immunogenicity of antigens (immunogens).
Epitopes are the immunologically active discrete sites on the antigen molecule that physically bind to antibodies, B-cell receptors, or T-cell receptors.
Immune system consists of many different cells, some of which acts as a part of innate immunity while lymphocytes are major players.
IgE is one of the five isotypes of human immunoglobulins and plays role in helminthic infestations and allergic reactions.
mRNA vaccines teach our cells how to make a protein. This protein triggers an immune response inside our bodies.
Radioimmunoassays are high sensitivity in vitro assay techniques to measure concentrations of antigens using specific antibodies.
When microbial toxins and specific antibodies combine and the active portion of the toxins are blocked, neutralization occurs.
Indirect fluorescent antibody test (IFA) is a semi-quantitative, sensitive, and rapid test to detect specific antibodies or antigens.
Phagocytosis is a process in which specialized cells engulf and digest extracellular pathogens. It is an important innate defense mechanism.
Based on the location of antigenic determinants sites, immunoglobulins are divided into, isotypes, allotypes, and idiotypes.
IgA is the second most abundant class of immunoglobulin. sIgA is a dimer and is confers mucosal immunity.
Antibodies are Y-shaped tetra-peptide molecules consisting 2H and 2 L chains. There are 5 classes of immunoglobulins IgG, IgA, IgM, IgE, and IgD.
Immunochromatography is a combination of chromatography and immunoassay to detect the presence of target analyte in a sample.
When most of a population is immune to an infectious disease, this provides indirect protection to those who are not immune to disease.
Serotyping is the classic tools for epidemiological study of organisms having multiple serotypes: E. coli, Salmonella, Vibrio, Shigella, S. pneumoniae.
Direct fluorescent antibody (DFA) test detects the presence of a particular antigen using a fluorescently labeled monoclonal antibodies (mAb).
Detection of specific antigens present in the sample (blood, urine, or CSF) using specific antibodies is the mainstay for the rapid diagnosis of infections.
These are antibodies derived from a single clone of a plasma cell. Monoclonal antibodies are used in the treatment of various diseases and cancers.
Heterophile antigens are antigens of similar nature found in phylogenetically unrelated species. They are involved in disease pathogenesis.
It is used to detect the presence of ‘incomplete’ Rh antibodies i.e. IgG antibodies capable of sensitising RBCs but incapable of causing hemagglutination.
Neutralization of pathogens, phagocytosis, mucosal immunity, ADCC and complement mediated lysis are major functions of antibodies.
B cells are major cells of humoral immunity, effector B cells produce antibodies. Find what Killer T-cells' and 'helper T-cells' do?
Superantigens are microbial peptides that can polyclonally activate up to 20% of T cells. e.g., Staphylococcal toxic shock toxin (TSST-1).
Detection of IgM, or Ab titre more than local cut-off titre or four-fold rise in Ab titre between acute and convalescent period is diagnostic.
B-cell response to T-dependent Ag requires assistance from helper T-cells but T-independent Ag can activate B cells without that help.
IgG antibody crosses the placenta and plays an important role in protecting the developing fetus. IgG is the most abundant Ig in serum.
Innate Immunity is present right from the birth but acquired or adaptive immunity is acquired during the course of life.
Primary immune response to Ag occurs on the first occasion. Subsequent encounter of B and T cells with same Ag leads to secondary response.
MHC molecules bind peptide fragments derived from pathogens and display them on the cell surface for recognition by the appropriate T cells.
Antigen is a foreign bio-molecule that induces a specific immune response and subsequently reacts with the products of the specific immune response.
Complement system is a part of the innate immune system
Western blotting or immunoblotting enables researchers to identify the specific protein from a mixture of proteins.
Vaccinations begin early, but regular doses continue through the first several years of childhood, with periodic updates and the addition of a few new vaccinations later on.
IgM is the largest pentameric immunoglobulin which is used as a marker of recent infection. IgM also activates complement pathway.
Widal test is one of the oldest and most widely used serological tests for the diagnosis of enteric fever.
In the presence of specific Abs to an infectious agent, any complement in the system is bound, leaving no residual complement for rxn with Abs to the RBCs.
Counterimmunoelectrophoresis is a modification of Ouchterlony method that speeds up migration of an antigen and antibody by applying an electrical current.
Agglutination tests detect Ab or Ag and involve agglutination of particulate antigens (bacteria, RBCs or Ag- or Ag-coated latex particles).