Autoimmnity Flashcards
What is autoimmunity
the presence of immune responses against self antigens
what can cause chronic inflammation
high titres of auto-antibodies or auto-reactive T cells
When is there a large potential for the development of auto reactive B/T cells
during normal lymphocyte development in primary lymphoid tissues
Which part of the Ig gene locus decides the class of antibody
constant region
Which variable gene segments does the heavy chain have
D
V
J
Which variable gene segments does the light chain have
V
J
What stage of the B cell is the chain sequences transcribed
progenitor B cell
What gives the variable region of the B antibody its specificity
1 gene segment at random is selected from D, V and J giving it a unique peptide sequence when translated
What happens to the gene segments not selected
are cut out, leaving only the 3 selected genes next to each other
How are auto-reactive T cells tested for that could respond to self antigens
receptors are tested in thymus against self antigens from across the body
when are progenitor B cells allowed to reach maturation?
if they do no have a strong reaction to self antigens during the “training phase”
How are immune cells with self-antigen receptors which reach maturation inactivated
regulatory T cells
How can genetics cause autoimmunity
single gene defects
complex genetic overlaps
genes expressed for HLAs
what is a common overlap of genes that causes autoimmune disease
HLA genes
What are MHC molecules also referred to
HLA (human leucocyte antigen)
