Regulation of CD4(+)NKG2D(+) Th1 cells in patients with metastatic melanoma treated with sorafenib: role of IL-15Rα and NKG2D triggering.

Beyond cancer-cell intrinsic factors, the immune status of the host has a prognostic impact on patients with cancer and influences the effects of conventional chemotherapies. Metastatic melanoma is intrinsically immunogenic, thereby facilitating the search for immune biomarkers of clinical responses to cytotoxic agents. Here, we show that a multi-tyrosine kinase inhibitor, sorafenib, upregulates interleukin (IL)-15Rα in vitro and in vivo in patients with melanoma, and in conjunction with natural killer (NK) group 2D (NKG2D) ligands, contributes to the Th1 polarization and accumulation of peripheral CD4(+)NKG2D(+) T cells. Hence, the increase of blood CD4(+)NKG2D(+) T cells after two cycles of sorafenib (combined with temozolomide) was associated with prolonged survival in a prospective phase I/II trial enrolling 63 patients with metastatic melanoma who did not receive vemurafenib nor immune checkpoint-blocking antibodies. In contrast, in metastatic melanoma patients treated with classical treatment modalities, this CD4(+)NKG2D(+) subset failed to correlate with prognosis. These findings indicate that sorafenib may be used as an "adjuvant" molecule capable of inducing or restoring IL-15Rα/IL-15 in tumors expressing MHC class I-related chain A/B (MICA/B) and on circulating monocytes of responding patients, hereby contributing to the bioactivity of NKG2D(+) Th1 cells.

Augmentation of cellular immune response by Ipomoea obscura and Ipobscurine alkaloid attenuates tumor growth in mice.

The immune status of the host plays a crucial role in controling the process of carcinogenesis. General or selective activation of various immunocompetent cells and their secretory function to maintain a healthy immune status may help in cancer prophylaxis, as well as therapy. The present study focused on the effect of Ipomoea obscura and Ipobscurine on cell-mediated immune response. In this study we evaluated the effect of I. obscura and an indole alkaloid fraction from I. obscura on effector mechanisms of cell-mediated immune response by analyzing cytotoxic T lymphocyte (CTL) activity, natural killer (NK) cell activity, antibody-dependent cell-mediated cytotoxicity (ADCC), and antibody-dependent complement-mediated cytotoxicity (ACC). The effect of I. obscura and Ipobscurine on interleukin-2 (IL-2) and interferon-γ (IFN-γ) levels was also analyzed. In the in vitro and in vivo systems, I. obscura and Ipobscurine treatment augmented cell-mediated immune response by enhancing the killing activity of CTL and NK cells from splenocytes in normal as well as tumor-bearing mice. ADCC and ACC were also enhanced significantly in both normal and tumor-bearing animals after drug administration, compared with untreated control. Administration of I. obscura and Ipobscurine significantly enhanced the production of IL-2 and IFN-γ in normal as well as tumor-bearing animals. This study reveals that both I. obscura and Ipobscurine have the potential to augment immune response through the enhanced secretion of IL-2 and IFN-γ by T cells and thereby inhibit tumor growth and as an alternative medicine for cancer treatment.

Fermented Noni Exudate-treated dendritic cells directly stimulate B lymphocyte proliferation and differentiation.

Noni juice as a folk medicine has been used for over two thousand years. Recently, some active ingredients of Noni juice have been successfully isolated and intensively studied. Because dendritic cells (DCs) are central regulators both in priming innate and adaptive immune responses and in maintaining self tolerance, in the current study we treated DCs with fermented Noni Exudate (fNE) in order to explore their function in regulating other immune cells. It was shown that fNE-treated DCs stimulate proliferation of splenocytes, among which, B cells are the major responsive cell group. The proliferative response of B cells to fNE-treated DCs is cell contact-dependent, CD40L-independent; and the adhesion feature of DCs was enhanced to form large DC-B conjugation cluster. Moreover, it was demonstrated that fNE-treated DCs promote B cell differentiation and Ig class switching. These results lay a foundation for the further exploration of fNE as a biological response modifier in the immune system.

