Gamma-tocotrienol,a radiation prophylaxis agent,induces high levels of granulocyte colony-stimulating factor

Gamma-tocotrienol (GT3), a promising radioprotectant, is shown to protect CD2F1 mice from radiation-induced neutropenia and thrombocytopenia when given 24 h prior to total-body irradiation. GT3 also is shown to increase white blood cells (WBC) and absolute neutrophil counts (ANC) transiently in peripheral blood. We hypothesized that increases in WBC and ANC may involve stimulation of hematopoiesis possibly by cytokines and growth factors. To evaluate the effects of GT3 on hematopoietic system, we measured various cytokines, chemokines and growth factors by cytokine array and Bio-Plex assays. Both showed strong induction of various cytokines and chemokines. GT3 treatment resulted in significant increases in G-CSF, IL-1α, IL-1β, IL-6, IL-12p70, IL-17, MIP-1α, and KC levels. G-CSF levels increased markedly within 12–24 h after administration (5441 pg/ml in GT3-treated groups compared to 17 pg/ml in vehicle control). Most of these cytokine levels were elevated in the presence or absence of radiation. Time-course analysis of G-CSF and IL-6 induction showed that both cytokines were induced transiently after GT3 administration, and returned to normal levels by 48 h post-administration. For G-CSF, the peak was observed between 12 and 24 h post-administration of GT3; however, the highest levels of IL-6 were obtained between 6 and 12 h. These results demonstrate that GT3 induced high levels of G-CSF and other inflammatory cytokines and chemokines within 24 h after administration. Survival studies reported showed that the most efficacious time for administering GT3 was 24 h prior to irradiation, possibly because it induced key hematopoietic cytokines in that time window. These results also suggest a possible role of GT3-induced G-CSF stimulation in protecting mice from radiation-induced neutropenia and thrombocytopenia.     

A clinical comparison of the efficacy and safety of biosimilar G-CSF and originator G-CSF in haematopoietic stem cell mobilization

BackgroundRecombinant granulocyte colony-stimulating factor (G-CSF) is widely used to mobilize haematopoietic stem cells. We compared the efficacy and safety of a biosimilar G-CSF (Zarzio^®, Sandoz Biopharmaceuticals) with the originator G-CSF (Neupogen^®, Amgen) in patients with haematological malignancies.MethodsA total of 108 patients were included in this study, 59 of whom were female (49 male), with an overall median age of 51 years (range 19–69). Patients had multiple myeloma (n = 46), non-Hodgkin's lymphoma (n = 28), Hodgkin's lymphoma (n = 26), or other diagnosis (n = 8). After administration of mobilizing regimens (primarily high-dose etoposide, high-dose cyclophosphamide, intermediate-dose Ara-C or ESHAP), patients were randomized to a standard daily 10 μg/kg dose of biosimilar G-CSF (n = 54) or originator G-CSF (n = 54).ResultsMedian duration of G-CSF administration was 8 days with both biosimilar G-CSF (range 4–17) and originator G-CSF (range 4–14). Both groups had a median of one apheresis with a median time until first apheresis of 11 days. There were no statistically significant differences between groups in the mean ± SD number of mobilized CD34+ cells/μL in peripheral blood or the number of CD34+ cells/kg body weight. Five patients (9%) in the originator G-CSF group and six patients in the biosimilar G-CSF group (11%) did not mobilize sufficient CD34+ cells. The adverse event profile was similar between groups.ConclusionsA biosimilar G-CSF (Zarzio^®) demonstrated similar efficacy and safety as the reference originator G-CSF (Neupogen^®) in hematopoietic stem cell mobilization in patients with haematological malignancies.     

Phloroglucinol Inhibits the in vitro Differentiation Potential of CD34 Positive Cells into Endothelial Progenitor Cells

Inhibiting the bioactivities of circulating endothelial progenitor cells (EPCs) results in significant inhibition of neovessel formation during tumor angiogenesis. To investigate the potential effect of phloroglucinol as an EPC inhibitor, we performed several in vitro functional assays using CD34⁺ cells isolated from human umbilical cord blood (HUCB). Although a high treatment dose of phloroglucinol did not show any cell toxicity, it specifically induced the cell death of EPCs under serum free conditions through apoptosis. In the EPC colony-forming assay (EPC-CFA), we observed a significant decreased in the small EPC-CFUs for the phloroglucinol group, implying that phloroglucinol inhibited the early stage of EPC commitment. In addition, in the in vitro expansion assay using CD34⁺ cells, treatment with phloroglucinol was shown to inhibit endothelial lineage commitment, as demonstrated by the decrease in endothelial surface markers of EPCs including CD34⁺, CD34⁺/CD133⁺, CD34⁺/CD31⁺ and CD34⁺/CXCR4⁺. This is the first report to demonstrate that phloroglucinol can inhibit the functional bioactivities of EPCs, indicating that phloroglucinol may be used as an EPC inhibitor in the development of biosafe anti-tumor drugs that target tumor angiogenesis.     

