University:
York University
Course:
SC/BIOL 3120 | Immunobiology
Academic year:

2023
Views:

149

Pages:

2
Author:

Niklas

TH2 cell end result - IgE production - mast cell degranulation - eosinophil activation type 2 response - pathogens inducing humoral immunity - fight against extracellular parasites example worms/helminths TH17 cells secrete IL-17 fight against extracellular pathogens bacteria/fungi Tfh cells t-follicular helper cells don't really play a role in disease migrate to germinal centers → regulate/strengthen B-cells Treg cells suppresses immune response when inhibited inhibits anti-tumor response 2 ways the body makes Treg cells 1) Natural Treg cells (nTreg) - made during T-cell development - TCR affinity for self - binds not too loose OR too tight → binds slightly too tight 2) Inducible Treg cells (iTreg) differentiated CD4+ T-cell Naive T cell Dendritic cell TCR MHC class II GATA-3 IL-4 IL-13 STAT6 Signal 1 Signal 2 CD80/86 CD28 T2-polarizing factors Cellular source of IL-4 IL-6 IL-23 TGF-B BORY! IL-17A, IL-17F, IL-22 ↓ IL-6 IL-21 Combats extracellular pathogens, bacteria/fungi in barrier tissues Autoimmunity Tissue inflammation IL-4, IL-21 Regulates affinity maturation of germinal center B cells IL-2 TGF-B FoxP3 Peripheral T cell IL-10, TGF-β How do Treg cells regulate? Treg are known to be CD4+, CD25+, FoxP3+ helper T cell on cell surface master transcriptional regulator express high levels of CD25 high levels of IL-2 1) cytokine deprivation 2) secrete inhibitory cytokines IL-10 and TGF-β 3) inhibit APC through direct contact leaving none for the proliferating T cells to bind to 4) cytotoxicity inhibit other T cells IPEX genetic lack of FoxP3 X-chromosome linked more common in males no FOXP3 multi-organ autoimmunity Reciprocal Inhibition Reciprocal Inhibition APC turned off turned on leads to transcription of master gene regulators T-Bet/GATA-3 STAT4 STAT6 GATA-3 Th1 Th2 Prerequistes Prerequistes