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Background: Hepatocellular carcinoma is a major type of liver cancer with poor prognosis.Aim: The aim of the study was to determine the prognostic significance of plasma interleukin-35 level in hepatocellular carcinoma.Methods: A total of 153 hepatocellular carcinoma patients and 153 healthy controls were enrolled. Blood samples were obtained at admission. Plasma interleukin-35 level was analyzed by enzyme-linked immunosorbent assay. Distribution of T cell subset and expression of Fas/FasL protein were detected by flow cytometry. The patients were followed up for 2 years. Poor prognosis was defined as death of hepatocellular carcinoma.Results: The plasma levels of interleukin-35 were significantly higher in the patients than the controls (25.1 ± 13.1, 9.3 ± 6.3 pg/mL, P < 0.001). After adjusted for multiple confounding factors, the multivariate logistic regression analyses reported that high level of interleukin-35 (≥25.0 pg/mL) was associated with the poor prognosis in the patients (OR 6.63, 95 % CI 3.27-13.47). Compared with the patients with low level of interleukin-35 (<25.0 pg/mL), the patients with high level of interleukin-35 showed higher frequencies of CD4+CD25+FoxP3+ and CD3+Foxp3+ regulatory T cells (P < 0.001 and P < 0.001) and also showed higher apoptosis levels of CD8+ T cells (P < 0.001).Conclusion: Circulating interleukin-35 concentration might be an independent prognostic indicator in hepatocellular carcinoma. Such prognostic significance could be partly involved in the activation of regulatory T cell and the apoptosis of CD8+ T cell. [ABSTRACT FROM AUTHOR]

Interactions of T cell antigen receptors (TCRs) with complexes of self peptide and major histocompatibility complex (MHC) are crucial to T cell development, but their role in peripheral T cell responses remains unclear. Specific and nonspecific stimulation of LLO56 and LLO118 T cells, which transgenically express a TCR specific for the same Listeria monocytogenes epitope, elicited distinct interleukin 2 (IL-2) and phosphorylated kinase Erk responses, the strength of which was set in the thymus and maintained in the periphery in proportion to the avidity of the binding of the TCR to the self peptide-MHC complex. Deprivation of self peptide-MHC substantially compromised the population expansion of LLO56 T cells in response to L. monocytogenes in vivo. Despite their very different self-reactivity, LLO56 T cells and LLO118 T cells bound cognate peptide-MHC with an identical affinity, which challenges associations made between these parameters. Our findings highlight a crucial role for selecting ligands encountered during thymic 'education' in determining the intrinsic functionality of CD4+ T cells. [ABSTRACT FROM AUTHOR]

Objective: Herpes simplex virus 1 (HSV-1) is regarded as an important underlying cause of Bell's palsy, but the immunologic mechanism remains unknown. Here, we employed a mouse facial paralysis model to investigate the expressions of CD4 T lymphocytes and interleukin (IL)-2 and -4 in the left draining cervical lymph nodes (LCLN) and spleen, as well as the inhibitory effects of glucocorticoids (GCs). Methods: HSV-1 was inoculated into the surface of the posterior auricle to generate the facial paralysis model. The paralyzed mice were divided into three groups; in one group without any treatment, mice were killed at different time points, and those in the other two groups were injected with methylprednisolone sodium succinate (MPSS) or with a combination of MPSS and GC receptor blocker (RU486). The expression levels of CD4 T lymphocytes and CD4-IL-2 and CD4-IL-4 cells in the LCLN and spleen were detected by fluorescence-activated cell sorting. Results: Expression levels of CD4, IL-2, and IL-4 first increased then decreased in LCLN and spleen and peaked 5 and 7 days, respectively, after the manifestation of facial paralysis. All the data at the peak points were significantly different compared with control ( p < 0.05), and these effects were inhibited by MPSS. Conclusion : Our results suggest that CD4, IL-2, and IL-4 participate in the HSV-1-induced facial paralysis immune response. MPSS can effectively attenuate HSV-1-mediated nervous system damage, which is associated with its inhibitory effect on expression of these inflammatory markers. [ABSTRACT FROM AUTHOR]

