Immunophenotyping characteristics of COVID-19 patients: Peripheral blood CD8+ HLA-DR+ T cells as a biomarker for mortality outcome.

INTRODUCTION: The goal of this study was to identify biomarker(s) to assign risk of mortality in COVID-19 patients to improve intensive care unit (ICU) and coronary care unit  management. A total of 100 confirmed COVID-19 patients admitted at Imam Khomeini Hospital in Tehran, were compared to 70 control subjects. Peripheral blood leukocyte was studied using staining reagents included CD3, CD4, CD8, HLA-DR, CD19, CD16, and CD56. The immunophenotyping analysis was evaluated using the FACSCalibur instrument. To investigate the cell density of lung infiltrating T cells, postmortem slides of needle necropsies taken from the lung tissue of 3 critical patients were evaluated by immunohistochemistry staining. The number of lymphocyte subpopulations was significantly lower in COVID-19 patients than in the control group. Regarding the disease severity, the absolute count of T, NK, and HLA-DR+ T cells were significantly reduced in severe patients compared to the moderate ones. The critical patients had a significantly lower count of CD8-HLA-DR+ T cells than the moderate cases. Regarding the disease mortality, based on univariate analysis, the count of HLA-DR+ T, CD8- HLA-DR+ T, and CD8+ HLA-DR+ T cells was associated with mortality in COVID-19 patients. Receiver operating characteristic curve analysis showed the count of CD8+ HLA-DR+ T cells is the best candidate as a biomarker for mortality outcome. Furthermore, pulmonary infiltration of T cells in the lung tissue showed only slight infiltrations of CD3+ T cells, with an equal percentage of CD4+ and CD8+ T cell subpopulation in the lung tissue. These findings suggest that close monitoring of the value of CD8+ HLA-DR+ T cells in COVID-19 patients may be helpful to identify high-risk patients. However, further studies with larger sample size are needed.

Dendritic cells loaded with exosomes derived from cancer stem cell-enriched spheroids as a potential immunotherapeutic option.

Cancer stem cells (CSCs) are responsible for therapeutic resistance and recurrence in colorectal cancer. Despite advances in immunotherapy, the inability to specifically eradicate CSCs has led to treatment failure. Hence, identification of appropriate antigen sources is a major challenge in designing dendritic cell (DC)-based therapeutic strategies against CSCs. Here, in an in vitro model using the HT-29 colon cancer cell line, we explored the efficacy of DCs loaded with exosomes derived from CSC-enriched colonospheres (CSCenr -EXOs) as an antigen source in activating CSC-specific T-cell responses. HT-29 lysate, HT-29-EXOs and CSCenr lysate were independently assessed as separate antigen sources. Having confirmed CSCs enrichment in spheroids, CSCenr -EXOs were purified and characterized, and their impact on DC maturation was investigated. Finally, the impact of the antigen-pulsed DCs on the proliferation rate and also spheroid destructive capacity of autologous T cells was assessed. CSCenr -EXOs similar to other antigen groups had no suppressive/negative impacts on phenotypic maturation of DCs as judged by the expression level of costimulatory molecules. Notably, similar to CSCenr lysate, CSCenr -EXOs significantly increased the IL-12/IL-10 ratio in supernatants of mature DCs. CSCenr -EXO-loaded DCs effectively promoted T-cell proliferation. Importantly, T cells stimulated with CSCenr -EXOs disrupted spheroids' structure. Thus, CSCenr -EXOs present a novel and promising antigen source that in combination with conventional tumour bulk-derived antigens should be further explored in pre-clinical immunotherapeutic settings for the efficacy in hampering recurrence and metastatic spread.

Morphological and molecular characteristics of spheroid formation in HT-29 and Caco-2 colorectal cancer cell lines.