Chicken egg yolk antibodies (IgY) modulate the intestinal mucosal immune response in a mouse model of Salmonella typhimurium infection

This study determined the effects of chicken egg yolk antibodies (IgY) on immune responses in the intestinal mucosal of mice infected with Salmonella typhimurium. Sixty, 28-day-old mice were divided into 4 groups and treated with streptomycin or sterile water for 2 days followed by 1 day without treatment. The control group was unchallenged whereas the mice in the other three groups were treated twice with 10⁹ CFU mL^− 1 S. typhimurium. For the next 3 days, control mice continued to receive no treatment whereas the mice in the remaining three groups were orally administered with 20 mg mL^− 1 of specific IgY, 20 mg mL^− 1 of nonspecific IgY or PBS. S. typhimurium activated gut-associated lymphoid tissue, increasing the release of IFN-γ and TNF-α in the mucosa and increased the number of activated T-lymphocytes and cytotoxic T-γδ. Specific IgY attenuated the increase in IFN-γ and TNF-α and the decrease in IL-10. S. typhimurium induced mobilization of CD8⁺ and CD8⁺ TCRγδ T cells in the epithelium and CD4⁺ and CD8⁺ T cells in the lamina propria reflecting an inflammatory process that was attenuated by IgY. These results suggest that specific IgY modulates intestinal mucosal immune responses during a S. typhimurium infection.     

Na +/H + exchanger inhibitor induces vasorelaxation through nitric oxide production in endothelial cells via intracellular acidification-associated Ca2 + mobilization

The objective of this study was to determine the mechanism by which Na⁺/H⁺ exchanger (NHE) inhibitors induce vasodilatation. The NHE inhibitors, 5-(N,N-dimethyl)-amiloride (DMA), cariporide, and amiloride, evoked endothelium-dependent relaxation in rat aortas with ED₅₀ values of 16, 89, and 148 μM, respectively, and these effects were abolished by treatment with N^G-nitro-l-arginine methyl ester (L-NAME). The relaxation effects induced by DMA and cariporide were strongly attenuated in aortas of the endothelial NO synthase (eNOS)-deficient mice, as compared to the effects in wild-type mice. The DMA-induced relaxation in rat aorta was attenuated by a calmodulin (CaM) inhibitor, calmidazolium, and a soluble guanylyl cyclase inhibitor, [1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, but was not affected by a phosphoinositide 3-kinase inhibitor, wortmannin. Immunoblots for endothelial eNOS on immunoprecipitated CaM complexes showed that DMA enhanced the association of eNOS with CaM in rat aortas. Both DMA and cariporide induced the reduction of intracellular pH (pHi) in bovine aortic endothelial cells (BAECs), which was accompanied by a sustained elevation of cytosolic Ca^2 + ([Ca^2 +]i). This DMA-induced rise of [Ca^2 +]i was not affected by removing external Ca^2 + from the buffer, but was abolished in thapsigargin-pretreated BAECs. These results suggest that lowering of pHi by NHE inhibitors in endothelial cells induces the mobilization of Ca^2 + from the thapsigargin-sensitive stores of endoplasmic reticulum, which in turn stimulates NO production via the CaM-dependent activation of eNOS.     

