Black-footed cats (BFC) are habitat specialists, occurring mostly in open low dwarf-shrub or grassland habitats, within in the Grassland, open Savannah and Nama Karoo biomes, with average rainfall of 100-500 mm, at altitudes up to 2000 m a.s.l. Distribution and densities are difficult to estimate due to the shy, nocturnal nature of BFCs and few records. Lack of confirmed records coupled with limited knowledge of presence in some areas, results in inaccurate conservation status and population size estimations across their range. Most of their distribution range is outside protected areas and habitat degradation and high mortality rates create high local extinction risk and limited recolonization. Habitat degradation or change, like overgrazing and bush encroachment impacts the suitable habitat available to BFCs. It is unlikely that BFCs occur continuously across the current range, thus a new approach is needed to delineate its distribution range and population connectivity more accurately. Here we represent the distribution range for black-footed cats using landscape and vegetation structure characteristics and confirmed records of the species to describe its range in more detail. They do not occur in mountainous terrain, true desert, or habitats with dense, tall vegetation. Subpopulations are isolated and not connected due to geographical barriers (mountains, rivers), fragmented suitable habitats across its range, and limited dispersal ability, resulting in genetic isolation, low survival outside these habitats and high risk of local extinction rate if threats are high/constant.
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HIV nonprogression despite persistent viremia is rare among adults who are naive to antiretroviral therapy (ART) but relatively common among ART-naive children. Previous studies indicate that ART-naive pediatric slow progressors (PSPs) adopt immune evasion strategies similar to those described in natural hosts of SIV. However, the mechanisms underlying this immunophenotype are not well understood. In a cohort of early-treated infants who underwent analytical treatment interruption (ATI) after 12 months of ART, expression of PD-1 on CD8+ T cells immediately before ATI was the main predictor of slow progression during ATI. PD-1+CD8+ T cell frequency was also negatively correlated with CCR5 and HLA-DR expression on CD4+ T cells and predicted stronger HIV-specific T lymphocyte responses. In the CD8+ T cell compartment of PSPs, we identified an enrichment of stem-like TCF-1+PD-1+ memory cells, whereas pediatric progressors and viremic adults had a terminally exhausted PD-1+CD39+ population. TCF-1+PD-1+ expression on CD8+ T cells was associated with higher proliferative activity and stronger Gag-specific effector functionality. These data prompted the hypothesis that the proliferative burst potential of stem-like HIV-specific cytotoxic cells could be exploited in therapeutic strategies to boost the antiviral response and facilitate remission in infants who received early ART with a preserved and nonexhausted T cell compartment.
