autoimmunity Flashcards
definition of autoimmunity
the presence of immune responses against self tissue/ cells
harmless autoimmunity
low titres of auto antibodies or autoreactive T cells
harmful autoimmunity
high titres of auto antibodies or auto reactive T cells
where are auto reactive T and B cells normally generated
primary lymphoid tissuse
what kills or inactivates auto reactive T and B cells
tolerance mechanisms
self tolerance
non responsiveness of lymphocytes to specific self antigens
how are auto reactive cells which were not inactivated by tolerance mechanisms restrained
Foxp 3+ regulatory T cells
central tolerance
deletion of self reactive lymphocytes in primary lymphoid tissues
peripheral tolerance
inactivation of self reactive lymphocytes in peripheral tissues that escaped central tolerance
regulatory T cells make up what
5-10% of the normal CD4+ T cell population
what are regulatory T cells crucial for
suppressing hyperreactive or auto reactive T cells via anti inflammatory cytokines
auto immunity results from
failure of immunological tolerance
factor contributing to auto immune disease
genes
monogenic disorders
single gene defects causing autoimmune diseases - rare - IPEX syndrome
IPEX syndrome presentation
X linked
mutation is FOXP3 gene
IPEX is the failure of peripheral tolerance mechanisms
