Diminished immune response to vaccinations in XXXX : Role of myeloid-derived suppressor and other myeloid cells.

@entity1956 @entity28 @entity19 @entity5 @entity39 @entity281 @entity3804
@entity28 is a chronic inflammatory condition associated with an increased production of cytokines and exacerbated immune response. However, @entity28 subjects are susceptible to @entity281 and respond poorly to vaccines. This study evaluated the immune responses of @entity28 @entity19 and the underlying mechanisms by exploring the roles of myeloid cells. Diet-induced @entity28 (DIO) @entity19 were prepared from C57BL/6J @entity19 fed a high-calorie and high-fat diet for 12 weeks. Humoral and cellular immune responses of DIO @entity19 to a @entity1956 vaccine containing the @entity1956 surface antigen (HBsAg) were assessed in sera and via a lymphoproliferative assay, respectively. The effects of @entity3804 (+)GR1(+) myeloid-derived suppressor cells (MDSC) and @entity3804 (+)GR1(-) non-MDSC on T cell proliferation and cytokine production were compared via a cell culture system. The production of cytokines, expression of activation and exhaustion markers, and proportions of apoptotic T cells were estimated with flow cytometry. Increased T and B lymphocyte proliferation and higher interferon-y and @entity5 @entity39 factor-a levels were detected in spleen cells and liver non-parenchymal cell cultures of DIO @entity19 compared to controls (p<0.05). However, antibody to HBsAg (anti-HBs) levels and HBsAg-specific T cell proliferation were significantly lower in DIO @entity19 compared to controls (p<0.05). The addition of MDSC, but not non-MDSC, induced a decrease in HBsAg-specific T cell proliferation, lower cytokine production, decrease in T cell activation, and increase in T cell exhaustion and apoptosis (p<0.05). MDSC play an important role in mediating impaired antigen-specific immunity.