Changes in regulatory T cells in patients with ovarian cancer undergoing surgery: Preliminary results

Regulatory T cells (Treg) suppress immune responses in patients with cancer. Surgery is the most effective therapeutic strategy for ovarian cancer (OC). However, the interplay between the Treg population and surgical resection remains unclear. 61 patients with OC who received no prior treatment were enrolled in the study. Treg percentages were characterized from peripheral blood mononuclear cells. We investigated CD4⁺ CD25⁺, CD4⁺ CD25⁺ Foxp3⁺, CD8⁺ CD28⁻, and CD8⁺ Foxp3⁺ Tregs in OC patients and their postoperative changes using flow cytometry. Treg percentages were significantly higher in OC patients than those in benign ovarian tumors (BOT) and healthy controls. Higher percentages of Tregs were found in patients with stage III/IV than stage I/II OC. Treg percentages were significantly decreased postoperatively. The postoperative Treg percentages in patients with stage I/II OC were similar to those in BOT patients, while postoperative Treg percentages in patients with stage III/IV OC remained higher. Tregs were markedly lower on postoperative day (POD) 3 than preoperatively. They increased slightly after 7 days, but remained lower than preoperative levels. These data suggested that Tregs continued to decline from POD 7 to POD 30. Treg percentages are correlated with the tumor burden and could be a key factor in monitoring the immunological status of patients with OC.     

Inosine Acedoben Dimepranol promotes an early and sustained increase in the natural killer cell component of circulating lymphocytes: A clinical trial supporting anti-viral indications

Inosine Acedoben Dimepranol (IAD), licensed for the treatment of cell-mediated immune deficiencies associated with viral infections, has been reported to impact a variety of immune parameters both in vitro and in vivo. Here we report the results from a clinical trial where multiple lymphocyte subsets – CD19 + B cells, CD3 + T cells, CD4 + T-helper cells, FoxP3^hi/CD25^hi/CD127^lo regulatory T cells (Tregs), CD3 −/CD56 + NK cells, and CD3 +/CD56 + NKT cells – were, together with serum immunoglobulins and IgG subclasses, followed during 14 days of IAD administration to ten healthy volunteers; these selected from 27 individuals pre-screened in vitro for their capacity to respond to IAD as gauged by increases in the percentage of Treg and/or NKT cells arising in PHA-stimulated cultures. While a transient spike and dip in Treg and T-helper fractions, respectively, was noted, the outstanding consequence of IAD administration (1 g po, qds) was an early and durable rise in NK cells. For half the cohort, NK cells increased as a percentage of total peripheral blood lymphocytes within 1.5 h of receiving drug. By Day 5, all but one of the volunteers displayed higher NK cell percentages, such elevation – effectively a doubling or greater – being maintained at termination of study. The IAD-induced populations were as replete in Granzyme A and Perforin as basal NK cells. The novel finding of IAD boosting phenotypically competent NK numbers in healthy individuals supports the drug's indicated benefit in conditions associated with viral infection and reinforces the potential for uplift where immune performance may be compromised.     

Gabapentin-induced changes of plasma cortisol level and immune status in hysterectomized women

AimWe have examined the effects of gabapentin (GBP) on stress-related changes of cortisol and catecholamines in patients who underwent hysterectomy because of uterine fibrinoids. Additionally, we have observed the effect of GBP on the immune status in the acute stress response to surgery.MethodsSixty patients scheduled for an abdominal hysterectomy were randomly assigned to the GBP administration 1 h before surgery (n = 30 pts), or to the placebo group (n = 30 pts). Blood samples were collected before and 24 h after the surgery. The intensity of pain was assessed by a visual analogue scale (VAS) every 8 h at rest. Immunomodulatory effects of GBP were determined by flow cytometry. We followed the total proportion of CD3⁺ lymphocytes, CD3⁺CD4⁺, CD3⁺CD8⁺, CD19⁺ B lymphocytes, CD16⁺CD56⁺CD3⁻NK cells and CD16⁺CD56⁺CD3⁺ NKT cells before and 24 h after hysterectomy. The plasma cortisol and catecholamines concentration was used to estimate the level of the stress response.ResultsVAS pain score at rest was significantly lower in the GBP group than in the placebo group (P = 0.003). Application of GBP significantly decreased the plasma cortisol level 24 h after the operation in comparison to the placebo group (P < 0,001). We found significant positive correlation between the VAS pain score and concentration of cortisol in all patients (P = 0.025). GBP reduced the concentration of catecholamines (p < 0.05). The proportion of CD3⁺ (P = 0.027) and CD3⁺CD4⁺cells (P = 0.006) was significantly lower in the GBP group 24 h after operation, while the contribution of CD19⁺ (P = 0.033) was significantly higher.ConclusionPreoperative administration of GBP reduced the pain scores at rest in patients at 0, 16 and 24 h after abdominal hysterectomy. Additionally, GBP reduced the stress response and changed immune parameters in the reaction to surgery.     

