Impact of Hemozoin on Hematological Outcomes and Innate Inflammatory Mediator Production in Infants and Young Children with Malarial Anemia

Malaria causes 300-500 million clinical cases and 1-3 million deaths per year, the majority of which occur in young African children. Ingestion of hemozoin by peripheral blood mononuclear cells (PBMC) initiates the cytokine-mediated cascade of immune dysregulation in malaria. Innate immunity plays a critical role in protective responses against infection, which are determined by an appropriate balance between pro- and anti-inflammatory mediators. Pro-inflammatory mediators (TNF-&#945, IL-12, IFN-&#947) that control parasitemia also contribute to pathology. Over-production of immunomodulatory cytokines (TGF-&#946, IL-10) suppresses the protective pro-inflammatory immune response. The effects of hemozoin on hematological outcomes and inflammatory mediator production in children with malarial anemia and the temporal kinetics of hemozoin-induced cytokine dysregulation in cultured PBMC were investigated in this study. Hematological analyses of healthy control (HC), uncomplicated malaria (UM), mild malarial anemia (MlMA), moderate malarial anemia (MdMA), and severe malarial anemia (SMA) groups revealed that age, temperature, and all erythrocyte, leukocyte, and platelet indices were significantly different between clinical categories. Neither parasitemia nor the prevalence of high density parasitemia (HDP) differed significantly between clinical groups. Stratification of study participants according to proportion of pigment-containing monocytes (PCM) demonstrated that parasitemia, HDP, temperature, and most leukocyte, erythrocyte, and platelet indices were significantly different between 0%, &#8804 10%, and > 10% PCM categories. The > 10% PCM category contained children with the lowest hemoglobin, hematocrit, and erythrocyte counts and the greatest proportion of children with SMA. Plasma IFN-&#945, IL-4, IL-6, IL-10, and IL-12p40/p70 levels differed significantly between clinical categories but not between UM and SMA groups. Plasma IFN-&#945, IFN-&#947, TNF-&#945, IL-1&#946, IL-2, IL-4, IL-6, IL-10, and IL-12p40/p70 were not significantly associated with % PCM. &#946-hematin-induced IL-1&#946, IL-2, IL-6, IL-12p35, IL-12p40, IL-18, IFN-&#945, IFN-&#947, TNF-&#945, LT-&#945, NOS-2A, COX-1, COX-2, IL-4, IL-10, and TGF-&#946 expression in cultured PBMC revealed a pro-inflammatory response that varied in magnitude among individuals. Importantly, innate inflammatory mediators modulate the adaptive immune response to Plasmodium parasites. Of public health significance, a better understanding of the molecular mechanisms governing these responses will facilitate the development of more immunogenic vaccines, through inclusion of cytokines or other compounds that activate the innate immune system

Programming dendritic cells for the 'kick and kill' of latent HIV-1

Finding a nontoxic, effective means to purge the latent HIV-1 reservoir in virally suppressed individuals undergoing antiretroviral therapy (ART) remains a major obstacle to a functional cure. The ‘kick and kill’ approach to controlling HIV-1 involves induction of HIV-1 latency reversal (LR) during ART to expose infected cells, while creating an arsenal of immune effector cells, such as cytotoxic T lymphocytes (CTL), capable of eliminating these targets. While pharmacological latency reversal agents (LRAs) have achieved limited success in ex vivo studies, none have been shown to reduce the latent reservoir in HIV-1-infected individuals. In addition, some LRAs have been shown to negatively impact antigen-specific CD8+ T cell effector responses in vitro. An optimal cure strategy must address not only induction of proviral gene expression but also clearance of reactivated cells presenting HIV-1-associated peptide epitopes by either highly functional CTL, or through incorporation of other immune-based strategies, including broadly neutralizing antibodies, T cell vaccines, or compounds modulating pro-apoptotic pathways. Conventional dendritic cells (DC) have been safely and widely used in HIV-1 clinical trials for their capacity to induce antigen-specific T cell responses, but their HIV-1 LRA potential has been underexplored. In this dissertation, I show that antigen-presenting monocyte-derived DC generated from chronic HIV-1-infected individuals on ART were shown to induce HIV-1 LR in autologous CD4+ T cells in an antigen-dependent manner. The LRA activity of DC does not appear to be a function of unidirectional communication from DC to CD4+ T cells, as DC-mediated LR was enhanced by bidirectional signaling events resulting from DC:CD4+ T cell cross-talk and sharply diminished by blockade of the CD40L/CD40 helper signaling pathway. Importantly, these data demonstrate the potential of this DC-based therapeutic to promote both the antigen-specific exposure and CTL killing of exposed CD4+ T cells harboring replication-competent provirus. Of public health significance, strategic inclusion of virus-associated MHC class II helper antigens in DC-based HIV-1 immunotherapies could serve both as a targeted means to safely unmask virus antigen-specific CD4+ T cells harboring HIV-1, and to support CTL responses that effectively target the DC-exposed latent reservoir as a functional cure strategy

Functional Cure of SIVagm Infection in Rhesus Macaques Results in Complete Recovery of CD4+ T Cells and Is Reverted by CD8+ Cell Depletion

