Th1 or Th2: How an Appropriate T Helper Response can be Made
✍ Scribed by Claudia Bergmann; J.Leo van Hemmen; Lee A. Segel
- Publisher
- Springer
- Year
- 2001
- Tongue
- English
- Weight
- 347 KB
- Volume
- 63
- Category
- Article
- ISSN
- 1522-9602
No coin nor oath required. For personal study only.
✦ Synopsis
Two types of T helper (Th) cells have been defined on the basis of their cytokine secretion patterns. The decision of a naive T cell to differentiate into Th1 or Th2 is crucial, since to a first approximation it determines whether a cell-mediated or humoral immune response is triggered against a particular pathogen, which profoundly influences disease outcome. Here we show that the internal behaviour of the T helper system, which emerges from regulatory mechanisms 'built into' the T helper system, itself can usually select the appropriate T helper response. This phenomenon arises from an initial Th1 bias together with the induction of Th1 → Th2 switches when Th1 effectors do not lead to efficient antigen clearance. The occurrence of these shifts is based on the antigen dose dependence of T helper differentiation, which is a consequence of asymmetries in cross-suppression. Critical for this feature is the rate with which Th2 cells undergo antigen-induced cell death.