Depletion of T lymphocytes ameliorates cardiac fibrosis in streptozotocin-induced diabetic cardiomyopathy

T cell infiltration has been associated with increased coronary heart disease risk in patients with diabetes mellitus. Effect of modulation of T cell trafficking on diabetes-induced cardiac fibrosis has yet to be determined. Therefore, our aim was to investigate the circulatory T cell depletion-mediated cardioprotection in streptozotocin-induced diabetic cardiomyopathy. Fingolimod (FTY720), an immunomodulatory drug, was tested in wild-type (WT) C57BL/6 and recombination activating gene 1 (Rag1) knockout (KO) mice without mature lymphocytes in streptozotocin-induced type 1 diabetic model. FTY720 (0.3 mg/kg/day) was administered intraperitoneally daily for the first 4 weeks with interim 3 weeks then resumed for another 4 weeks in 11 weeks study period. T lymphocyte counts, cardiac histology, function, and fibrosis were examined in diabetic both WT and KO mice. FTY720 reduced both CD4⁺ and CD8⁺ T cells in diabetic WT mice. FTY720-treated diabetic WT mouse myocardium showed reduction in CD3 T cell infiltration and decreased expression of S1P₁ and TGF-β1 in cardiac tissue. Fibrosis was reduced after FTY720 treatment in diabetic WT mice. Rag1 KO mice exhibited no CD4⁺ and CD8⁺ T cells in the blood and CD3 T cells in the heart. Diabetic Rag1 KO mouse hearts appeared no fibrosis and exhibited preserved myocardial contractility. FTY720-induced antifibrosis was abolished in diabetic Rag1 KO mice. These findings demonstrate that chronic administration with FTY720 induces lymphopenia and protects diabetic hearts in WT mice whereas FTY720 increases cardiac fibrosis and myocardial dysfunction in diabetic Rag1 KO mice without mature lymphocytes.     

CXCR5+ CD8+ T cells could induce the death of tumor cells in HBV-related hepatocellular carcinoma

The follicular CXCR5⁺ CD8⁺ T cells have recently emerged as a critical cell type in mediating peripheral tolerance as well as antiviral immune responses during chronic infections. In this study, we investigated the function of CXCR5⁺ CD8⁺ T cells in HBV-related hepatocellular carcinoma patients. Compared to CXCR5⁻ CD8⁺ T cells, CXCR5⁺ CD8⁺ T cells presented elevated PD-1 expression but reduced Tim-3 and CTLA-4 expression. Upon anti-CD3/CD28 stimulation, CXCR5⁺ CD8⁺ T cells demonstrated higher proliferation potency than CXCR5⁻ CD8⁺ T cells, especially after PD-1 blockade. CXCR5⁺ CD8⁺ T cells also demonstrated significantly higher granzyme B synthesis and release, as well as higher level of degranulation. Tumor cells were more readily eliminated by CXCR5⁺ CD8⁺ T cells than by CXCR5⁻ CD8⁺ T cells. Interestingly, we found that B cells were more resistant to CXCR5⁺ CD8⁺ T cell-mediated killing than tumor cells, possibly through IL-10-mediated protection. In addition, the CXCR5⁺ CD8⁺ T cell-mediated cytotoxic effects on tumor cells could be significantly enhanced by PD-L1 blockade. Together, we presented that in patients with in HBV-related hepatocellular carcinoma, CXCR5⁺ CD8⁺ T cells could mediate tumor cell death more potently than the CXCR5⁻ CD8⁺ T cells in vitro while the autologous B cells were protected.     

A higher frequency of CD4+ CXCR5+ T follicular helper cells in patients with newly diagnosed Henoch–Schönlein purpura nephritis

