The mucosae-associated epithelial chemokine (MEC/CCL28) modulates immunity in HIV infection

CCL28 (MEC) binds to CCR3 and CCR10 and recruits IgA-secreting plasma cells (IgA-ASC) in the mucosal lamina propria (MLP). Mucosal HIV-specific IgA are detected in HIV-infection and exposure. The CCL28 circuit was analyzed in HIV-infected and-exposed individuals and in HIV-unexposed controls; the effect of CCL28 administration on gastrointestinal MLP IgA-ASC was verified in a mouse model.CCL28 was augmented in breast milk (BM) plasma and saliva of HIV-infected and –exposed individuals; CCR3+ and CCR10+ B lymphocytes were increased in these same individuals. Additionally: 1) CCL28 concentration in BM was associated with longer survival in HIV vertically-infected children; and 2) gastro-intestinal mucosal IgA-ASC were significantly increased in VSV-immunized mice receiving CCL28.CCL28 mediates mucosal immunity in HIV exposure and infection. CCL28-including constructs should be considered in mucosal vaccines to prevent HIV infection of the gastro-intestinal MLP via modulation of IgA-ASC

An La-related protein controls cell cycle arrest by nuclear retrograde transport of tRNAs during diapause formation in Artemia

BACKGROUND: In eukaryotes, tRNA trafficking between the nucleus and cytoplasm is a complex process connected with cell cycle regulation. Such trafficking is therefore of fundamental importance in cell biology, and disruption of this process has grave consequences for cell viability and survival. To cope with harsh habitats, Artemia has evolved a special reproductive mode to release encysted embryos in which cell division can be maintained in a dormancy state for a long period. RESULTS: Using Artemia as a peculiar model of the cell cycle, an La-related protein from Artemia, named Ar-Larp, was found to bind to tRNA and accumulate in the nucleus, leading to cell cycle arrest and controlling the onset of diapause formation in Artemia. Furthermore, exogenous gene expression of Ar-Larp could induce cell cycle arrest in cancer cells and suppress tumor growth in a xenograft mouse model, similar to the results obtained in diapause embryos of Artemia. Our study of tRNA trafficking indicated that Ar-Larp controls cell cycle arrest by binding to tRNAs and influencing their retrograde movement from the cytoplasm to the nucleus, which is connected to pathways involved in cell cycle checkpoints. CONCLUSIONS: These findings in Artemia offer new insights into the mechanism underlying cell cycle arrest regulation, as well as providing a potentially novel approach to study tRNA retrograde movement from the cytoplasm to the nucleus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12915-016-0239-4) contains supplementary material, which is available to authorized users

Vegetation of Patagonia

In this chapter, we describe the major phytogeographic provinces of Patagonia. Emphasis is placed on physiognomic vegetation formations, internal heterogeneity, and degree of anthropic disturbance. Main vegetation formations within provinces include temperate forests, steppes, moorlands, and shrublands. Internal plant heterogeneity is high in all provinces and is associated with climate, soils, altitude, and natural (e.g., volcanism) or anthropogenic disturbances. The most important anthropogenic disturbance varies among provinces in relation to vegetation formations. Domestic grazing is a widespread disturbance agentin steppes and shrublands, while oil and natural gas extraction may also cause disturbances affecting local plant communities in some areas. In contrast, clearing for agriculture and afforestation are common in temperate forests. Invasion of exotic plants and animals are also a threat for the conservation of pristine vegetation. Disturbances, together with the ongoing climate change, can strongly influence vegetation structure and functioning that in turn could affect populations of wild animals, particularly lizards.Fil: Bisigato, Alejandro Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Bertiller, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentin