Immuno 3 Flashcards
more specific definition of lymphocytes
substance (foreign to body) that provokes a specific response by the lymphocytes
what is tolerance and what will happen if your body loses this tolerance?
tolerance is that your immune system know its own antigens (if immune system loses tolerance, then you get autoimmune diseases)
what are surface radicals? what is another name for this
epitope
-on a cell that is antigenic, usually a small patch of amino acids
3 classifications of antigens of human origin
- autoantigens
- homologous antigens
- organ specific antigens
what are auto antigens?
your own antigens, if you lose tolerance to auto antigens, it will cause an autoimmune disorder
what are homologous antigens?
just a little bit genetically different from your neighbor of the same species (example is ABO blood type)
example of homologous antigens
-transplant rejection possibility because immune system thinks it is foreign- have to take immunosuppressants the rest of life
what are organ specific antigens?
your immune system does not know about these antigens (because they have been isolated from the immune system)
example of organ specific antigens
lens in the human eye
problem from organ specific antigens in cataract surgery of the lens of the eye
lens liquifies and if some of that spills out during surgery, it can get into circulatory system and cause
- phacolytic glaucome
- phacolyitc uveitis (inflammation)
what is required for antigen presentation to T cells
major histocompatibility complex (MHC)
-2 special proteins I and II
MHC class I vs. MHC class II biochemical difference
- MHC Class I has 1 heavy chain
- MHC Class II has 2 heavy chains
how is MHC Class I used?
- a billboard for killer T cells
- when virus is inside cell
- results in killer T cell destroying that cell
what kinds of cells can present MHC Class I and II?
MHC I- most cells have the ability to do this
MHC II-only certain antigen presenting cells (APCs) can do this
how is MHC Class II used?
antigen is displayed on surface for information to the helper T cells
-which secrete various substances and get immune response going
list of consequences of antibody antigen reactions
- activation of B and T cells
- activation of complement
- phagocytosis
first step in Ab-Ag coupling activation of B and T cells
coupling of Ag-Ab= cognate, antibody finds its cognate antigen, and cognate antigen displayed by infected cell
second “fail safe” from Ab-Ag rxn activation of B and T cells
“fail safe” is a protein on the helper T cell on APC which locks up- keeps immune system kicking off/on immune response
-the “2nd key” required
what is complement?
a system of 20 different proteins in the blood stream which can be activated
what occurs when complement is activated?
there is a chain reaction and there is substance which can be very destructive to human cells and pathogen (lysis, cytotoxic)
how many ways can these 20 complements be activated/combined and what is the most common way?
3 different ways
-usually hear about the classical route of activation and coupling together of these components
when complement is activated, where does it attach
attached to antigen
“fixed to antigenic cell”
end result of complement and what occurs:
membrane- attack complex
“drill a hole” right through the cell wall, fluid rushes in and cell bursts
what is a phagocytic cell
type of cell that will ingest other cells, resulting in engulfment
