E3: Tolerance Flashcards
the 2 tolerance types are __ and ___
central and peripheral
1 cel subtype that is important in thymic development is the
regulatory T cell
where in the thymus do T cells become thymocytes
thymus cortex
in the thymus cortex, thymocytes ___ and ___ toward the medulla
proliferate, migrate
T calls are called into the thymus by ___
cytokines
when T cells arrive at the periphery of the cortex, they are called ___
thymocytes
location of T cell migration through the thymus
periphery, cortex, medulla
as thymocytes travel through the thymus, what 2 cells will they encounter
dendritic, thymic epithelial cells
thymic epithelial cells present ___ antigens
self
__ __ thymocytes do not express CD4 or CD8
double negative
double neg thymocytes do not express ___
receptors
double negative thymocytes proliferate under what Interlukin
7
TCRs are functional when they become ___ ___ and express __ and ___
double positive, CD4 and CD8
TCR receptors can identify lots of ___ receptors
epitope
when T cell receptors are functional, they express the co____ ____
stimulatory receptors
once thymocytes become double positive, they can ___ to express one of the two CDs
differentiate
cortical cells present ___ and ___
MHC 1 MHC 2
cortical thymic epithelial cells are unique because they present what
MHC 1 and 2
cortical cells interacting with thymocyte, if it recognizes one MHC stronger than the other this will cause the cell to commit to a cell type.
if it doesn’t recognize MHC 1 or 2, the cell will undergo ___
apoptosis.
MHC 1 and MHC 2 help trigger a ___ to be made
complex
the x2 positive thymocytes the cell lines stop expressing the other CD molecule once they interact with this cell ___ with either MHC 1 or MHC 2.
lymphocyte
when the cells select for MHC recognition is called ___ selection
positive selection
after they become single expression, they are then exposed to more MHC molecule. Negative selection can occur here if it binds __ ___
too tightly
negative selection is there to prevent _____ response
autoimmune
once passing positive selection, the cell is released into the ___
periphery
once a cell leaves the thymus, are they mature or naive?
naive
DP thymocytes are
double positive
if a thymocyte has strong binding with MHC 1, it is ___ committed
CD8+
if a thymocyte has strong binding with MHC 2, it is ___ committed
CD4+
negative selection is also known as
central tolerance
only cells that pass pos and neg selection are released as ___ T cells
naive
___ selection is about the recognition of MHC
positive
___ selection is about recognition of self.
negative
the number of thymocytes decreases as TCR affinity ___
increases
Tolerance is the process of removing cells that are too selective to __ ___
self antigens
TregHelper cells are developed in response to what
an intermediate T cell that has affinity for MHC 1
what is the definition of central tolerance
deletion of lymphocytes before they mature
what is the definition of tolerance
the prevention of an immune response against self structures
Treg cells __ the immune response
surpress
peripheral reg cells are responsive to things in the __
tissues
where does peripheral tolerance occur
outside bone marrow and thymus
peripheral tolerance occurs via induction of what cell
pTreg
peripheral tolerance actively generates….
(a specific cell that is ___ing the immune system)
inhibiting lymphocytes
cells are made to be bad at __ recognition and good at __ recognition
self, foreign
Thelp and T-Cytotoxic cells
cells in the periphery are ones that bind loosely to __ __
self antigens
clonal activation is the activation and differentiation of ___ lymphocytes that recognize __ ___
effector, self antigens
peripheral tolerance is the __, ___, or __ of regulatory function in lymphocytes recognizing self antigens
deletion, anergy, induction
can B cells be trained as well in central tolerance?
yes
____ cells negatively regulate immune response
Treg
Treg cells ___ regulate the immune response
negatively
Treg job in the thymus, ___.
dampen
Tells interacting with tolerogens can: 1 2 or 3
apoptosis, anergic, or be regulated
T cells that interact with tolerogens that are regulated are done so by __ ____
Treg cell secretions
___ can enhance the dampening of the immune response
tolerogens
Tolerogens can enhance the dampening of immune repose by the following what 5 mechanisms.
deplete pro inflammatory cytokines, secrete inhibitory cytokines, direct killing, shut down allergic response, inhibit APCs