The frequency and function of regulatory T cells (Tregs) were studied in stage II-III melanoma patients who were enrolled in a phase II randomized trial of vaccination with HLA-A*0201-modified tumor peptides versus observation. The vaccinated patients received low-dose cyclophosphamide (CTX) and low-dose interleukin-2 (IL-2). Tregs were analyzed in the lymph nodes (LNs) of stage III patients who were undergoing complete lymph node dissection and in peripheral blood mononuclear cells (PBMCs) collected before vaccination and at different time points during the vaccination period. The LNs of the vaccinated patients, which were surgically removed after two rounds of vaccination and one dose of CTX, displayed a low frequency of Tregs and a less immunosuppressive environment compared with those of the untreated patients. The accurate time-course analysis of the PBMCs of patients enrolled in the vaccination arm indicated a limited and transient modulation in the frequencies of Tregs in PBMCs collected after low-dose CTX administration and a strong Treg boost in those PBMCs collected after low-dose IL-2 administration. However, a fraction of the IL-2-boosted Tregs was functionally modulated to a Th-1-like phenotype in the vaccinated patients. Moreover, low-dose IL-2 promoted the concomitant expansion of conventional activated CD4 T cells. Despite the amplification of Tregs, IL-2 administration maintained or further increased the number of antigen-specific CD8 T cells that were induced by vaccination as demonstrated by the ex vivo human leukocyte antigen-multimer staining and IFN-γ ELISpot assays. Our study suggests that the use of CTX as a Treg modulator should be revised in terms of the administration schedule and of patients who may benefit from this drug treatment. Despite the Treg expansion that was observed in this study, low-dose IL-2 is not detrimental to the functional activities of vaccine-primed CD8 T cell effectors when used in the inflammatory environment of vaccination. [ABSTRACT FROM AUTHOR]

Transforming growth factor beta (TGF-β)- and Interleukin-2 (IL-2)-mediated signaling enables the generation and expansion of induced regulatory T (iTreg) cells that carry high hopes for the treatment of chronic inflammatory and autoimmune diseases. Knowledge about factors stabilizing their lineage commitment and lifespan, however, is limited. Here, we investigated the behavior of iTreg cells, derived from apoptosis-defective mouse mutants, during activated cell autonomous cell death, triggered by cytokine-deprivation, or activation-induced cell death (AICD) after restimulation of the T-cell receptor, and compared these responses with those of effector T cells. We observed that iTreg cells were much more sensitive to IL-2-deprivation but poorly susceptible to AICD. In fact, when apoptosis was compromised, T-cell receptor (TCR)-religation resulted in methylation-independent, ERK- and PI3K/mTOR-mediated loss of Foxp3 expression, impaired suppressive capacity and effector cytokine production. Although iTreg cells prevented colitis induction they rapidly lost Foxp3-GFP expression and gained ability to produce effector cytokines thereby imposing Th1 cell fate on resident effector cells. Surprisingly, iTreg cell conversion itself was limited by TGF-β-mediated Bim/Bcl2L11-dependent apoptosis. Hence, the very same cytokine that drives the generation of iTreg cells can trigger their demise. Our results provide novel insights in iTreg cell biology that will assist optimization of iTreg-based therapy. [ABSTRACT FROM AUTHOR]

