Human Bone Marrow Mesenchymal Stem Cells Promote the M2 Phenotype in Macrophages Derived from STEMI Patients.

Acute ST-elevation myocardial infarction (STEMI) leads to myocardial injury or necrosis, and M1 macrophages play an important role in the inflammatory response. Bone marrow mesenchymal stem/stromal cells (BM-MSCs) are capable of modulating macrophage plasticity, principally due to their immunoregulatory capacity. In the present study, we analyzed the capacity of MSCs to modulate macrophages derived from monocytes from patients with STEMI. We analyzed the circulating levels of cytokines associated with M1 and M2 macrophages in patients with STEMI, and the levels of cytokines associated with M1 macrophages were significantly higher in patients with STEMI than in controls. BM-MSCs facilitate the generation of M1 and M2 macrophages. M1 macrophages cocultured with MSCs did not have decreased M1 marker expression, but these macrophages had an increased expression of markers of the M2 macrophage phenotype (CD14, CD163 and CD206) and IL-10 and IL-1Ra signaling-induced regulatory T cells (Tregs). M2 macrophages from patients with STEMI had an increased expression of M2 phenotypic markers in coculture with BM-MSCs, as well as an increased secretion of anti-inflammatory cytokines and an increased generation of Tregs. The findings in this study indicate that BM-MSCs have the ability to modulate the M1 macrophage response, which could improve cardiac tissue damage in patients with STEMI.

Mesenchymal Stem/Stromal Cells Derived from Cervical Cancer Promote M2 Macrophage Polarization.

Macrophages with the M2 phenotype promote tumor development through the immunosuppression of antitumor immunity. We previously demonstrated the presence of mesenchymal stem/stromal cells (MSCs) in cervical cancer (CeCa-MSCs), suggesting an immune protective capacity in tumors, but to date, their effect in modulating macrophage polarization remains unknown. In this study, we compared the capacities of MSCs from normal cervix (NCx) and CeCa to promote M2 macrophage polarization in a coculture system. Our results demonstrated that CeCa-MSCs, in contrast to NCx-MSCs, significantly decreased M1 macrophage cell surface marker expression (HLA-DR, CD80, CD86) and increased M2 macrophage expression (CD14, CD163, CD206, Arg1) in cytokine-induced CD14+ monocytes toward M1- or M2-polarized macrophages. Interestingly, compared with NCx-MSCs, in M2 macrophages generated from CeCa-MSC cocultures, we observed an increase in the percentage of phagocytic cells, in the intracellular production of IL-10 and IDO, the capacity to decrease T cell proliferation and for the generation of CD4+CD25+FoxP3+ Tregs. Importantly, this capacity to promote M2 macrophage polarization was correlated with the intracellular expression of macrophage colony-stimulating factor (M-CSF) and upregulation of IL-10 in CeCa-MSCs. Furthermore, the presence of M2 macrophages was correlated with the increased production of IL-10 and IL-1RA anti-inflammatory molecules. Our in vitro results indicate that CeCa-MSCs, in contrast to NCx-MSCs, display an increased M2-macrophage polarization potential and suggest a role of CeCa-MSCs in antitumor immunity.

Altered Vaginal Microbiota Composition Correlates With Human Papillomavirus and Mucosal Immune Responses in Women With Symptomatic Cervical Ectopy.

Cervical ectopy is a benign condition of the lower genital tract that is frequently detected in women of reproductive age. Although cervical ectopy is regarded as a physiological condition, some women experience symptoms such as leucorrhoea, persistent bleeding and recurrent vaginal infections that require medical intervention. Cervical ectopy has not been linked to cervical cancer, but it is thought to facilitate the acquisition of sexually transmitted diseases (STDs), like Human Papillomavirus (HPV) infection, as it provides a favorable microenvironment for virus infection and dissemination. We and others have described the presence of oncogenic HPV types in women with symptomatic cervical ectopy. The relevance of this finding and the impact of symptomatic cervical ectopy on the cervicovaginal microenvironment (vaginal microbiota, immune and inflammatory responses) are currently unknown. To shed some light into the interplay between HPV, the vaginal microbiota and mucosal immune and inflammatory responses in the context of this condition, we enrolled 156 women with symptomatic cervical ectopy and determined the presence of HPV using a type-specific multiplex genotyping assay. Overall, HPV was detected in 54.48% women, oncogenic HPV types were found in more than 90% of HPV-positive cases. The most prevalent HPV types were HPV16 (29.4%), HPV31 (21.17%) and HPV18 (15.29%). Next, we evaluated the vaginal microbial composition and diversity by 16S rDNA sequencing, and quantified levels of cytokines and chemokines by flow cytometry using bead-based multiplex assays in a sub-cohort of 63 women. IL-21 and CXCL9 were significantly upregulated in HPV-positive women (p=0.0002 and p=0.013, respectively). Women with symptomatic cervical ectopy and HPV infection had increased diversity (p<0.001), and their vaginal microbiota was enriched in bacterial vaginosis-associated anaerobes (Sneathia, Shuttleworthia, Prevotella, and Atopobium) and depleted in Lactobacillus spp. Furthermore, the vaginal microbiota of women with symptomatic cervical ectopy and HPV infection correlated with vaginal inflammation (IL-1ß, rho=0.56, p=0.0004) and increased mucosal homeostatic response (IL-22, rho=0.60, p=0.0001). Taken together, our results suggest that HPV infection and dysbiotic vaginal communities could favor a vaginal microenvironment that might delay the recovery of the cervical epithelium in women with symptomatic cervical ectopy and favor STDs acquisition.

