Little is known about the immunobiology of interleukin-17 (IL-17)-producing T cells and regulatory T cells (Treg) in chronic lymphocytic leukemia (CLL). In this study, the frequencies of Th17, Tc17, and CD39(+) Treg cells were enumerated in peripheral T cells isolated from 40 CLL patients and 15 normal subjects by flow cytometry. Our results showed a lower frequency of Th17 and Tc17 cells in progressive (0.99 ± 0.12 % of total CD3(+)CD4(+) cells; 0.44 ± 0.09 % of total CD8(+) cells) compared to indolent patients (1.57 ± 0.24 %, p = 0.042; 0.82 ± 0.2 %, p = 0.09) and normal subjects (1.78 ± 0.2 %, p = 0.003; 0.71 ± 0.09 %, p = 0.04). Decrease in IL-17-producing T cells was associated with CD39(+) Treg cells expansion. Variation of IL-17-producing cells and Treg cells in indolent and progressive patients was neither associated to the expression levels of Th1- and Th2-specific transcription factors T-bet and GATA-3 nor to the frequencies of IFN-γ and IL-4-producing CD4(+) T cells in a selected number of samples. Additionally, suppressive potential of CD4(+) Treg was similar in CLL patients and normal subjects. Our data indicate that progression of CLL is associated with downregulation of IL-17-producing T cells and expansion of Treg cells, implying contribution of these subsets of T cells in the progression of CLL.

Little is known regarding the immunobiology of regulatory T (Treg) cells in hematopoietic malignancies, particularly in chronic lymphocytic leukemia (CLL). In the present study, we showed that the frequencies of CD8(+) and CD4(+) Treg cells were significantly increased in progressive as compared with indolent CLL patients and normal subjects. Enriched CD4(+) Treg cells induced a similar level of inhibition in polyclonally activated B cells and effector T cells from CLL patients and normal subjects. Our results suggest that the increase in circulating Treg cells may result in downregulation of tumor-specific immune response, leading to tumor expansion and disease progression.

Macrophages have recently gained attention in systemic lupus erythematosus (SLE) pathogenesis for their role in the anti-inflammatory clearance of apoptotic cells. The M1/M2 polarization of macrophages improves efferocytic capability. Peroxisome proliferator-activated receptor γ is proposed to function in the expansion of the M2 subpopulation. Pioglitazone is a peroxisome proliferator-activated receptor γ agonist with a variety of anti-inflammatory effects. In this paper, we investigated the ex vivo alterations of monocyte-derived macrophages of 15 newly diagnosed SLE patients and 10 normal subjects triggered by apoptotic cells among SLE patients following pioglitazone treatment. The phagocytosis capacity of macrophages and M1/M2 polarization (CD86/CD163) was evaluated. The supernatants were also analyzed for the expression of interleukin (IL)-10, IL-12, transforming growth factor β1 and TNF-α. The mRNA expression of IL-1β and mannose receptor C-type 1 were also quantified among treated and non-treated monocyte-derived macrophages. We found that efferocytosis is defective among monocyte-derived macrophages of SLE patients and might be a major underlying mechanism involved in the sustained inflammation. Pioglitazone could enhance alternative activation of monocyte-derived macrophages and consequently immunomodulation in these patients.

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The Wnt molecules are a family of secretory glycoproteins implicated in proliferation and differentiation of both normal and malignant cells. Despite extensive investigation of the WNT genes expression profile in various tumors, little is known about their expression in chronic lymphocytic leukemia (CLL). In this study, the expression profile of 14 WNT genes was investigated in a large number of Iranian patients with CLL. Semi-quantitative RT-PCR was performed on peripheral blood leukemic cells obtained from 62 patients with CLL. Peripheral blood mononuclear cells isolated from 11 age matched normal subjects served as control to determine baseline expression level of these genes. Our results have demonstrated significant up-regulation of WNT-3, WNT-4, WNT-5B, WNT-7B, WNT-9A, WNT-10A, and WNT-16B in patients with CLL compared to normal subjects (p < 0.05 to p < 0.0001). WNT gene expression analysis in different CLL subtypes showed a similar pattern of expression in progressive and indolent clinical subtypes. Over-expression of WNT-5A and WNT-9A genes was observed in patients with no mutation in their immunoglobulin (Ig) variable region heavy chain (Ig VH) genes compared to those with mutated Ig VH genes. Comparison between patients expressing VH1 (n = 9), VH3 (n = 40) and VH4 (n = 12) gene families, revealed down-regulation of WNT-3 and WNT-9A in VH3 positive patients. Our results indicate up-regulation of many members of the WNT gene family in CLL suggesting involvement of the Wnt canonical and/or noncanonical signaling pathways in CLL tumorigenesis.