The transcription factors T-bet and Bcl-6 are required for the establishment of a T helper type 1 cell (TH1 cell) and follicular helper T cell (TFH cell) gene-expression profile, respectively. Here we found that high concentrations of interleukin 2 (IL-2) inhibited Bcl-6 expression in polarized TH1 cells. Mechanistically, the low concentrations of Bcl-6 normally found in effector TH1 cells did not repress its target genes because a T-bet-Bcl-6 complex masked the Bcl-6 DNA-binding domain. TH1 cells increased their Bcl-6/T-bet ratio in response to limiting IL-2 conditions, which allowed excess Bcl-6 to repress its direct target Prdm1 (which encodes the transcriptional repressor Blimp-1). The Bcl-6-dependent repression of Blimp-1 effectively induced a partial TFH profile because Blimp-1 directly repressed a subset of TFH signature genes, including Cxcr5. Thus, IL-2-signaling regulates the Bcl-6-Blimp-1 axis in TH1 cells to maintain flexibility with a TFH cell-like gene profile. [ABSTRACT FROM AUTHOR]

CD4-unhelped CD8+ T cells are functionally defective T cells primed in the absence of CD4+ T cell help. Given the co-stimulatory role of natural-killer group 2, member D protein (NKG2D) on CD8+ T cells, we investigated its ability to rescue these immunologically impotent cells. We demonstrate that augmented co-stimulation through NKG2D during priming paradoxically rescues memory, but not effector, CD8+ T cell responses. NKG2D-mediated rescue is characterized by reversal of elevated transcription factor T-box expressed in T cells (T-bet) expression and recovery of interleukin-2 and interferon-? production and cytolytic responses. Rescue is abrogated in CD8+ T cells lacking NKG2D. Augmented co-stimulation through NKG2D confers a high rate of survival to mice lacking CD4+ T cells in a CD4-dependent influenza model and rescues HIV-specific CD8+ T cell responses from CD4-deficient HIV-positive donors. These findings demonstrate that augmented co-stimulation through NKG2D is effective in rescuing CD4-unhelped CD8+ T cells from their pathophysiological fate and may provide therapeutic benefits. [ABSTRACT FROM AUTHOR]

The IL-2/IL-2R signaling pathway has an important role in autoimmunity. Several genes identified in genome-wide association (GWA) studies encode proteins in the IL-2/IL-2R signaling cascade that are associated with autoimmune diseases. One of these, PTPN2, encodes a protein tyrosine phosphatase that is highly expressed in T cells and regulates cytokine signaling. An intronic risk allele in PTPN2, rs1893217(C), correlated with decreased IL-2R signaling in CD4+ T cells as measured by phosphorylation of STAT5 (phosphorylated STAT5 (pSTAT5)). We modeled an additive single nucleotide polymorphism (SNP) genotype, in which each copy of the risk allele conferred a decrease in IL-2R signaling (P=4.4 × 10−8). Decreased pSTAT5 impacted IL-2Rβ chain signaling resulting in reduced FOXP3 expression in activated cells. This phenotype was not due to overt differences in expression of the IL-2R, molecules in the IL-2R signaling cascade or defects in STAT5. However, the rs1893217(C) risk variant did correlate with decreased PTPN2 expression in CD4+CD45RO T cells (P=0.0002). Thus, the PTPN2rs1893217(C) risk allele associated with reduced pSTAT5 in response to IL-2 and reduced PTPN2 expression. Together, these data suggest that decreased expression of PTPN2 may indirectly modulate IL-2 responsiveness. These findings, identified through genotype/phenotype relationships, may lead to identification of novel mechanisms underlying dysregulation of cytokine signaling in autoimmunity. [ABSTRACT FROM AUTHOR]

