Multiple Players in the Mechanical Control of T Cell Quiescence

Naive T cells are kept in a quiescence state, characterized by small cell size, with low proliferative and metabolic activities, until antigen engagement. T lymphocyte quiescence is a tightly controlled mechanism regulated by multiple quiescence‐associated factors. Loss or impaired functions of these factors regularly result in spontaneous activation of T cells that is ensured by fatal autoimmune diseases. Elucidating the mechanism to facilitate the switch on or off of T cells could be beneficial to ameliorate pathology triggered by T cell hyperactivation or dysfunction. In this chapter, we discuss multiple quiescence‐associated factors along with the mechanisms utilized to promote lymphocyte quiescence and longevity

Momordica charantia suppresses inflammation and glycolysis in lipopolysaccharide-activated RAW264.7 macrophages

Macrophage activation is a key event that triggers inflammatory response. The activation is accompanied by metabolic shift such as upregulated glucose metabolism. There are accumulating evidences showing the anti-inflammatory activity of Momordica charantia. However, the effects of M. charantia on inflammatory response and glucose metabolism in activated macrophages have not been fully established. The present study aimed to examine the effect of M. charantia in modulating lipopolysaccharide (LPS)-induced inflammation and perturbed glucose metabolism in RAW264.7 murine macrophages. The results showed that LPS-induced NF-?B (p65) nuclear translocation was inhibited by M. charantia treatment. In addition, M. charantia was found to reduce the expression of inflammatory genes including IL6, TNF-a, IL1ß, COX2, iNOS, and IL10 in LPS-treated macrophages. Furthermore, the data showed that M. charantia reduced the expression of GLUT1 and HK2 genes and lactate production (-28%), resulting in suppression of glycolysis. Notably, its effect on GLUT1 gene expression was found to be independent of LPS-induced inflammation. A further experiment also indicated that the bioactivities of M. charantia may be attributed to its key bioactive compound, charantin. Taken together, the study provided supporting evidences showing the potential of M. charantia for the treatment of inflammatory disorders

Signal Transducer and Activator of Transcription (STATs) Proteins in Cancer and Inflammation: Functions and Therapeutic Implication

Signal Transducer and Activator of Transcription (STAT) pathway is connected upstream with Janus kinases (JAK) family protein and capable of integrating inputs from different signaling pathways. Each family member plays unique functions in signal transduction and crucial in mediating cellular responses to different kind of cytokines. STAT family members notably STAT3 and STAT5 have been involved in cancer progression whereas STAT1 plays opposite role by suppressing tumor growth. Persistent STAT3/5 activation is known to promote chronic inflammation, which increases susceptibility of healthy cells to carcinogenesis. Here, we review the role of STATs in cancers and inflammation while discussing current therapeutic implications in different cancers and test models, especially the delivery of STAT3/5 targeting siRNA using nanoparticulate delivery system

β Mangostin suppress LPS-induced inflammatory response in RAW 264.7 macrophages in vitro and carrageenan-induced peritonitis in vivo

Ethnopharmacological relevance: The fruit hull of Garcinia mangostana Linn. has been used in traditional medicine for treatment of various inflammatory diseases. Hence, this study aims to investigate the in vitro and in vivo anti-inflammatory effect of β mangostin (βM), a major compound present in Garcinia mangostana. Materials and methods: The in silico analysis of inflammatory mediators such as cyclooxygenase (COX) and nuclear factor-kappa B (NF-kB) were performed via molecular docking. Further evaluation of anti-inflammatory effect was conducted in lipopolysaccharide (LPS) induced RAW 264.7 macrophages. Suppression of activated NF-kB was analyzed by high content screening. βM triggered inhibition of COX-1 and COX-2 in vitro were studied using biochemical kit. The in vivo model used in this study was carrageenan-induced peritonitis model, where reduction in carrageenan-induced peritonitis is measured by leukocyte migration and vascular permeability. In addition, the evaluation of βM׳s effect on carrageenan induced TNF-α and IL-1β release on peritoneal fluid was also carried out. Results: Treatment with βM could inhibit the LPS-induced NO production but not the viability of RAW 264.7. Similarly, βM inhibited PGE2 production and the cytokines: TNF-α and IL-6. The COX catalyzed prostaglandin biosynthesis assay had showed selective COX-2 inhibition with a 53.0±6.01% inhibition at 20 µg/ml. Apart from this, βM was capable in repressing translocation of NF-kB into the nucleus. These results were concurrent with molecular docking which revealed COX-2 selectivity and NF-kB inhibition. The in vivo analysis showed that after four hours of peritonitis, βM was unable to reduce vascular permeability, yet could decrease the total leukocyte migration; particularly, neutrophils. Meanwhile, dexamethasone 0.5 mg/kg, successfully reduced vascular permeability. The levels of TNF-α and IL-1β in peritoneal fluid was reduced significantly by βM treatment. Conclusion: The current study supports the traditional use of Garcinia mangostana fruit hull for treatment of inflammatory conditions. In addition, it is clear that the anti-inflammatory efficacy of this plant is not limited to the presence of α and γ, but β also with significant activity

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival