14.2 Specific Responses CMI

In cell-mediated immunity response, an _________ must be processed and presented by APCs or by other __________ cells to the ___ cell. The antigen is complexed with other proteins (_____) and transported to the T cell membrane.

antigen; infected; T; MHC;

CD stands for _________ of differentiation

cluster

CD4 is expressed on ________ helper T cells. It is a co-receptor for the ____ cell receptor (TCR) and is specific for the class ___ MHC protein. Ex. ____ infects CD4+ cells

mature; T; II; HIV

CD8 is mostly expressed on the surface of _________ T cells and is a co-receptor for the ______. CD8 is specific for the class ___ MHC protein

cytotoxic; TCR; I

Thymocytes are ________ cells in the thymus

immature

Some thymocytes initially express both _____ and ____ proteins. They are called double-________ cells

CD4 and CD8; positive

When double-positive cells (CD4+/CD8+) interact with MHC class II proteins, they will become ____ cells. If they interact well with MHC class I, they become ____ cells.

CD4+; CD8+

MHC stands for major __________ complex and consists of a group of _______ that encode proteins on the cell membrane.

histocompatibility; genes

In humans, MHC genes are often called human ________ antigen (HLA) genes because they were first found in __________

leukocyte; leukocytes

All tissue cells (except for rbcs) are marked with a combo of ____________ antigens on the PM

histocompatibility

MHC genes produce class __ and class __ molecules

I and II

All ________ cells in the body can process and present _______ in association with MHC molecules. This signals to the immune system whether the cell is ________ or not

nucleated; antigens; infected

In general ___________, _______ cells and ___ cells have the ability to present antigens to activate T cells, so they are called professional ______

macrophages; dendritic; B; APCs

MHC I mcs found on all _______ cells signal to the immune system that they cell is _________

healthy; normal

In a healthy cell, proteins in the cytoplasm are degraded by enzyme ___________ and then processed into ____-antigen ________. These bind with MHC __ antigen-binding cleft and are present on cell ________

proteasome; self; epitopes; I; PM

MHC antigens are useful during transplants because they can help ______ recipient to donner by looking at similarity of MHC _______

match; antigens

MHC class II mcs are normally found on _____. CD4 on the _______ T cell binds to APC's MHC class II molecule and the _____ secretes cytokines that stimulate the proliferation of helper T cell. Helper T cells secrete other cytokines to initiate ________ immune response and _____

APCs; helper; APC; humoral; CMI

The CD8+ receptor on cytotoxic T lymphocytes (CTL) binds to MHC class I molecule on the __________ body cells which triggers cell ________

infected; death

T cell activation:

1. Antigen/MHC complex binds to TCR and co-receptor which is either ____ or ____

2. Co-stimulation - _________ released from APC to T cell

3. T cell undergoes _________ and differentiates into _______ T cells, ________ T cells, or __________ T cells

CD4 or CD8; cytokines; mitosis; memory; helper; cytotoxic

T Helper Cells:

- CD__ and MHC ___

- B and T cell _______ and activation

- release chemical factors: ____, _____, and ____

4; II; growth; ILs; TNF; IFN

Cytotoxic T cells:

- CD___ and MHC ___

- ____ specific cells

- perforins - ______ in cell membranes and granzymes - attack ________ of target cells

8; I; kill; holes; proteins

Memory T cell:

- interact with antigen _________

later

T cells that have not been exposed to an antigen are called ________

naive

1. Helper T cells can release cytokines to make more _______ of themselves

2. Helper T cells can stimulate ___ cells to make memory ___ cells

3. Helper T cells can secrete cytokines that can activate _______ T cells

clones; B; B; cytotoxic

Nonspecific and specific immune responses both have:

- ________

- phagocytes

- TNF, ILs, and _____

complement; IFN