Phenotypic Features of Circulating Leukocytes from Non-human Primates Naturally Infected with Trypanosoma cruzi Resemble the Major Immunological Findings Observed in Human Chagas Disease

Background

Cynomolgus macaques (Macaca fascicularis) represent a feasible model for research on Chagas disease since natural T. cruzi infection in these primates leads to clinical outcomes similar to those observed in humans. However, it is still unknown whether these clinical similarities are accompanied by equivalent immunological characteristics in the two species. We have performed a detailed immunophenotypic analysis of circulating leukocytes together with systems biology approaches from 15 cynomolgus macaques naturally infected with T. cruzi (CH) presenting the chronic phase of Chagas disease to identify biomarkers that might be useful for clinical investigations.

Methods and Findings

Our data established that CH displayed increased expression of CD32⁺ and CD56⁺ in monocytes and enhanced frequency of NK Granzyme A⁺ cells as compared to non-infected controls (NI). Moreover, higher expression of CD54 and HLA-DR by T-cells, especially within the CD8⁺ subset, was the hallmark of CH. A high level of expression of Granzyme A and Perforin underscored the enhanced cytotoxicity-linked pattern of CD8⁺ T-lymphocytes from CH. Increased frequency of B-cells with up-regulated expression of Fc-γRII was also observed in CH. Complex and imbricate biomarker networks demonstrated that CH showed a shift towards cross-talk among cells of the adaptive immune system. Systems biology analysis further established monocytes and NK-cell phenotypes and the T-cell activation status, along with the Granzyme A expression by CD8⁺ T-cells, as the most reliable biomarkers of potential use for clinical applications.

Conclusions

Altogether, these findings demonstrated that the similarities in phenotypic features of circulating leukocytes observed in cynomolgus macaques and humans infected with T. cruzi further supports the use of these monkeys in preclinical toxicology and pharmacology studies applied to development and testing of new drugs for Chagas disease.     

Does small-sided-games’ court area influence metabolic,perceptual, and physical performance parameters of young elite basketball players?

The purpose of this study was to investigate the effect of court size on physiological responses and physical performance of young elite basketball players. Twelve male basketball players (18.6 ± 0.5 years; 88.8 ± 14.5 kg; 192.6 ± 6.5 cm) from an under-19 team performed two small-sided games (matches) with different court areas (28x15 m and 28x9 m; 28x15 and 28x9 protocols). The number of players (3x3) was kept the same in each protocol. The players performed a repeated-sprint ability (RSA) test before and after each match. Blood lactate concentration was collected before (pre) and after (post) the matches, and the session rating of perceived exertion (session-RPE) was determined 30 minutes after the match. Best and mean time in the RSA test were not different between the 28x15 and the 28x9 match protocols (p > 0.05). A significant difference was observed for lactate concentration from pre- to post-match (p < 0.05) in both protocols (28x15 and 28x9); however, there was no significant interaction between protocols. A similar session-RPE mean score (28x15: 7.2 ± 1.4 and 28x9: 6.6 ± 1.4) was detected for both protocols (p > 0.05, ES=0.41). In summary, the results of the current study suggest that the different court areas induced similar responses. Although there was no significant difference in effort perception, players tended to perceive a greater effort in the larger court size.     

Trichoderma aureoviride URM 5158 and Trichoderma hamatum URM 6656 are Biocontrol Agents that act against Cassava Root rot through different Mechanisms

Trichoderma has been used to manage a large number of pathogens, but there is a gap in the mechanisms used by these biocontrol agents regarding the physiological response of cassava plants (Manihot esculenta) when it is subjected to cassava root rot. The aims of this study were to investigate the antagonist activity of ten Trichoderma isolates against Fusarium solani on potato dextrose Agar (PDA), to quantify the chitinase production, to select and test in vivo the best isolate from each experiment and to assess the physiological response of cassava to the production of oxidative enzyme complex production (ascorbate peroxidase, catalase, peroxidase and polyphenol oxidase). All Trichoderma isolates have shown competitive capability against F. solani, and Trichoderma hamatum URM 6656 showed the highest inhibition of pathogen growth (88.91%). All isolates have shown chitinase activity, but Trichoderma aureoviride URM 5158 produced the highest amount of chitinase. T. hamatum URM 6656 and T. aureoviride URM 5158 were selected to be applied in vivo. The two Trichoderma strains reduced 64 and 60% of the disease severity in the shoot and 82 and 84% in the root. Cassava plants infected with Trichoderma have shown the highest peroxidase and ascorbate peroxidase production. Our results have indicated that T. aureoviride URM 5158 is an effective biocontrol agent against cassava root rot caused by F. solani, because it presented competitive antagonist capability in vitro, the highest chitinase production, and reduced the cassava root rot severity. The application of T. aureoviride has led to the maximum enzyme activity of reactive oxygen species group in cassava plants.     