Background: After the recent discovery of Th17 cells, it was proposed that Th17 responses are involved in the pathogenesis of inflammatory bowel diseases (IBD). CD4(+)CD25(+) regulatory T cells (Treg) are considered to be an attractive tool for the treatment of IBD. Here, we investigated whether Treg are capable of suppressing Th17-mediated colitis.Methods: Naive CD4(+) T cells were transferred into SCID mice with or without Treg. In some experiments, Treg were transferred into recipient mice with established colitis. Mice treated with Treg were injected with an anti-transforming growth factor (TGF)-β mAb or control IgG. Clinical symptoms of colitis, histological changes and cytokine expressions were investigated.Results: SCID mice transferred with naive CD4(+) T cells developed chronic colitis with significant increases in Th1 and Th17 cytokine expressions in the colon. When Treg were co-transferred with naive CD4(+) T cells, development of colitis was prevented, and Th17 cytokine expressions were markedly reduced. Similarly, when Treg were transferred into mice with established colitis, the colitis was significantly ameliorated in association with dramatic reductions in Th17 cytokine expressions. Injection of anti-TGF-β mAb abolished the Treg-mediated suppression with significant elevations in Th17 cytokine productions.Conclusion: This adoptive transfer model of colitis was associated with augmented Th1 and Th17 responses, and Treg were capable of suppressing colonic inflammation by downregulating Th17 responses as well as Th1 responses via TGF-β. Consequently, Treg transfer therapy is expected to be efficacious for IBD even if Th17 is involved in the pathogenesis. [ABSTRACT FROM AUTHOR]

Crohn's disease is considered to be caused either by an excess of T-cell effector functions and/or by a defective regulatory T-cell compartment. The aim of this study was to assess in Crohn's disease the frequency of circulating CD4(+)CD25(high) T cells that possess regulatory T-cell functions and CD4(+)CD25(low) T cells that contain activated T cells. Flow cytometry of peripheral blood was used to assess CD4(+)CD25(high) and CD4(+)CD25(low) T-cell frequencies in a cohort of 66 patients with Crohn's disease in comparison to 19 patients with ulcerative colitis and 31 healthy individuals enrolled as controls. The CD4(+)CD25(high) T-cell frequency was significantly lowered in naïve Crohn's disease (P = 0.013) and in ulcerative colitis (P = 0.001). CD4(+)CD25(low) T-cell frequency was increased in Crohn's disease (P = 0.0001) and in ulcerative colitis (P = 0.0002). Both CD4(+)CD25(high) and CD4(+)CD25(low) T-cell frequencies are altered in naïve Crohn's disease resulting in an imbalance between both populations and a relative contraction of the CD4(+)CD25(high) T-cell population. [ABSTRACT FROM AUTHOR]

CD4+ T helper cells are known to play an integral role in the generation of CD8+ T-cell immune responses. We have previously shown that co-administration of DNA vaccines containing E6 or E7 protein of human papillomavirus 16 (HPV-16) combined with DNA encoding invariant (Ii) chain in which class II-associated Ii peptide (CLIP) region is replaced with the CD4+ T helper epitope, PADRE (Pan-DR-epitope) (Ii-PADRE DNA) enhanced HPV antigen-specific CD8+ T-cell immune responses in vaccinated mice. In the current study, we investigated the enhancement of HPV E7-specific CD8+ T-cell immune responses by PADRE-specific CD4+ T cells. We showed that intradermal administration of Ii-PADRE DNA at the same location as E7-expressing DNA is necessary to generate strong E7-specific CD8+ T-cell immune responses. We also showed that PADRE-specific CD4+ T cells generated by Ii-PADRE DNA vaccination expressed Th1 cytokine profile. Furthermore, our in vitro study demonstrated that PADRE-specific CD4+ T cells stimulated with PADRE-loaded dendritic cells secrete IL-2 that leads to the proliferation of E7-specific CD8+ T cells. Thus, our data suggest that activated PADRE-specific CD4+ T helper cells may be required at the vicinity of E7-specific CD8+ T cells where they secrete IL-2, which enhances the E7-specific CD8+ T-cell immune responses generated by DNA vaccination.Gene Therapy (2008) 15, 677–687; doi:10.1038/sj.gt.3303102; published online 14 February 2008 [ABSTRACT FROM AUTHOR]

