Overview + Antigens Flashcards
The immune system is what 3 things
Specific, systemic and has memory
Antigens are substances that do what
Provoke an immune response
What are the strongest antigen
Protein
Ability of a molecule to act as an antigen depends on what
Size and complexity
What are the immunogenicity parts of an antigen called
Antigenic determinants
Primary response of the immune system is what
Produce protective proteins known as antibodies
Another word for antibodies
Immunoglobulins/ Ig
Antibodies are produced by what
B lymphocytes/Plasma cells
Antibodies bind specifically to their antigens to form what
Immune complexes
Immune complex formation has several consequences. Describe the 4 consequences
1) toxic antigens are neutralised as the complex prevents antigen from spreading further
2) complexes activate formation of inflammatory mediators
3) immune complexes formed on the surface of bacteria, activate certain plasma proteins (complement) to drill holes into the bacterial cell membrane which causes bacteria to burst and die (lysis)
4) complexes target structures for phagocytosis and leads to destruction
Name the two types of immunity
Humoral and cellular
Humoral immunity is mediated by and involves what
Antibody mediated and involves B lymphocytes
Cellular immunity is mediated and involves what
Cell mediated immunity and involves T lymphocytes
B lymphocytes produce antibodies, naive lymphocytes produce unique antibodies from what
Random combination and rearrangement of gene products
Naive lymphocytes are found where
Lymphoid tissues
Binding of the antigen to the correct B lymphocyte activates what and why
Mitosis so that more of the antibody is produced
Some copies of the selected b lymphocyte produce large amount of antibodies while some produce small amounts. What are the names of these two cells
Large amount - plasma cells
Small amount - memory cells
Memory cells are expressed where
Surface of the b lymphocyte as a receptor
T lymphocytes display what on their surface that behave like what
Display proteins that behave like antibodies
However why are the proteins on the t lymphocytes not true antibodies
The proteins are not secreted, they bind to antigens that are on the surface of abnormal cells
T lymphocytes are directed to what instead of free antigens
Tissue cells
Name the 2 types of cells that process and display antigens on their surfaces for T lymphocytes to detect
Antigen presenting cells/APCs and Abnormal cells
APCs do what
Phagocytise leukocytes which present fragments of antigens on their surfaces for the T lymphocyte to detect
T lymphocytes that react with
1) APCs are what
2) Abnormal cells are what
1) Helper T (Th) cells
2) Cytotoxic T (Tc) cells/ Killer T cells
Activated Th cells stimulate what
Activities of other lymphocytes by synthesising a special class of regulatory (hormone like) compounds known as CYTOKINES/LYMPHOKINES
Is immune response different from a primary, non specific inflammatory response?
Yes
How many responses are there for tH cells
2
Describe th1 response
Participate in cell mediated immunity. Controlling intracellular pathogens viruses and bacteria
Describe th2 response
Provide help for B cells so for hummoral immunity.
Antibodies are needed to control what
Extra cellular, blood and body fluids
Activated Tc cells physically attack what
Cell membrane of abnormal cells causing the cell to lyse and die
Sub populations of T cells could become what
Memory cells
So Th cells can produce either immunity. Attack on infected cells or secretion of antibodies
Lol
Name 4 autoimmune diseases
MS, Diabetes 1, Rheumatoid arthritis and systemic lupus erythematosus SLE
Describe what the immune system attacks for MS and SLE
Ms - myelin on axons of nerves
SLE - Whole body causing red rash on face