T follicular helper (TFH) cells play an important role in the humoral immune responses. The aim of this study was to examine the frequency of different subsets of CD4⁺ CXCR5⁺ TFH cells and B cells in patients with new-onset Henoch–Schönlein purpura nephritis (HSPN). The numbers of different subsets of CD4⁺ CXCR5⁺ TFH cells, B cells and the constituents of serum cytokines were detected in a total of 25 patients with newly diagnosed HSPN before and after treatment, and in 14 healthy controls (HC). The potential connection of these cells with the clinical characteristics in HSPN patients was analyzed. The numbers of circulating CD4⁺ CXCR5⁺, CD4⁺ CXCR5⁺ ICOS⁺ and CD4⁺ CXCR5⁺ PD-1⁺ TFH cells, CD86⁺ CD19⁺, CD38⁺ CD19⁺ B cells and serum IL-2, IL-4, IL-17A, IL-21 and IFN-γ were significantly higher in HSPN patients (p < 0.05) than in HC. Before and after treatment the numbers of CD4⁺ CXCR5⁺ TFH cells were negatively correlated with the values of eGFR (r = − 0.7162, p < 0.05; r = − 0.732, p < 0.05, respectively). Similarly the numbers of CD4⁺ CXCR5⁺ PD-1⁺ TFH cells were negatively correlated with 24-h urinary proteins (r = − 0.4013, p < 0.05; r = − 0.7857, p < 0.05, respectively), and the numbers of CD4⁺ CXCR5⁺ ICOS⁺ TFH cells were positively correlated with the levels of serum IL-21 (r = 0.5186, p < 0.05; r = 0.8503, p < 0.05, respectively) and 24-h urinary protein (r = 0.6045, p < 0.05; r = 0.833, p < 0.05, respectively) in these patients, regardless of treatment. Following treatment the numbers of CD4⁺ CXCR5⁺, CD4⁺ CXCR5⁺ PD-1⁺, and CD4⁺ CXCR5⁺ ICOS⁺ TFH cells, as well as serum levels of IL-21 were significantly reduced, however IL-4 levels were noticeably increased (p < 0.05). A higher frequency of circulating CD4⁺ CXCR5⁺ TFH cells existed in patients with HSPN and may be a viable therapeutic target.     

Inhibition of human cervical carcinoma growth by cytokine-induced killer cells in nude mouse xenograft model

Cervical cancer is a major cause of cancer mortality in women worldwide and is an important public health problem for adult women in developing countries. Despite aggressive treatment with surgery and chemoradiation, the outcomes for cervical cancer patients remain poor. In this study, the antitumor activity of cytokine-induced killer (CIK) cells against human cervical cancer was evaluated in vitro and in vivo. Human peripheral blood mononuclear cells were cultured with IL-2-containing medium in anti-CD3 antibody-coated flasks for 5 days, followed by incubation in IL-2-containing medium for 9 days. The resulting populations of CIK cells comprised 95% CD3⁺, 3% CD3⁻CD56⁺, 35% CD3⁺CD56⁺, 11% CD4⁺, < 1% CD4⁺CD56⁺, 80% CD8⁺, and 25% CD8⁺CD56⁺. At an effector-target cell ratio of 100:1, CIK cells destroyed 56% of KB-3-1 human cervical cancer cells, as measured by the ⁵¹Cr-release assay. In addition, CIK cells at doses of 3 and 10 million cells per mouse inhibited 34% and 57% of KB-3-1 tumor growth in nude mouse xenograft assays, respectively. This study suggests that CIK cells may be used as an adoptive immunotherapy for cervical cancer patients.     

CD4+ B220+ TCRγδ+ T cells produce IL-17 in lupus-prone MRL/lpr mice

Systemic lupus erythematosus is an autoimmune disease with comprehensive immune cell disorders. Recent studies suggested that pro-inflammatory cytokine IL-17 plays important role in lupus, leaving the cellular sources and their pathogenic and physiologic characters largely unknown. In the current study, by using lupus-prone MRL/lpr mice, we demonstrated that Th17 response prevails in lupus disease regarding significantly accumulated serum IL-17, increased IL-17-producing splenocytes, and elevated phospho-STAT3 in CD4⁺ T cells. Intracellular staining revealed that unusual CD4⁺ B220⁺ T cells are major IL-17-producing cells, whereas conventional CD4⁺ B220⁻ T cells are major IFN-γ-producing cells. Subsequent studies showed that CD4⁺ B220⁺ cells contains both αβ and γδ T cells in the spleen and thymus of MRL/lpr mice. Further study showed that around 60% of γδ T cells in MRL/lpr mice co-express both B220 and CD4 on their surface, and are the major RORγt⁺ cells in MRL/lpr mice. Finally, CD4⁺ B220⁺ T cells alone do not proliferate, but could enhance the proliferation and IFN-γ-production of conventional CD4⁺ B220⁻ T cells. Our findings suggest the pathogenic role of unusual CD4⁺ B220⁺ T cells in lupus disease in MRL/lpr mice according to their IL-17-producing ability and stimulatory function for conventional CD4⁺ B220⁻ T cells.     

