Autoimmunity Flashcards
Peripheral tolerance:
inactivation of self-reactive lymphocytes in peripheral tissues (lymph nodes, spleen, tonsils) that escapes central tolerance e.g. by TREG cells
Central tolerance:
Deletion of self-reactive lymphocytes in primary lymphoid tissues
Regulatory T cells:
Inactivate auto-reactive T lymphocytes in perhipheral tissues which escape the central tolerance via production of anti-inflammatory cytokines
Regulatory T cells:
Inactivate auto-reactive T lymphocytes in perhipheral tissues which escape the central tolerance via production of anti-inflammatory cytokines
What is IPEX syndrome?
X linked mutation in the FOXP3 gene (involved in TREG development)
Role of HLA genes:
Encode for MHC cells - several HLA alleles have been identified which predispose individuals to autoimmune diseases
Autoimmune disease is most common in…
Females
Light chains are composed of
V and J segments
Heavy chains are composed of:
V D J segments
Lymphopoiesis
Stem cells → Lymphoid progenitors → progenitor B cell → Antibody expression
Harmless autoimmunity
Low titres of auto-antibodies and auto-reactive T cells
Harmful autoimmunity:
High titres of auto-antibodies and auto-reactive T cells causes significant tissue/organ damage or chronic inflammation
How do drugs effect antigens:
Interaction with self antigens can cause alteration of self-antigens
Example of super-antigens:
Bacteria responsible for toxic shock can reactivate autoreactive T cells which have been inactivated by TREG cells
Antigens sequestration:
Antigens in tissues that do not normally communicate with blood/lymph can be exposed due to trauma, causing an autoimmune reaction
