Generation of antigen-loaded dendritic cells in a serum-free medium using different cytokine combinations

Dysbiosis of pro-inflammatory and anti-inflammatory salivary cytokines during psoriasis providing a therapeutic window and a valuable diagnostic aid in future

The objective of this article is to evaluate the salivary levels of tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukin-2 (IL-2), and IL-10 in patients with active psoriasis and compare them with those in healthy control subjects. This study included 60 subjects who were clinically diagnosed cases with active psoriasis (categorized further into 33 mild to moderate and 27 severe cases based on the Psoriasis Area Severity Index score) and 60 age- and gender-matched healthy control subjects. Levels of TNF-α, IFN-γ, IL-2, and IL-10 in the unstimulated saliva of subjects were determined via enzyme-linked immunosorbent assay (BT Lab). The salivary levels of TNF-α, IFN-γ, and IL-2 were significantly higher, whereas IL-10 concentration was significantly reduced in psoriatic patients in comparison to controls, and the difference increased with the progressing severity of the disease. Assessment of cytokine profiles in psoriasis patients is significant for diagnostic validation and monitoring the disease severity. Saliva offers an alternate, noninvasive, and readily available biological sample for evaluating cytokine levels. Extensive research in this field has been recommended for better scientifically proven conclusions.

The synergistic and enhancive effects of IL-6 and M-CSF to expand and differentiate functional dendritic cells from human monocytes under serum-free condition

BACKGROUND

Dendritic cells (DCs) are differentiated from monocytes, and have a strong ability to perform phagocytosis, present antigens and activate T cell immune response. Therefore, DCs are one of the key factors in fighting cancer in immunotherapy, and it is an important issue to develop a serum-free system for DC differentiation and expansion in vitro for clinical application.

RESULTS

In this study, IL-6 and M-CSF were determined and a concentration combination of cytokines was optimized to develop an optimal DC serum-free differentiation medium (SF-DC Optimal) that can effectively differentiate CD14⁺ monocytes into CD40⁺CD209⁺ DCs. After differentiation, the morphology, growth kinetics, surface antigen expression, phagocytosis ability, cytokine secretion, mixed lymphocyte reaction and stimulation for maturation of the differentiated DCs were checked and confirmed. Importantly, this research is the first report finding that the addition an extra low concentration of IL-6 and M-CSF exhibited a synergistic effect with GM-CSF and IL-4 to generate higher numbers and more fully functional DCs than the addition of GM-CSF and IL-4 only under serum-free condition.

CONCLUSION

A large number of functional DCs can be generated by using SF-DC Optimal medium and provide an alternative source of DCs for related basic research and clinical applications.

Validation of immunogenic PASD1 peptides against HLA-A*24:02 colorectal cancer

Colorectal cancer is the third commonest malignancy in Asia including Malaysia. The immunogenic cancer-testis antigens, which are expressed in a variety of cancers but with limited expression in normal tissues except the testis, represent an attractive approach to improve treatment options for colorectal cancer. We aimed to validate four PASD1 peptides as the immunotherapeutic targets in colorectal cancer. First, PASD1 mRNA and protein expression were determined via real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. The PASD1 peptides specific to HLA-A*24:02 were investigated using IFN-y-ELISpot assay, followed by the cytolytic and granzyme-B-ELISpot assays to analyze the cytolytic effects of CD8⁺ T cells. Gene and protein expressions of PASD1 were detected in 20% and 17.3% of colorectal cancer samples, respectively. PASD1(4) peptide was shown to be immunogenic in colorectal cancer samples. CD8⁺ T cells raised against PASD1(4) peptide were able to lyze HLA-A*24:02+ PASD1+ cells. Our results reveal that PASD1(4) peptide represents a potential target for colorectal cancer.