Diamondback moth performance and preference for leaves of Brassica oleracea of different ages and strata

The preference–performance hypothesis predicts that moth behaviour links plant variations with caterpillar attack and distribution, and the plant‐age hypothesis states that specialist herbivores are more successful in exploring younger plant tissue. We integrated these predictions to investigate underlying mechanisms by which moths and caterpillars of Plutella xylostella L. (Lepidoptera: Plutellidae) track and exploit within‐plant variability of leaf age and stratification. We measured leaf proteins, glucosinolates and fibre, as well as larval choice, developmental performance, and moth oviposition preference with regard to leaf age classes (young, mature and senescent) of three varieties (collard, cauliflower and cabbage) of the main host plant Brassica oleracea L. Larvae consistently fit the prediction that specialist herbivores prefer and perform better on young, upper leaves that have the highest protein level, despite the highest content of defence compounds. Conversely, moths laid more eggs on fibrous and less nutritious leaves from the lower and senescent stratum. We argue that the leaf stratification of host plants imposes conflicting selective pressures concerning offspring feeding and protection on adult females. If egg mortality is catastrophic on the upper nutritious leaves in a particular microclimatic context (e.g. sun, heat, winds, drought or rain‐washing), then oviposition preference will remain for the suboptimal lower and senescent leaves. The ability of larvae to spread upwards over the plant to access the more nutritious leaf stratum is critical when eggs are preferentially laid on the protective low‐quality leaves.     

Selenium and mercury levels in rat liver slices co-treated with diphenyl diselenide and methylmercury

Organoseleno-compounds have been investigated for its beneficial effects against methylmercury toxicity. In this way, diphenyl diselenide (PhSe)₂ was demonstrated to decrease Hg accumulation in mice, protect against MeHg-induced mitochondrial dysfunction, and protect against the overall toxicity of this metal. In the present study we aimed to investigate if co-treatment with (PhSe)₂ and MeHg could decrease accumulation of Hg in liver slices of rats. Rat liver slices were co-treated with (PhSe)₂ (0.5; 5 µM) and/or MeHg (25 µM) for 30 min at 37 °C and Se and Hg levels were measured by inductively coupled plasma mass spectrometry (ICP-MS) in the slices homogenate, P1 fraction, mitochondria and incubation medium. Co-treatment with (PhSe)₂ and MeHg did not significantly alter Se levels in any of the samples when compared with compounds alone. In addition, co-treatment with (PhSe)₂ and MeHg did not decrease Hg levels in any of the samples tested, although, co-incubation significantly increased Hg levels in homogenate. We suggest here that (PhSe)₂ could exert its previously demonstrated protective effects not by reducing MeHg levels, but forming a complex with MeHg avoiding it to bind to critical molecules in cell.     

HPV18 Utilizes Two Alternative Branch Sites for E6~*I Splicing to Produce E7 Protein

Human papillomavirus 18(HPV18) E6 and E7 oncogenes are transcribed as a single bicistronic E6 E7 pre-mRNA. The E6 ORF region in the bicistronic E6 E7 pre-mRNA contains an intron. Splicing of this intron disrupts the E6 ORF integrity and produces a spliced E6~*I RNA for efficient E7 translation. Here we report that the E6 intron has two overlapped branch point sequences(BPS) upstream of its 30 splice site, with an identical heptamer AACUA■C, for E6~*I splicing. One heptamer has a branch site adenosine(underlined) at nt 384 and the other at nt 388. E6~*I splicing efficiency correlates to the expression level of E6 and E7 proteins and depends on the selection of which branch site. In general, E6~*I splicing prefers the 30 ss-proximal branch site at nt 388 over the distal branch site at nt 384. Inactivation of the nt 388 branch site was found to activate a cryptic acceptor site at nt 636 for aberrant RNA splicing. Together, these data suggest that HPV18 modulates its production ratio of E6 and E7 proteins by alternative selection of the two mapped branch sites for the E6~*I splicing, which could be beneficial in its productive or oncogenic infection according to the host cell environment.