IMM250H1 Lecture Notes - Lecture 4: Stromal Cell, Dn1, B Cell
Document Summary
Dn -> isp cd8+ -> dp -> sp cd8+ or cd4+ Larger vessels located near and around cortical medullary junction. Hematopoietic progenitors can differentiate iinto multiple lineages on bone marrow stromal cells. Signalling leads to cleaveage of intracellular notch, which turns on gene transcription. Hpcs give rise to t cells when cultured in vitro with op9-dli stromal cell line. Icn -> binds to csl and coa -> t cell commitment block b cell commitment. Cd117+ - entry into cortex requires chemotaxis - ccr9 and ccr7, which are redundant together but if both knocked out, absolutely defect. Where most proliferating thymocytes are (label via brdu) Immediately adjacent to capsule, dense band of proliferating cells. Beta selection finished - therefore save from aptoptosis. Up regulation of cd4 and cd8 surface expression. Perimedullar - recruitment of marrow-derived progenitors from the blood; expand dn1 pool; retention and release of dn1; t cell lineage specification.