Inflammationisacomplexresponseinvolvingmanydifferentcellsandsignalingmolecules,includingthesecretionofthecytokineIL-17byactivatedTcells.IL-17secretionisrestrictedtospecificsubsetsofTcellsbutthereceptorforIL-17iswidelyexpressedthroughoutthebody,includingfibroblastsandepithelialcells.InflammatoryresponsesinvolvingIL-17probablycontributetoarthritis,asthma,skinimmunereactionsandautoimmunedisorders.FibroblastsandothercellsstimulatedbyIL-17areinducedthemselvestosecreteinflammatoryandhematopoieticcytokines,includingIL-6,IL-8,G-CSFandStemCellFactor(SCF).Thesecytokinesinturnprovokearangeofactivities,includingthestimulationofneutrophilproliferationanddifferentiation. Contributor:GlennCroston REFERENCES: