Review of Immunology Pt. 2 Flashcards
What hypersensitivity?
Production of **IgE antibodies **leading to the immediate release of vasoactive means another mediators from mast cells later recruitment of inflmatory cells.
mass release of histamines= hypotension, SHOCK, anaphylaxis
Immediate Type I Hypersensitivity
What hypersensitivity?
Production of IgG, IgM which Bind to antigenson target cells are tissues -> phagocytosis, or lysis of target cell, by activated complement Fc receptors; recruitment of leukocytes
Latent reaction; chronic inflammation
Antibody Mediated Type 2 Hypersensitivitys
What hypersensitivity?
Deposition of antigen antibody complexes, -> complement activation -> recruitment of leukocytes by complement products in FC receptors -> release of enzymes and other toxic molecules
Immune complex-mediated Hypersensitivity Type 3
What hypersensitivity?
Activated T lymphocytes ->
1. release of cytokines inflamation and macrophaes activation
2. T-cell mediated cytotoxicity
T-cell mediated Hypersensitvity Type 4
WHy hypersensitivity caases this?
- Vascular dialation
- Edema
- Smoth muscle contractio
- tissue injury
- Inflammation
=Anaphlyaxis, bronchial asthma, allergies
Type 1
WHat kind of hypersensitivity rxn?
- Phagocytosis & cell lysis
- Some inflammatiin
- Functuon derangmenr w/out cell tissue unjry
Ex. Autoimmune hemolytic anemia, Good pastrure syndrome
Type 2
- Inflammation
- necrotizing vasculitis (fibrinoid necrosis)
Systemic Lupus Erythematosus, Arthus reaction
Type 3 Hypersensitivity
- Perivascular cellular infiltrates
- Edeama
- Granuloma formation
- Cell destruction
Contact dermitits, multiples sclerosis, Type 1 diabetets, TB
Type 4 hypersensisvity
Immmune response! T cells
What is signala?
The signal that **drives the differentiation **of undifferentiated, (naïve ) helper T cells go down to the Th-1 type of differentiate which direction is a cell mediated delayed hyperpersensitivity response against the organism
Il-12
significant role in the mucosal immunity of the gastrointestinal (GI) tract (this will include the mucosa of the mouth
recruits neutriphils to site of bacterial infections, o2
immune responders (called Th-17)
paired with IL-4 stimulates development of cells, enhances class switdh to IgE
Th-2 Cell
Activates macrophaes to kill intracellular protienes
Th-1 Cells
HLA is housed on what? WHy is this significant?
Housed on MHC CLass I and II. Used Class I for matchign with donors, more specificty.
CD4 helper cell activation and production of IL-2 will only occure if what?
Only occur if B7 proiten on APC binds the CD28 protien on the T-Cell.
WHen a CD8 Cytotoxic t cell binds via its TCR to the Class I MHC on virus infected cell, what helps stavlized this connection?
CD28 Portien on CD8 T cell
What protien is used to turn off CD4 helper T cell.
Binds to B7 on APC and displaces CD28
(CTLA-4)
inhibit T-cell acitvation, reduce organ rejection
Mutant T cells that do not have CTLA-4 that cant be deactivated causes what?
Autoimmune disorders
enhancers of cellular immunity, are used to increase immunity, this is in trials to be used as a potential therapy to reduce the tolerance of immune system to tumor cells and thus help mount a response against them
Antagonists of CTLA4 (
Agonists of CTLA4 are used coupled with ____ to reduce immunity and are in trials to treat immune disorders such as Rheumatoid arthritis and renal transplants in specific patients (with EBV virus).
IG, antibody is an inhibitor of an inhibitor of the immune response
- globulin proteins that react specifically with the antigen that stimulated their production.
*20% of protein in blood Plasma
*alpha, beta, gamma globulins
IgG, IgM, IgA, IgD, IgE
Antibodies
WHat antibody?
1.majority in serum
2. smallest; monomer
3. Opsinization
4. Complement activation
5. Ellict pro-inflammatory response
4. Divalent
4. Transplacental passage
5. Most abundant Ig in newborns
IgG
Gamma globulin
- 15% in serum
- monomer or dimer
- Highest levels in body b/c all in mucous membrane
- secreted in breast milk
- Prevent attachment of microbs to mucous membranes
IgA
alpha globulin
- Pentamer (serum) or monomer (surface of B cells); class switch
- largest
- *Main starter *of hummoral response
- Complement fixation
- Antigen receptor on B cell
IgM
- monomer
- suface of many B cells
- just kinda there…
IgD
- Mediates allergic response ; hypersensitivity 1
- smallest amount in serum
- activates histamines
- monomers
- Defense from parasites.
