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In CD38-deficient (Cd38-/-) mice intraperitoneal injection of pristane induces a lupus-like disease, which is milder than that induced in WT mice, showing significant differences in the inflammatory and autoimmune processes triggered by pristane. Extracellular vesicles (EV) are present in all body fluids. Shed by cells, their molecular make-up reflects that of their cell of origin and/or tissue pathological situation. The aim of this study was to analyze the protein composition, protein abundance, and functional clustering of EV released by peritoneal exudate cells (PECs) in the pristane experimental lupus model, to identify predictive or diagnostic biomarkers that might discriminate the autoimmune process in lupus from inflammatory reactions and/or normal physiological processes. In this study, thanks to an extensive proteomic analysis and powerful bioinformatics software, distinct EV subtypes were identified in the peritoneal exudates of pristane-treated mice: 1) small EV enriched in the tetraspanin CD63 and CD9, which are likely of exosomal origin; 2) small EV enriched in CD47 and CD9, which are also enriched in plasma-membrane, membrane-associated proteins, with an ectosomal origin; 3) small EV enriched in keratins, ECM proteins, complement/coagulation proteins, fibrin clot formation proteins, and endopetidase inhibitor proteins. This enrichment may have an inflammation-mediated mesothelial-tomesenchymal transition origin, representing a protein corona on the surface of peritoneal exudate EV; 4) HDL-enriched lipoprotein particles. Quantitative proteomic analysis allowed us to identify an anti-inflammatory, Annexin A1- enriched pro-resolving, neutrophil protein signature, which was more prominent in EV from pristane-treated Cd38-/- mice, and quantitative differences in the protein cargo of the ECM-enriched EV from Cd38-/- vs WT mice. These differences are likely to be related with the distinct inflammatory outcome shown by Cd38-/- vs WT mice in response to pristane treatment. Our results demonstrate the power of a hypothesis-free and data-driven approach to transform the heterogeneity of the peritoneal exudate EV from pristanetreated mice in valuable information about the relative proportion of different EV in a given sample and to identify potential protein markers specific for the different small EV subtypes, in particular those proteins defining EV involved in the resolution phase of chronic inflammation., Proyecto del plan estatal, Ministerio de Ciencia e Innovacion PT13/0001/011, CSIC PT17/0019/0010 PID2020-119567RB-I00

© 2021 Martínez-Blanco, Domínguez-Pantoja, Botía-Sánchez, Pérez-Cabrera, Bello-Iglesias, Carrillo-Rodríguez, Martin-Morales, Lario-Simón, Pérez-Sánchez-Cañete, Montosa-Hidalgo, Guerrero-Fernández, Longobardo-Polanco, Redondo-Sánchez, Cornet-Gomez, Torres-Sáez, Fernández-Ibáñez, Terrón-Camero, Andrés-León, O’Valle, Merino, Zubiaur and Sancho., The absence of the mouse cell surface receptor CD38 in Cd38−/− mice suggests that this receptor acts as a positive regulator of inflammatory and autoimmune responses. Here, we report that, in the context of the chronic graft-versus-host disease (cGVHD) lupus inducible model, the transfer of B6.C-H2bm12/KhEg(bm12) spleen cells into co-isogenic Cd38−/− B6 mice causes milder lupus-like autoimmunity with lower levels of anti-ssDNA autoantibodies than the transfer of bm12 spleen cells into WT B6 mice. In addition, significantly lower percentages of Tfh cells, as well as GC B cells, plasma cells, and T-bet+CD11chi B cells, were observed in Cd38−/− mice than in WT mice, while the expansion of Treg cells and Tfr cells was normal, suggesting that the ability of Cd38−/− B cells to respond to allogeneic help from bm12 CD4+ T cells is greatly diminished. The frequencies of T-bet+CD11chi B cells, which are considered the precursors of the autoantibody-secreting cells, correlate with anti-ssDNA autoantibody serum levels, IL-27, and sCD40L. Proteomics profiling of the spleens from WT cGVHD mice reflects a STAT1-driven type I IFN signature, which is absent in Cd38−/− cGVHD mice. Kidney, spleen, and liver inflammation was mild and resolved faster in Cd38−/− cGVHD mice than in WT cGVHD mice. We conclude that CD38 in B cells functions as a modulator receptor that controls autoimmune responses., S and MZ received financial support through “Proyecto del Plan Estatal”: SAF2017–89801-R. The IPBLN-CSIC Proteomics Unit belonged to ProteoRed-ISCIII (PRB2; PRB3) and was supported by grants PT13/0001/0011 (IPBLN-CSIC) and PT17/0019/0010 (CIB-CSIC; IPBLN-CSIC). RM: Project: SAF2017-82905-R. FO'V: Cátedra MIS IMPLANT-UGR. The stay of AC-G in Sancho’s lab was supported by a fellowship-contract JAE-Intro (CSIC). The stay of MD-P in Sancho’s lab was supported by a 1-year post-doctoral fellowship (Reference No. 502492) from the Consejo Nacional de Ciencia y Tecnología (CONACYT) of México. EA-L was recipient of a postdoctoral fellowship from the regional Andalusian Government.

Which sex has a more determinant role in reproductive performance? This is a long standing question in evolutionary ecology. Theory predicts and several pieces of evidence have indicated that females are more determinant than males. However, a direct test of this hypothesis has never been made. Here we perform such a direct test by using an alternative analytical approach, controlling for age and/or individual experience, and a captive population of the house sparrow Passer domesticus, a monogamous bi‐parental dimorphic species in which both sexes contribute with approximately equal amounts of parental care. In this species, it has been demonstrated that contribution by males to offspring parental care is crucial to maximize reproductive success. Captive conditions with absence of predators and availability of food ad libitum allow us to control several important factors that may affect reproductive performance, such as environmental fluctuations in resource availability and differences in territory quality, without affecting reproductive performance. We consider four types of pairs, and our main prediction derived from the hypothesis is that mixed pairs involving an experienced female (FBM × EF) should present better reproductive performance than mixed pairs involving a first‐time breeder female (EM × FBF). Our results confirm the general pattern reported in other bird species that older or more experienced individuals enjoy a higher reproductive success than first‐time breeders. In addition, in agreement with our main prediction, we found that FBM × EF produced significantly more fledglings and had higher fledging success than EM × FBF. Our results, for the first time demonstrate the broadly accepted statement that females have a more determinant role than males in reproductive performance.