Indoleamine 2,3-dioxygenase is dispensable for the immunomodulatory function of stem cells from human exfoliated deciduous teeth

Objective: In this study, we sought to better understand the immunoregulatory function of stem cells derived from human exfoliated deciduous teeth [SHED]. We studied the role of the interferon gamma [IFN-gamma]-indoleamine 2,3-dioxygenase [IDO]-axis in immunoregulation of SHED compared to bone marrow derived mesenchymal stem cells [BMMSCs] under the same conditions

Materials and Methods: In this cross-sectional study, recently isolated human T cells were stimulated either by mitogen or inactivated allogeneic peripheral blood mononuclear cells [PBMCs]. These T cells were subsequently co-cultured with, either SHED or BMMSCs in the presence or absence of 1-methyl-tryptophan [1-MT] or neutralizing anti-human-IFN-gamma antibodies. In all co-cultures we evaluated lymphocyte activation as well as IDO activity

Results: SHED, similar to conventional BMMSCs, had anti-proliferative effects on stimulated T cells and reduced their cytokine production. This property of SHED and BMMSCs was changed by IFN-gamma neutralization. We detected IDO in the immunosuppressive supernatant of all co-cultures. Removal of IDO decreased the immunosuppression of BMMSCs

Conclusion: SHED, like BMMSCs, produced the IDO enzyme. Although IFN-gamma is one of inducer of IDO production in SHED, these cells were not affected by IFN-gamma in the same manner as BMMSCs. Unlike BMMSCs, the IDO enzyme did not contribute to their immunosuppression and might have other cell-type specific roles

The effect of progesterone and 17-β estradiol on membrane-bound HLA-G in adipose derived stem cells

Membrane-bound HLA-G (mHLA-G) discovery on adipose derived stem cells (ADSCs) as a tolerogenic and immunosuppressive molecule was very important. Many documents have shown that HLA-G expression can be controlled via some hormones such as progesterone (P4) and estradiol (E2). Therefore, this study was designed to evaluate progesterone and estradiol effects on mHLA-G in ADSCs at restricted and combination concentrations. Three independent cell lines were cultured in complete free phenol red DMEM and subcultured to achieve suffi cient cells. These cells were treated with P4, E2 and P4 plus E2 at physiologic and pregnancy concentrations for 3 days in cell culture conditions. The HLA-G positive ADSCs was measured via monoclonal anti HLA-G-FITC/MEMG-09 by means of flow cytometry in nine groups. Data were analyzed by one way ANOVA and Tukey's post hoc tests. There were no signifi cant values of the mean percentage of HLA-G positive cells in E2-treated and the combination of P4 plus E2-treated ADSCs compared to control cells (p value>0.05) but P4 had a signifi cant increase on mHLA-G in ADSCs (p value<0.05). High P4 concentration increased mHLA-G but E2 and the combination of P4 plus E2 could not change mHLA-G on ADSCs.

CD107a expression and IFN-gamma production as markers for evaluation of cytotoxic CD3+ CD8+ T cell response to CMV antigen in women with recurrent spontaneous abortion

Some evidence has shown a relationship between primary human cytomegalovirus [CMV] infection and pregnancy loss. The impact of CMV infection reactivation during pregnancy on adverse pregnancy outcomes is not completely understood. It is proposed that altered immune response, and therefore, recurrence or reactivation of latent CMV infection may relate to recurrent spontaneous abortion [RSA]; however, few data are available in this regard. To find out about any cell mediated defect and reactivation of latent CMV infection in women with RPL, cellular immunity to the virus has been evaluated by specific cytotoxic T lymphocyte [CTL] response to CMV. In a case control study, CTL CD107a expression and intercellular IFN-gamma production in response to CMV pp65 antigen and staphylococcus enterotoxin B [SEB] in women with RSA were assessed by flow cytometric analysis. Forty-four cases with history of recurrent pregnancy and forty-four controls with history of successful pregnancies were included. The FACSCaliber flow cytometer were used for analysis. No significant difference was observed between CD107a expression and IFN-gamma production in response to CMV PP65 antigen in RPL patients and control group. However, the cytotoxic response to SEB antigen in patients with RPL was significantly lower than control group [p=0.042]. The results of this study show that impaired CD107a expression and IFN-gamma production as CTL response to CMV does not appear to be a major contributing and immune incompetence factor in patients with RPL, but cytotoxic T cell response defect to other antigens requires to be assessed further in these patients