In total, 16 patients with cytologically proven malignant effusion from colorectal cancer were treated by locoregional administration of the streptococcal preparation OK-432 alone or OK-432 plus the T-cell growth factor interleukin (IL)-2, and the action mechanism of the treatment was studied. A positive clinical response, showing a cytologic disappearance of cancer cells and decrease of effusion, was observed in nine of 11 (82%) patients treated with OK-432 alone and in all five patients treated with OK-432 plus IL-2. Flow cytometric analysis revealed that OK-432 plus IL-2 locally induced acute inflammation-like responses, including serial cellular infiltrations of granulocyte migration within a matter of hours, and activation of macrophages and T lymphocyte involvement within the following days, and that a predominant expansion of CD3+CD4+ lymphocytes (CD: cluster of differentiation) was induced by in vitro stimulation with IL-2 of locoregional cells after the OK-432 administration (OK/IL-2AK cells). The OK/IL-2AK cells produced tumour necrosis factor-a and interferon-?, but these cells did not produce IL-4 and IL-6. The OK/IL-2AK cells expressed potent killing activity against autologous tumour cells. This activity was abrogated by treatment of the lymphocytes with anti-CD3, -CD4, -TCRaß antibody, and by the treatment of target cells with anti-human leukocyte antigen (HLA)-DR antibody. The OK/IL-2AK cells expressed Fas-L gene, and flow cytometric analysis demonstrated HLA-DR expression in approximately 75% of CEA+ or cytokeratin+ effusion cells. TCRVß gene analysis of the OK/IL-2AK cells showed an oligoclonal usage of TCRß20, which was also involved in the cytotoxic mechanism of the OK/IL-2AK cells. Single-strand conformational polymorphism analysis demonstrated the clonotypes for the TCRVß20 gene, and the CDR3s of the gene were sequenced. The clonotypic PCR using the TCRVß20-CDR3 sequences could detect the CDR3-identical TCRs in effusion lymphocytes from the other patients. Taken together, it is suggested that locoregional administration of OK-432 plus IL-2 is highly effective for the management of malignant effusion from colorectal cancer. OK-432 plus IL-2 induces autologous tumour-reactive CD4+ Th1 killer lymphocytes, which recognise tumour antigen(s) presented with HLA class II molecules on effusion tumour cells by means of preferential usage of TCRVß20. The clonotypic PCR using the TCRVß20-CDR3 sequences may be informative for treating malignant effusion from colorectal cancer using OK-432 plus IL-2.British Journal of Cancer (2003) 89, 1876-1884. doi:10.1038/sj.bjc.6601379 www.bjcancer.com [ABSTRACT FROM AUTHOR]

Arising from B. Venkatesh et al. 505, 174-179 http://dx.doi.org/10.1038/nature12826 (2014)Recently in this journal, Venkatesh and co-workers published their analysis of the elephant shark (Callorhinchus milii, a chimaera) genome sequence. Their analyses suggested that at the evolutionary level of cartilaginous fish, only a primordial T-helper-cell (TH-cell) system was established, geared towards a TH1-type response, because they could not find several important candidate genes, or gene features, necessary for other types of TH cells. However, in contrast to Venkatesh and co-workers, I am able to find elephant shark candidate genes for interleukin-2 (IL-2), IL-4, IL-5 and IL-13, which have important roles in mammalian TH2 and T-regulatory-cell (Treg-cell) systems; furthermore, I feel that claims by the authors of absent CD4 and FOXP3 functions in cartilaginous fish are insufficiently substantiated. Therefore, I believe that major conclusions by the authors regarding proposed unique features of the T-cell system in the elephant shark are based on false arguments, or, as in the case of their CD4 model, are premature. There is a Reply to this Brief Communication Arising by Venkatesh, B. et al. 511, 10.1038/nature13447 http://dx.doi.org/10.1038/nature13447 (2014). [ABSTRACT FROM AUTHOR]

The article reports on a research study which discusses the role of the tumour suppressor protein p53 in the proliferation control of CD4 T cells. Findings reveal the inhibition of interleukin-2 (IL-2) induced T cell proliferation by p53 through cell cycle block. The critical role of T cell receptor (TCR) signalling for CD4 T cell responses is also noted.