In Vitro Effects of Curcumin in Free and Phytosomal Forms on the Expression of T Helper1 and Regulatory T Cells' Transcription Factors in Collagen-Induced Arthritis.

Background: Curcumin as a polyphenolic compound has a potential capacity to reduce autoimmune reactions by skewing the balance of Thelper1 (Th1)/regulatory T cells (Treg) toward Treg cells. However, the low absorption and bioavailability of this agent have prompted researchers to use various drug delivery systems such as phytosomes to reduce these drawbacks. To date, few studies have evaluated the effects of phytosomal curcumin (nano-curcumin) on immune responses. Hence, we compared the modulatory effects of curcumin in free and phytosomal form on the expression of Th1 and Treg transcription factors, T-bet (T-box-containing protein) and Foxp3 (forkhead box p3), respectively, in a collagen-induced arthritis model (CIA). Materials and Methods: Following the induction of CIA, splenocytes were isolated and re-stimulated with collagen in the absence or presence of two different doses of curcumin in free and phytosomal form. Then, expression of T-bet and Foxp3 was assessed by real-time PCR. Results: The expression of T-bet was reduced in curcumin and phytosomal curcumin groups rather than in the untreated group. The level of T-bet was not significantly different between free and phytosomal groups. Moreover, mRNA expression of Foxp3 enhanced after treatment with curcumin, while phytosomal curcumin groups showed no difference in comparison with the untreated group. Conclusions: curcumin in nano/free form showed a modulatory effect on the expression of T-bet. However, only free-form enhanced Foxp3 expression, which could be owing to the low amount of curcumin in the phytosomal complex rather than free-form at the same dose or due to leakage of curcumin from the complex.

Enhancement the antioxidative and immunomodulatory functions of mesenchymal stem cells by tetrandrine.

In this study, mesenchymal stem cells (MSCs) were primed with Tetrandrine (TET) having anti-inflammatory and immunomodulatory effects to examine the effects of this molecule on the antioxidative potential of MSCs as well as their modulatory effects on activated peripheral blood mononuclear cells (PBMCs). The viability of primed MSCs was detected using MTT assay and Trypan blue staining. Moreover, flow cytometry technique was applied to evaluate cell cycle distribution and immunophenotype of MSCs. The production of superoxide dismutase 3 (SOD3), malondialdehyde (MDA), kynurenine, TGF-ß, and IFN-γ were also measured by spectrophotometry to assess the alteration of antioxidative and immunomodulatory potential of MSCs. Then, TET-primed MSCs were cocultured with PBMCs. The MTT assay was used to measure the proliferation of PBMCs. Cell cycle progression of PBMCs and frequency of regulatory T cells were evaluated using Flow cytometry. ELISA assay was also applied to determine the concentrations of TGF-ß and IFN-γ after coculturing. According to our data, TET enhanced the secretion of SOD3 and kynurenine from MSCs, while the production of IFN-γ was reduced. No changes were observed in the viability, proliferation, and immunophenotype of MSCs after priming with TET. Moreover, the proliferation and frequency of PBMCs in the S and G2/M phases of cell cycle reduced after co-culturing with TET-primed MSCs. The concentration of TGF-ß was increased in the supernatant of PBMCs, but the level of IFN-γ was reduced. Our data suggested this priming method as a novel strategy for increasing the antioxidative and immunomodulatory activity of MSCs.

Metabolic Regulation of T cell Activity: Implications for Metabolic-Based T-cell Therapies for Cancer

Immunometabolism is an emerging field in tumor immunotherapy. Understanding the metabolic competition for access to the limited nutrients between tumor cells and immune cells can reveal the complexity of the tumor microenvironment and help develop new therapeutic approaches for cancer. Recent studies have focused on modifying the function of immune cells by manipulating their metabolic pathways. Besides, identifying metabolic events, which affect the function of immune cells leads to new therapeutic opportunities for treatment of inflammatory diseases and immune-related conditions. According to the literature, metabolic pathway such as glycolysis, tricarboxylic acid cycle, and fatty acid metabolism, significantly influence the survival, proliferation, activation, and function of immune cells and thus regulate immune responses. In this paper, we reviewed the role of metabolic processes and major signaling pathways involving in T-cell regulation and T-cell responses against tumor cells. Moreover, we summarized the new therapeutics suggested to enhance anti-tumor activity of T cells through manipulating metabolic pathways.

Protective potential of piroxicam on human peripheral blood mononuclear cells against the suppressive capacity of glioblastoma cell lines.

Dexamethasone, a common medication used in the treatment regimen of glioblastoma, has broad inhibitory effects on the immune responses. Here, in an in vitro study, we examined the effects of piroxicam, a potent substitute for dexamethasone, on peripheral blood mononuclear cells (PBMCs) co-cultured with two glioblastoma cell lines, U-87 MG and A-172 cells. MTT assay was used to determine the proliferation of PBMCs treated with piroxicam, or dexamethasone. In addition, to evaluate the effects of drugs on the cell cycle distribution, DNA content per cell was analyzed in PBMCs and A-172 cell lines using flow cytometry. Oxidative parameters, including superoxide dismutase-3 (SOD3) activity and total anti-antioxidant capacity, lactate dehydrogenase (LDH) activity, as well as IFN-γ and TGF-ß levels were measured in PBMCs alone or in the presence of cell lines using ELISA. Unlike dexamethasone, piroxicam showed a protective effect on PBMCs against both glioblastoma cell lines. Furthermore, while dexamethasone reduced the proliferation of PBMCs, piroxicam had no adverse effect on the proliferation. Cell cycle analysis showed a reduction in the G2/M phase in piroxicam-treated A-172 cells. Additionally, dexamethasone limited the cell cycle progression by increasing the fraction of PBMCs in G0/G1. Interestingly, after co-culturing piroxicam-treated PBMCs with cell lines, a remarkable rise in the LDH activity was observed. Although not significant, piroxicam partially decreased TGF-ß levels in both cell lines. Our findings suggested a protective effect of piroxicam, but not dexamethasone, on PBMCs against inhibitory mechanisms of two glioblastoma cell lines, U-87 and A-172 cells.