IMM250H1 Study Guide - Mhc Class Ii, Mhc Class I, T-Cell Receptor
Document Summary
Intestinal intra epithelial lymphocytes (ilel) developed t cells have no access to rest of organism. Lymphocyte homeostasis: blood and secondary lymphoid organs have roughly constant number of t and b cells. Despite reduced t cell production as you grow. Allotype specific antibody (against an antibody) will not recognize antibody of a different allotype. After f1 backcross 50% pups heterozygous for selected allotype. Ab produced in initial response has lower affinity than those produced later. High does of ag activates high and low affinity ab b cells. Low doses of ag activates only high affinity ab b cells. Frequency for b cell for any ab is 10-5. T cell activation requires apc with compatible mhc. Incubate with apc of certain mhc allotype and ag. 1% of t cells in population recognize allogeneic mhc. T cells react to mhc of the species (allogeneic) but not to self mhc. Mhc expressed on thymic epithelium (te) positively and negatively selects t cell repertoire.
