Cytotoxic T Cells + regulations of T and B cells

Cytotoxic T cell function

Recognize and destroy cells infected with a specific pathogen.

Perforin in cytotoxic T cells

Creates channels in the membrane of infected cells.

Direct cytotoxic T cell destruction

Cytotoxic T cells release perforin, creating membrane channels that allow fluid to enter and cause the infected cell to burst.

Granzymes

Digestive enzymes released by cytotoxic T cells that enter infected cells through perforin channels.

Indirect cytotoxic T cell destruction

Granzymes enter infected cells and trigger apoptosis.

Apoptosis

Programmed self-destruction of a cell.

Perforin process

Perforin changes shape in the presence of calcium, penetrates the target cell membrane, and forms pores that allow salt and water to enter.

Cytotoxic T cell vs NK cell

Both use perforin, but cytotoxic T cells recognize specific pathogen antigens while NK cells act nonspecifically.CD8 cells

CD4 cells

Helper T cells that enhance development and activation of B cells and T cells.

Helper T cell percentage

Helper T cells make up approximately 60–80% of T cells according to the slides.

Regulatory T cells

T cells that suppress immune activity after the immune response has completed its job.

Why are regulatory T cells needed

Cytotoxic T cells are not self-regulated, so regulatory T cells help shut down their activity.

B cell regulation

Plasma cells are self-regulated and eventually die when their cellular resources have been depleted by antibody production.