Lecture 3: T-cell activation and effector functions

Question 1

IL1

Answer 1

Class: Interleukins
Secreted by: monocytes/macrophages
Effects: Autocrine, B-cell proliferation, T-cells (IL-2nd signal for T-cell activation), pyrogen, acute phase (liver synthesizes proteins)

Question 2

IL2

Answer 2

Class: Interleukins
Secreted by: CD4+ T cells
Effects: Autocrine, proliferation/differentiation of T-cell, B-cell, NK
Other: main source from TH1

Question 3

IL4

Answer 3

Class: Interleukins
Secreted by: CD4+ T cells
Effects: B-cell proliferation (2nd signal for B-cell activation), class switching (IgE)

Question 4

IL7

Answer 4

Class: Interleukins
Secreted by: Thymic cortical epithelial cells and Bone marrow stroma
Effects: T/B cell proliferation during development
Other: Come from type VI epithelioreticular cells

Question 5

Interferon: α/β

Answer 5

Secreted: All cells (monos, fibroblasts)
Effects: Induces “antiviral state” (degrades DNA/RNA to prevent repl), activates NKs
Other: interfere with viral replication

Question 6

Interferon: γ

Answer 6

Secreted: T-cells, NK cells
Effects: Induces "antiviral state", class switching, IgG2, IgG3, mac activation

Question 7

Chemokines: cc/ cxc

Answer 7

Secreted: Many cell types
Effects: 
cc: attract monos and T-cells
cxc: attracts neutrophils (IL8)
Other: classified based on the position of the first two cysteine residues in the protein (cc: cysteines adjacent to one another and cxc: cysteins that are separated by one AA)

Question 8

TnF α and β

Answer 8

Secreted by: many cell types (α), T and B cells (β)
Effects: Directly kill tumor cells, activate monocytes/macrophages, expression of adhesion molecules
Other: upregulate adhesion molecules on epithelial cells to mediate diapedesis of WBCs to tissue at site of infection

Question 9

Pyrogens

Answer 9

IL1, IL6, TNα

Question 10

Neutropenia

Answer 10

Decreased numbers of phagocytic cells

Question 11

Four steps of emigration/extravasion of Naive T-cells into secondary Lymphoid Tissues

Answer 11

1) Rolling Adhesion: P/E selectins on endothelial cells bind to L-selectin found on all circulating leukocytes and SLOW DOWN these cells from speeding through the vessels
2) Tight binding: Cells STOP moving (via further interaction between integrins)
3) Diapedesis: transit through endothelial cells into tissue and move to selective areas
4) Migration within T-cells area: Deep cortext (during which CD4+ Tcells may become activated)

Question 12

Cytokines present to convert Naive CD4+ cell (Th-0) into Th-1

Answer 12

Il-12, IFNγ, TGF-β

Question 13

Cytokines present to convert Naive CD4+

Answer 13

IL-4 and IL-10

Question 14

Cytokines (2nd signal) that Th2 secretes and what cells do they activate?

Answer 14

IL4, IL5, IL6, IL13

B-cells –> plasma cells –> antibodies

Question 15

Cytokines (2nd signal) that TH1 secretes and what cells do they activate?

Answer 15

IL2, IFNγ, and TNFβ
CD8 Tcells (i.e. macrophages and NK)--> cell mediated immunity