Immunizations Flashcards
Mucosal immunity- how is antigen recognized?
M-cells take up antigen, APC presents it to TH2-cell, th2-cell activates B-cell.
Antibody associated with mucosal immunity?
DIMERIC IgA
pIgR = epithelial IgA receptor
pIgR has secretory component that breaks off when in lumen
Also IgG. FcRn transports IgG through epithelium and endothelium to lumen
Types of IgA- difference? switching between them?
IgA1= longer hinge region, increased flexibility, increased susceptibility to proteases
IgA2- better for pathogens with IgA protease
IgA1==>IgA2 with APRIL TNF cytokine
How does T-cell reach intestinal epithelium?
- L-Selectin+A4B7 (t-cell): Madcam1 (blood vessel endothelium)
- squeezes through ENDOthelium into lamina propria
- CCR9: CCL25 (released by EPIthemium)
- AeB7: E-cadherin
Where are T/Bcells activated (for gut related immunity?)
peyer’s patches.
- B/T-cells enter peyers patch via HEV
- APC presents antigen to T-cell= activated T-cell
- T-cell activates B-cell (plasma cell makes IgA)
- T/B cells exit peyers patch via afferent lymph vessel ==>mesenteric lymph node==> efferent vessel==> blood==> exit endothelium to lamina propria
Healthy intestine has these cells in the lamina propria.
Has this in epithelium
LP: CD8, CD4, plasma cell, IgA, DC, mast cell, macrophage
Epithelium= Intraepithelial CD8 t-cell
Even without gut infection….
activated effector T-cells predominate
Even without gut infection….
activated effector T-cells predominate
Examples of
- Inactivated/killed vaccine
- Live attenuated vaccine
- Subunit Vaccine
- RIP= rabies, influenza, polio
- chicken, rota, yellow, oral polio
- HBV
Examples of
- Inactivated/killed vaccine
- Live attenuated vaccine
- Subunit Vaccine
- RIP= rabies, influenza, polio
- chicken, rota, yellow, oral polio, MMR
- HBV
How can you make attenuated vaccines?
take human virus and put it into monkey cell- virus adapts to monkey cell and is no longer pathogenic in human– take back out and stick in human.
Active immunization
Antigen==> Antibody development
ex: vaccine
Passive immunization
formed antibodies injected into recipient (MABs)
ex: for treating x-linked agammaglobulinemia; anti-HBV Ig to infants born from HepB+ mothers
HepA vaccine
recommended for all children
To make vaccine against polysaccharide…
conjugate it to protein (Toxoid)
Ab binds polysaccharide==> endocytosis==> digestion
Expression of protein to Th2 via MHCII
Th2 activates B-cell = Ab against polysac
(CD40:CD40L; MHC:TCR)
To make vaccine against polysaccharide…
conjugate it to protein (Toxoid)
Ab binds polysaccharide==> endocytosis==> digestion
Expression of protein to Th2 via MHCII
Th2 activates B-cell = Ab against polysac
(CD40:CD40L; MHC:TCR)
Adjuvant- definition
Ex: Alum, oil emulsion, microbial product
increases inflammation so immune response to antigen is sufficient (so antibodies are made)
= antigen independent inflammation
Adjuvant receptors
NOD, TLR==> NFKB pathway activated= innate immune response
Found on APC, B-cells, t-cells , tissue cells
Co-stimulatory receptors
p71, p72; activated by adjuvants
Adjuvant binding action on cell
activate APC
Increased co-stimulatory molecules and MHC
Induce chemokines to recruit phagocytes
Benefits of adjuvants
less active component needed, fewer repeat vaccinations, induction of immune response in old/young/weak,
why doesn’t secondary immune response produce___?
No IgA because when B-cell binds antigen that is bound by IgG, it is deactivated
Secondary immune response is (x3)
faster, larger antibody response (IgG, IgA, IgE), an increased affinity.
TVOP
trivalent oral polio- not used in US.
Adverse events possibilities:
- Hep B
- Measle
- DTP
- Tetanus toxoid containing vaccines
- Hep B==> anaphylaxis
- Measles==> thrombocytopenia, anaphylaxis, disseminated disease (immunocompromised)
- GBS, brachial neuritis, anaphylaxis
No effective vaccines for?
Measles, HIV, HepC
New technologies in vaccine design
Gene cloning and expression
genetic engineering to make less pathogenic attenuated vaccines
peptide epitopes instead of whole proteins
DNA vaccines
vaccines with cytokines= IL12 to boost Th1 immune response.
