Guest guest Posted November 28, 2006 Report Share Posted November 28, 2006 There has been a " hole " in the Th1/Th2 paradigm that may have been filled in recently. Whereas the Th1 effector cells facilitate the targeting of intracellular pathogens (including viruses) and Th2 cells facilitate the targeting of parasites and worms, what is dedicated to facilitating the targeting of extracellular bacteria? In back-to-back papers, published in Nature Immunology, two teams independently demonstrated the Th17 lineage as being distinct from the Th1 and Th2 lineages: http://tinyurl.com/yxcmkh http://tinyurl.com/y2e599 The review I read on this... http://tinyurl.com/y2o68v .....says that each of the three T helper cell types antagonize the development of the other two. It's been known for some time that Th1 cells antagonize Th2 cell development with IFNg, and Th2 cells antagonize Th1 cell development with IL-4. Turns out that both of these cell types antagonize the development of Th17 cells. For its part, Th17 cells use TGFbeta to antagonize the development of the other two cell types. The authors of this review suggest that the Th17 cells fill the hole in the Th1/Th2 paradigm: " Given the prominent association of IL-23 and IL-17 with host protection in a growing number of bacterial infection models (e.g. Klebsiella pneumoniae [51]), it is not unlikely that the Th17 lineage evolved to cope with a range of extracellular bacterial pathogens,….. " This will dramatically alter the way in which various immune pathologies are perceived, but we'll have to wait a few years to find out how. Matt Quote Link to comment Share on other sites More sharing options...
Guest guest Posted November 30, 2006 Report Share Posted November 30, 2006 Yes this is big BIG news. But I didn't think TH2 pathway was well understood.. So not sure how they could be calling TH17 distinct. I haven't read all the way through the papers yet. I'll hold my comments till I know more. Barb > > There has been a " hole " in the Th1/Th2 paradigm that may have been > filled in recently. Whereas the Th1 effector cells facilitate the > targeting of intracellular pathogens (including viruses) and Th2 > cells facilitate the targeting of parasites and worms, what is > dedicated to facilitating the targeting of extracellular bacteria? > > In back-to-back papers, published in Nature Immunology, two teams > independently demonstrated the Th17 lineage as being distinct from > the Th1 and Th2 lineages: > > http://tinyurl.com/yxcmkh > > http://tinyurl.com/y2e599 > > > The review I read on this... > > > http://tinyurl.com/y2o68v > > ....says that each of the three T helper cell types antagonize the > development of the other two. It's been known for some time that > Th1 cells antagonize Th2 cell development with IFNg, and Th2 cells > antagonize Th1 cell development with IL-4. Turns out that both of > these cell types antagonize the development of Th17 cells. For its > part, Th17 cells use TGFbeta to antagonize the development of the > other two cell types. > > The authors of this review suggest that the Th17 cells fill the hole > in the Th1/Th2 paradigm: > > " Given the prominent association of IL-23 and IL-17 with host > protection in a growing number of bacterial infection models (e.g. > Klebsiella pneumoniae [51]), it is not unlikely > that the Th17 lineage evolved to cope with a range of extracellular > bacterial pathogens,….. " > > This will dramatically alter the way in which various immune > pathologies are perceived, but we'll have to wait a few years to > find out how. > > Matt > Quote Link to comment Share on other sites More sharing options...
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