Humoral & Cell-mediated immunity

Humoral immunity B-cells! Fight pathogens in the blood Starts when B-cell binds with epitope on antigen Needs to be activated by a helper T-cell B-cell undergoes mitosis to become memory B-cells and plasma cells Plasma cells produce antibodies. -Antibodies mark the pathogen for easy detection by macrophages 4. Memory B-cells are for a later exposure

Cell-mediated immunity T-cells! Destroy HOST infected cells Process begins when helper T-cell binds with antigen fragment on MHC II molecule of an antigen-presenting cell (ex. macrophage)

Cell-mediated immunity continued… Antigen-presenting cell releases cytokines to activate the helper T-cell The helper T-cell then produces cytokines to activate B-cells and cytotoxic T-cells Cytotoxic T-cells bind with MHC I molecules on all host cells to check for infection -If infected, perforins and granzymes released to induce apoptosis