Exam 2- Chapter 8 Flashcards
(40 cards)
How does a T cell respond to an MHC molecule on another cell?
By proliferating and differentiating to become an effector T cell
Where do T cells recognize specific antigens presented?
In secondary lymphoid organs
What happens after T cells recognize specific antigens?
The T cells are activated and begin to build their army
Function of Dendritic cells
Capture some of the invading antigen and take it to the secondary lymphoid tissues
Where do dendritic cells present the antigen?
On their surface with MHC receptors
Where do dendritic cells carry antigens from a skin infection?
From blood infections?
From resp. GI and repro tracts?
Skin- lymph nodes
Blood- Spleen
Resp, GI and repro- MALT (mucosal associated lymphoid tissue
Where are immature dendritic cells located?
In the skin and peripheral tissues
Mature (activated) dendritic cells are located:
In the lymph nodes — the dendrites elongate here
How do macrophages help dendritic cells?
They add an effector function by breaking down the pathogens
Receptor-mediated internalization of small volumes of extracellular fluid. Receptor mediated
Micropinocytosis
Nonspecific ingestion of larger volumes.
Macropinocytosis
Processing via MCH Class II pathway is to be seen by
Naive T cells
Dendritic cells that use micropinocytosis
They bring up smaller but more specific volumes.
What MHC class is used with pinocytosis? Why?
Class II, because it is drawing up the component voluntarily.
T cells enter lymph nodes through:
Blood and bind to endothelial cells inside
Where do T cells encounter dendritic cells presenting antigens?
In the bottleneck
How does a T cell find its antigen?
T cell receptor examines and touches each dendritic cells to see if there is a match. Takes a little time
It is also checking every MHC presented
2 routes a naive T cell can take
In the blood or in the afferent lymph coming from an upstream lymph node
Intracellular signals are set off by:
The TCR and MHC: peptide complex as well as a secondary costimulatory signal (most important)
What activates naive T cells
Signals from TCR, co-receptors and co stimulatory receptors
What assists with T cell proliferation/differentiation?
IL-2- uses auto rinse and paracrine activity
What happens to self reactive T cells
They lack co stimulation, leads to anergic
State when T cells cannot become activated, divide, differentiate or even respond
Anergy
Categories of CD4 T cells
TH1 cells
TH2 cells
Treg cells
