Class-modeling analysis reveals T-cell homeostasis disturbances involved in loss of immune control in elite controllers

Despite long-lasting HIV replication control, a significant proportion of elite controller (EC) patients may experience CD4 T-cell loss. Discovering perturbations in immunological parameters could help our understanding of the mechanisms that may be operating in those patients experiencing loss of immunological control. Methods A case–control study was performed to evaluate if alterations in different T-cell homeostatic parameters can predict CD4 T-cell loss in ECs by comparing data from EC patients showing significant CD4 decline (cases) and EC patients showing stable CD4 counts (controls). The partial least-squares–class modeling (PLS-CM) statistical methodology was employed to discriminate between the two groups of patients, and as a predictive model. Results Herein, we show that among T-cell homeostatic alterations, lower levels of naïve and recent thymic emigrant subsets of CD8 cells and higher levels of effector and senescent subsets of CD8 cells as well as higher levels of exhaustion of CD4 cells, measured prior to CD4 T-cell loss, predict the loss of immunological control. Conclusions These data indicate that the parameters of T-cell homeostasis may identify those EC patients with a higher proclivity to CD4 T-cell loss. Our results may open new avenues for understanding the mechanisms underlying immunological progression despite HIV replication control, and eventually, for finding a functional cure through immune-based clinical trials.projects RD12/0017/0031, RD16/0025/ 0013, and SAF2015-66193-R as part of the Health Research and Development Strategy, State Plan for Scientific and Technical Research and Innovation (2008– 2011 and 2013–2016) and cofinanced by the Institute of Health Carlos III (ISCIII), Sub-Directorate General for Research Assessment and Promotion and European Regional Development Fund. NR is a Miguel Servet investigator from the ISCIII (CP14/00198), Madrid, Spain. C Restrepo was funded by project RD12/0017/ 0031 and is currently funded by project RD16/0025/0013. M García is a predoctoral student co-funded by grant CP14/00198 and an Intramural Research Scholarship from Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD)

Can a fast­growing early­successional tree (Ochroma pyramidale, Malvaceae) accelerate forest succession?

Species-specific traits of trees affect ecosystem dynamics, defining forest structure and understorey development. Ochroma pyramidale is a fast-growing tree species, with life-history traits that include low wood density, short-lived large leaves and a narrow open thin crown. We evaluated forest succession in O. pyramidale-dominated secondary forests, diverse secondary forests, both 10–15 y since abandonment, and rain forests by comparing height, density and basal area of all trees (> 5 cm dbh). Furthermore, we compared species richness of understorey trees and shrubs, and basal area and density of trees of early- and late-successional species ( 15%) and leaf litter (> 10 cm) were both highest in O. pyramidale forests, which positively affected density of understorey trees and shrubs and negatively affected density of late-successional trees. In conclusion, O. pyramidale forests presented structural features similar to those of rain forest, but this constrained the establishment of understorey tree species, especially late-successional species, decreasing successional developmen

Tropical rain-forest matrix quality affects bat assemblage structure in secondary forest patches

We studied Phyllostomidae bat assemblage structure in patches of secondary forest dominated by the pioneer tree Ochroma pyramidale, largely (.85%) or partially (,35%) surrounded by a matrix of tropical rain forest, to test 3 hypotheses: the highest bat diversity and richness is observed in the matrix rain forest in comparison to secondary forest patches; the proportion of rain forest surrounding secondary forest positively affects bat diversity and richness; and canopy openness is an important structural variable negatively affecting bat abundance. Rain-forest control sites had the highest bat species diversity and richness, and contributed more to total diversity than did secondary forest. Bat diversity was similar between secondary forest patches largely enclosed by rain forest and their controls, but higher diversity, richness, and contribution to total diversity were recorded in largely enclosed patches compared to partially enclosed patches. Partially enclosed patches were dominated by 2 small, frugivorous understory bat species (Carollia sowelli and Carollia perspicillata), whereas largely enclosed patches were dominated by 2 large-bodied, canopy-dwelling, frugivorous bats (Artibeus lituratus and Artibeus jamaicensis), which primarily feed on figs, a tree species that is abundant in rain forest. Bat diversity, richness, and contribution to total diversity were positively correlated with the proportion of area with rain forest, and bat abundance was negatively correlated with canopy openness

Restoration of Forest Ecosystems in Fragmented Landscapes of Temperate and Montane Tropical Latin America

Temperate and tropical montane forests in Latin America represent a major natural resource at both regional and national levels for a number of reasons - biological, climatic, economic, cultural. Native tree species in these forests share conservation problems because of deforestation, habitat degradation, overall biodiversity loss and integrity of landscape structure. However, literature on forest restoration research and practices in these ecosystems is scanty and dispersed. We integrate forest restoration experiences aimed at a variety of purposes that allow us to gain insight over several years under contrasting ecological, social and economic conditions in six study regions: the Argentinian Andes, the IX and X Regions in Chile (including northern Chiloe Island), and central Veracruz and the central and northern Highlands of Chiapas (Mexico). By comparing analogous conditions and highlighting differences among the study sites, current pitfalls can be identified and used to define a minimum set of elements to be considered in a protocol for restoration practices. The restoration studies reviewed here include a wide variety of ecological and socio-economic circumstances that allow the identification of broad guidelines, criteria and indicators for planning, implementing and monitoring ecological restoration programmes. We conclude with statements that suggest approaches, strategies and concrete actions that might be considered as lessons learned and inputs for best practice in forest restoration research and programmes conducted in other developing regions