ANTIGEN
any foreign material that stimulate an immune response in the body
antibody
a protein that is produced as a result of the immune response to an antigen
humoral immunity
immunity involving the transformation of B lymphocytes into plasma cell that produce and secret antibodies to a specific antigen
cell-mediated immunity
immune response that does not involve antibody but involve activation of phagocytes n release of various cytokines in response to an antigen
organ of immune system
- thymus
- bone marrow
- lymph nodes
- spleen
- tonsils
- peyer’s patches
function immune system
- differentiate between ‘self’ (body’s own cells) n ‘non-self’
- destroy ‘non-self’ (foreign cells)
major histocompatibility complex MHC
the marker of group of molecules that place on the outer surface of body’s own cell
autoimmune disease
abnormal situation when the immune system attack the body’s own cell
main players in the immune response system
lymphocytes
two main type of lymphocytes
- T CELLS
- produce in bone marrow then move to thymus where they mature
- involve in cell-mediated response
- B CELLS
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types of T cells
- helper T cells (CD4)
- cytotoxic T cells / killer T cells (CD8)
- suppressor T cells
- memory T cells
helper T cells (CD4)
- activate B cells n killer T cells
killer T cells (CD8)
- attack cells of the body infected
- also attack cancer cells
- infected cell release perforin that forms a pore in target cell
suppressor T cells
keep the immune system in check, once the infection is controlled, the system is switched off
memory T cells
remain after the pathogen have been killed to enabling it to response quickly to future infection
B cell
- form in bone marrow, then move to lymphoid organ
- involve in humoral response
- produce antibodies in response to antigen
how it work
- the B cells finds an antigen which matches its receptor
- it waits until it is activated by a helper T cell
- the B cell divide to produce plasma cell n memory cell
- plasma cell produce antibodies that attach to the current invaders
- eater cells eat the intruders marked with antibodies
- if the same intruders invade again, memory cell help to activate the immune system much faster
specific body defense
antibody
- igA
- igD
- igE
- igG
- igM
igA
protects the mucous membrane n internal cavities against infection (provide immunity to infant digestive tract)
igE
- causes allergies
- fight against parasitic disease
- found on surface of basophil n mast cell
igD
on B cell surface, initiate immune response
igM
1st antibody produced during infection. Effective against microbes n agglutinating antigens
igG
- enhances phagocytosis, neutralize toxins n viruses
- protects fetus n newborn
acquired immunity
active production of antibody
