Interaction With T Cells
After APCs have phagocytosed pathogens, they usually migrate to the vast networks of lymph vessels and are carried via lymph flow to the draining lymph nodes (this network is collectively known as the Lymphatic system). The lymph nodes become a collection point to which APCs such as dendritic cells (DCs) can interact with T cells. They do this by chemotaxis, which involves interacting with chemokines that are expressed on the surface of cells (e.g., endothelial cells of the high endothelial venules) or have been released as chemical messengers to draw the APCs to the lymph nodes. During the migration, DCs undergo a process of maturation; in essence, they lose most of their ability to further engulf pathogens, and they develop an increased ability to communicate with T cells. Enzymes within the cell digest the swallowed pathogen into smaller pieces containing epitopes, which are then presented to T cells using MHC.
Recent research indicates that only certain epitopes of a pathogen are presented because they are immunodominant, it seems as a function of their binding affinity to the MHC. The stronger binding affinity allows the complex to remain kinetically stable long enough to be recognized by T cells.
Read more about this topic: Antigen-presenting Cell
Famous quotes containing the words interaction with t, interaction with, interaction and/or cells:
“The act of putting into your mouth what the earth has grown is perhaps your most direct interaction with the earth.”
—Frances Moore Lappé (b. 1944)
“UG [universal grammar] may be regarded as a characterization of the genetically determined language faculty. One may think of this faculty as a ‘language acquisition device,’ an innate component of the human mind that yields a particular language through interaction with present experience, a device that converts experience into a system of knowledge attained: knowledge of one or another language.”
—Noam Chomsky (b. 1928)
“Here is this vast, savage, howling mother of ours, Nature, lying all around, with such beauty, and such affection for her children, as the leopard; and yet we are so early weaned from her breast to society, to that culture which is exclusively an interaction of man on man,—a sort of breeding in and in, which produces at most a merely English nobility, a civilization destined to have a speedy limit.”
—Henry David Thoreau (1817–1862)
“If I’d written all the truth I knew for the past ten years, about 600 people—including me—would be rotting in prison cells from Rio to Seattle today. Absolute truth is a very rare and dangerous commodity in the context of professional journalism.”
—Hunter S. Thompson (b. 1939)