Immunology Lecture 04 Cell Interaction Molecules

Front 1

Why are cell interaction molecules generally call co-receptors?

Back 1

Each molecule has a specific cell surface ligand and both cell surface molecules can transduce signals

Front 2

Name two molecules that interact with the MHC

Back 2

CD4 and CD8

Front 3

Characteristics of CD4

Back 3

Helper cells, ligand is MHC II, facilitates signal transduction in conjunction with the CD3 complex

Front 4

Characteristics of CD8

Back 4

Cytotoxic cells; ligand is MHC I; augements T cell activation by directly contributing to signal transduction

Front 5

What does T cell LFA-1 (CD11a/CD18) bind to

Back 5

ICAM-1 and ICAM-2 on the APC.

Front 6

What does APC LFA-1 bind to

Back 6

ICAM-3 on the T cell (DC-SIGN on dentritic cells)

Front 7

When is LFA-1 important

Back 7

Early stages of the immune response, greatly facilitating stabilization of T cell contact with APCs

Front 8

What is Leukocyte Adhesion deficiency (LAD)

Back 8

Immunodeficiency disease resulting from deficiency in LFA-1 or ligands for endothelial selectins

Front 9

What is CD2

Back 9

Single chain protein found primarily on T cells. Ligand is LFA-3. Functions to both mediate cell-cell adhesion and facilitate TCR signal transduction in conjunction with the CD3 complex

Front 10

Where is CD 28 found

Back 10

Primarily on T cells

Front 11

What is the ligand for CD28

Back 11

B7, expressed primarily on APCs

Front 12

What does CD28 binding to its ligand accomplish

Back 12

Results in generation of CD28 signals to the T cell, required for IL-2 production, T cell proliferation, and acquisition of T cell effector functions

Front 13

What is the CD28 homologue and what does it do

Back 13

CTLA-4; transmits negative signal to T cells, inhibiting their activation. Also binds B7; limits the amount of T cell proliferation and maintains tolerance to self antigens

Front 14

Where is CD40 expressed

Back 14

Activated B cells, dendritic cells, macrophages and thymic epithelium

Front 15

Where is the CD40 ligand found

Back 15

Activated CD4 cells, though it does not play a role in activation

Front 16

What does CD40 binding to its ligand acheive

Back 16

Helps mediate activation of B cells by T cells; also crucial for immunoglobulin class switching, resulting in production of IgG, IgA, and IgE

Front 17

What is the immunological synapse

Back 17

Formation of a stable interaction between the T cell and APC

Front 18

What does the immunological synapse facilitate

Back 18

Clustering of T cell receptors, as they engage peptide + MHC

Front 19

What are supramolecular activation clusters (SMACS)

Back 19

Cell surface molecules involved in the interaction at the IS

Front 20

How are SMACS characterized

Back 20

Central area consisting of the TCR, CD4, and CD28, surrounded by a ring of LFA-1 molecules

Front 21

What are cytokines

Back 21

Proteins that mediate immune responses, including inflammatory responses. Also mediate the development of cells associated with the immune response.

Front 22

Name the three actions of cytokines

Back 22

Autocrine, Paracrine, and Exocrine

Front 23

What are the general groupings of cytokines based on function

Back 23

Mediate hematopoiesis; mediate non-antigen specific immunity; mediate lymphocyte activation, growth, and differentiation; mediate effector cell activation; chemoattractants

Front 24

How is the IL-2 receptor composed?

Back 24

Three chains ,α β and γ. β has a low affinity for IL-2 without the help of the α chain. γ is bound to the β chain

Front 25

What is Rapamycin

Back 25

Immunosuppressive drug that functions by blocking transduction from the IL-2 receptor and other cytokine receptors

Front 26

What causes septic shock

Back 26

Endotoxin -stimulated overproduction of cytokines, including TNF-α and IL-1

Front 27

What is the receptor for HIV

Back 27

CD4

Front 28

What is the receptor for the major rhinovirus serotype

Back 28

ICAM-1. The virus competitively inhibits binding of LFA-1 to ICAM-1