IMIN200 Lecture Notes - Memory T Cell, Clonal Anergy, T-Cell Receptor
10 Apr 2014
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Document Summary
After studying lecture #9, you should be familiar with the following concepts: cellular immunity. Such microbes can arise by escaping the phagolysosome of phagocytic cells, or by directly entering cells, for example through interactions with cell surface receptors. Cell- mediated immune responses are mediated by t cells and always require the interaction of t cells with other cells: t cell activation. Na ve t cells require two signals for their activation detection of antigen through the tcr and delivery of second signals through antigen presenting cells (apcs). A classical second signal is provided by b7 on apcs. Apcs only express b7 upon detection of microbial pamps. B7 binds cd28 on t cells and provides the second signal. In the absence of second signals, t cells become anergic. Activated t cells undergo a rapid expansion program known as clonal expansion, whereby the stimulated. Note that clonal expansion is strictly limited to activated t cells.