BACKGROUND: Relapse and metastasis in colorectal cancer (CRC) are often attributed to cancer stem-like cells (CSCs), as small sub-population of tumor cells with ability of drug resistance. Accordingly, development of appropriate models to investigate CSCs biology and establishment of effective therapeutic strategies is warranted. Hence, we aimed to assess the capability of two widely used and important colorectal cancer cell lines, HT-29 and Caco-2, in generating spheroids and their detailed morphological and molecular characteristics. METHODS: CRC spheroids were developed using hanging drop and forced floating in serum-free and non-attachment conditions and their morphological features were evaluated by scanning electron microscopy (SEM). Then, the potential of CSCs enrichment in spheroids was compared to their adherent counterparts by analysis of serial sphere formation capacity, real-time PCR of key stemness genes (KLF4, OCT4, SOX2, NANOG, C-MYC) and the expression of potential CRC-CSCs surface markers (CD166, CD44, and CD133) by flow cytometry. Finally, the expression level of some EMT-related (Vimentin, SNAIL1, TWIST1, N-cadherin, E-cadherin, ZEB1) and multi-drug resistant (ABCB1, ABCC1, ABCG2) genes was evaluated. RESULTS: Although with different morphological features, both cell lines were formed CSCs-enriched spheroids, indicated by ability to serial sphere formation, significant up-regulation of stemness genes, SOX2, C-MYC, NANOG and OCT4 in HT-29 and SOX2, C-MYC and KLF4 in Caco-2 spheroids (p-value < 0.05) and increased expression of CRC-CSC markers compared to parental cells (p-value < 0.05). Additionally, HT-29 spheroids exhibited a significant higher expression of both ABCB1 and ABCG2 (p-value = 0.02). The significant up-regulation of promoting EMT genes, ZEB1, TWIST1, E-cadherin and SNAIL1 in HT-29 spheroids (p-value = 0.03), SNAIL1 and Vimentin in Caco-2 spheroids (p-value < 0.05) and N-cadherin down-regulation in both spheroids were observed. CONCLUSION: Enrichment of CSC-related features in HT-29 and Caco-2 (for the first time without applying special scaffold/biochemical) spheroids, suggests spheroid culture as robust, reproducible, simple and cost-effective model to imitate the complexity of in vivo tumors including self-renewal, drug resistance and invasion for in vitro research of CRC-CSCs.

Increased cytoplasmic expression of DLL4 is associated with favorable prognosis in colorectal cancer.

Aims: DLL4 of the Notch pathway is a key regulator of VEGF expression, which mediates tumor neovascularization and stem cell self-renewal in colorectal cancer (CRC). The authors investigated the association of DLL4 expression with the clinicopathological characteristics and survival outcomes of CRC patients. Methods: DLL4 expression level was evaluated in 199 CRC samples using immunohistochemistry analysis of tissue microarrays. Results: The high expression of DLL4 was inversely associated with distant metastasis (p < 0.029), tumor recurrence (p < 0.04) and longer overall survival following curative surgery compared with those with low DLL4 expression with 95% CI (log-rank test: p = 0.050). In univariate analysis, histological grade (hazard ratio: 3.859; 95% CI: 1.081-13.784; p = 0.038) was a strong prognostic risk factor, affecting the overall survival of CRC patients. Conclusion: The authors' results demonstrate that DLL4 expression might be considered a favorable prognostic factor for overall survival in CRC patients.

Primary colonospheres maintain stem cell-like key features after cryopreservation.

The development of efficient and repeatable protocols for biobanking and prolonged storage of cancer stem cells (CSCs), with minimum alterations in biological function, is valuable and desired, particularly for retrospective analysis and clinical applications. In particular, data regarding the effect of cryopreservation on CSCs's functional features is scarce. In this regard, few studies have been shown that 3D spheroid structures, which enriched for CSCs, can keep their biological phenotype and genetic profiles. Here, for the first time, we present data on cryopreservation of CT-26 colonospheres, with the focus on essential stem cell-like properties after thawing. Tumor biopsy-derived colonospheres were frozen in standard freezing media (90% fetal bovine serum + 10% dimethyl sulfoxide) and stored in liquid nitrogen for 10 months. Then, cryopreservation effect on preservation of CSCs-related features was verified using real-time polymerase chain reaction for evaluation of stemness genes and flow cytometry for the putative colorectal CSC surface biomarkers. The self-renewal capacity of thawed spheres was also compared with their fresh counterparts using serial formation assay. Finally, tumorigenic capacity of both groups was evaluated in immunocompetence mouse model. Our data indicated that postthawed colonospheres had high viability without drastic alteration in biological and structural features and maintained self-renewal potential after sequential passages. Real-time analysis showed that both fresh and frozen colonospheres displayed similar expression pattern for key stemness genes: SOX2 and OCT4. Cryopreserved spheroids expressed CD133, CD166, and DCLK1 CSCs surface biomarkers at elevated levels when compared with parental as non-cryopreserved counterparts. Our electron scanning microscopy micrographs clearly demonstrated that postthawed colonospheres retain their integrity and cell surface morphology and characteristics. We also found that both fresh and frozen spheroids were equally tumorigenic. This study represented an effective strategy for reliable storage of intact CT-26 colonospheres; this can provide researchers with a functionally reliable repository of murine colorectal CSCs for their future CSCs projects.

Different frequencies of memory B-cells induced by tetanus, botulinum, and heat-labile toxin binding domains.

