Immunology Flashcards
what is the difference between MHC 1 and MHC 2?
MHC 1 expressed on all cells - presents to cytotoxic CD* T cells, triggering apoptosis. normally in case of intracellular organisms ie virus, parasites
MHC 2 expressed on APC cells (especially dendritic cells) - present to helper T cells, priming them for further action
which type of cell is the most common antigen presenting cell (APC)?
dendritic cell
what are primary vs secondary lymphoid organs?
primary - where immune cells deveop/mature (ie thymus, bone marrow)
secondary - where immune cells interact with antigens (ie lymph nodes, spleen)
what are the main subtypes of T helper cells, and which cytokines do they secrete?
Th1 - Interferon gamma, IL2
Th2 - secretes IL4, IL5, IL13
Th17 - IL17A, IL17F, IL22
which T helper cell subtype is associated with allergic and parasitic infections?
T helper 2
which T helper cell is most likely to be involved in viral infections?
TH1
which T helper cell is most likely to be involved in bacterial and fungal infections?
TH17
how do T helper cells coordinate an immune response against an infection?
through cytokine release
which type of T helper cell secretes interferon gamma?
TH1
what is the role of cytokines?
- communicate locally/at a distance
- recruit more cells
- coordinate immune cell activity
what are the enzymes used by cytotoxic T cells and NK cells to kill infected cells?
perforin
granzyme
what cytokine do NK cells secrete?
interferon gamma
what do NK cells do?
help kill infected cells if T cell response is not optimal
which type of immunoglobulin does breast milk contain?
IgA
what are the physiological changes that occur on the target cell membrane as a result of opsonisation?
- negative charge removed so phagocytes can bind
- increase in number of receptors for phagocytes to bind to
what is the aetiology of primary immunodeficiency diseases?
genetic abnormalities (mutations)
how can primary immunodeficiency diseases be classified?
- abnormalities in innate immune system
- abnormalities in lymphocyte development
- abnormalities in lymphocyte reaction to antigens
what is the main primary immunodeficiency disease that results from abnormalities in lymphocyte development?
severe combined immunodeficiency (SCID)
what types of immunodeficiency disorders are hypogammaglobulinaemia and agammaglobulinaemia?
primary immunodeficiencies, resulting from abnormal immune reaction to antigens
what is seen is common variable immunodeficiency (CVID)?
low levels of IgG
what are the three mechanisms by which genetic changes can cause primary immunodeficiency disease?
- single nucleotide polymorphisms
- mutations
- polygenic causes
how is primary immunodeficiency treated?
mild cases - antibiotic prophylaxis
severe cases - immunoglobulin replacement therapy
what is the treatment for Severe Combined Immunodeficiency (SCID)?
- stem cell transplant early in life
- gene therapy if no suitable stem cell donor
what is the pathology behind SCID?
lymphocyte precursors are mutated so don’t respond to growth factors promoting differentiation
what’s the acronym that characterises infections seen in immunocompromised patients?
SPUR:
serious, persistent, unusual, recurrent
what is the common presentation of immunodeficiency caused by abnormalities in antibodies and T cells respectively?
- antibody abnormality: recurrent respiratory infections
- T cell abnormality: serious viral, fungal and intracellular infections