Biological Landscape of Triple Negative Breast Cancers Expressing CTLA-4.

Patients with triple-negative breast cancer (TNBC) have a poor prognosis, partly because of the absence of targeted therapies. Recognition of the key role of immune responses against cancer has allowed the advent of immunotherapy, focused on the inhibition of negative immune checkpoints, such as CTLA-4. CTLA-4 is also expressed in some cancer cells, but its activity in tumor cells is not completely understood. Thus, the aim of the present work was to determine the biological landscape and functions of CTLA-4 expressed in TNBC cells through preclinical and in silico analysis. Exploration of CTLA-4 by immunohistochemistry in 50 TNBC tumors revealed membrane and cytoplasmic expression at different intensities. Preclinical experiments, using TNBC cell lines, showed that stimulation of CTLA-4 with CD80 enhances activation of the ERK1/2 signaling pathway, while CTLA-4 blockade by Ipilimumab induces the activation of AKT and reduces cell proliferation in vitro. We then developed an analytic pipeline to define the effects of CTLA-4 in available public data that allowed us to identify four distinct tumor clusters associated with CTLA-4 activation, which are characterized by enrichment of distinctive pathways associated with cell adhesion, MAPK signaling, TGF-ß, VEGF, TNF-α, drug metabolism, ion and amino acid transport, and KRAS signaling, among others. In addition, blockade of CTLA-4 induced increased secretion of IL-2 by tumor cells, suggesting that the receptor regulates cellular functions that may impact the immune microenvironment. This is relevant because a deep characterization of immune infiltrate, conducted using public data to estimate the abundancies of immune-cell types, showed that CTLA-4-activated-like tumors present a conditional immune state similar to an escape phenotype exploited by cancer cells. Finally, by interrogating transcriptional predictors of immunotherapy response, we defined that CTLA-4 activation correlates with high immune scores related to good clinical predicted responses to anti-CTLA-4 therapy. This work sheds new light on the roles of activated CLTA-4 in the tumor compartment and suggests an important interplay between tumor CLTA-4-activated portraits and immune-infiltrating cell populations.

Mesenchymal Stem/Stromal Cells Derived from Dental Tissues: A Comparative In Vitro Evaluation of Their Immunoregulatory Properties Against T cells.

Bone marrow mesenchymal stem/stromal cells (BM-MSCs) have immunoregulatory properties and have been used as immune regulators for the treatment of graft-versus-host disease (GVHD). Human dental tissue mesenchymal stem cells (DT-MSCs) constitute an attractive alternative to BM-MSCs for potential clinical applications because of their accessibility and easy preparation. The aim of this in vitro study was to compare MSCs from dental pulp (DP-MSCs), gingival tissue (G-MSCs), and periodontal ligament (PDL-MSCs) in terms of their immunosuppressive properties against lymphoid cell populations enriched for CD3+ T cells to determine which MSCs would be the most appropriate for in vivo immunoregulatory applications. BM-MSCs were included as the gold standard. Our results demonstrated, in vitro, that MSCs from DP, G, and PDL showed immunoregulatory properties similar to those from BM, in terms of the cellular proliferation inhibition of both CD4+- and CD8+-activated T-cells. This reduced proliferation in cell co-cultures correlated with the production of interferon-γ and tumor necrosis factor alpha (TNF-α) and the upregulation of programmed death ligand 1 (PD-L1) in MSCs and cytotoxic T-cell-associated Ag-4 (CTLA-4) in T-cells and increased interleukin-10 and prostaglandin E2 production. Interestingly, we observed differences in the production of cytokines and surface and secreted molecules that may participate in T-cell immunosuppression in co-cultures in the presence of DT-MSCs compared with BM-MSCs. Importantly, MSCs from four sources favored the generation of T-cell subsets displaying the regulatory phenotypes CD4+CD25+Foxp3+ and CD4+CD25+CTLA-4+. Our results in vitro indicate that, in addition to BM-MSCs, MSCs from all of the dental sources analyzed in this study might be candidates for future therapeutic applications.