Along with robust immunogenicity, an ideal vaccine candidate should be able to produce a long lasting protection. In this regard, the frequency of memory B-cells is possibly an important factor in memory B-cell persistency and duration of immunological memory. On this basis, binding domains of tetanus toxin (HcT), botulinum type A1 toxin (HcA), and heat-labile toxin (LTB) were selected as antigen models that induced long-term, midterm and short-term immune memory, respectively. In the present study, the frequency of total memory B-cells after immunization with HcT, HcA and LTB antigens after 90 and 180 days, and also after one booster, in 190 days, was evaluated. The results showed a significant correlation between frequency of total memory B-cells and duration of humoral immunity. Compared to other antigens, the HcT antibody titers and HcT total memory B-cell populations were greater and persistent even after 6 months. At 6 months after the final immunization, all HcT- and HcA-immunized mice survived against tetanus and botulinum toxins, and also LT toxin binding to GM1 ganglioside was blocked in LTB-immunized mice. We conclude the frequency of memory B-cells and their duration are likely a key factor for vaccine memory duration.

Assessment of Treg/Th17 axis role in immunopathogenesis of chronic injuries of mustard lung disease.

PURPOSE: Sulfur mustard (SM) lung is a heterogeneous disease associated with abnormal inflammatory immune responses. The Th17/Treg axis imbalance is associated with the pathogenesis of chronic inflammatory pulmonary disease. We aimed to determine the distribution of different Th17 and Treg cells in patients with SM lung and chronic obstructive pulmonary disease (COPD) and evaluate the clinical implications in this homeostasis. METHODS: In this analytical cross-sectional study, CD4 (+) Foxp3(+ )Treg and CD4(+) IL-17(+ )Th17 cells were measured in peripheral blood mononuclear cells (PBMCs) and transbronchial biopsy (TBB) samples of 15 SM-exposed patients, 12 COPD and 13 healthy controls (HCs). The potential correlation between the ratio of Th17/Tregs and lung function was evaluated with multivariate logistic regression (MLR) analysis. RESULTS: The frequency of CD4 (+) FoxP3(+) Tregs and CD4 (+) IL-17(+) Th17 was increased ∼1.7-fold (8.71/4.95) and ∼2.7-fold (1.028/0.371) respectively, in the PBMC of SM patients compared with the health controls (p < 0.001). The results indicated that there were increases in the frequency of Th17 and Tregs cells in the patients with COPD versus the HC, that is, ∼2.6-fold (0.987/0.371) and ∼1.4-fold (7.12/4.95), respectively; but they did not reach to SM level (p ≥ 0.05). Moreover, in the TBB samples, the CD4 (+) IL-17(+ )Th17 and CD4(+) FoxP3(+ )Tregs numbers were significantly higher in SM and COPD patients than HC (p < 0.05). The Th17 and Treg cells were inversely correlated with forced expiratory volume in 1s (FEV1%) (r = -0.351, p = 0.001; r = -0.344, p = 0.021) and FEV1/FVC (r = -0.44, p = 0.001; r = -0.302, p = 0.011), respectively. Instead, positive correlations were found between Treg/Th17 ratios and forced FEV1%pred (r = 0.156, p = 0.007), as well as FEV1/FVC ratio (r = 0.334, p = 0.006). CONCLUSIONS: The imbalance of Th17/Treg has a key role in immunopathogenesis of chronic phase of mustard lung disease.

Menstrual blood-derived stromal stem cells from women with and without endometriosis reveal different phenotypic and functional characteristics.

Retrograde flow of menstrual blood cells during menstruation is considered as the dominant theory for the development of endometriosis. Moreover, current evidence suggests that endometrial-derived stem cells are key players in the pathogenesis of endometriosis. In particular, endometrial stromal stem cells have been suggested to be involved in the pathogenesis of this disease. Here, we aimed to use menstrual blood, as a novel source of endometrial stem cells, to investigate whether stromal stem cells from endometriosis (E-MenSCs) and non-endometriosis (NE-MenSCs) women differed regarding their morphology, CD marker expression pattern, proliferation, invasion and adhesion capacities and their ability to express certain immunomodulatory molecules. E-MenSCs were morphologically different from NE-MenSCs and showed higher expression of CD9, CD10 and CD29. Furthermore, E-MenSCs had higher proliferation and invasion potentials compared with NE-MenSCs. The amount of indoleamine 2,3-dioxygenase-1 (IDO1) and cyclooxygenase-2 (COX-2) in E-MenSCs co-cultured with allogenic peripheral blood mononuclear cells (PBMCs) was shown to be higher both at the gene and protein levels, and higher IDO1 activity was detected in the endometriosis group. However, NE-MenSCs revealed increased concentrations of forkhead transcription factor-3 (FOXP3) when compared with E-MenSCs. Nonetheless, interferon (IFN)-γ, Interleukin (IL)-10 and monocyte chemoattractant protein-1 (MCP-1) levels were higher in the supernatant of E-MenSCs-PBMC co-cultures. Here, we showed that there are inherent differences between E-MenSCs and NE-MenSCs. These findings propose the key role MenSCs could play in the pathogenesis of endometriosis and further support the retrograde and stem cell theories of endometriosis. Hence, considering its renewable and easily available nature, menstrual blood could be viewed as a reliable and inexpensive material for studies addressing the cellular and molecular aspects of endometriosis.

