BIO 320 Lecture Notes - Lecture 5: Lymph Node, Basophil, Wound Healing
Document Summary
Secondary lymphoid organs: activation, clonal selection (maturation, central vs. peripheral tolerance. Types of cells: b cells, macrophages, dendritic cells, can present cd4 or cd8. 2 regions: fab antigen-binding fragment, fc- crystalline fragment. Igd monomer: low concentration in the blood, also found on surface of b cells as one type of receptor, has been shown to activate basophils and mast cells to produce antimicrobial factors. Ige monomer: lowest concentration in the blood, mediates allergic reactions and responds to parasites. Igg monomer: 80-85% of circulating immunoglobulin (highest concentration, readily crosses placenta and is found in breast milk. Igm pentamer: large in size, secreted in primary immune response. Clonal deletion: central tolerance, apoptosis, b cells can try to reprogram. Igm dominates, followed by relatively high igg: response takes 3-5 days. Igm levels about the same, but igg about 4x higher than initial response. Dendritic cells present to cd4: mhc-ii, migrate to lymph node. In some cases, they can present to cd8+