IgE
descirbe structure of antibody
Fc fragment, base (2 constant heavy chains) linked by disulfied bonds
Fab fragments, hinge a light chain attach to each heavy chain.
End of light and heavy has a variable region. Antigen binding site 5-10 aa
Y shaped
Two important genes that encode recombinases are _____
Mutations in these genes arrest the development of lymphocytes and result in* severe combined immunodeficiency*
RAG-1 and RAG-2
____ using a relativley small number of genes (similar to TCR genes) are used to produce a** large number of different/specific antibodies** (100 million different kinds).
VDJ Recombination
Each immunoglobunlin chain consits of 2 distinct regions:
1. and 2.
- Variable (V)
- Constant (C)
There is a seperate gene pool for each type of what?
Immunoglobulin Chains;
2 lights and 5 heavy chains
Each pool of genes for each type of immunoglobulin chain contains diffrent gene segemens for the:
What letters..
- V
- D (diversity only on Heavy Chain)
- J (joining)
- C genes
During B-cell differentiation, the first translocation ____ as the first antibody produced in a primary response.
IgM
After genetic rearrangement the rest of the gene pool (that was not used) is discarded this is why that particular _____ becomes committed to that one specific antibody specific to small spectrum of antigen(s).
B cell
Clonal expansion of that one B cell/plasma cell means the body has met that ____ and selected the prope cell, expanded it and produced a large sum of antibody (titer)
Antigen
Prior to the release of the antibdoy a ____ portion is added to the H-chain
Sugar portion
IgG molecule consists of two ____ chains and two ____ chains linked by disulfide bonds (molecular formula H2L2).
2 light and 2 heavy
What subclass of IgG
makes up most (65%)
IgG1
What subclass of IgG
antibody is directed against polysaccharide antigens and is an important host defense against encapsulated bacteria.
IgG2
crosses the placenta not only due to size, but its _____ attached to placental cells
Fc portion
What is the most abundant immunoglobulin in newborns?
IgG
What to Immunoglobulin in newborns?
IgG
If we make antibodies from one** single clone of cells **(for example a plasma cell tumor or myeloma) these are homogenous
monoclonal
Another inhibitory protein on the surface of T cells
PD-1 (programmed cell death-1)
PD-1 interact with its ligand (PDL-1) on the surface of ____ like dendritic cells and macrophages.
the immune response is inhibited similar to CTLA-4
APC
Antibodies & Antagonistic drugs agaisnt PD-1 and CTLA-4 do what?
Enhance immune response and are effective against some cancers.
How are T-cells activated?
- Via an APC with MHC-II that binds to a T-cell receptor on a CD4 T cell, which then produces IL-2 which will onyl occur if B7 protien on APC binds to CD28 on CD4 t-cell.
- A virus-infected cell uses its **MHC-I to present viral antigen–> viral antigen recognized by TCR (it is specific to that antigen) -> IL-2 produced by the helper T-cell activates this CD8 cell **to kill the viral infected cell. -> CD8 protein helps stabilize the interaction between the two cells.
consists of two polypeptides, both of which are encoded by genes in the human leukocyte antigen (HLA) locus
Class II MHC
only one of its polypeptide encoded by the HLA locus and β2 - microglobulin (β2 MG), which is encoded somewhere else
Class I MHC
Th-1 Cells produced what cytokiene?
acitvate macropahges + kill intracellular microbs
Gamma Interferon
Th-2 Cells produced what cytokiene?
Stimulate development of Th-2 cells and enhace class switching to IgE
Interlukin-4 (IL-4)
Th-17 Cells produced what cytokiene?
Recruit Neutrophils to site of infection
Interlukin-17 (IL-17)
____ The stmulator signal that drives differentiation of naive helper T cells to go down the Th-1type differentiated
Drivers cell mediated response (Delayed Hypersensistivy) agaisnt organism
IL-12
Interaction of a specific lipoprotien(surface of bacteria) and TLR on macrophaes induced the production of what signal?
IL-12
