11. Activation of T lymphocytes Flashcards
what type of cells are constantly in the blood
naive T cells
what are the type of cells that can activate T cells
dendritic cells
where do naive T cells go from blood
2ndary lymph nodes where they meet dendritic cells
what is the movement from lymph nodes to organ they are needed
homing
how do activated T cells get to correct area
randomly go through circulation until it get to correct area
what helps to complete T cell differentiation
macrophages
what can effector T cells activate
Follicular B cells
how do Ag get to lymph nodes
mature/ activated Dendritic cells ingest and cleave Ag for presentation on membrane and take from periphery to lymph nodes
how do T cells find correct Ag
interact with many until find correct one
where do activated T cells go
remain in lymph nodes to help B lymphocytes or migrate to sites of infection to activate macrophages
what is induced by T cell recognizing Ag
IL2 secretion and clonal expansion
who do effector CD4+ T cells respond to Ags
produce cytokines
what do cytokines from activated CD4+ cells induce
recruitment and activation of leukocytes as well as activation of B cells
what is the function of CD8+ cell
kill infected or altered cells
what is activated by effector CD 4+ cells
macrophages, B cells and inflammation
what are the types of CD 4+ cells
effector and memory
CD 8 cells other name
cytotoxic T lymphocytes
what types of cells do naive CD 8 cells become
effector and memory CD8 cells
how does immune response work against intracellular pathogens
kill the host cell with macrophage ingestion then phagocytosis
how long does it take memory cells to differentiate
3-5 days so window opportunity due to innate immunity first
fever with no sickness is caused by
memory cells
what is induced when T cells have Ag recognition and co-stimulation
secrete cytokines, proliferation, differentiation into effector and memory cells
function of effector T cells
eliminate microbes and cause tissue damage
what happens after Ag is eliminated
T cell response declines