In vitro\ex vivo generation of cytotoxic T lymphocytes

The in vitro generation of human cytotoxic T lymphocytes (CTL) is a reliably approach useful not only to assess intrinsic CD8(+) T cell responses in individuals but also to screen immunogenic antigens that could be considered as candidates for adoptive immunotherapeutic approaches. In vitro methods to expand CTL require culturing naïve T cells with antigen-presenting cells (APC) as stimulator cells that express specific antigens. Here, we describe the protocol for generating CTL against target antigens presented by monocyte-derived dendritic cells (DCs).

In vitro activation of cytotoxic T-lymphocytes by hTERT-pulsed dendritic cells

Multiple myeloma has been considered a weakly immunogenic malignancy that can cause profound defects in the immune system. An important issue for the immunotherapy of myeloma is the identification of appropriate tumor-associated antigens (TAAs). Recently, hTERT (human telomerase reverse transcriptase) was detected on a majority of human malignancies. In the studies reported here, we studied antigen-specific and HLA-A2-restricted cytotoxic activity against an ARH77 myeloma cell line in vitro. An HLA-A2-specific hTERT-derived nonapeptide ((540)ILAKFLHWL(548)) was used as a TAA. Myeloma-specific cytotoxic activity of hTERT-reactive cytotoxic lymphocytes (CTLs) was established by repeated stimulation of the CTLs via dendritic cells loaded with hTERT-derived nonapeptide. These studies were able to demonstrate that hTERT-reactive T-lymphocytes can be identified and expanded using relatively simple in vitro techniques consisting of antigen-specific stimulation, immunomagnetic sorting, and then induction of rapid expansion.

Validation of the COSTIM bioassay for dendritic cell potency

Dendritic cells (DCs) are increasingly prepared in vitro for use in clinical trials of human disease. Their utility in experimental immunotherapy has driven significant advances in the manufacture of these cells. Thus it has become imperative that, in concert with other quality control measures, a potency test be utilized for the GMP/GLP lot-release of DC products for preclinical and clinical studies. For this purpose we developed a novel method named the 'COSTIM bioassay', which selectively measures co-stimulatory activity, or functional potency of the DCs. In this method, T-cells stimulated with a sub-optimal amount of anti-CD3 antibody are unable to proliferate unless a source of co-stimulation (DCs) is added to the culture. We describe our validation of this method in this paper.

Psoriasis pathophysiology: current concepts of pathogenesis

Psoriasis vulgaris is a common skin disorder characterised by focal formation of inflamed, raised plaques that constantly shed scales derived from excessive growth of skin epithelial cells. The disease is defined by a series of linked cellular changes in the skin: hyperplasia of epidermal keratinocytes, vascular hyperplasia and ectasia, and infiltration of T lymphocytes, neutrophils, and other types of leucocyte in affected skin. In a relatively short period, psoriasis vulgaris has been conceptualised as a T lymphocyte mediated autoimmune disease and new biological therapies that target T cells have just entered routine clinical practice. Similarly, rapid progress has been made towards dissecting cellular and molecular pathways of inflammation that contribute to disease pathogenesis. This short review presents current pathogenic concepts that have emerged from genetic, genomic, and cellular information obtained in basic studies and from clinical studies of selective immune targeting drugs.

Apoptosis of monocytes and the influence on yield of monocyte-derived dendritic cells

Monocyte-derived dendritic cells (DC) are currently under extensive evaluation as cell vaccines for cancer treatment. The requirement for large-scale cell products demands optimized and standardized protocols. However, the yield of DCs from inoculated monocytes is reported to be always lower than 50%. In this present study we investigated whether this cell loss was caused by the properties of the starting population of inoculated monocytes. CD14 cells were enriched by immunomagnetic-bead selection and analyzed for apoptosis by an annexin V/propidium iodide assay. We found that 37.8+/-11.1% (n=8) of freshly isolated monocytes from buffy coats of healthy donors underwent programmed cell death. Further analysis of the fate of apoptotic cells during differentiation suggested phagocytosis. Monocytes were differentiated with GM-CSF and interleukin-4 into a viable, non-apoptotic population of immature dendritic cells. Addition of tumor necrosis factor-alpha and prostaglandin E2 resulted in fully matured dendritic cells, which were evaluated by phenotypic analysis and by allogeneic and MHC class-I-restricted T-cell responses. About 90.2+/-16.7% of the non-apoptotic monocyte population differentiated to viable matured dendritic cells. These results indicate that the yield of dendritic cells is mainly influenced by the percentage of apoptotic cells in the inoculum, and this has implications for DC generation in clinical applications.

