W4.1 Flashcards
Innate immunity review
“(Natural, Native)
- evolutionarily less advanced
- same response regardless of stimuli
- first line of defense
- rapid response
- no memory - same response every time
- pattern recognition receptors “
Adaptive immunity review
“(Specific)
- more advanced
- each response is tailored to stimulus
- take longer to develop initially, but are much more effective
- stronger responses with each exposure
- Ability to remember previous infections “
The goal of the immune system
to survey the body for potential pathogens, find cells that can recognize that pathogen, and kill/remove it
Adaptive immune system (humoral vs cell mediated immunity)
“H - B lymphocyte
CM - Helper and Cytotoxic T cell”
Antigen
any substance that can be specifically bound by an antibody or T cell receptor
Lymphocytes
“A subset of WBCs that can be distinguished on the basis of
morphology, histologic staining, immunologic functions, and extracellular/surface markers “
how to identify T cells
Flow cytometry recognizes CD2, CD3, CD4, CD8
how to identify B cells
Flow cytometry recognizes CD19, CD20, CD22, and surface immunoglobulin
how to identify NK cells
Flow cytometry recognizes CD16 and CD56
Lymphocytes importance and size
”- primary importance in the adaptive immune system
- 7-10 um diameter
- rounded, indented nucleus; chromatin stains deep blue
- rise from hematopoietic stem cell in the bone marrow, differentiate in primary lymphoid organs “
Lymphocytes percentage(s) of the WCBs and peripheral blood
”- 20-40% of circulating WBCs
- B cells (10-20%, T cells (61-89%), NK (22%)”
Flow Cytometry
How cells are identified
“by size, densitiy, and expression of surface proteins
B (CD19, CD20), T (CD3), Monocytes (CD14), NK (CD16, CD56) “
Secondary Lymphoid Tissue
“includes : spleen, lymph nodes, appendix, tonsils, other mucosal associated lymphoid tissue
- main contact with foreign antigens takes place
- spleen filters for antigens”
similarity of T and B lymphocytes in the lymphoid system
recirculate continuously from the bloodstream to the secondary lymphoid organs and back
APC
antigen presentation cell
Lymph Node (lymph flows in through)
“Lymph flows into the node from surrounding tissue through the afferent vessel
(includes fluid and cell from the tissues, especially APCs that hange out in these tissues looking for antigen) “
Lymph Node (lymph fluid is inspected by, ->?)
“Once in the lymph node, the lymph fluid is inspected by lymph node resident APCs;
- debris, antigen, dead/dying cells are taken up by lymph node APCs and are presented to naive T and B cells that circulate via the blood) “
Lymph Node (inspection results in no infection)
“The APCs will display ““self peptide”” and not express costimulatory molecules
(naive lymphocytes signaled “” everything is ok, live, recirculate throughout the body and be happy””)
Lymph Node (inspection results in foreign material)
”- Tissue APCs likely have already taken it up
- (in the lymph) lymph node APCs recognize foreign antigen, become activated, express costimulatory molecules -> ““activation signals”” to lymphocytes
Lymph Node (lymph leaving the node)
inspected/filtered lymph and cells leave the node through the efferent vessels and eventually into the bloodstream
Immune repertoire
“Total collection of specificities
- T and B cells diverse specificites
- 10 bill receptors to recognition “
ideal immune repertoire
”- large enough to recognize any potential microbe/invader/antigen/pathogen
- specific enough to only respond to microbes/pathogens/antigens/ that are present
