Intro to Immunology Flashcards
what is the purpose of the immune system
defense against infectious microbes
what was the origin of the first vaccine
pus from cowpox administered to people to protect from smallpox
what does cross-reactivity mean in reference to the smallpox vaccine
A cowpox antigen was administered, host developed Ab to cowpox, which protected host from different “smallpox” antigens
what is the only human infectious diseease to be completely eradicated
smallpox
what are the 2 components of the immune system and which is considered the early phase ? which is late phase ?
innate - early
adaptive - late
which immune response involves barrier defenses, and what are the barrier defenses
innate
- physical (skin, mucous membranes)
- chemical (sweat, saliva)
- biological (normal flora)
what immune response it antigen specific
adaptive
all leukocytes are derived from where ?
hematopietic stem cells in bone marrow
hematopoetic stem cells can differentiate into 2 kinds of cells, what are they
myeloid progenitor cells
lymphoid progenitor cells
what specific types of cells are derived from myeloid progenitor cells
- Granulocytes (basophils, eosinophils, nuetrophils)
- Monocytes
- Dendritic cells
what types of cells are derived from lymphoid progenitor cells
NK cells
B cells
T cells
cells derived from myeloid progenitor cells are all apart of _____ immunity
innate
of the cells derived from lyphoid progenitor cells, which are apart of the adaptive immune response
B and T cells
neutrophils are _____ in order to respond to trouble, and make up what percentage of leokocytes
first, 50-75 %
phagocytes
what specific cells play a large role in allergies and only make up about 0.2 % of leukocytes
basophils and mast cells
what is the main function of eosinophils, and what percentage of leukocytes do the make up
fight off/destroy parasites that are too large to be phagocytized
2-5 %
what cells are especially effective against viruses and tumor cells, how do they do this
NK cells, dont need MHC complex to recognize antigens
important cuz virus and tumor cells downregulate MHC complexes
what is the main role of monocytes and what percentage of leukocytes do they make up
phagocytes, antigen presentation, housekeeping
5-10 %
what cells are the main link between the innate and adaptive immune system, how do they do this
dendritic cells (also monocytes a lil) -do this by presenting antigens to T cells
what are the 2 “arms” of the adaptive immmune system
humoral immunity
cell mediated immunity
humoral immunity specifically targets ______ pathogens with the aid of what cells
extracellular
-B cells producing antibodies
cell mediated immunity specifically targets _______ pathogens using what cells
intracellular
-T cells
what are the 2 types of T cells and what is their function
cytotoxic t cells - kill and induce apoptosis
helper t cells - secrete cytokines which activate cytotoxic t cells
what are the 3 Cluster of Differentiation (CD) markers for T cells
CD3 - T cells
CD4 - Helper t cells
CD8 - cytoxic t cells
what are the 3 types of antigens
immunogen - normal Ag eliciting immune response
tolerogen - something that is immune-nonresponsive (tolerant)
allergen - Ag inducing hypersensitivity/allergic rxn
what is the difference b/w endogenous and exogenous Ag
endogenous - w/in body and presented by CD8 cells
exogenous - outside body and presented by CD4
what activates naive B and T cells to enter the lymph node from circulation
APC cells binding an antigen at site of infection then transporting to the lymph node
why does adaptive immunity take about a week to actually elicit a response
clonal expansion, differentiation, and multiplication of B and T cells
——-> once enough of them then travel to infection site
explain process of how an activated lymphocyte (t cell) can travel from the lymph node to site of infection
1 - decrease L selectin getting naive T cell in circulation
2 - increase E and P selectin cause it to slow near site
3 - integrins cause to to slow more
4 - chemokines cause it to stop at infection site
what effect do cytokines have on E and P selectins
they increase (makes sense cuz increase cytokines during inflamation)
what are the 3 “non-specific” receptors of the innate immune system that detect microbes
- scavenger
- mannose
- N-formyl-methionyl
- * all signal for phagocytosis***
what does the innate immune system use to detect antigens
Toll like receptors - TLRs
-also known as pattern recognition receptors
what/how do TLRs or pattern recognition receptors recognize which tells them theres an antigen
pathogen associated molecular patterns (PAMPS)
In general, what does activation of a TLR cause
signal cascade of lots of immune cells in innate response
what do T cells of the adaptive immune response NEED in order to detect specific antigens
MHC complex
CD4 t cells (helper) use what MHC complex to recognize specific antigens, what about CD8 (cytotoxic)
MHC II
MHC I