Psoriasis vulgaris: an interplay of T lymphocytes, dendritic cells, and inflammatory cytokines in pathogenesis

PURPOSE OF REVIEW

Discuss and update concepts and hypotheses for the pathogenesis of psoriasis based on new research reports (primarily from 2003 and early 2004).

RECENT FINDINGS

Increases in newly defined dendritic cell subsets, cytokines, and chemokines have been identified in psoriasis lesions and have modified views of T-cell-mediated pathogenesis. In addition, the psoriasis transcriptome has been defined by large-scale genomic expression studies, and these data suggest distinct molecular mechanisms of type 1 T-cell-mediated inflammation. Somewhat surprisingly, therapeutic clinical trials suggest that tumor necrosis factor is a major pathogenic cytokine in psoriasis, whereas translational studies point to roles of other innate pathways mediated by heat shock proteins, glycolipids, natural killer T cells, or dendritic cells in disease pathogenesis.

SUMMARY

An interactive network of inflammatory cytokines, chemokines, dendritic cells, and type 1 T cells or natural killer T cells potentially drives pathogenic inflammation in psoriasis vulgaris. Continued clinical studies with defined immune antagonists provide a critical means to dissect the contribution of different cell subsets and genomic pathways to the pathogenesis of psoriasis vulgaris.

Generation of dendritic cells using cell culture bags--description of a method and review of literature

Anticancer immunotherapy using dendritic cell-based vaccines is a strategy aimed at the induction and maintenance of immune responses against cancer cells. Clinical applications of dendritic cells (DCs) require stringent adherence to Good Manufacturing Practice (GMP) methods and rigorous standardization of DC-based vaccine preparation. Recently, closed systems for DC culture have been developed with a goal to minimize the risk of contamination. Here, we compare the yield, immunophenotype, and functional properties of DCs generated in Lifecell X-Fold culture bags and in plastic wells, both from adherence-selected monocytes, and review the current literature on closed systems for DC generation. We found that both the overall yield and the yield of CD83+ cells in cell culture bags was lower than in the standard culture method. No statistically significant differences were observed in the expression of DC immunophenotypic markers. The capability of DCs cultured in bags and in wells to induce the proliferation of allogeneic mononuclear cells were equivalent. The performance of DCs in mixed lymphocyte reaction correlated significantly (p = 0.005) with the CD83 expression but not with the CD80, CD86, HLA-DR, CD1a, and CD1c expression. We conclude that the immunophenotype and stimulatory properties of DCs cultured in closed cell culture bags are similar to those generated by conventional method using cell culture wells.

Dendritic cell-based immunotherapy for the treatment of hematological malignancies

Dendritic cells (DCs) are professional antigen-presenting cells and are frequently used in current immunotherapy protocols. The administration of DCs loaded with tumor-associated proteins or peptides results in the induction of immune responses against different types of malignant cells. Methods for large-scale generation of DCs in a sufficient quality and quantity have permitted their use in clinical experiments. DC-based vaccines have already shown promise in follicular non-Hodgkin's lymphoma, and to some extent, in other hematological malignancies. Several strategies have been developed to boost their potency as a new and relatively non-toxic treatment modality. Our review focuses on clinical trials using DCs in the treatment of hematologic malignancies and on recent studies of the immunophenotype, development, and maturation of DCs may have an important impact on designing DC-based antitumor vaccines.