Circulating endothelial progenitor cells are reduced in hemodialysis patients

SUMMARY

Objective: The risk of cardiovascular disease in hemodialysis patients is far greater than in the general population. Endothelial progenitor cells (EPCs) circulating in the peripheral blood contribute to neovascularization in the ischemic tissue. EPCs are considered to be included in CD34 positive (CD34⁺) or AC133 positive (AC133⁺) mononuclear cells (MNCs). This study's aim was to determine the number and functional activity of EPCs in hemodialysis patients and age-matched control subjects.

Methods: The numbers of CD34⁺ MNCs and AC133⁺ MNCs in the peripheral blood were quantified by flow cytometry. The peripheral blood EPCs were also examined by an in vitro culture assay. The levels of serum vascular endothelial growth factor (VEGF) were measured by sandwich enzyme immunoassay.

Results: The numbers of CD34⁺ MNCs and AC133⁺ MNCs were significantly reduced by 56% and 49%, respectively, in hemodialysis patients (n?=?50) compared with control subjects (n?=?36). The number of EPCs determined by the culture assay was also significantly reduced by 41% in hemodialysis patients compared with control i subjects. Multivariate analysis revealed that none of the atherosclerotic risk factors were independent predictors of reduced CD34⁺ MNC counts. The serum VEGF levels in hemodialysis patients were not different from those in control subjects and did not correlate with CD34⁺ MNC counts.

Conclusion: Circulating EPCs are significantly reduced in hemodialysis patients, which might be related to impaired neovascularization and cardiovascular disease in these patients.     

In vitro cytopathic effects of mycotoxin T-2 on human peripheral blood T lymphocytes

The trichothecene mycotoxin T-2 is reported to exhibit immunotoxic activity. The potential presence of T-2 in foods renders it as public health hazard and its toxicity needs to be better understood. We investigated the in vitro effects of T-2 at sub-toxic (0.1 ng/ml) and toxic (10 ng/ml) levels on freshly isolated human peripheral blood lymphocytes (PBLs). We observed no direct influence on untreated PBLs. The toxic dose of T-2, however, totally inhibited phytohemagglutinin-induced T lymphocyte proliferation and caused early apoptosis that peaked after 8 h of exposure. Both major T lymphocyte subsets (CD4⁺ and CD8⁺) were affected as they appeared to show a positive response to T-2 at 8 h followed by their sharp reduction after 96 h. Further investigation on the naïve (CD45RA⁺) and memory (CD45RO⁺) subpopulations confirmed these observations and indicated that T-2 affected equally all the subpopulations studied, although PHA preferentially stimulated CD45RO⁺ T lymphocytes. Sub-toxic T-2 appeared to exhibit co stimulatory properties to PHA-stimulated cells. These results support the hypothesis that T-2 affects the activation-induced cell death mechanism of T lymphocytes.     

CD163+ M2-type tumor-associated macrophage support the suppression of tumor-infiltrating T cells in osteosarcoma

Osteosarcoma is one of the most common childhood cancers with high numbers of cancer-related deaths. Progress in conventional therapies is showing limited improvement. An adaptive T cell-based immunotherapy represents a promising new therapeutic option, but to improve its efficacy, regulatory mechanisms in osteosarcoma need further elucidation. Here, to evaluate the regulatory effect of tumor microenvironment of T cells in osteosarcoma, we examined the peripheral blood (PB) and tumor infiltrating (TI) T cells, and their correlations with PB and tumor immune characteristics. We found that TI T cells contained significantly higher levels of TIM-3⁺ PD-1⁻ and TIM-3⁺ PD-1⁺ cells than their PB counterparts. Similar to that in chronic HIV and HCV infections, these TIM-3⁺ PD-1⁻ and TIM-3⁺ PD-1⁺ T cells presented reduced proliferation and proinflammatory cytokine secretion in response to stimulation. Presence of M2-type (CD163⁺) macrophages exacerbated T cell immunosuppression, since frequencies of CD163⁺ tumor-associated macrophages were directly correlated with the frequencies of suppressed TIM-3⁺ PD-1⁺ T cells. Moreover, depletion of CD163⁺ macrophages significantly improved T cell proliferation and proinflammatory cytokine production. Overall, our data presented an intratumoral T cell-specific immunosuppression that was amplified by M2-type tumor-associated macrophages.     