Distribution of HLA-B*27 alleles in patients with ankylosing spondylitis in Iran

HLA-B*27 is strongly associated with ankylosing spondylitis [AS]. It represents a family of alleles that differ among ethnic groups. The aim of this study was to determine the distribution of HLA-B*27 alleles in AS patients and healthy controls in Isfahan [Iran]. Sixty AS patients and 430 healthy blood donors were selected. All subjects were HLA-B*27 positive by flow cytometry. HLA-B*27 subtypes were determined by PCR-SSP. Forty patients [66.7%] and 17 controls [3.95%] were HLA-B*27 positive. Subtypes detected by PCR-SSP were B*2705, B*2702, B*2704 and B*2707. One patient was B*2702/B*2710. No significant difference was found in the distribution of these alleles between AS patients and controls. Although Caucasian subtypes are predominant among Iranians, this population is characterized by a combination of both specific Caucasian and Oriental subtypes. However such results should be interpreted carefully because of the small sample size in our investigation and definitive conclusion awaits more ethnic-group studies

Evaluation of CD11b expression on peripheral blood neutrophils for early detection of neonatal sepsis

Neonatal sepsis is a disease of infants who are less than 1 month of age. These infants are clinically ill, and their blood culture are positive for bacteria. The reported incidence of neonatal sepsis for allinfants is 1 to 10 per 1000 live births. The mortality rate is 4.2-26%. The clinical signs are not specific and diagnosis of neonatal sepsis is one of the most difficult tasks in clinical medicine. The aim of this work was determination of CD11b sensitivity and specificity for early detection of neonatal sepsis. We studied 65 neonates with gestational age of 27 to 38 weeks who were suspected for sepsis within the 28 days of life. Whole blood was obtained from neonates to determine CD11b expression on peripheral blood neutrophils by flow cytometry. C-Reactive protein [CRP] was measured qualitatively. Neonates were divided into two groups. Classification was based on the result of the blood culture. In the sepsis group all of the neonates [n = 8] showed positive blood culture and clinical symptoms. In the suspected group [n = 57] the neonates showed clinical signs but blood cultures were negative. Sensitivity and specificity of CD11b were 75%, 100% respectively. Also positive and negative predictive values of CD11b were 100% and 86% respectively. Results of present study and previous studies showed that measurement of neutrophil surface markers can be useful for diagnosis of infection in the early phases. Also, the quantitative measurement of CRP in addition to CD11b further enhances the ability to diagnose infections and improves sensitivity and negative predictive value by 100%

Effects of recombinant human erythropoietin pretreatment on anti HLA antibody titer: a preclinical experience in rats

Erythropoietin [EPO] was first known as a factor for red blood cell proliferation and differentiation. New studies show the effects of EPO on immune system. In this study, the effects of pretreatment with recombinant human erythropoietin [rHuEPO] on the anti-human leukocyte antibody [anti-HLA] titer were determined. Three groups of rats were sensitized with human lymphocytes. Two of the groups were given 20 or 100 IU/Kg rHuEPO after two sensitizations with human lymphocytes. Control group did not receive rHuEPO. Microlymphocytotoxicity method was used to detect anti-HLA antibodies. Treatment with rHuEPO caused a significant decline in anti-HLA antibody titer compared to control group. Also, pretreatment with rHuEPO suppressed antibody response after repeated antigenic stimulation. Such results could be due to the effects of rHuEPO on the number or the activity of the B and the T cells. Moreover, the dose of rHuEPO and the length of treatment might affect anti-HLA antibody titer