Immunology Flashcards
What is IgG?
MONOMER
Most abundant isotype in blood serum. It enhances phagocytosis of bacteria and viruses and fixes complement and passes to the foetal circulation.
What is IgA?
MONOMER/ DIMER
(found in tissue fluid only!)
is the most predominant immunoglobulin in breast milk. It is also found in other secretions of the digestive, respiratory and urogenital tract systems. It is the most commonly produced immunoglobulin in the body.
What is IgM?
PENTAMER
It is the first immunoglobulin to be secreted in response to an infection. It fixes complement but does not pass on to the foetal circulation.
What is IgD?
MONOMER
Role in the immune system is largely unknown. It is involved in the activation of B cells.
What is IgE?
MONOMER
It mediates Type I Hypersensitivity reactions. Provides immunity to parasites such as helminths.
What are PAMPs?
Pathogen Associated Molecular Patterns.
They are ligands expressed on the surface of pathogens which allow them to be detected by immune cells.
PAMPs have the ability to activate: macrophages, Mast cells and NK cells
What are PRRs?
Pattern Recognition Receptors.
Found on innate immune cells that are receptors for PAMPs found on pathogens.
What is a Neutrophil?
Primary phagocytic cell in acute inflammation. It is the most common type of white blood cell and has a multi-lobbed nucleus (4 lobes).
What is a Basophil?
releases histamine during an allergic reaction. It expresses IgE receptors on the cell surface and has a bi-lobbed nucleus (2 lobes).
What is a Mast Cell?
present in tissues and are similar in function to basophils but derived from different cell lines. Releases histamine during an allergic reaction.
What is a Eosinophil?
defends the body against protozoan and helminthic infections. They have a bi-lobbed nucleus (2 lobes).
What is a Monocyte?
differentiate in macrophages. They are kidney shaped.
What is a Macrophage?
involved in phagocytosis of cellular debris and pathogens. They act as an antigen presenting cell.
What is a Natural Killer Cell?
they induce apoptosis in virally infected and tumour cells.
What is a Dendritic Cell?
act as an antigen presenting cell for T cells,
What are Helper T cells?
are involved in the cell mediated immune response. They recognise antigens presented by MHC Class II molecules and express CD4.
What are Cytotoxic T cells?
are involved in the cell mediated immune response. They recognise antigens presented by MHC Class I molecules and express CD8. They induce apoptosis in virally infected and tumour cells.
What are B cells?
is a major cell of the humoral immune response. they act as an antigen presenting cell and mediates hyper acute organ rejection.
What is Opsonisation?
the coating of pathogens by humeral factors (opsonins) to facilitate phagocytosis.
It is mediated by special Fc receptors that bind specifically to the constant region of the IgY (gamma) heavy chain of IgG.
Examples include: C3b, CRP, IgG/ IgM.
What is Neutralisation?
is the ability of antibodies to block the site on bacteria or viruses that they use to enter their target cell.
What are Cytokines?
are a diverse collection of small proteins produced in response to infection, inflammation and tissue damage.
Describe some cytokines and their functions?
- Interferons: anti-viral activity.
- TNF-alpha: a pro-inflammatory cytokine.
- Chemokines: control and direct cell migration.
- Interleukins: various functions.
What is Primary Lymphoid Tissue?
site of leukocyte development. Includes the thymus and bone marrow.
What is Secondary Lymphoid Tissue?
site where T cells and B cells become activated by antigen. Includes the adenoid tonsils, lymph nodes, spleen, payer’s patch.
What is Secondary Lymphoid Tissue?
site where T cells and B cells become activated by antigen. Includes the adenoid tonsils, lymph nodes, spleen, payer’s patch.
What is Agglutination?
the action of an antibody when it cross-links multiple antigens and so produces clumps of antigens.
What are Monoclonal Antibodies and why are they used?
they are antibodies that are made by identical immune cells that are all clones of a unique parent cell. They are used in therapy to neutralise TNFalpha
What are Monoclonal Antibodies and why are they used?
they are antibodies that are made by identical immune cells that are all clones of a unique parent cell. They are used in therapy to neutralise TNFalpha
What are NETs?
They are Neutrophil Extracellular Traps?
Activated neutrophils release intracellular structures (NETs) into the extracellular environment. They serve to immobilise pathogens, preventing them from spreading and facilitating their phagocytosis.
