Specific Responses Cell Mediated

How must antigens be processed and presented

via specific antigen presenting cells or by other infected cells

Where is CD4 expressed on?

mature helper T cells (Th), monocytes, macrophages, dendritic cells

What is CD4?

A co-receptor for the T cellular receptors and is specific for the class II MHC proteins. This gets infected HIV

Where is CD8 expressed on?

surface of cytotoxic T cells and TK cells

What is CD8

A co-receptor for the T cell receptor (TCR) and is specific for the class I MHC protein

Thymocytes

immature cells in the thymus. These can be expressed in both CD4 and CD8 proteins

What are double positive cells

these interact well with MHC class II molecules will eventually become CD4+ cells whereas rhinovirus that interact well with MHC class I molecules mature into CD8+ cells.

Major histocompatibility complex

consists of a group of genes that encode proteins found on the cell membrane

In humans what are MHC genes reffered to?

human leukocyte antigen (HLA)

All tissue cells are marked with…

a characteristic combination a histocompatibility antigens on the surface of the cell membrane

Professional antigen presenting cells (APCS)

Immune cells that specialize in presenting an antigen to a T-cell such as dendritic cells, manipulated and B cells

How many nucleated cells in the bad have mechanisms for processing and preserving antigens in association with MHC molecules?

All nucleated cells

MHC I molecules are found on,,, and signal to…

all normal and healthy nucleated cells and signal to the immune system that the cell is a normal “self” cell

What do proteins in the cytoplasm degraded by then processed by?

proteasomes And processe into self-antigen epitopes

When MHC antigens has greater variance between the donor and recipient, then what happens to the likely hood of transplant rejection?

the greater the change of transplant rejection

Organ trasplants are

tissue that transplanted from one person to another contains antigens that can be foreign to the recipient due to the characteristic combination of MHC antigens

proteasomes

enzyme complexes responsible for degradation and processing of proteins

MHC class II moleecules occur on

APCs

how does CD4 effect APCs MHC class II molecules?

They dock to an APCs MHC class II molecules

how does helper T cell effect secretion of cytokines?

The binding of helper T cells promotes secretion of cytokines by the APC

Cytokines… proliferation of helper T cells

Stimulates

Helper T cells secrete…

other cytokines to initiate both the humoral response and the CMI

Humoral response

secretion of antibodies by plasma cells

CMI

attack on infected cells

MCH class I molecules occur on…

all nucleated cells and present epitopes to cytotoxic T lymphocytes (CTLs)

CTLs express?

CD8+ and T cell receptors

What is the purpose of the CD8 receptor on a CTL?

Docking onto a MHC class I molecule

What occurs if the CTL’s TCR fits the epitope within the MHC class I molecule?

the CTL triggers cell death

What ability do professional APCs have?

They can present antigens specifically for the purpose of activating T cells because they have both teh MHC I and MHC class II. They are foregin antigens to helper T cells

Virus infected cells present with?

Antigens originating inside a body cell to cytotoxic T cells

Cross presentation, as of now, is primarily a function of which APC?

dendritic cells

Antigen/MHC complex will bind to?

T cells receptor and the co receptor CD4 or CD8

When T cell activation occurs there is?

co-stimulation

what is an example of co-stimulation?

cytokines released from the APC can act on the T cell to help activate it

T cell activation will differentiate into…

memory T cells, T helper cells, and cytotoxic T cells

Memory T cells…

interact with antigen

Why are T helper cells important?

the George and activation of T and B cells and the release of chemical factor IL, TND, and IFN

Cytotoxic cells..

kills specific cells, perforins, and granzymes

perforins

proteins that punch holes in cell membranes

Granzymes

enzymes that attack protein of target cells

Overall, what is the trend with nonspecific immune responses

• rashly acts sooner

  • Different components: inflammatory response

Overall, what is the trend with specific immune responses

• high degree of specificity

• Memory

• T cells, B cells, antibodies

  • Antigen presenting cells