IMM250H1 Chapter Notes - Chapter 5: Naive T Cell, Mhc Class I, Cd28
27 Oct 2018
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5. 1 multiple signals are required for naive lymphocyte activation. Extracellular signals - transmitted across cell membrane and activate transcription factors: encounter with cognate (complementary) antigen, binding of complementary pair - signaling molecules on naive lymphocyte + leukocyte. Dc > b7:cd28 interaction (for t cells) Th > cd40l:cd40 (for b cells: cytokines. Di erentiation + cloning into e ector cells / memory cells (+ are soluble) Cytokines are antigen-speci c: short half life and usually local, cytokine-speci c receptors on lymphocyte. Antigen receptor signaling of tcr and bcrs: have associated signaling molecules to transmit signals. Tcr - cd3 complex and zeta chain. Naive cd4+t cell > th cells: activate naive cd8+t cells > become ctl, activate naive b cells > plasma cells. Mature dc can: present peptides in both mhc class i and ii, and express costimulatory molecule b7 - for naive t cell. B7- > b7+ - becomes mobile only after interaction with pathogen (mature dc)