The Reconstitution of T-cells after Allogeneic Hematopoietic Stem Cell Transplant in a Pediatric Patient with Congenital Amegakaryocytic Thrombocytopenia (CAMT).

BACKGROUND: Congenital amegakaryocytic thrombocytopenia (CAMT) is a bone marrow failure syndrome with autosomal recessive inheritance characterized by the lack of megakaryocytes and thrombocytopenia. The cause of the disease is a mutation in the c-Mpl gene, which encodes the thrombopoietin (TPO) receptor. The main treatment for this genetic disorder is an allogeneic hematopoietic stem cell transplant (allo-HSCT). However, transplant-related mortality, development of acute and chronic graft-versushost disease (GvHD), and susceptibility to opportunistic infections are major barriers to transplantation. Delay in the reconstitution of T cells and imbalance in the regeneration of distinct functional CD4 and CD8 T-cell subsets mainly affect post-transplant complications. We report a case of CAMT, who developed acute GvHD but had no signs and symptoms of chronic GvHD following allo-HSCT. CASE PRESENTATION: At the age of four, she presented with petechiae and purpura. In laboratory investigations, pancytopenia without organomegaly, and cellularity less than 5% in bone marrow biopsy, were observed. A primary diagnosis of idiopathic aplastic anemia was made, and she was treated with prednisolone, cyclosporine, and anti-thymocyte globulin (ATG), which did not respond. Genetic analysis revealed the mutation c.1481T>G (p. L494W) in exon 10 of the c-Mpl gene, and the diagnosis of CAMT was confirmed. The patient underwent allo-HSCT from a healthy sibling donor. Alloimmunization reactions and immune disorders were present due to long-term treatment with immunosuppressive medications and repeated blood and platelet transfusions. Hence, the regeneration of T-lymphocytes after allo-HSCT was evaluated. CONCLUSION: Successful treatment of acute GvHD prevented advancing the condition to chronic GvHD, and this was accompanied by delayed T-cell reconstitution through an increase in Treg:Tcons ratio.

Preventive cancer stem cell-based vaccination modulates tumor development in syngeneic colon adenocarcinoma murine model.

BACKGROUND: Cancer stem cells (CSCs), a rare sub-fraction of tumor cells, with the capability of self-renewal and strong oncogenicity are tightly responsible for chemo and radio resistance and tumor metastasis in colorectal cancer. Hence, CSCs targeting would improve the efficacy of therapeutic strategies and clinical outcomes. METHODS: Here, using three-dimensional CSC spheroids and syngeneic mice model, we evaluated the cancer preventive impact of CSCs-based vaccination. CSCs enrichment was performed via colonosphere formation from CT-26 cell line and CT-26-derived tumor biopsy and characterized by confirming high expression of key stemness genes (OCT4, SOX2, and NANOG) and CSC-related surface biomarkers (CD166, DCLK1, and CD133) via real-time PCR and flow cytometry, respectively. Then, the stemness phenotype and self-renewal in CSC-enriched spheroids were further confirmed by showing serial sphere formation capacity, clonogenicity potential, and enhanced in vivo tumorigenic capacity compared to their parental counterparts. CSCs lysates were used as vaccines in prophylactic settings compared to the parental cell lysate and PBS groups. RESULT: Immunization of syngeneic mice with CSCs lysates was effective in the prevention of tumor establishment and significantly decreased tumor growth rate accompanied by an improvement in survival rate in tumor-bearing mice compared to groups subjected to parental cells lysate and PBS. These results, for the first time, showed that mice immunized with cell lysate from tumor biopsy-derived spheroids are resistant to tumor induction. Immunofluorescence staining indicated that only the serum antibodies from CSC-vaccinated mice reacted with colonospheres. CONCLUSIONS: These findings represent CSCs lysate-based vaccination as a potential approach to hampering immunotherapy failure of colorectal cancer which along with other traditional therapies may effectively apply to prevent the establishment of aggressive tumors harboring stemness features.

