Cellular Cooperation Cytokines- Hudig Flashcards
What is an epitope?
the part of an antigen molecule to which an antibody attaches itself.
What kinds of cells can present MHC II?
dendritic cells and macrophages
sometimes cells that are induced to become APCs
T or F Every cell in the body has MHC class I all the time except for RBC
T
YOu hav to have (blank) to activate any other type of lymphocyte (any immune reaction)
CD4
Can B cells recognize native antigens (meaning the protein is not broken down enzymatically, i.e in its original state)?
Yes :)
So how does your body respond to a virus?
APC cells (macrophages or dendrites) will chew it up and present it to TFH cells which will recognize and bind which will allow it to secrete IL2 and divide. It will then stimulate TH2 or TH1 cells. Th2 will make B cells via IL4 and stimulate antibody production while Th1 will make CTLs via IFN
MHC 1 and MHC II “present” peptides from (same/different) sources.
different
(blank) present peptides from intracellular sources; such as cytoplasmic tagging, degradation, MHC 1 presentation, virally infected cells.
MHC 1
(blank) present peptides from extracellular sources such as ingestions, degredation
MHC II
What kinds of cells are the ONLY kind of cell that can present MHC II?
APCs
MHC 1 is found on all cells except for (blank)
RBCs
What does MHC I need to present the self or non self proteins?
it needs proteosomes (in the cytoplasm generates SMALL peptides)
What does MHC II need?
it needs endosomal degredations where it will generate big peptides with some albumin
T or F
Both MHC I and II systems present “self” peptides all the time without infections
T
What is an example of an extracellular source of an antigen?
virions that are released from host cells and bacteria
(blank) eliminate virally infected cells to clear most infections
CTL
(blank) are essential for control of chronic viruses
CTLs
Peptides of INTRAcelular proteins are dispayed by (blank) proteins all the time
MHC I
(blank) proteins are on all the cells of th ebody except RBC
MHC I
(blank) is the co receptor for antigen in MHC I
CD8
How can a CTL detect the viraly infected cell when the virus is hidden inside an infected cell?
CD8 CTL recognize antigen peptides displayed on the plasma membrane of cells in MHC I proteins
Where inside the cell were the viral proteins made?
On the cell’s ribosomes
Describe the MHC I proteosome process?
proteins get ubiquinated and sent to the proteosome to be chopped up and then it gets collected by TAP (transporter of antigenic peptides) > TAP brings them to the ER. Then the MHC I takes these to the golgi where they re taken to the cell surface and bind to CTLs :)
Where did the viral peptide come from?
the virus replicated itself inside the cell where it was ubquinated and taken in by a proteosome
What class of MHC presents the viral peptides?
MHC I
Is the responding T cell CD4 or CD8?
CD8
Could self peptides be presented the same way?
Yes
T or F All cells (except RBC) have greater than 30,000 MHC I molecules per cell with greater than 1000 different peptides.
T
Each MHC I molecule contains a self or a viral peptide
T or F
T
Many different CD(blank) T cells each recognize one of the many MHC1 viral peptide combinations displayed by a single cell.
8
How is it possible for a CTL to recognize a protein antigen on the inside of a virus?
Outside is recognized by antibodies, inside by CTLs. All viral proteins are inside the infected cell, then they go through proteosomes where their broken down peptides will enter the ER and be loaded onto MHCI proteins
Why are CTLs hard to monitor for vaccine development?
MHC antigen “restriction” (meaning they must dually bind to ag peptide and an EXACT MATCH to a MHC protein)
Since most people have different MHC 1 molecules, it is really hard to make a vaccine that will mach multiple people
T or F
most of us are completely different in our MHC 1
T
What would be the only way to tes cytotoxic T lymphocyte anti-viral vaccines?
only if the MHC1 of the acceptor were the same as the donor of the CTLs
Proteosomes for MHC I cut proteins into pepties of how many amino acids?
8-11
How big do pepties need to be for presentation in MHC II?
20-30 AAs
Explain how MHC II are able to present their peptides to APCs
ingestion of microbe into endosome
endosomal digestions
merge with lysosome
peptide presenation on outside of APC
Where can you find MHC II?