Mesenchymal stem cells upregulate Treg cells via sHLA-G in SLE patients

BackgroundSoluble human leukocyte antigen-G (sHLA-G) is a non-classical HLA class I molecule, exhibiting strong immunosuppressive properties by inducing the differentiation of T regulatory cells (Treg). Mesenchymal stem cells (MSCs) transplantation alleviates disease progression in systemic lupus erythematosus (SLE) patients. However, the underlying mechanisms are largely unknown.ObjectivesTo explore whether sHLA-G is involved in upregulating effects of MSCs on Treg, which contributes to therapeutic effects of MSCs transplantation in SLE.MethodsThe serum sHLA-G levels of SLE patients and healthy controls were detected by ELISA. The percentages of peripheral blood CD4 + ILT2 +, CD8 + ILT2 +, CD19 + ILT2 + cells and Treg cells were examined by flow cytometry. Ten patients with active SLE, refractory to conventional therapies, were infused with umbilical cord derived MSCs (UC-MSCs) and serum sHLA-G was measured 24 h and 1 month after infusion. The mice were divided into three groups: C57BL/6 mice, B6.MRL-Fas^lpr mice infused with phosphate buffer saline (PBS), and B6.MRL-Fas^lpr mice infused with bone marrow MSCs (BM-MSCs). Then, the concentrations of serum Qa-2 were detected. Peripheral blood mononuclear cells (PBMCs) were isolated from SLE patients and co-cultured with UC-MSCs for 3 days at different ratios (50:1, 10:1, and 2:1) with or without HLA-G antibody, and the frequencies of CD4 + CD25 + Foxp3 + T cells were then determined by flow cytometry.ResultsThe concentrations of serum sHLA-G were comparable between SLE patients and healthy controls. However, there was a negative correlation between sHLA-G levels and SLE disease activity index (SLEDAI) scores in active SLE patients (SLEDAI > 4). We found that serum sHLA-G levels were negatively correlated with blood urea nitrogen, serum creatinine and 24-hour urine protein in SLE patients. The sHLA-G levels were significantly lower in SLE patients with renal involvement than those without renal involvement. The expression of ILT2 on CD4 + T cells from SLE patients decreased significantly compared to that of healthy controls. A positive correlation between the frequencies of Treg and CD4 + ILT2 + T cells was found in SLE patients. The levels of sHLA-G increased 24 h post UC-MSCs transplantation. The concentrations of Qa-2 in BM-MSCs transplanted mice were significantly higher than those of control group. In vitro studies showed that MSCs increased the frequency of Treg cells in SLE patients in a dose-dependent manner, which was partly abrogated by the anti-HLA-G antibody.ConclusionsOur results suggested that MSCs may alleviate SLE through upregulating Treg cells, which was partly dependent on sHLA-G.     

Effects of taurocholic acid on immunoregulation in mice

ContextCurrently, there is a dramatically growing interest in Chinese traditional medicines, especially in the therapy of inflammatory diseases. Taurocholic acid (TCA), as a kind of natural bioactive substance of animal bile acid, has medicinal applications to treat a wide range of inflammatory diseases.ObjectiveThe study was designed to evaluate the effects of TCA on cytokine secretion, such as TNF-α and IL-1β and on the ratio of CD4⁺/CD8⁺, which is beneficial for understanding the mechanism of TCA on immunoregulation preliminarily, and also will benefit our further research.Materials and methodsThe gene and protein expressions of TNF-α and IL-1β were measured by real time RT-PCR and ELISA in serum, spleen and lymphocytes respectively. The ratio of CD4⁺/CD8⁺ in peripheral blood and lymphocytes was measured by flow cytometry.ResultsOur present study has shown that lipopolysaccharide (LPS) and cyclosporin A (CsA) could increase or decrease the gene and protein expressions of TNF-α and IL-1β respectively. TCA (0.25 g/kg, 0.125 g/kg) could recover the suppressed expressions of TNF-α and IL-1β and increase the ratio of CD4⁺/CD8⁺. In vitro, TCA (15 μg/mL) could inhibit the increased production of TNF-α and IL-1β; TCA (0.15 μg/mL–15 μg/mL) could inhibit the increased gene expressions of IL-1β and TNF-α. TCA (0.15 μg/mL) could recover the suppressed expressions of TNF-α and IL-1β.ConclusionThe function of immunoregulation of TCA may be accomplished through modulating the gene and protein expressions of TNF-α and IL-1β and elevating CD4⁺/CD8⁺ T-cell ratio.