Unbalanced T-cell subsets in pediatric patients with beta-thalassemia.

BACKGROUND: Beta-thalassemia major is an autosomal recessive disorder in hemoglobin synthesis. Ineffective erythropoiesis is the main characteristic of the disease, which results in anemia following the extensive destruction of red blood cells. Chronic antigenic stimulation following frequent blood transfusions lead to immune abnormalities, especially regarding T cells, which is one of the reasons for the high susceptibility to infection in beta-thalassemia. METHODS: Six pediatric patients and six age- and sex-matched healthy children were selected. Immunophenotyping of functional T-cells was performed using flow cytometry with staining for surface and intracellular markers. The proliferative response of T lymphocytes was also investigated after labeling with CFSE and following stimulation with anti-CD3 and anti-CD28. RESULTS: Examination of T lymphocyte subpopulations showed a significant increase in regulatory T cells (Tregs) in beta-thalassemia patients. Hence, the Treg:Tcons (conventional T cells) and Treg:CD8 ratios were significantly increased. In addition, a significant increase in CD8 T cell proliferation activity was observed. Multivariate analysis showed a significant association of central memory cells with serum ferritin levels and the duration of transfusion. In particular, patients with cytomegalovirus (CMV) infection exhibited a significant increase in CD4 central memory cells. CONCLUSION: Patients with beta-thalassemia have functionally distinct CD4 and CD8 T cell subsets imbalances, and this may contribute to their high susceptibility to infections and immune dysregulation.

T helper 17 and regulatory T-cell profile and graft-versus-host disease after allogeneic hematopoietic stem cell transplantation in pediatric patients with beta-thalassemia.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment option for hereditary hemoglobin disorders, such as beta-thalassemia; However, this procedure is not without constraints, mainly engendering complications such as acute graft-versus-host disease (aGvHD), chronic GvHD (cGvHD), and susceptibility to infections. The clinical outcomes of allo-HSCT are highly dependant on the quality and quantity of T-cell subsets reconstitution. Following the allo-HSCT of six pediatric patients afflicted with beta-thalassemia, their mononuclear cells were isolated, and then cultured with a combination of phorbol myristate acetate (PMA)/ionomycin and Brefeldin A. The content of CD4 T-cell subsets, including T helper 17 (Th17) cells and regulatory T cells (Tregs), were determined by specific conjugated-monoclonal antibodies three and six months post-HSCT. An increased frequency of total CD4 T-cells, Tregs and Th17 cells was observed at day 90 and 180 after allo-HSCT, albeit the numbers were still lower than that of our healthy controls. In patients who developed cGvHD, a lower Th17/Treg ratio was observed, owing it to a decreased proportion of Th17 cells. In conclusion, creating balance between Th17 and Treg subsets may prevent acute and chronic GvHD in patients after allo-HSCT.

Disturbance in the reconstitution of distinct T-cell subsets and the incidence of GvHD following allo-HSCT in pediatric patients with non-malignant hematological disorders.

BACKGROUND: The reconstitution of different T-cell subsets following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is critical for efficient pathogen protection and the prevention of graft-versus-host disease (GvHD). In particular, studies have highlighted the importance of balanced ratios of regulatory T-cells (Tregs) and distinct functionally T-cells in preventing acute and chronic GvHD. METHODS: We evaluated the regeneration of CD4 and CD8 T-cell subpopulations in nine pediatric patients with non-malignant disorders following allo-HSCT from a fully HLA-identical donor. RESULTS: CD4 and CD8 T-cells were higher 12 months after the transplant but still lower than in healthy controls and pre-transplant. However, we found after allo-HSCT, central memory and effector memory cell subsets were the predominant phenotypes in the CD4 and CD8 T-cell populations, respectively. In patients who had developed acute GvHD, there was an increase in the frequency of TEMRA (effector memory T cells that re-express CD45RA) cells within the CD4 T-cell population. Meanwhile, in patients with chronic GvHD, we observed a decrease in Th1 cells in CD4 T-cells and effector memory cells within the CD8 T-cell population. In addition, we found decreased TEMRA cell subsets in CD4 and CD8 T-cell populations in chronic GvHD. CONCLUSION: Our findings suggest a possible relationship between the influence of acute GvHD and its prevention on delayed CD4 T-cell reconstitution and, reciprocally, unbalanced regeneration of CD4 and CD8 T-cell subsets in the development of chronic GvHD.

