lecture 2 & 3- cells and tissues of the adaptive immune system& leukocyte circulation and migration into tissue Flashcards
how long do naive lymphocytes have before they die if they do not recognize Ag
1-3 months
what cytokines play a key role in T cell development
IL-1, 2, 6, and 7
where are naive T cells maintained
in the periphery without proliferating
what cytokines play key role in B cell development
contact with stromal cells and IL-1, 6, and 7
where do lymphocytes not circulate
eyes, brain and testicles
what is a key step in the cooperation between CD4+ T heeler cells and B cells for Ab responses to PROTEIN Ags
B cells present Ags to T helper cells in the LNs
define plasma cells
terminally differentiated B cells which produce and secrete large amounts of Abs
what do Ag-activated B cells primarily produce in the spleen
Abs against microbial polysaccharides
what are some professional APCs
DC, tissue macrophages, B cells
define APCs
cells that capture, process and display Ags to lymphocytes and provide signals that stimulate the proliferation and differentiation of the lymphocytes
what type of cells can activate naive T cells in the LNs
dendritic cells
what can macrophages and B cells present Ag to
effector T cells but not naive T cells
what lineage are DCs from
myeloid lineage
how do DCs acquire Ags
using phagocytosis, receptor-mediated endocytosis, and pinocytosis
what type of receptors do macrophages and DCs typically express
Ags made by microbes and not mammalian cells
where do classical DCs reside
in skin, mucosa, and organ parenchyma
where do classical DCs migrate to after activation
LNs
what do plasmacytoid DCs do
early cellular responders to viral infection: recognize nucleic acids of intracellular viruses and produce soluble proteins (TYPE 1 interferons)
what do follicular dendritic cells do
bind and display unprocessed Ags on their surface for recognition by B CELLS ONLY
describe recirculation
ability of lymphocytes to repeatedly home to secondary lymphoid organs, reside there transiently and return to the blood
define leukocyte homing
cell migration out of the blood and into peripheral tissues or to a site of an infection or injury
what is inflammation triggered by
recognition of microbes and dead tissues in innate immune responses and is refined and prolonged during adaptive immune responses
what does an inflammatory response deliver
delivers the cells and molecules of host defense to sites where offending agents need to be combated
list in order the steps of leukocyte recruitment
tethering, rolling, adhesion and stop, transmigration in the tissue
