Nkx2-5+Islet1+ Mesenchymal Precursors Generate Distinct Spleen Stromal Cell Subsets and Participate in Restoring Stromal Network Integrity

SummarySecondary lymphoid organ stromal cells comprise different subsets whose origins remain unknown. Herein, we exploit a genetic lineage-tracing approach to show that splenic fibroblastic reticular cells (FRCs), follicular dendritic cells (FDCs), marginal reticular cells (MRCs), and mural cells, but not endothelial cells, originate from embryonic mesenchymal progenitors of the Nkx2-5+Islet1+ lineage. This lineage include embryonic mesenchymal cells with lymphoid tissue organizer (LTo) activity capable also of supporting ectopic lymphoid-like structures and a subset of resident spleen stromal cells that proliferate and regenerate the splenic stromal microenvironment following resolution of a viral infection. These findings identify progenitor cells that generate stromal diversity in spleen development and repair and suggest the existence of multipotent stromal progenitors in the adult spleen with regenerative capacity

Genetic diversity among viruses associated with sugarcane mosaic disease in Tucumán, Argentina

Sugarcane leaves with mosaic symptoms were collected in 2006--07 in Tucumán (Argentina) and analyzed by reverse-transcriptase polymerase chain reaction (RT-PCR) restriction fragment length polymorphism (RFLP) and sequencing of a fragment of the Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV) coat protein (CP) genes. SCMV was detected in 96.6% of samples, with 41% showing the RFLP profile consistent with strain E. The remaining samples produced eight different profiles that did not match other known strains. SCMV distribution seemed to be more related to sugarcane genotype than to geographical origin, and sequence analyses of CP genes showed a greater genetic diversity compared with other studies. SrMV was detected in 63.2% of samples and most of these were also infected by SCMV, indicating that, unlike other countries and other Argentinean provinces, where high levels of co-infection are infrequent, co-existence is common in Tucumán. RFLP analysis showed the presence of SrMV strains M (68%) and I (14%), while co-infection between M and H strains was present in 18% of samples. Other SCMV subgroup members and the Sugarcane streak mosaic virus (SCSMV) were not detected. Our results also showed that sequencing is currently the only reliable method to assess SCMV and SrMV genetic diversity, because RT-PCR-RFLP may not be sufficiently discriminating.Instituto de Biotecnologia y Biologia Molecula

ZIGOMICOSI SISTEMICA IN UNA MACACA FASCICULARIS XENOTRAPIANTATA DI RENE

Una Macaca fascicularis, sottoposta a nefrectomia bilaterale, ha ricevuto un trapianto di rene da suino transgenico. 15 giorni dopo il trapianto, il primate ha evidenziato un quadro clinico compatibile con insufficienza renale: edema generalizzato con incremento del 20% del peso e aumento dei parametri ematici di funzionalit\ue0 renale, associati a marcata neutrofilia. 19 giorni post-trapianto, l\u2019animale \ue8 stato sottoposto a eutanasia per insufficienza renale e deterioramento delle condizioni generali. L\u2019esame necroscopico ha evidenziato, oltre a rigetto d\u2019organo, edema sottocutaneo diffuso, materiale purulento in corrispondenza della ferita chirurgica, effusione emorragica addominale, aree puntiformi biancastre su fegato, peritoneo, pancreas e sierosa intestinale e linfadenopatia meseraica. L\u2019esame istologico della ferita chirurgica ha evidenziato pannicolite e miosite, piogranulomatose e settiche, focalmente estese, con estesa steatonecrosi, trombosi e reazione da corpo estraneo (filo di sutura) con funghi intralesionali e intravascolari. L\u2019esame istologico della cavit\ue0 addominale ha evidenziato peritonite e sierosite intestinale, purulente con trombosi, funghi intralesionali e invasione vascolare e linfonodale; peritonite granulomatosa, con reazione da corpo estraneo (filo di sutura); pancreatite, purulenta e necrotizzante, con funghi intralesionali ed emboli fungini. In base alle caratteristiche morfologiche, la diagnosi eziologica \ue8 di zigomicosi cutanea, sistemica ed embolica. La zigomicosi nell\u2019uomo si osserva in soggetti immunocompromessi, con recente aumentata incidenza tra i riceventi di trapianto d\u2019organo. Nell\u2019animale la via d\u2019ingresso \ue8 in genere attraverso una ferita cutanea. La malattia non \ue8 contagiosa e l\u2019ambiente \ue8 la fonte d\u2019infezione. Il reperto pi\uf9 caratteristico \ue8 l\u2019invasione dei vasi ematici, del tessuto perineurale e gli infarti tissutali che determinano una malattia sistemica. Esiste solo un caso descritto di zigomicosi sistemica in Macaca fascicularis, mentre la forma cutanea \ue8 stata descritta in altri primati

