Image_4_Human CD8+HLA-DR+ Regulatory T Cells, Similarly to Classical CD4+Foxp3+ Cells, Suppress Immune Responses via PD-1/PD-L1 Axis.JPEG

We have previously identified a human CD8+HLA-DR+ regulatory T cell subset with the ability to suppress proliferation of autologous PBMCs responder cells through cell contact and CTLA-4 co-inhibitory molecule. The present study characterizes the complete phenotype of CD8+HLA-DR+ Treg cells which showed great similarities with classical CD4+ cells expressing forkhead box P3 (FOXP3). The shared features included the expression of programmed cell death protein 1 (PD-1), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), C-C chemokine receptor type 4 and 5 (CCR4 and CCR5), low expression of CD127, and a memory and effector-like phenotype. CD8+HLA-DR+ Treg-induced suppression on CD8+ responder T cells was abrogated by an anti-PD1 neutralizing antibody. Anti-PD-1 did not abrogate the suppressor effect induced on responder CD4+ T cells. In addition, CD8+HLA-DR+ Treg induced a preferential death on responder CD8+ T cells. This effect was not reversed by PD-1 neutralization. After activation, most CD8+HLA-DR+ Treg acquire programmed death-ligand 1 (PD-L1) expression. Interestingly, PD-L1 may induce apoptosis through CD80 expressed on activated CD8+ responder T cells. After PBMCs stimulation, CD8+HLA-DR+ Treg cells showed an increased frequency of IFN-γ and TNFα positive cells and higher degranulation. These data strongly argue against CD8+HLA-DR+ Treg being exhausted cells. Overall, the data presented in this study indicate that CD8+HLA-DR+ Treg and CD4+FOXP3+ Treg share phenotypic and functional features, which may provide cues to similar involvements in the control of antitumor immune responses and autoimmunity.</p

Image_5_Human CD8+HLA-DR+ Regulatory T Cells, Similarly to Classical CD4+Foxp3+ Cells, Suppress Immune Responses via PD-1/PD-L1 Axis.JPEG

We have previously identified a human CD8+HLA-DR+ regulatory T cell subset with the ability to suppress proliferation of autologous PBMCs responder cells through cell contact and CTLA-4 co-inhibitory molecule. The present study characterizes the complete phenotype of CD8+HLA-DR+ Treg cells which showed great similarities with classical CD4+ cells expressing forkhead box P3 (FOXP3). The shared features included the expression of programmed cell death protein 1 (PD-1), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), C-C chemokine receptor type 4 and 5 (CCR4 and CCR5), low expression of CD127, and a memory and effector-like phenotype. CD8+HLA-DR+ Treg-induced suppression on CD8+ responder T cells was abrogated by an anti-PD1 neutralizing antibody. Anti-PD-1 did not abrogate the suppressor effect induced on responder CD4+ T cells. In addition, CD8+HLA-DR+ Treg induced a preferential death on responder CD8+ T cells. This effect was not reversed by PD-1 neutralization. After activation, most CD8+HLA-DR+ Treg acquire programmed death-ligand 1 (PD-L1) expression. Interestingly, PD-L1 may induce apoptosis through CD80 expressed on activated CD8+ responder T cells. After PBMCs stimulation, CD8+HLA-DR+ Treg cells showed an increased frequency of IFN-γ and TNFα positive cells and higher degranulation. These data strongly argue against CD8+HLA-DR+ Treg being exhausted cells. Overall, the data presented in this study indicate that CD8+HLA-DR+ Treg and CD4+FOXP3+ Treg share phenotypic and functional features, which may provide cues to similar involvements in the control of antitumor immune responses and autoimmunity.</p

Image_3_Human CD8+HLA-DR+ Regulatory T Cells, Similarly to Classical CD4+Foxp3+ Cells, Suppress Immune Responses via PD-1/PD-L1 Axis.JPEG

