Moreover, FcγRIIA mediated platelet activation has been reported to involve other accessory molecules such as Cbl . Taken together, our observations suggest that separate and distinct signaling pathways are responsible for triggering phagocytosis, endocytosis and secretion. Further studies into the interaction of FcγRIIA
with various signal and adapter molecules may shed light on the requirements for each of these processes. This work was supported by grants from the National Institutes of Health, NHLBI (to ADS), an Arthritis Foundation Investigator Award (to RGW), and an American Academy of Allergy, Asthma and Immunology student research fellowship (to ABD). “
“The identification of DC-derived signals orchestrating activation of Th1 and Th17 immune responses has advanced our understanding on how these inflammatory responses develop. NVP-BEZ235 ic50 However, whether specific signals delivered by DCs also participate in the regulation of Th2 immune responses remains largely unknown. In this study, we show that administration of antigen-loaded, IL-6-deficient DCs to naïve mice induced an exacerbated Th2 response, high throughput screening compounds characterized by the differentiation of GATA-3-expressing T lymphocytes secreting
high levels of IL-4, IL-5, and IL-13. Coinjection of wild type and IL-6-deficient bone marrow-derived dendritic cells (BMDCs) confirmed that IL-6 exerted a dominant, negative influence on Th2-cell development. This finding was confirmed in vitro, Prostatic acid phosphatase where exogenously added IL-6 was found to limit IL-4-induced Th2-cell differentiation. iNKT cells were required for optimal Th2-cell differentiation in vivo although their activation occurred independently of IL-6 secretion by the BMDCs. Collectively, these observations identify IL-6 secretion as a major, unsuspected, mechanism whereby DCs control the magnitude of Th2 immunity. “
“Experimental crescentic glomerulonephritis is driven by systemic cellular immune responses. A pathogenic role for T helper type 1 (Th1)
and Th17 cells is well established. T-bet, a key transcription factor required for Th1 lineage commitment, and retinoic acid-related orphan receptor-γt (Rorγt), a key Th17 transcription factor, are required for full expression of disease. Similarly, several Th1- and Th17-associated cytokines have been implicated in disease augmentation. The role of Th2 cells in the disease is less clear, although Th2-associated cytokines, interleukin (IL)-4 and IL-10, are protective. We sought to determine the role of signal transducer and activation of transcription 6 (STAT6), a key regulator of Th2 responses, in experimental crescentic glomerulonephritis. Compared to wild-type mice, histological and functional renal injury was enhanced significantly in STAT6–/– mice 21 days after administration of sheep anti-mouse glomerular basement membrane globulin. Consistent with the enhanced renal injury, both Th1 and Th17 nephritogenic immune responses were increased in STAT6–/– mice.