A cell-based system for screening hair growth-promoting agents.

Androgen-inducible transforming growth factor beta (TGF-beta1) derived from dermal papilla cells (DPCs) is a catagen inducer that mediates hair growth suppression in androgenetic alopecia (AGA). In this study, a cell-based assay system was developed to monitor TGF-beta1 promoter activity and then used to evaluate the effects of activated TGF-beta1 promoter in human epidermal keratinocytes (HaCaT). To accomplish this, a pMetLuc-TGF-beta1 promoter plasmid that expresses the luciferase reporter gene in response to TGF-beta1 promoter activity was constructed. Treatment of HaCaT with dihydrotestosterone, which is known to be a primary factor of AGA, resulted in a concentration-dependent increase in TGF-beta1 promoter activity. However, treatment of HaCaT with the TGF-beta1 inhibitor, curcumin, resulted in a concentration-dependant decrease in TGF-beta1 expression. Subsequent use of this assay system to screen TGF-beta1 revealed that HaCaT that were treated with apigenin showed decreased levels of TGF-beta1 expression. In addition, treatment with apigenin also significantly increased the proliferation of both SV40T-DPCs (human DPCs) and HaCaT cells. Furthermore, apigenin stimulated the elongation of hair follicles in a rat vibrissa hair follicle organ culture. Taken together, these findings suggest that apigenin, which is known to have antioxidant, anti-inflammatory, and anti-tumor properties, stimulates hair growth through downregulation of the TGF-beta1 gene. In addition, these results suggest that this assay system could be used to quantitatively measure TGF-beta1 promoter activity in HaCaT, thereby facilitating the screening of agents promoting hair growth.

Optimization of in vitro expansion of macaque CD4 T cells using anti-CD3 and co-stimulation for autotransfusion therapy.

BACKGROUND: Our laboratory has previously shown that adoptive transfer of in vitro-expanded autologous purified polyclonal CD4(+) T cells using anti-CD3/CD28-coated beads induced antiviral responses capable of controlling SIV replication in vivo. METHODS: As CD4(+) T cells comprise several phenotypic and functional lineages, studies were carried out to optimize the in vitro culture conditions for maximal CD4(+) T-cell expansion, survival and delineate the phenotype of these expanded CD4(+) T cells to be linked to maximal clinical benefit. RESULTS AND CONCLUSIONS: The results showed that whereas anti-monkey CD3gamma/epsilon was able to induce T-cell proliferation and expansion in combination with antibodies against multiple co-stimulatory molecules, monkey CD3epsilon cross reacting antibodies failed to induce proliferation of macaque CD4(+) T cells. Among co-stimulatory signals, anti-CD28 stimulation was consistently superior to anti-4-1BB, CD27 or ICOS while the use of anti-CD154 failed to deliver a detectable proliferation signal. Increasing the relative anti-CD28 co-stimulatory signal relative to anti-CD3 provided a modest enhancement of expansion. Additional strategies for optimization included attempts to neutralize free radicals, enhancement of glucose uptake by T cells or addition of T-cell stimulatory cytokines. However, none of these strategies provided any detectable proliferative advantage. Addition of 10 autologous irradiated feeder cells/expanding T cell provided some enhancement of expansion; however, given the high numbers of T cell needed, this approach was deemed impractical and costly, and lower ratios of feeder to expanding T cells failed to provide such benefit. The most critical parameter for efficient expansion of purified CD4(+) T cells from multiple monkeys was the optimization of space and culture conditions at culture inception. Finally, anti-CD3/28-expanded CD4(+) T cells uniformly exhibited a central memory phenotype, absence of CCR5 expression, marked CXCR4 expression in vitro, low levels of caspase 3 but also of Bcl-2 expression.