The anti-inflammatory role of macrophages in apoptotic cells (ACs) clearance is involved in Systemic Lupus Erythematosus (SLE) pathogenesis. The efferocytic capability of macrophages is altered by M1/M2 polarization. Histone deacetylase inhibitors (HDACi) are proposed to enhance the expansion of M2 macrophages. Sodium valproate (VPA) is an HDACi with different anti-inflammatory properties. Here, we aimed to investigate the effects of HDACi by VPA on the polarization of monocyte-derived macrophages (MDMs) and regulating the expression of anti-inflammatory cytokines in SLE. We studied the ex vivo alterations of MDMs among 15 newly diagnosed SLE patients and 10 normal subjects followed by ACs and VPA treatments. M1/M2 polarization was assessed by expression of CD86/CD163, IL1-β, IDO-1, and MRC-1 among treated and non-treated MDMs. We also evaluated the production of IL-10, IL-12, TGF-β1, and TNF-α cytokines in the cell culture supernatants. CD163 was overexpressed upon VPA treatment, while CD86 showed no significant change. IL1-β and IDO-1 genes were significantly downregulated, and the mRNA expression of MRC-1 was increased among VPA-treated MDMs of SLE patients. The anti-inflammatory cytokines (IL-10 and TGF-β1) were overproduced while TNF-α level was decreased in response to VPA. The population of classically activated macrophages was more prevalent among SLE patients and efferocytosis was defected. VPA could successfully enhance the anti-inflammatory immune response through alternative activation of MDMs in SLE patients.

Immunosuppression in acute myeloid leukemia (AML) is an important mechanism of tumor escape. CD200, as an immunosuppressive molecule, is overexpressed in some hematological malignancies and it has also been shown to be an independent prognostic factor in AML. In the current study, simultaneous CD200 expression and Foxp3(+) regulatory T cell levels were investigated in Iranian patients with AML by flow cytometry. We also assessed the effect of CD200-CD200R blockade on Th1 and T-reg cytokine production and T cell proliferation in autologous AML- and monocyte-DC mixed lymphocyte reactions (MLRs). ELISA assay was performed to detect IL-2, IL-12, IFN-γ, IL-10, and TGF-β production in MLR supernatants. Expression of Foxp3, IL-10, and TGF-β mRNAs in MLRs were detected by real-time PCR. Our results demonstrated significant overexpression of CD200 (P = 0.001) in association with higher frequencies of Foxp3(+) T cells in AML patients (r = 0.8, P < 0.001). Blocking of CD200-CD200R interaction demonstrated a significant decrease in TGF-β and IL-10 expression in AML-DC MLRs and a significant increase in IL-12 and IFN-γ expression in monocyte-DC MLRs. Elevated T cell levels with lower Foxp3 intensity was also shown in CD200-CD200R-blocked MLRs. Expression of IL-10 mRNA declined significantly only in AML-DC MLRs where CD200-CD200R interaction was blocked and the same result was observed for TGF-β and Foxp3 mRNA in both AML- and monocyte-DC MLRs. These data present a significant role for CD200 in suppressing anti-tumor immune response through stimulation of regulatory mechanisms in AML patients and suggest that CD200 may have a prognostic value in this malignancy and its blockade may be used as a target for AML immunotherapy.

Fc receptor-like (FCRL) 1-5 molecules are exclusively expressed in B-cells and have recently been considered as potential targets for immunotherapy of B-cell malignancies. In this study, the expression pattern of FCRL1-5 molecules was investigated in Iranian patients with B-cell chronic lymphocytic leukemia (B-CLL). Our RT-PCR results have demonstrated that all FCRL molecules, except FCRL4, were expressed in the vast majority of the patients with B-CLL. However, comparison of the relative mRNA expression levels of FCRL between B-CLL (n 5 86) and elderly normal subjects (n 5 10) revealed significantly lower expression levels of FCRL1 (p < 0.0001), FCRL3 (p 5 0.01) and FCRL4 (p 5 0.002), but not FCRL2 or FCRL5, in cases with B-CLL. No significant differences were observed between the indolent and progressive subtypes of patients with B-CLL. Comparison between the mutated and unmutated subtypes revealed a significantly higher expression level of FCRL3 (p 5 0.017) in patients with mutated CLL. Surface and intracytoplasmic expression of FCRL1, 2, 4 and 5 in leukemic cells of 12 patients by flow cytometry revealed similar results to those obtained by RT-PCR with a few exceptions. Thus, while FCRL4 was expressed in only 2 samples at intracytoplasmic level, FCRL1 and 2 were expressed in the majority of samples, both at surface and intracytoplasm. FCRL5 protein was also detected in 10 samples, but surface expression was confirmed in only 2. Analysis of B-cells from 5 normal subjects by flow cytometry revealed higher expression levels of FCRL molecules compared to CLL. Our results indicate differential expression of FCRL molecules in B-CLL and suggest the potential implication of FCRL1 and 2 for immunotherapeutic interventions.