IFN-γ-Preconditioned Human Gingival-Derived Mesenchymal Stromal Cells Inhibit Plasmacytoid Dendritic Cells via Adenosine.

Plasmacytoid dendritic cells (pDCs) are vital players in antiviral immune responses because of their high levels of IFN-α secretion. However, this attribute has also implicated them as critical factors behind the immunopathogenesis of inflammatory diseases, and no currently available therapy can efficiently inhibit pDCs' aberrant activation. Mesenchymal stromal cells (MSCs) possess stromal immunomodulatory functionality, regulating immune cell activation through several mechanisms, including the adenosinergic (CD39/CD73/adenosine) pathway. The IFN-γ preconditioning of bone marrow MSCs improves their inhibitory properties for therapy applications; however, isolating human gingival tissue-derived MSCs (hGMSCs) is more accessible. These cells have shown better immunomodulatory effects, yet the outcome of IFN-γ preconditioning and its impact on the adenosinergic pathway has not been evaluated. This study first validated the immunoregulatory properties of primary-cultured hGMSCs, and the results showed that IFN-γ preconditioning strengthens CD39/CD73 coexpression, adenosine production, and the regulatory properties of hGMSC, which were confirmed by describing for the first time their ability to reduce pDC activation and their IFN-α secretion and to increase the frequency of CD73+ pDC. In addition, when CD73's enzymatic activity was neutralized in hGMSCs, adenosine production and the IFN-γ preconditioning effect were restrained. This evidence might be applied to design hGMSCs- and adenosine-based immunotherapeutic strategies for treating inflammatory disorders that are associated with pDC overactivation.

Epidemiology of childhood acute leukemias in marginalized populations of the central-south region of Mexico: results from a population-based registry.

Introduction: Acute leukemias (AL) are the main types of cancer in children worldwide. In Mexico, they represent one of the main causes of death in children under 20 years of age. Most of the studies on the incidence of AL in Mexico have been developed in the urban context of Greater Mexico City and no previous studies have been conducted in the central-south of the country through a population-based study. The aim of the present work was to identify the general and specific incidence rates of pediatric AL in three states of the south-central region of Mexico considered as some of the marginalized populations of Mexico (Puebla, Tlaxcala, and Oaxaca). Methods: A population-based study was conducted. Children aged less than 20 years, resident in these states, and newly diagnosed with AL in public/private hospitals during the period 2021-2022 were identified. Crude incidence rates (cIR), standardized incidence rates (ASIRw), and incidence rates by state subregions (ASIRsr) were calculated. Rates were calculated using the direct and indirect method and reported per million children under 20 years of age. In addition, specific rates were calculated by age group, sex, leukemia subtype, and immunophenotype. Results: A total of 388 cases with AL were registered. In the three states, the ASIRw for AL was 51.5 cases per million (0-14 years); in Puebla, it was 53.2, Tlaxcala 54.7, and Oaxaca de 47.7. In the age group between 0-19 years, the ASIRw were 44.3, 46.4, 48.2, and 49.6, in Puebla, Tlaxcala, and Oaxaca, respectively. B-cell acute lymphoblastic leukemia was the most common subtype across the three states. Conclusion: The incidence of childhood AL in the central-south region of Mexico is within the range of rates reported in other populations of Latin American origin. Two incidence peaks were identified for lymphoblastic and myeloid leukemias. In addition, differences in the incidence of the disease were observed among state subregions which could be attributed to social factors linked to the ethnic origin of the inhabitants. Nonetheless, this hypothesis requires further investigation.

Low Prevalence of ETV6::RUNX1 Fusion Gene in a Hispanic Population.

ETV6::RUNX1 is a genetic rearrangement of good prognosis in children with acute lymphoblastic leukemia (ALL). In Mexico, its prevalence is low in comparison with Caucasian populations. We developed a novel TaqMan one-step RT-qPCR approach to assess the prevalence of four genetic rearrangements in a cohort of Hispanic children with ALL from Mexico City. The prevalence of common fusion gene transcripts was as follows: TCF3::PBX1 7.7%; BCR::ABL1p 190 3.3%; and KMT2A::AFF1 2.8%, and ETV6::RUNX1was observed with low prevalence (10.5%) in comparison to that reported for developed countries. This is consistent with previous findings on Mexican children with ALL and similar to those reported on children from Hispanic populations. The confirmation of a low prevalence of ETV6::RUNX1 in children of a Hispanic origin represents an advancement in the description of genetic factors of ALL in these populations.

miRNAs Contained in Extracellular Vesicles Cargo Contribute to the Progression of Idiopathic Pulmonary Fibrosis: An In Vitro Aproach.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease. Lesions in the lung epithelium cause alterations in the microenvironment that promote fibroblast accumulation. Extracellular vesicles (EVs) transport proteins, lipids, and nucleic acids, such as microRNAs (miRNAs). The aim of this study was to characterize the differentially expressed miRNAs in the cargo of EVs obtained from the LL97 and LL29 fibroblast cell lines isolated from IPF lungs versus those derived from the CCD19 fibroblast cell line isolated from a healthy donors. We characterized EVs by ultracentrifugation, Western blotting, and dynamic light scattering. We identified miRNAs by small RNA-seq, a total of 1144 miRNAs, of which 1027 were known miRNAs; interestingly, 117 miRNAs were novel. Differential expression analysis showed that 77 miRNAs were upregulated and 68 were downregulated. In addition, pathway enrichment analyses from the Gene Ontology and Kyoto Encyclopedia of Genomes identified several miRNA target genes in the categories, cell proliferation, regulation of apoptosis, pathways in cancer, and proteoglycans in cancer. Our data reveal that miRNAs contained in EVs cargo could be helpful as biomarkers for fibrogenesis, diagnosis, and therapeutic intervention of IPF.