Suppressive effect of pregnant serum on murine dendritic cell function.

AIM: Tolerance to the semi-allogenic fetal graft by the maternal immune system is a medical enigma. Many aspects of immunoregulation at the feto-maternal interface have been clarified, but systemic effects of pregnancy on the immune system are still elusive. The present study was undertaken to determine whether mid-pregnancy mouse serum has an inhibitory effect on dendritic cells (DC) function. MATERIAL AND METHODS: Mid-gestational sera were obtained from allogenic pregnant Balb/c mice (Balb/c × C57BL/6) on days 9-11 of gestation. Splenic DC were purified from Balb/c mice, and treated with mid-pregnancy mouse serum. Antigen pulsed DC were injected into mice palms. After 5 days, draining lymph nodes were removed, cultured in the presence of cognate antigen, and proliferation of responding cells was measured by (3)H-thymidin incorporation. Interleukin (IL)-10 and interferon-gamma (IFN-γ) production by stimulated lymph node antigen-specific cells was also measured in culture supernatants using sandwich ELISA. RESULTS: Treatment of DC with pregnant mouse serum markedly blocked their ability to induce antigen-specific lymphocyte proliferation and IFN-γ and IL-10 production by primed lymph node cells in comparison with non-pregnant serum-treated DC. CONCLUSION: Pregnant mouse serum has an inhibitory effect on DC capacity to induce antigen-specific proliferation and cytokine secretion by lymph node cells. The suppressive effects of pregnant serum on DC could be considered as one of the mechanisms responsible for the systemic immunomodulation observed during pregnancy.

Effect of menstrual blood-derived stromal stem cells on proliferative capacity of peripheral blood mononuclear cells in allogeneic mixed lymphocyte reaction.

AIM: Menstrual blood stromal stem cells (MBSCs) have been demonstrated to exhibit stem cell properties such as the capability for self-renewal and multipotency, allowing for multilineage differentiation. In addition, this cell type has various immunomodulatory effects. In this study, we examined the potential effect of MBSCs on proliferation of peripheral blood mononuclear cells (PBMCs) in allogeneic mixed lymphocyte reaction (MLR). MATERIALS AND METHODS: Menstrual blood was collected from healthy donors after menstrual blood flow initiated and its mononuclear cell fraction was separated. Cells were subsequently cultured and adherent cells were allowed to propagate and used as stem cells. Flowcytometric immunophenotyping was performed using a panel of monoclonal antibodies including CD44, CD45, CD34, CD9, CD29, CD10, CD38, CD105, CD73, CD133, STRO-1 and Oct-4A. For functional analysis, PBMCs were co-cultured with MBSCs, collected after 4 days and added to allogeneic PBMCs. 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay was carried out to evaluate cell proliferation. RESULTS: MBSCs showed surface and intracellular markers of mesenchymal stem cells with the exception of the high expression of Oct-4A. MBSCs affected the proliferative response of PBMC in a dose-dependent manner. At ratio of 1:1 to 1:2, MBSCs inhibited, while at lower ratios (1:32 to 1:64) stimulated the proliferative capacity of allogeneic PBMCs. CONCLUSION: According to the present study, MBSCs exert their immunoregulatory effects on allogeneic PBMCs in a dose-dependent manner. This finding can be considered as a valuable point in future cell therapy strategies, when this cell population is used.

The frequencies of peripheral blood CD5+CD19+ B cells, CD3-CD16+CD56+ NK, and CD3+CD56+ NKT cells and serum interleukin-10 in patients with multiple sclerosis and neuromyelitis optica spectrum disorder.

