Immunology Flashcards
Innate immunity:
PAMP’s (pathogen-associated molecular patterns- conserved patterns in microorganisms) bind to recognition receptors, such as ______
- TLR
Innate immunity:
Complement cascade plays important role in defense against ____ and _____
- bacterial and viral infections
_____ and ____ are antimicrobial peptides of teh innate immune system.
- cahtelicidins
- defensins
Cathelicidins and defensins, part of the innate immune system, are increased in ______ and decreased in ______
- increased in psoriasis (less infections than you would think)
- decreased in atopic derm
Adaptive immunity:
- involves generation of antigen-specific _____ and _____
- B and T cells
Adaptive immunity
Recognition of self-antigens as foreign leads to _____
- autoimmune processeses
Immunologic mediators:
- cytokines bind to cellular receptors leading to ____
- activation or inhibition of downstream signaling pathways
Immunologic mediators:
- cytokines have traditionally been classified into three groups:
- interleukins
- lymphokines
- chemokines
TLR recognize _____ and are usually expressed on _____
- recognize PAMP’s (pathogen associated molecular patterns)
- expressed on APC’s
Interaction between TLR’s, APC’s and PAMPs on pathogens leads to activation of _____ and presentation of antigen to ____. This is a link between the innate and adaptive immune system.
- activation of APC
- presentation of antigen to T-cells
Activation of TLRs leads to ____ of pathogen, followed by proinflammatory environment with secretion of cytokines and chemokines.
- phagocytosis of pathogen
All TLRs except ____ use the ____ signaling pathway following activation.
- except TLR3
- myd88 signaling pathway
What are the general functions of complement pathway?
- direct lysis of bacteria
- opsonization of bacteria
- chemotaxis
- clearing immune complexes (hence complement deficiency leads to increased risk of lupus)
- activating immune respones
- anaphylaxis
The three complement pathways are:
- classical pathway
- alternative pathway
- lectin/mannase-binding pathway
All three complement pathways lead to formation of ____
- membrane attack complex, C5b to C9
Membrane attack complex forms a transmembrane ____ in the pathogenic organisms cell membrane leading to____
- channel/pore
- leading to cell lysis/death
Classical pathway of complement is activated by ___
- immune complexes (Ab-Ag complex)
Alternative pathway of complement works by:
- recognizing microbial cell surface structures (without antibodies)
Lectin pathway of complement is activated by:
- mannose-binding lectin protein
Membrane attack complex subunits are numbers___ to ____:
- C5b-C9
___ and ___ are anaphylatoxins in the complement pathway.
- C3a, C5a
Adaptive immune response results in generation of ____, ____, ____, and _____
- Cytotoxic T-cells
- CD4 T-helper cells
- Th17 T-cells
- antibodies
Three main cell type families important in the adaptive immune response are:
- lymphocytes (T-cells, B-cells, NK-cells)
- Monocytes (dendritic cells, macrophages, Langerhan cells)
- Granulocytes (mast cells, eosinophils, neutrophils)
B-cells come from stem cells in ____
- bone marrow
Main function of B-cells is ____
- antibody production and differentiation into plasma cells
B-lymphocyte isotype can switch (IgM to IgG, IgA, or IgE) if they interact with _____
- T-helper cells
Memory B-cells (upon repeated exposure to antigen) have ____ affinity antibody production, _____ isotype switching in presence of T-helper cells
- increased
- increased
B-cell markers/receptors include:
- MHC class II
- CD 19
- CD 20
T-cells are derived from ____ , mature in_____, and reside in _____
- derived from bone marrow
- mature in thymus
- reside in paracortex of lymph nodes
Stimulation of T-cells leads to____ release or ____
- cytokine release or cell lysis
T-cells are stimulated when it recognizes an antigen, but only when the antigen is complexed with _____
- MHC I or II
In addition to stimulation of T-cells by antigen+MHC, there are constimulatory signals on the cell surface of T-lymphocytes and APCs, these include:
- CD28 on T-cell binding B7-1, and B7-2
- CD2 on T-cells binding to LFA-3
- LFA-1 on T-cells binding to ICAM-1 on APCs
CTLA-4 on T-cells binds to APCs leading to _____
- inhibition
Ipilimumab blocks ____ signaling pathway leading to _____
- CTLA4 (which usually inhibits T-cell activation)
- leading to greater T-cell activation and antimelanoma tumor activity
T-helper 1 (th1) cells activate _____
- activate macrophages
Th1 differentiation requires stimulation by ____ and ____
- IL-12
- IFN-gamma
Th1 cells produce:
- IFN-gamma
- IL-2
- IL-12
- TNF-alpha
Th2 cells activate _____
- eosinophils
____ is a key cytokine that stimulates Th2 proliferation.
- IL-4
Th2 cells produce:
- IL -4,5,6,10, and 13
Th17 cells are dependent on activation of transcription factors ____ and ____ which are mutated in ____ syndrome
- ROR-gamma-T and STAT3
- Job’s syndrome
Th17 cells recruit ____ that can destroy extracellular pathogens.
- neutrophils
Treg cells downregulate immune response and express ____ and transcription factor ____
- CD25
- FOXP3
CD8+ cytotoxic T cells recognize cytoplasmic antigens when bound to ____
- MHC class I
CD8 cells kill via ____ pathway, and use ____ ligand to bind on target cells.
- perforin/granzyme pathway (perforin enables granzyme to enter cytoplasm of virally infected cells)
- use Fas ligand to bind Fas on target cells leading to cell death
NK cells are a component of the ____ immune system
- innate
Cell surface markers for NK cells
- CD2
- CD 56
- CD 16
NK cells identify ___ or ___ cells and destroy them using ____ pathway
- viral or tumor cells
- perforin/granzyme pathway
NK cells secrete ____ which enhances phagocytic capability of macrophages
- IFN-gamma
Monocytes/macrophages are derived from____ in the bone marrow
- CD34+ progenitor cells in bone marrow
Macrophage markers:
- CD11a/b/c, CD 6, MHC II
Eosinophils are derived from
- bone marrow
Eosinophils have important role in defense against ____ infections and ____ diseases
- parasitic/helminth infections
- allergic diseases
____ protein leads to degranulation of mast cells/basophils
- Major basic protein
Mast cells are derived from ____ expressing____, ____, ____
- bone marrow progenitor cells expressing CD 34/c-kit/CD13
Mast cells express high levels of ____ which is critical for survival and proliferation of mast cells
- C-kit receptor
Mast cells are important in ___ type hypersensitivity reactions
- immediate
Neutrophils are produced in ____
- bone marrow
First cell to arrive in acute inflammatory site is the ____
- neutrophil
Neutrophils function to destroy microbial pathogens by ____ followed by oxidation via ____
- phagocytosis
- oxidation via Reactive oxygen species
MHC locus is found on chromosome ___
- chromosome 6
MHC locus key role is to ____
- present antigen to T-cells
T-cells only recognize antigens if antigen has _____
- MHC
MHC 1 present antigens to ____ and are present on ____ cells
- CD8+ T cells
- present on all nucleated cells
MHC II present antigens to . ____
- T-helper cells
MHC II is expressed on what type of cells?
- APC’s