Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.
Transcript of Immunology
Killer T Cell
Helper T Cell
MHC found on chromosome 6
MHC is polygenic and polymorphic
type 1 Interferons
Watch out nearby cells, there is a virus!
inhibit viral protein synthesis
degrade viral DNA
inhibit viral gene expression
one Ag binding site
2. Positive Selection
3. Negative Selection
1. V(D)J rearrangement
beta chain rearrangement occurs first (D to J, then V to DJ. plus constant region C)
alpha chain next (V and J, plus a constant region C)
TcR must bind weakly to MHC (CORTEX)
TcR must not bind to self antigen being displayed by dendritic cells and macrophages in the corticomedullary zone
activated B-cells undergo rounds of mutation (somatic hypermutation, aka affinity maturation) to select for higher affinity clones in the germinal centre of a lymph node
Naive B cells express IgM and IgD.
isotype switching will change the isotype of the Ab. The constant region of the Ab is coded by the "C" region with the greek letter that matches its name. Ie, IgG has a C(gamma) constant region.
3) cytokine signaling recognition (naive and memory T-cells)
1) MHC-peptide-TcR recognition
2) co-stimulation recognition (CD28 on T cell and B7 on the dendritic cell)
Are initially made in bone marrow, interact with stromal cells and the IL-7 receptor
Pro B Cell: Heavy Chain Rearrangement V(D)J
Pre B-Cell: the chain associates with a surrogate light chain and Ig which together form a pre-B-cell receptor (not yet able to recognize antigen)
Immature B-Cell: Light chain rearrangement (V-J) of first the kappa chain gets 2 tries, then the lamda chain gets 2 tries -> mature IgM -> expressed on cell surface
Negative Selection: if recognize self antigen, they are destroyed
Go to the lymph nodes!!!
ADCC: can bind to the Fc of IgG which binds to antigen on infected cell then kill it
Main place to find me:
highest in small intestine
IgG1 &3- CONS
Sensitization for Killing by NK
Sensitization of mast cells
sensitization of mast cells
epithelial layer, bound to mast cells
doesnt really do much, found in very small amounts
When can a B cell act all on its own without the help of a Th cell?
1) Specific Ag like LPS can elicit a polyclonal response without MHC presentation (it can bind to CD14 and provide the required signal)
2) bacterial polysaccharides with repetitive structure called TI-2 polymers can trigger Ab response by cross-linking several receptors at once
T-Cell independent activation
T-cell dependent activation
Ag binding to BCR leads to endocytosis
Ag is presented on MHC class II
Seeing the Ag, and the CD40 together, the T cell gets ACTIVATED
it secretes CYTOKINES which in turn activates the B cell
The activation of CD40 by the TH cell results in proliferation (aka CLONAL EXPANSION) and maturation of the B cell.
the activated B cell will migrate to a lymph node, where it will undergo AFFINITY MATURATION, and ISOTYPE SWITCHING
memory cells are B cells which remain in the circulation long after the Ag has been cleared from the system
Memory B Cell
Chronic Asthma, Chronic Allergic Rhinitis
Contact Dermatitis, Tuberculin rxn
Allergy, Asthma, Anaphylxis
Serum Sickness, Lupus,
Soluble/Cell Associated Ag?
Mast cell activation
Kill virus infected cells
and B cells
mostly viruses, some intracellular bacteria
mostly microbes in vesicles, some extracellular bacteria
activate B cells, Ig class switch
enhance neutrophil response
suppress T-cell response
signal to be this cell
upregulate FasL for programmed cell death
Membrane Attack Complex
Ab bound to Ag
Microbial surface (absence of Ab)
lectin bound to mannose
neutrophils monocytes, mast cells
Meet: The Cytokines
like to start fires (inflammation)
then call for help (neutrophils)
generally made by macrophages
Mainly an inhibitory cytokine. made by macrophages and Th2 cells (often SELF inhibitory
IL-12 is produced by macrophages and dendritic cells, and causes release of IFN gamma and differentiation of Th cells to become TH1
IL-2 is released by T cells, and is a major growth factor for T cells, and also promotes growth of B cells
IL-4 and IL-5 are produced by TH2 cells and macrophages (IL-4), and cause the immune response to shift toward a TH2 response, activating antibody response (B cells) and eosinophils
TGF beta inhibits the proliferation of T cells and activation of macrophages
Anti- Imflammatory Cytokines of TH2 (Humoral) Response
Pro-inflammatory Cytokines of the cell base TH1 response
complement binding and opsonization
CTLA4- expressed after activation, in place of CD28, turns down the immune response