Extracellular Vesicles in Veterinary Medicine

Extracellular vesicles (EVs) are cell-derived membrane-bound vesicles involved in many physiological and pathological processes not only in humans but also in all the organisms of the eukaryotic and prokaryotic kingdoms. EV shedding constitutes a fundamental universal mechanism of intra-kingdom and inter-kingdom intercellular communication. A tremendous increase of interest in EVs has therefore grown in the last decades, mainly in humans, but progressively also in animals, parasites, and bacteria. With the present review, we aim to summarize the current status of the EV research on domestic and wild animals, analyzing the content of scientific literature, including approximately 220 papers published between 1984 and 2021. Critical aspects evidenced through the veterinarian EV literature are discussed. Then, specific subsections describe details regarding EVs in physiology and pathophysiology, as biomarkers, and in therapy and vaccines. Further, the wide area of research related to animal milk-derived EVs is also presented in brief. The numerous studies on EVs related to parasites and parasitic diseases are excluded, deserving further specific attention. The literature shows that EVs are becoming increasingly addressed in veterinary studies and standardization in protocols and procedures is mandatory, as in human research, to maximize the knowledge and the possibility to exploit these naturally produced nanoparticles

KIT somatic mutations and immunohistochemical expression in canine oral melanoma

Canine oral melanoma (COM) is an aggressive neoplasm with a low response to therapies, sharing similarities with human mucosal melanomas. In the latter, significant alterations of the proto-oncogene KIT have been shown, while in COMs only its exon 11 has been adequately investigated. In this study, 14 formalin-fixed, paraffin-embedded COMs were selected considering the following inclusion criteria: unequivocal diagnosis, presence of healthy tissue, and a known amplification status of the gene KIT (seven samples affected and seven non-affected by amplification). The DNA was extracted and KIT target exons 13, 17, and 18 were amplified by PCR and sequenced. Immunohistochemistry (IHC) for KIT and Ki67 was performed, and a quantitative index was calculated for each protein. PCR amplification and sequencing was successful in 97.62% of cases, and no single nucleotide polymorphism (SNP) was detected in any of the exons examined, similarly to exon 11 in other studies. The immunolabeling of KIT was positive in 84.6% of the samples with a mean value of 3.1 cells in positive cases, yet there was no correlation with aberration status. Our findings confirm the hypothesis that SNPs are not a frequent event in KIT activation in COMs, with the pathway activation relying mainly on amplification

Systemic fatal type II coronavirus infection in a dog: Pathological findings and immunohistochemistry.

A case of fatal systemic coronavirus infection is described in a 53-day-old Pekinese dog. Pathological findings and immunohistochemical identification using a monoclonal anti-canine Coronavirus antibody are included. Visceral lesions consisted of extensive fibrinopurulent bronchopneumonia, multiple renal cortical infarcts, severe coalescing centrilobular hepatic fatty change with minimal random hepatic necrosis, and multifocal splenic haemorrhage with lymphoid depletion. Moderate chronic diffuse enteritis was associated with intraluminal adult ascarids. Identification of type I and type II coronavirus in this subject had been previously confirmed by genotype-specific real-time reverse transcription-polymerase chain reaction (RT-PCR) assays of the intestinal contents, while only Coronavirus type II was detected in visceral organs. This case represents the first description of morphological lesions associated with a type II pantropic fatal coronavirus infection in the dog