Term
| Precipitation vs Agglutination |
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Definition
Precipitation: Immune complex formation
with molecular antigens(SOLUBLE Ag anAb)
Agglutination: Immune complex formation
with antigenic particles(erythrocytes)
Beads or RBC are coated with antigen |
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Term
| Direct Vs Indirect Coombs |
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Definition
Direct Coombs test: Test for presence
of antigen.
Detect antibodies on patients
erythrocytes.
Indirect: Tests for presence of
antibodies.(anti erythrocyte) |
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Term
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Definition
radioisotope linked mAb reagent.
Antibody in patient serum competes with
radioactive labeled test antibody |
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Term
Enzyme-linked immunosorbent Assays
(Elisa) |
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Definition
Direct: antigen. Indirect: antibodies
Indirect summary:
1st layer: Target Antigen
2nd Layer: patients specimen(looking for Ab)
3rd layer: reagent that binds 2nd layer
and is coupled to Tag or enzyme |
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Term
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Definition
Ag mixed with test serum.
Standard amount of complement added
erythrocytes coated with Abs added
RBC lysis(Negative for AB) All red
Intact RBC(+ for AB) small red do.
If pt has antibody, Ag-Ab complex would have formed. No free Ab to use complement. |
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Term
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Definition
Isotypes: HLA-A, HLA-B, HLA-C
CD8 binds β2 domain of MHC-I. Presents
endogenous antigen
Single polypeptide chain + non MHC protein β2 microglobulin.
Expressed codominantly(both alleles)
Found on All cells except RBCs |
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Term
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Definition
Isotypes: HLA-DR, DP, DQ
Cd4 binds a3 domain of MHC-II. Presents
Exogenous antigen.
Expressed on Hematopoeitic and APC cells
(B-cells,, macrophages, dendritic)
Two polypeptide chains a and β.
Expressed co-dominantly |
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Term
| Homozygyotes vs heterozygotes MHC |
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Definition
Homozygous:
3 MHC-I molecules
3 MHC-II molecules
Heterozygotes:
4 to 6 MHC I molecules
4 to >6 MHC II molecules
MHC II has alpha and beta chain.
Hybrids an form. |
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Term
| Peptide binding Grooves MHC |
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Definition
MHC-I:
Has close ends and binds peptides
with 8-10 aa residues
MHC II:
Open ends and binds peptides that have
13-20 AA residues |
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Term
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Definition
MHC-I like protien
CD1 associate with β2 globulin
Allows presentation of hydrophobic
lipid antigens.
Important for NKT cells |
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Term
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Definition
Almost All cells are capable of
presenting antigen via MHC I
Professional APCs process foreign
antigen and present via MHCII
(Dendritic cells, macrophages, Bcells)
Co-stimulation via binding of CD80/86
on APC to CD28 on T-cell required for
induction of immune response |
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Term
Exogenous MHC pathway
(macrophages -> kill intravesicular bacteria/parasites, B-cells secrete Ig) |
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Definition
Antigen is:
Endocytosed, Hydrolytic enzymes cleave to peptides. Enter MIIC(vesicle with MHC)
MHC II
Li(invariant chain) prevents peptide
binding in ER
Traffick to MIIC
Invariant chain cleaved to CLIP
CLIP exhanged for peptide with help
from HLA-DM/DO |
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Term
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Definition
Cytosolic Antigen:
Proteolytic cleavage to peptides by
proteasome or immuno proteasome
Transport to ER through TAP.
MHC binds peptide of appropriate length and leaves ER.
Transported through golgi to cell survace. |
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Term
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Definition
Transports peptdies from cytosol to ER
Upregulated by IFN-y.
ATPase dependent
Along with tapasin, calreticulin, calnexin) loads peptides into MHC I |
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Term
| Cross-presentation by dendritic Cells |
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Definition
Exogenous Ag can reach MHC-I
Through cross-presentation
Dendritic cells can present exongenous Ag on MHC I. Viruses and tumor cells |
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Term
| Presentation of lipid antigens |
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Definition
Lipid antigens are presented to T cells by CD1.
Tap and HLA-DM independent
CD1 binds self gliycolipid, travels to membrane, endocytosed and switches for glycolipid of mycobacterium. |
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Term
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Definition
RF = IgM anti-IgG
Take patients serum.
Add latex particle with IgG on it.
If patient has RF it will bind to latex particle(IgG) and agglutinate |
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