Mice deficient in CD38 develop an attenuated form of collagen type II-induced arthritis

CD38, a type II transmembrane glycoprotein expressed in many cells of the immune system, is involved in cell signaling, migration and differentiation. Studies in CD38 deficient mice (CD38 KO mice) indicate that this molecule controls inflammatory immune responses, although its involvement in these responses depends on the disease model analyzed. Here, we explored the role of CD38 in the control of autoimmune responses using chicken collagen type II (col II) immunized C57BL/6-CD38 KO mice as a model of collagen-induced arthritis (CIA). We demonstrate that CD38 KO mice develop an attenuated CIA that is accompanied by a limited joint induction of IL-1β and IL-6 expression, by the lack of induction of IFNγ expression in the joints and by a reduction in the percentages of invariant NKT (iNKT) cells in the spleen. Immunized CD38 KO mice produce high levels of circulating IgG1 and low of IgG2a anti-col II antibodies in association with reduced percentages of Th1 cells in the draining lymph nodes. Altogether, our results show that CD38 participates in the pathogenesis of CIA controlling the number of iNKT cells and promoting Th1 inflammatory responses

Averting inflammation by targeting the cytokine environment.

Cytokines are key instigators and regulators of immune responses and therefore hold great potential as targets for new therapeutic strategies. However, the selection of which cytokines to target, and in particular the identification of which cytokines regulate the rate-limiting steps of disease pathways, is crucial to the success of such strategies. Moreover, balancing the need for ablating pathological inflammatory responses and simultaneously maintaining the ability to control infectious agents is a key consideration. Recent advances in our understanding of cytokine networks, as well as technical progress in blocking cytokines in vivo, are likely to be a source for new drugs that can control chronic inflammatory diseases