BACKGROUND: Multiple sclerosis (MS) and neuromyelitis optica syndrome disease (NMOSD) are inflammatory diseases of the central nervous system. The pathogenesis and treatments for these two conditions are very different. Natural killer (NK) and natural killer T (NKT) cells are immune cells with an important role in shaping the immune response. B cells are involved in antigen presentation as well as antibody and cytokine production. There is conflicting evidence of the roles of NK, NKT, and B cells in the two conditions. We aimed to compare the frequency of CD3-CD16+CD56+NK, CD3+ CD56+ NKT, and CD5+CD19+ B cells in the peripheral blood and serum Interleukin-10 (IL-10) in patients with MS and NMOSD. METHODS: CD19+CD5+ B, CD3- CD16+CD56+ NK, and CD3+CD56+ NKT cells were quantitated by flow cytometry in 15 individuals with Interferon-Beta (IFN-ß) treated relapsing-remitting MS (RRMS), 15 untreated RRMS, and 15 NMOSD patients as well as 30 healthy controls (HC). Serum IL-10 was measured using an enzyme-linked immunosorbent assay (ELISA). RESULTS: The percentage of CD3-CD56+CD16+ NK cells in the peripheral blood of IFN-treated MS (1.81 ± 0.87) was significantly lower than for untreated RRMS (4.74 ± 1.80), NMOSD (4.64 ± 1.26) and HC (5.83 ± 2.19) (p < 0.0001). There were also differences for the percentage of CD3-CD16+ and CD3-CD56+ cells (p < 0.001 and p < 0.0007; respectively). IFN-treated RRMS (2.89 ± 1.51) had the lowest proportion of CD3+CD56+ among the study groups (p < 0.002). Untreated RRMS (5.56 ± 3.04) and NMOSD (5.47 ± 1.24) had higher levels of CD3+CD56+ than the HC (3.16 ± 1.98). The mean percentage of CD19+CD5+ B cells in the peripheral blood of untreated RRMS patients (1.32 ± 0.67) was higher compared to the patients with NMOSD (0.30 ± 0.20), HC (0.5 ± 0.22) and IFN-treated RRMS (0.81 ± 0.17) (p < 0.0001). Serum interleukin-10 was significantly higher in the IFN-treated RRMS (8.06 ± 5.39) and in HC (8.38 ± 2.84) compared to untreated RRMS (5.07 ± 1.44) and the patients with NMOSD (5.33 ± 2.56) (p < 0.003). CONCLUSIONS: The lower proportion of CD3-CD56+ CD16+ NK and CD3+CD56+ cells in peripheral blood of IFN-treated RRMS compared to other groups suggests the importance of immunomodulation in patients with RRMS disorder. Based on the differences in CD19+CD5+ B cells and serum IL-10 between patients and HC, supplementary assessments could be of value in clarifying their roles in autoimmunity.

2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin potential impacts on peripheral blood mononuclear cells of endometriosis women.

Endometriosis happens following the implantation of endometrial-derived tissues outside the uterine cavity. It has been suggested that 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin (TCDD) is involved in endometriosis development. Furthermore, aryl hydrocarbon receptor (AHR), as a TCDD receptor, has been demonstrated to regulate immune responses. Nonetheless, data regarding the mechanisms, through which TCDD influences the immune system in endometriosis, are still inconclusive. Therefore, frequency of regulatory T cells (Tregs) and the expression of FOXP3, AHR and indoleamine 2, 3-dioxygenase 1 (IDO1) from endometriosis and non-endometriosis individuals were investigated in the absence and presence of TCDD; also, the concentration of IL-6 and kynurenine in the supernatant of cultures was assessed. The impact of TCDD-treated PBMCs on the migration capacity of menstrual blood-derived stromal stem cells (MenSCs) and monocyte chemoattractant protein-1 (MCP-1) and IL-6 production was determined. Here, we found that AHR and IDO1 expression levels were lower in endometriosis PBMCs; however, TCDD treatment increased AHR, FOXP3, IDO1, IL-6, and Treg levels in the endometriosis group (P ≤ 0.05-0.0001). TCDD-treated PBMCs increased the migration capacity of MenSCs and up-regulated MCP-1 and IL-6 levels in the PBMCs/MenSCs co-culture (P ≤ 0.01-0.0001). In conclusion, these results shed light on the probable mechanisms, through which AHR activation by chemical toxicants can impact inflammatory immune mediators involved in the development of endometriosis; also, these data support the idea that TCDD could promote endometriosis progression.

Evaluation of the immunomodulatory effect of the 14 kDa protein isolated from aged garlic extract on dendritic cells.

Garlic is used all over the world for treatment of different diseases. A wide range of biological activities of garlic has been verified in vitro and in vivo. One of major proteins of garlic which has been isolated and purified is the 14 kDa protein. This protein has been shown to have immunomodulatory effects. In this study, the effect of the 14 kDa protein isolated from aged garlic extract (AGE) was investigated on maturation and immunomodulatory activity of dendritic cells (DC). Proteins were purified from AGE by biochemical method; the semi-purified 14 kDa protein was run on gel filtration Sephadex G50 and its purity was checked by SDS-PAGE. DC were isolated from spleen of BALB/c mice by Nycodenz centrifugation and their adhesiveness to plastic dish. 14 kDa protein from AGE was added to overnight culture of DC medium and the expression percentage of CD40, CD86, and MHC-II was evaluated by flowcytometric analysis. Also, proliferation of T-cells was measured by allogenic mixed lymphocyte reaction (MLR) test. The purified 14 kDa protein isolated from AGE increased the expression of CD40 molecule on DC, but it did not influence CD86 and MHCII molecules. Furthermore, no significant differences were noticed in the pulsed-DC with 14 kDa protein and non-pulsed DC on the MLR.