Silent red blood cell autoantibodies: Are they naturally occurring or an effect of tolerance loss for a subsequent autoimmune process?

Unexpected anti-red blood cell (RBC) alloantibodies are routinely investigated in immunohematology and blood banking since their existence in pregnant women may induce haemolytic disease of the foetus and newborn, and their presence in donors may induce haemolytic transfusion reactions or hyperacute rejection in solid organ transplantation. Unexpected anti-RBC alloantibodies may target antigens of the most blood types excluding the expected antibodies targeting the ABO antigens. Their incidence in humans was originally linked to alloimmunization events such as blood transfusions, transplants, or pregnancies. But later, many findings revealed their existence in pathogenic processes such as malignancies, infections, and autoimmune diseases; and usually (but not always) associated to autoimmune haemolytic anaemia (AIHA). Nevertheless, unexpected anti-RBC autoantibodies are also occasionally found in healthy individuals in the absence of AIHA and with no history of alloimmunization or the associated pathologic processes. Hence, they are generally known as non-clinically significant, are excluded for typification and called "silent red blood cell autoantibodies (SRBCAA)". This review highlights evidence related to genetic predisposition, molecular mimicry, immune dysregulation, and immune tolerance loss surrounding the existence of anti-RBC antibodies, describing the presence of SRBCAA as possible early witnesses of the development of autoimmune diseases.

Human platelets and megakaryocytes express defensin alpha 1.

Platelets are anucleate cells that have a role in several innate immune functions, including the secretion of proteins with antimicrobial activity. Several studies have demonstrated the ability of platelets to secrete thrombin-induced platelet microbicidal proteins and antimicrobial peptides, like hBD-1. However, the expression and secretion of defensins of the alpha family by platelets have not been fully elucidated. The aim of this study was to characterize the expression of defensin alpha 1 (DEFA1) in human platelets and megakaryocytes. Our data indicate that DEFA1 mRNA and protein are present in peripheral blood platelets and in the megakaryoblastic leukemia cell line (MEG-01). DEFA1 co-localize with α-granules of platelets and MEG-01 cells, and was also detected in cytoplasm of MEG-01 cells. The assay of our in vitro model of platelet-like particles (PLPs) revealed that MEG-01 cells could transfer DEFA1 mRNA to their differentiated PLPs. Furthermore, platelets secreted DEFA1 into the culture medium when activated with thrombin, adenosine diphosphate, and lipopolysaccharide; meanwhile, MEG-01 cells secreted DEFA1 when activated with thrombopoietin. Platelet's secreted DEFA1 can rebind to platelet's surface and have antibacterial activity against the gram-negative bacteria Escherichia coli. In summary, our data indicate that both, human platelets and megakaryocytes, can express and secrete DEFA1. These results suggest a new role of platelets and megakaryocytes in the innate immune response.

Presence of HPV DNA in extracellular vesicles from HeLa cells and cervical samples.

INTRODUCTION: The main cause of cervical cancer is an infection of keratinocytes in the basal layer of the stratified epithelium of the cervix by human papillomavirus (HPV). Other than in cervical samples, HPV DNA has been found in serum and other fluids but its origin is unclear. Extracellular vesicles (EV) could be a conveyance of viral DNA given their emerging role in cellular communication. The content of EV derived from cervical cells has not been properly explored and it is not known whether or not they contain HPV DNA. METHODS: We evaluated the DNA content of exosomes purified from cultures of HeLa cells by Next Generation Sequencing (NGS) and confirmed its presence by PCR. The presence of HPV DNA was also evaluated by PCR and NGS in EV from HPV-positive cervical samples without apparent lesion or with LSIL. RESULTS: We detected the integrated form of viral-DNA in exosomes from HeLa cells by NGS and confirmed its presence by PCR. The search for HPV sequences in EV obtained from cervical exudate samples without apparent lesion or with LSIL, where we expected to find the viral genome as an episome, indicated that HPV DNA, including the E6 and E7 oncogenes, is present in these EV. CONCLUSION: HPV DNA, including the viral oncogenes E6/E7, is found in exosomes regardless of the integration status of the virus in the infected cell.

Quercetin Reverses Rat Liver Preneoplastic Lesions Induced by Chemical Carcinogenesis.

Quercetin is a flavonoid widely studied as a chemopreventive agent in different types of cancer. Previously, we reported that quercetin has a chemopreventive effect on the liver-induced preneoplastic lesions in rats. Here, we evaluated if quercetin was able not only to prevent but also to reverse rat liver preneoplastic lesions. We used the modified resistant hepatocyte model (MRHM) to evaluate this possibility. Treatment with quercetin was used 15 days after the induction of preneoplastic lesions. We found that quercetin reverses the number of preneoplastic lesions and their areas. Our results showed that quercetin downregulates the expression of EGFR and modulates this signaling pathway in spite of the activated status of EGFR as detected by the upregulation of this receptor, with respect to that observed in control rats. Besides, quercetin affects the phosphorylation status of Src-1, STAT5, and Sp-1. The better status of the liver after the treatment with quercetin could also be confirmed by the recovery in the expression of IGF-1. In conclusion, we suggest that quercetin reversed preneoplastic lesions by EGFR modulation and the activation state of Src, STAT5, and Sp1, so as the basal IGF-1.