We have previously identified a human CD8+HLA-DR+ regulatory T cell subset with the ability to suppress proliferation of autologous PBMCs responder cells through cell contact and CTLA-4 co-inhibitory molecule. The present study characterizes the complete phenotype of CD8+HLA-DR+ Treg cells which showed great similarities with classical CD4+ cells expressing forkhead box P3 (FOXP3). The shared features included the expression of programmed cell death protein 1 (PD-1), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), C-C chemokine receptor type 4 and 5 (CCR4 and CCR5), low expression of CD127, and a memory and effector-like phenotype. CD8+HLA-DR+ Treg-induced suppression on CD8+ responder T cells was abrogated by an anti-PD1 neutralizing antibody. Anti-PD-1 did not abrogate the suppressor effect induced on responder CD4+ T cells. In addition, CD8+HLA-DR+ Treg induced a preferential death on responder CD8+ T cells. This effect was not reversed by PD-1 neutralization. After activation, most CD8+HLA-DR+ Treg acquire programmed death-ligand 1 (PD-L1) expression. Interestingly, PD-L1 may induce apoptosis through CD80 expressed on activated CD8+ responder T cells. After PBMCs stimulation, CD8+HLA-DR+ Treg cells showed an increased frequency of IFN-γ and TNFα positive cells and higher degranulation. These data strongly argue against CD8+HLA-DR+ Treg being exhausted cells. Overall, the data presented in this study indicate that CD8+HLA-DR+ Treg and CD4+FOXP3+ Treg share phenotypic and functional features, which may provide cues to similar involvements in the control of antitumor immune responses and autoimmunity.</p

Image_1_Human CD8+HLA-DR+ Regulatory T Cells, Similarly to Classical CD4+Foxp3+ Cells, Suppress Immune Responses via PD-1/PD-L1 Axis.jpeg

We have previously identified a human CD8+HLA-DR+ regulatory T cell subset with the ability to suppress proliferation of autologous PBMCs responder cells through cell contact and CTLA-4 co-inhibitory molecule. The present study characterizes the complete phenotype of CD8+HLA-DR+ Treg cells which showed great similarities with classical CD4+ cells expressing forkhead box P3 (FOXP3). The shared features included the expression of programmed cell death protein 1 (PD-1), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), C-C chemokine receptor type 4 and 5 (CCR4 and CCR5), low expression of CD127, and a memory and effector-like phenotype. CD8+HLA-DR+ Treg-induced suppression on CD8+ responder T cells was abrogated by an anti-PD1 neutralizing antibody. Anti-PD-1 did not abrogate the suppressor effect induced on responder CD4+ T cells. In addition, CD8+HLA-DR+ Treg induced a preferential death on responder CD8+ T cells. This effect was not reversed by PD-1 neutralization. After activation, most CD8+HLA-DR+ Treg acquire programmed death-ligand 1 (PD-L1) expression. Interestingly, PD-L1 may induce apoptosis through CD80 expressed on activated CD8+ responder T cells. After PBMCs stimulation, CD8+HLA-DR+ Treg cells showed an increased frequency of IFN-γ and TNFα positive cells and higher degranulation. These data strongly argue against CD8+HLA-DR+ Treg being exhausted cells. Overall, the data presented in this study indicate that CD8+HLA-DR+ Treg and CD4+FOXP3+ Treg share phenotypic and functional features, which may provide cues to similar involvements in the control of antitumor immune responses and autoimmunity.</p

HFD-induced metabolic and histological alterations in the liver and the reversal effects of curcumin.

(A) Top: Hematoxylin and eosin staining of liver sections from normal chow (NC)-fed and high-fat diet (HFD)-fed mice with or without curcumin supplementation (10X and 40X magnification). Curcumin prevented HFD-induced steatosis, ballooning and liver inflammation. Bottom: Masson's trichrome staining of liver sections from HFD-fed mice reveals signs of mild perisinusoidal fibrosis (10X and 40X magnification). (B) Body weight gain in NC- and HFD-fed mice with or without curcumin supplementation, starting at week 4 (arrow) (*p(C) The blood glucose concentrations were measured upon conclusion of the dietary treatments, and glycemia was determined at basal conditions (Basal) and after glucose administration. Left: a similar blood glucose concentration was observed among the four groups. Right: hyperglycemia was observed in HFD-fed mice at 120 min after an intraperitoneal glucose injection (2 g/kg). Curcumin ameliorated the hyperglycemic conditions. (*p(D) Total serum cholesterol levels were measured upon conclusion of the dietary treatments. The HFD induced higher levels of cholesterol than the normal chow regardless of curcumin administration (*p<0.05). The box and whiskers show the non-parametric statistics: the median, lower and upper quartiles and confidence interval around the median. The Kruskal-Wallis test with Dunn’s post-test was performed.</p

Effect of linoleic acid on reactive oxygen species production in human monocytes and liver macrophages.

