Animal Physiology - Immune System B

Cell-mediated immunity cells (There are 3 pookie)

• T-Cells

• Macrophages

• Dendritic Cells

Where do T-Cells mature?

The Thymus

Cytotoxic T-lymphocytes (CTL) role

• Kill virally infected cells

Helper T-Lymphocytes (T_H) role

Help B cells respond appropriately

What cell does the HIV virus kill?

Helper T-Lymphocytes

Role of Humoral Immunity

To block infections and eliminate extracellular microbes

Roles of Cell-Mediated Immunity

• Elimination of phagocytosed microbes

• Killing infected cells and eliminating reservoirs of infection

What do Lymph Nodes do?

• Hold a lot of B and T cells

• Trap microbes, cancer cells, and viruses

• Produce immune cells to fight off lymphnodes

Where in a Lymph Node could I find some B cells?

Lymphoid follicle

Where in a Lymph Node could I find some T cells?

Paracortex

Major Histocompatibility Complex (MHC) Genes

A set of genes that create MHC proteins

What do MHC proteins do?

Present peptide fragments to T cell receptors on T-Cells to help them decide if it is foreign

Besides a viral Ag, what else can a T-Cell recognize?

Some aspect of the host surface

T-Cell Receptors

Monospecific surface receptors on T-Cells with Constant and Variable Regions that result in a ton of diversity

Where are Class I MHC proteins found?

On most cells

Where are Class II MHC proteins found?

B-Cells, Dendritic Cells, Macrophages

What do Class I MHCs bind?

Peptides from intracellular proteins

What do Class II MHCs bind?

Peptides from extracellular proteins

What exactly does the T-Cell recognize?

An Ag bound to MHC