Culture density of menstrual blood-derived stromal/stem cells determines the quality of T cell responses: An experimental study.

BACKGROUND: Menstrual blood-derived stromal/stem cells (MenSCs) are a new population of refreshing and highly proliferative stem cells. Immunomodulatory effects of MenSCs profoundly depend on their relative density. OBJECTIVE: To find whether MenSCs cultured at varying numbers would differentially affect the allogenic peripheral blood mononuclear cells (PBMCs) key features. MATERIALS AND METHODS: PBMCs were co-cultured with various MenSCs numbers. PBMCs proliferation was investigated via 3 H-thymidine incorporation. Flow cytometry was used to assess human leukocyte antigen (HLA)-DR, HLA-ABC, HLA-G, and co-stimulatory markers on MenSCs and the percentage of regulatory T cells (Tregs) among PBMCs. The concentration of cytokines was determined in supernatant of co-cultures. RESULTS: The support of PBMCs proliferation at low MenSCs densities correlated with higher levels of pro-inflammatory interferon gamma (IFN-γ) in MenSCs/PBMCs co-culture and increased expression of HLA-DR by MenSCs. On the other hand, the suppressive property of MenSCs at higher densities was independent of Treg frequency, but correlated with a high concentration of Interleukin (IL)-6 and IL-10 in the co-cultures. CONCLUSION: Totally, at different seeding densities, MenSCs could differentially interact with PBMCs leading to significant changes in the level of anti- and/or pro-inflammatory factors. These preliminary in vitro results are suggested to be taken into consideration in experimental models of MenSC-based immunomodulation. Nonetheless, for efficient utilization of MenSCs anti-inflammatory features in pre-clinical disease models, we still need to broaden our knowledge on MenSC-immune system cross-talk; this could play a part in designing more optimized MenSCs injection modalities in the case of future pre-clinical and subsequently clinical settings.

Endometrial mesenchymal stem/stromal cells: The Enigma to code messages for generation of functionally active regulatory T cells.

BACKGROUND: Regulatory T cells (Tregs) play an important role in fine-tuning of immune responses and are pivotal for a successful pregnancy. Recently, the importance of mesenchymal stem cells in regulation of immune responses in general and Tregs in particular has been highlighted. Here, we hypothesized that menstrual stromal/stem cells (MenSCs) contribute to uterine immune system regulation through induction of functionally active Tregs. METHODS: MenSCs were collected from 18 apparently healthy women and characterized. Bone marrow mesenchymal stem cells (BMSCs) served as a control. The effect of MenSCs on proliferation of anti-CD3/CD28-stimulated T CD4 + cells and generation of Tregs with or without pre-treatment with mitomycin C, IFN-γ and IL-1ß was evaluated by flow cytometry. The potential role of IDO, PGE2, IL-6, IL-10, and TGF-ß on proliferation of T CD4 + cells and generation of Tregs was assessed using blocking antibodies or agents. IDO activity was evaluated in MenSCs and BMSCs culture supernatants by a colorimetric assay. IL-10 and IFN-γ production in MenSCs-primed T CD4 + was measured using intracellular staining. To investigate the functional properties of Tregs induced by MenSCs, Treg cells were isolated and their functional property to inhibit proliferation of anti-CD3/CD28-stimulated PBMCs was assessed by flow cytometry. RESULTS: According to the results, proliferation of T CD4 + lymphocytes was enhanced in the presence of MenSCs, while pre-treatment of MenSCs with pro-inflammatory cytokines reversed this effect. PGE2 and IDO were the major players in MenSCs-induced T cell proliferation. Non-treated MenSCs decreased the frequency of Tregs, whereas after pre-treatment with IFN-γ and IL-1ß, they induced functional Tregs with ability to inhibit the proliferation of anti-CD3/CD28-stimulated PBMCs. This effect was mediated through IL-6, IL-10, TGF-ß and IDO. IFN-γ/IL-1ß-treated MenSCs induced IL-10 and IFN-γ production in CD4 + T cells. CONCLUSION: Collectively, these findings indicate that immunomodulatory impact of menstrual blood stem cells (MenSCs) on generation of Tregs and inhibition of T cells proliferation is largely dependent on pre-treatment with IFN-γ and IL-1ß. This is the first report on immunomodulatory impact of MenSCs on Tregs and highlights the pivotal role of endometrial stem cells in regulation of local endometrial immune responses.