Lecture 18 (post midterm)

Question 1

Main CD4+ T cell Effector function

Answer 1

Activation of macrophages, B cells, and other cells

Question 2

Main CD8+ T cell Effector function

Answer 2

Killing of infected target cells and macrophage activation

Question 3

Main action of Tfh (follicular T helper cells)

Answer 3

Activate B cells through
Signal 1–>p:BCR
Signal 2–>Th2 cytokines
Linked recognition

Question 4

Overall roles of Effector T cells

Answer 4

1) Activate B cells (Tfh)
2) Activate macrophages (Th1)
3) Directly Kill infected cells (Tc)

Question 5

Pathway of B and T cells to site of infection (exit lymph node)

Answer 5

Efferent lymphatic vessels–>thoracic duct–>blood stream

Question 6

Overall action of Cell mediated immunity

Answer 6

Th1 cytokines promote cytotoxic t cell (Tc) killing and macrophage reactive oxygen species (ROS) killing

Question 7

Main action of Signal 3

Answer 7

Differentiation
Signal 3–>cytokines direct T cell differentiation into different effector cell types

Question 8

What does Lymphocyte activation induce

Answer 8

Proliferation and differentiation (of T cells)

Question 9

What causes proliferation in T cells

Answer 9

Response to IL-2

Question 10

What do T cells differentiate into

Answer 10

CD4+ T Helper cells: from Th0 or Th1, Th2, Tfh, Th17, or other
CD8+ T cells: CTL (cytotoxic T lymphocyte)
Regulatory T cells

Question 11

Function of L-selectin

Answer 11

L-selectin targets naive T cells to HEV (high endothelial venules) to enter the lymph node

Question 12

Function of VLA-4

Answer 12

VLA-4 binds to receptors on the endothelial cells near inflamed tissue

Question 13

CD4 Effector T cell subtypes

Answer 13

TH1, TH2, TH17, TFH, Treg

Question 14

Function of Signal 3 cytokines

Answer 14

AKA: Polarizing cytokines
Regulating differentiation of T helper cell subsets

Question 15

What induces cytokine secretion?

Answer 15

Antigen presenting cells (APCs) binding to pathogen associated molecular patterns (PAMPs) via PRRs (pattern recognition receptors)

Question 16

How do cytokines induce signaling

Answer 16

Through STAT proteins
Phosphorylated STAT proteins act as transcription factors
All naive CD4 T cells must express ALL STAT proteins (to be able to differentiate into any depending on which STAT gets phosphorylated)

Question 17

Function of Master Transcriptional regulator

Answer 17

Ex. T-Bet, GATA-3
Determines functionality of T cell
Leads to different T cell subsets
Responsible for expression of effector cytokines