Autoimmune disease Flashcards
what attacks the body during an autoimmune disease
T & B cells
what is the humeral response of an autoimmune disease mediated by
B cells
in a humeral response, what is the target against
microbes which are outside of the cell & they produce antibodies against those microbes
what is the cellular response led my in an autoimmune disease
T cells & T lymphocytes
how does the cellular response take place by T cells in an autoimmune disease
T helper cells, which when detect an e.g. microorganism or detect something is wrong, will release cytokines in order to recruit neutrophils, macrophages, B cells into the area
what do cytotoxic T cells do when it finds the infection
it will induce apoptosis
what does an autoimmune disease cause
immune reactions against self antigen (the body itself becomes foreign)
how many % of the population has an autoimmune disease
1-2%
what three prerequisites/evidence is there that there is an autoimmune disease
- presence of an immune reaction specific for a self antigen or tissue
- evidence that the immune complex is the primary cause
- absence of any other aetiology
what is self tolerance
the lack of responsiveness to an individuals own antigens (i.e. own proteins/DNA)
our immune system can tolerate ourselves, we don’t usually attack ourselves so autoimmune is breakdown of self tolerance
which cells that recognise our cells as ‘the self’ that are constantly being produced, must be eliminated
lymphocytes - T & B cells
what does removal of auto reactive T & B cells result in
autoimmune disease
which cells need to be eliminated if they recognise the body as foreign
T & B cells
where are T cells produced
thymus
where are B cells produced
bone marrow
what is central tolerance
when T cells that recognise ‘self’ are removed in the thymus and B cells that recognise ‘self’ are removed in the bone marrow
however the process is not 100% fool proof and some T or B cells which are non tolerant/that recognise ‘self’, escape to the periphery and are auto reactive
when central tolerance is not 100% effective, by what other means can the T or B cells (that are non tolerant) which have escaped to the periphery be removed
via peripheral tolerance
what is peripheral tolerance
Anergy: prolonged or irreversible functional inactivation of lymphocytes (when cleared in peripheral part of body)
many interactions between CD28 and B7 and regulatory T cells that can induce anergy apoptosis (in periphery) in auto reactive T cells (to destroy T cells)
when do we induce a T cell response in relation to the peptide
if it is non self
when do we induce apoptosis in relation to the peptide
when it is self
what induces anergy
tissue cell or APC lacking B7
what causes the non up regulation of B7
when auto reactive T cell comes along & binds to the self peptide cell on the MHC protein, because the cell is not infected, it is not going to up regulate B7, so the cell hangs around and becomes anergic/inactive as it doesn’t get co-stimulation from B7, so lack in B7 induces anergy
what causes the up regulation of B7
bacteria inside a cell
what is one way of muzzling the T cell
by moving B7 = don’t get activation of the T cell