APCS
inducible on B cells and endothelial cells
YOur body cannot tolerate if your chemicals in your body have become (blank)
covalenty bound (cuz youve altered your protein)
Only (blank) things have proteins
living
(blank) give more diversity per size than nucleic acds and than sugars.
amino acids
(blank) recognize only peptides from foreign protein
CD4 T helper
(blank) cell help is needed for almost all immune responses
CD4 T cell hep
Is there little immunity or a lot of immunity to anything foreign that lacks proteins and why?
little because you need protein to stimulate CD4 which stimulates all the other ones
What are the APCs in the skin called? in the lymphoid organs? Whats the third APC not mentioned so far?
langerhans
dendritic
macrophages
What can APCs create in innate immunity?
IL-1 and TNF alpha
What cells have TLRs that can detect LPS?
APCs
Why is it important that APCs secrete IL-1 and TNF alpha?
because this is important for both T and B cells to respond to their antigen
In which MHC would inactivated polio peptides be presented for Memory T cells?
MHC II
If you have a live virus what cells would proliferate?
CD4 and CD8s and B cells and IL-1 from macrophages
If a donor had been immunized with a live attenuated virus that infects lymphocytes and hi PBMCs re-stimulated with the live lymphotropic virus, what cells would proliferate?
CD4 and CD8 because the virus would be attenuated the body would just clear them out
Why do you need a live attentuate virus for viruses that spread by syncytia?
Because inactived viruses can only make antibodies which will do nothing for viruses within cells. you need a CD8 response which will only happen if you can actually get a live virus to elicit an infectious response to trigger MHC 1 cells to present to the CD8 cells
How are chronic viruses able to persist?
because they have all kinds of evasion mechanisms
What is HIVs invasion mechanisms that allows it to persist?
it has a protein called nef that blocks MHC 1 synthesis
What is herpes simplex virus’s mechanisms that allows it to persist?
HSP blocks TAP activity so you cannot load viral peptides into the ER to allow for MHC 1 to take them up
How can you generate a CTL?
need a pro APC and a T helper,
you need a CTL and a MHC1
(2 antigens (infected cell + antigen presented by APC and and 4 cell types)
How many cells do you need to generate an antibody and how do you do it?
three cells APC, T cell, BCell
APC tells TFH to make IL2 which tells TH2 to make IL4 and IL4 tells B cells to utilize the native antigen to make antibodies :))
What are these:
small proteins that are secreted by leukocytes upon stimulation and that promote responses among leukocytes
interleukins
What are these:
interleukins made by lymphocytes
lymphokines
What are these:
small proteins that are secreted by many cell types upon stimulation, and that promote responses by leukocytes and other cells.
cytokines
Do resting B cells secrete immunoglobulins?
no
MHC 1 alpha chans dimerized with a small protein called (blank)
beta-2 microglobulin
T or F
Beta-2-microglobulin is not encoded within the MHC gene complex
T
What are all the cytokines and lymphokines essential to generate antibodies?
Lymphokines: gamma IFN, IL-2, IL-4, IL-5
Cytokines: IL-1, TNF alpha, IL-4, IL-5
What receptors do B cells use for costimulation?
CD40
What receptor do T cells use for costimulation?
CD28
What happens with signal 1 without signal 2?
Death or anergy
B cells require (blank) signals in order to respond to antigen
2
What are the 2 signals B cells need to respond to an antigen?
an antigen and a costimulatory signal CD40L (found on T helper cells)
What is the second signal for T cells? Where does the T cell get it?
B7 or CD80/86
B cells and macrophages
Do all B cell responses need T cell help?
no, B cells that respond to LPS can briefly secrete IgM without T cell help
What cells are cells with TLRs that can detect LPS and other patterns of pathogens?
APCs
Ag presentation and T and B cell proliferation occur in (blank) regions of lymphoid organs
distinct
What happens to B cells that are differentiating and dividing in the lymph node?
they become plasma cells and move to the medulllary cords and then they go to the bone marrow
What wil you find in the lymphoid follice?
B cell and occasional T cell
What are the specialize cells in the epithelium of the gut that take antigens from the gut and carry them into follicles?
M cells
