A gastric cancer cell derived extracellular compounds suppresses CD161+CD3- lymphocytes and aggravates tumor formation in a syngeneic mouse model.

Evasion of the immune system is often associated with malignant tumors. The cancer cell microenvironment plays an important role in tumor progression, but its mechanism is largely unknown. Here we show that an extracellular compound derived from gastric cancer (GC-EC) selectively suppresses CD161+CD3- natural killer (NK) cells. Splenocytes treated with GC-EC showed considerable proliferation and the CD161+CD3- NK cell population was time-dependently suppressed. Intracellular staining of IFN-γ was shown to be down-regulated in concert with granzyme B and perforin. A cytotoxicity assay of splenocytes treated with GC-EC against K-562 cells showed a significant reduction in cytolytic activity. Further, the immune-suppressive effect of GC-EC was more evident in a syngeneic tumor model in C57BL/6 mice. Animals treated with B16 F10 and GC-EC exhibited more aggravated tumor formation than animals treated with B16 F10 only. We demonstrated that inhibition of apoptosis while increasing PI3 K/AKT levels may provoke tumor formation by GC-EC. A cytokine array revealed the presence of several cytokines in GC-EC that negatively regulate immune cytolytic activity and could be potential candidates for immune-suppressive effects.

Ginseng compound K incorporated porous Chitosan/biphasic calcium phosphate composite microsphere for bone regeneration.

There is a substantial for the bone graft materials in the clinical field. Porous, stable and biodegradable bone microsphere scaffold using biopolymer chitosan was studied, and biphasic calcium phosphate was added to improve mechanical and osteoconductivity properties later ginseng compound K was added for improving its medicinal properties. They were characterized using FTIR and XRD that showed the apatite crystal in the composite microsphere scaffolds were structurally similar to that of biogenic apatite crystals. Scanning electron microscopy images confirmed the presence of hydroxyapatite on the surface of the composite microspheres. In vitro results infers that the composite microspheres are biocompatible with NIH 3T3 and MG63 cells and capable of supporting growth and spreading of MG-63 cells. Further, Osteogenic markers expression was found to be higher in rat bone marrow stem cells seeded on microsphere scaffolds compared to control. The prepared biocomposite porous microsphere scaffold developed in this study can be used as an alternative for the bone regeneration or bone tissue engineering.

Biological effects of cyclosporin A on CD3-CD161+ and CD3+CD161+ lymphocytes.

Cyclosporin A (CSA) is a widely used drug to prevent the immune cell function. It is well known that CSA blocks transcription of cytokine genes in activated T cells. The connection between T cells and CSA has been well established. However, the effect of CSA on natural killer (NK) cells is not thoroughly understood. Therefore, in the present study, splenocytes and peripheral blood mononuclear cells (PBMCs) were treated with CSA in the presence of concanavalin A (Con A) or interleukin-2 (IL-2). CSA at higher concentrations induces apoptosis and inhibition of proliferation, while lower concentrations showed synergistically enhanced proliferation in splenocytes and PBMCs. Further, CSA favored the in vitro conversion of CD3+CD161+ cells. Splenocytes and PBMC were found to have synergistic proliferation with Con A, and PBMC exhibited significantly higher expression of NKp30, NKp44, and granzyme B along with enhanced cytotoxicity against K-562 cells in CSA-treated animals. Proliferation assay also showed that proliferation of CD161+ cells was higher in CSA-treated animals. Collectively, our results suggest that CSA differentially influences the population, function, and expression of the NK cell phenotype.