Lecture 16 Thrush Flashcards
Central Tolerance
self-reactive cells are destroyed in the primary lymphoid organs (bone marrow or thymus)
Peripheral Tolerance
where self-reactive cells that accidentally are suppressed
what circumstances can induce tolerance
high doses of antigen persistence of antigen in host i.v. or oral introduction absence of adjuvants low levels (or lack) of co-stimulator molecules
what happens if tolerance fails
autoimmunity is formed
Function of t regs
to inhbit immune response of self reactive cells
What are T regs?
CD4 +, CD25 + and t cells
Which gene helps to stimulate the t regs? what happens if it is mutated?
Foxp3; autoimmunity
What causes autoimmunity?
B cells or T cells
failure of central or peripheral tolerance
apoptosis (lack of Fas)
some MHC (HLA-B27; HLA-DQ6)
What causes autoimmunity?
sequestered antigens that body doesnt recognize
altered self infections
Why do women have more autoimmunity than men?
more Ab
more CD4 t cells
Hashimoto’s
due to autoantibodies and Th1 cells inflammation/ cytotoxicity damage to thyroid gland genetic component middle aged japanese women also environmental
Autoimune (pernicious) Anemia
autoantibodies
antibodies to intrinsic factor (clumping)
recognized by phagocytic cells t be gobbled up
individual can not produce vit B12
Diabetes
due to CTL attack on islet beta cells
Abs can play a role
M. Gravis
antibodies block acetylchoilne receptors
SLE lupus
primarily in women 20-40 years of age ANA antibodies against nuclear components systemic (butterfly rash) immune complexes form
