BIO SCI E124 Study Guide - Midterm Guide: Macrophage, Allele, Dendritic Cell
Document Summary
Lag phase: takes a few days before response gets started. Memory cells live for very long time (in absence of stimulation by pathogen). -> high number of specific b cells when infection occurs. -> memory b cells become activated faster - increased efficiency. Peak of response 100 - 1000 times higher than primary response. Memory response completely depends on t cell help. T cells recognize antigen with tcell receptor (tcr) Important: recognizes antigen only on the cell surface ==> requires antigen to be processed (cut into small fragments) and to be displayed on cell surface together with mhc (major histocompatibility complex) Mhc i: --> present antigen to ctl (like killer t cells?) Mhc ii:--> present to cd4+ t helper cells. Mhc is a collection of genes located on a stretch of dna. Hla (human leukocyte antigen) complex encodes for mhc. Gene products dp dq dr hla-b hla-c hla-a.
