Exam 1 - Chapter 4 - B cells

what is the name of the normal protein turnover machinery in the cytoplasm that is involved with MHC I

proteasomes

what is the special protein used to prevent endogenous/self peptides from getting onto MHC II

invariant chain

MCH I is ___ at both ends while MHC II is ____ at both ends

closed, open

how long are MHC I proteins compared to MHC II

8-11 aa

13-25 aa

what are the subunits that make MHC I

alpha 1,2,3 and Beta 2 microglobulin

what are the subunits that make up MHC II

alpha 1, 2

beta 1,2

what are the type of proteins MHC I presents

enzymes, structural proteins, proteins encoded by viruses, parasite proteins

what part of the cell acts as a wood chipper to chew up cellular protein?

proteasomes

what are the transport proteins which move protein fragments to the ER to be attached to MHC I

TAP 1 and TAP 2

once the peptides are bound to MHC I they form the peptide-MHC I complex which then gets transported where

cell surface

where are MHC II molecules made? where do they get injected?

cytosol, ER

in the ER, a ____ is added to an MHC II to prevent MHC II from binding endogenous proteins

invariant chain

the MHC II/invariant chain complex is released from the ER in an ___ which then fuses with the ___ containing the extracellular proteins which were phagocytized by the APCs. The extracellular proteins are then broken down in the endosome to produce fragments ___ aa in length. At the same time, the invariant chain is broken down to allow the binding site on ___ to open and allow extracellular protein to bind

endosome, phagosome, 13-25, MHC II

peptides of MHC I molecules are anchored where? What about MHC II?

ends, center

what is the stimulatory signal needed to activate APC cells

B7/CD28

which cells participate in "wine tasting" of extracellular fluid

dendritic cells

what are 2 things that can activate dendritic cells

1. chemical signals from cells in battle

2. PRRs recognizing PAMPS

once activated, a dendritic cell stays in the tissue for about __ hours. It is actively and aggressively participating in ____/_____ which causes ___ to be loaded with exogenous antigens. Because activated dendritic cells (APDCs) are at the site of injury, they can become infected with viruses which are then displayed on ____. They then leave the area through the ____ system to the nearest ____ and there is an increased expression of _____

6, phagocytosis/endocytosis, MHC II, MHC I, lymphatic, lymph node, B7

t/f

APDCs are short lived and allow new APDCs to present the latest up to date information

true

where are sentinel cells (macrophages) located? Do they travel like dendritic cells?

areas of body exposed to outside world

no

activated AP dendritic cells activate ____ cells in the lymph node

activated macrophages ____ experienced T cells in the tissue

naive T cells

re-stimulate

what do activated B cells express high levels of

MHC II and B7

a helper T cell needs ____ and ___ to be activated

MHC II, B7

t/f

a b cell can activate a t cell and a t cell can activate a b cell

true

what does cross-presentation refer to

exogenous proteins can be presented by MHC I and activate killer t

endogenous proteins can be presented by MHC II and activate helper t

why is it important to have an exception to the normal MHC presentation rules (cross-presentation)

allows education of t cells to recognize self