<p>(A) The stimulation index for reactive oxygen species production in monocytes was higher in patients with NAFLD (n = 12) than in control subjects (n = 10). The box and whiskers indicate the non-parametric statistics: the median, lower and upper quartiles and confidence interval around the median. A two-tailed Mann-Whitney U test was used; *p = 0.036. (B) DCF-MFI, 2', 7’-dichlorofluorescein median fluorescence intensity. Linoleic acid increased reactive oxygen species production in liver macrophages from patients with NAFLD (n = 12). Lines connect the “Basal” and “Linoleic acid” values for each patient. A Wilcoxon matched-pairs signed rank test was performed; *p = 0.001. (C) The stimulation index in monocytes and liver macrophages from patients with NAFLD were positively correlated. Spearman´s rank correlation coefficients test was used.</p

Demographic, anthropometric and biochemical baseline data of patients with NAFLD and control individuals.

<p>Demographic, anthropometric and biochemical baseline data of patients with NAFLD and control individuals.</p

The effects of leptin on IFN-γ production and T cell-associated alterations in liver samples from patients with NAFLD.

<p>(A) The fold of increase index for IFN-γ production in leptin-stimulated circulating CD4⁺ cells was higher in patients with NAFLD (n = 10) than in control subjects (n = 10; *p = 0.011). <b>(B)</b> The percentage of CD4⁺ cells among the total non-parenchymal cell population was higher in patients with NAFLD (n = 10) than in control subjects (n = 10), *p = 0.030. <b>(C)</b> Compared with control subjects (n = 9), patients with NAFLD (n = 9) showed increased hepatic mRNA expression levels of IFN-γ (*p = 0.012), T-bet (*p = 0.020) and CCL20 (*p = 0.007) as measured by quantitative PCR. The 2^-ΔΔCt method was used to calculate the mRNA fold change. The box and whiskers indicate the non-parametric statistics: the median, lower and upper quartiles and confidence interval around the median. A two-tailed Mann-Whitney U test was used for the statistical analysis.</p

Diagram of the experimental design.

<p>Experimental design using human peripheral blood mononuclear cells (PBMCs), human or mouse liver cells. PMA: phorbol myristate acetate, H₂DCFDA: 2’7’-dichlorofluorescein diacetate.</p

Curcumin effects on linoleic acid- and leptin-induced the production of reactive oxygen species and cytokines as well as the infiltration of CD4⁺ cells in HFD-fed mice.

<p><b>(A)</b> After they were treated with linoleic acid ex vivo, liver macrophages from HFD-fed mice showed a higher stimulation index for reactive oxygen species production (*p<0.05 vs. normal chow-fed mice). In vivo curcumin administration of HFD-fed mice (HFD+curcumin) prevented the increase in the stimulation index (*p<0.05 vs. HFD-fed mice). <b>(B)</b> Ex vivo linoleic acid stimulation of hepatocytes from all the experimental groups resulted in similar stimulation indexes for reactive oxygen species production. <b>(C)</b> TNF-α production induced by ex vivo leptin treatment was higher in liver macrophages from HFD-fed mice (*p<0.05 vs. normal chow-fed mice). In vivo curcumin treatment of HFD-fed mice also prevented the increase in TNF- α production (*p<0.05, HFD+curcumin vs. HFD). <b>(D)</b> The percentage of CD4⁺ cells among the non-parenchymal cell populations was higher in HFD-fed mice (*p<0.01 vs. normal chow-fed mice). In vivo curcumin treatment also prevented the increase in CD4⁺ cell recruitment (*p<0.01, HFD+curcumin vs. HFD). The box and whiskers show the non-parametric statistics: the median, lower and upper quartiles and confidence interval around the median. The Kruskal-Wallis test with Dunn’s post-test was performed.</p