BIO SCI M121 Lecture Notes - Lecture 30: Leukocyte Extravasation, Lymph Node, Mhc Class Ii
6 Apr 2017
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Purpose: put the lymphocytes to work: need to deliver them to the correct tissues. Roles of different organs: blood, tissues: pathogen can infect here. Drain to lymph node through afferent lymphatics: lymph nodes: traps and present tissue-derived antigens. Travel to blood through efferent lymphatics: spleen: traps blood pathogens and present. Figure 1: 4 phases: rolling - activation - firm adhesion - trans ec migration. Homing: process of which t cells leave bloodstream and enter t cell zone of a lymph node. Need addressins: addressins can be ig, selectins are mucins, for getting into gut: madcam, for getting into skin: e-selectin, for getting into lymph node: cd34. Chronic inflammation: ag can"t be removed, lymphocyte/ m / scar accumulation granuloma. Ctl: antigen specific, acquired through interaction between tcr . Mhc/peptide: requires costimulation through b7 cd28, il-2 binds on il-2r, proliferation. Dendritic cells present antigen pre-ctl to ctl. Ctl travels through bloodstream to infected cell.
