Hypersensitivity and autoimmune disease Flashcards
autoimmune disease is and why
failure or breakdown of immune system that maintains tolerance to self tissues. loss of tolerance due to abnormal selection or lack of control of self reactive lymphocytes (B and T cells)
autoimmune disease can come from
susceptible gene or environment eg drugs, trauma, food, infection
autoimmune disease treatment
blanket immunosuppression but this is not good so trying to start targeted selective approach
hypersensitivity responses are
harmful immune responses that may produce tissue injury and cause disease. 4 types. damaging effector mechanisms
Types II is ______ mediated. some detail
IgG. IgG antibodies come into contact with antigens on surface of self cells. complement activation and cell lysis. IgM too. eg red blood cell destruction after transfusion mismatch of blood types
Type IV is______ mediated. some detail
T cell. produce cytokines and that induces inflammatory response. or just kill using CD8 cells alone
Type I is ___ mediated. some detail
IgE. activates T helper cell which causes release of IgE from B cells which activate mast cell which releases histamines and cytokines which bring about inflammation, allergy related, very quick response
difference between type II and type III
location of antigens. type 2- cell bound, type 3- they are soluble
immunological tolerance
state of unresponsiveness to specific antigen. prevents adaptive responses that are damaging ie controlling B and T cell responses. can be exploited by tumours and microbes
Types III is ______ mediated. some detail
IgG antibodies come into contact with antigen and antigens are loose and so they form an immune complex which brings about inflammatory response by complement activation. eg rheumatoid arthritis
Th types
Th1- macrophages, Th2-eosinophils, Th17- activate neutrophils TfH- B cells