Understanding the mechanism of infection control in elite controllers (EC) may shed light on the correlates of control of disease progression in HIV infection. However, limitations have prevented a clear understanding of the mechanisms of elite controlled infection, as these studies can only be performed at randomly selected late time points in infection, after control is achieved, and the access to tissues is limited. We report that SIVagm infection is elite-controlled in rhesus macaques (RMs) and therefore can be used as an animal model for EC HIV infection. A robust acute infection, with high levels of viral replication and dramatic mucosal CD4+ T cell depletion, similar to pathogenic HIV-1/SIV infections of humans and RMs, was followed by complete and durable control of SIVagm replication, defined as: undetectable VLs in blood and tissues beginning 72 to 90 days postinoculation (pi) and continuing at least 4 years; seroreversion; progressive recovery of mucosal CD4+ T cells, with complete recovery by 4 years pi; normal levels of T cell immune activation, proliferation, and apoptosis; and no disease progression. This “functional cure” of SIVagm infection in RMs could be reverted after 4 years of control of infection by depleting CD8 cells, which resulted in transient rebounds of VLs, thus suggesting that control may be at least in part immune mediated. Viral control was independent of MHC, partial APOBEC restriction was not involved in SIVagm control in RMs and Trim5 genotypes did not impact viral replication. This new animal model of EC lentiviral infection, in which complete control can be predicted in all cases, permits research on the early events of infection in blood and tissues, before the defining characteristics of EC are evident and when host factors are actively driving the infection towards the EC status

SIVagm Infection in Wild African Green Monkeys from South Africa: Epidemiology, Natural History, and Evolutionary Considerations

Pathogenesis studies of SIV infection have not been performed to date in wild monkeys due to difficulty in collecting and storing samples on site and the lack of analytical reagents covering the extensive SIV diversity. We performed a large scale study of molecular epidemiology and natural history of SIVagm infection in 225 free-ranging AGMs from multiple locations in South Africa. SIV prevalence (established by sequencing pol, env, and gag) varied dramatically between infant/juvenile (7%) and adult animals (68%) (p<0.0001), and between adult females (78%) and males (57%). Phylogenetic analyses revealed an extensive genetic diversity, including frequent recombination events. Some AGMs harbored epidemiologically linked viruses. Viruses infecting AGMs in the Free State, which are separated from those on the coastal side by the Drakensberg Mountains, formed a separate cluster in the phylogenetic trees; this observation supports a long standing presence of SIV in AGMs, at least from the time of their speciation to their Plio-Pleistocene migration. Specific primers/probes were synthesized based on the pol sequence data and viral loads (VLs) were quantified. VLs were of 104-106 RNA copies/ml, in the range of those observed in experimentally-infected monkeys, validating the experimental approaches in natural hosts. VLs were significantly higher (107-108 RNA copies/ml) in 10 AGMs diagnosed as acutely infected based on SIV seronegativity (Fiebig II), which suggests a very active transmission of SIVagm in the wild. Neither cytokine levels (as biomarkers of immune activation) nor sCD14 levels (a biomarker of microbial translocation) were different between SIV-infected and SIV-uninfected monkeys. This complex algorithm combining sequencing and phylogeny, VL quantification, serology, and testing of surrogate markers of microbial translocation and immune activation permits a systematic investigation of the epidemiology, viral diversity and natural history of SIV infection in wild African natural hosts. © 2013 Ma et al

Roadmap on machine learning in electronic structure

In recent years, we have been witnessing a paradigm shift in computational materials science. In fact, traditional methods, mostly developed in the second half of the XXth century, are being complemented, extended, and sometimes even completely replaced by faster, simpler, and often more accurate approaches. The new approaches, that we collectively label by machine learning, have their origins in the fields of informatics and artificial intelligence, but are making rapid inroads in all other branches of science. With this in mind, this Roadmap article, consisting of multiple contributions from experts across the field, discusses the use of machine learning in materials science, and share perspectives on current and future challenges in problems as diverse as the prediction of materials properties, the construction of force-fields, the development of exchange correlation functionals for density-functional theory, the solution of the many-body problem, and more. In spite of the already numerous and exciting success stories, we are just at the beginning of a long path that will reshape materials science for the many challenges of the XXIth century

ARIA digital anamorphosis : Digital transformation of health and care in airway diseases from research to practice

Digital anamorphosis is used to define a distorted image of health and care that may be viewed correctly using digital tools and strategies. MASK digital anamorphosis represents the process used by MASK to develop the digital transformation of health and care in rhinitis. It strengthens the ARIA change management strategy in the prevention and management of airway disease. The MASK strategy is based on validated digital tools. Using the MASK digital tool and the CARAT online enhanced clinical framework, solutions for practical steps of digital enhancement of care are proposed.Peer reviewe

ARIA digital anamorphosis: Digital transformation of health and care in airway diseases from research to practice

Digital anamorphosis is used to define a distorted image of health and care that may be viewed correctly using digital tools and strategies. MASK digital anamorphosis represents the process used by MASK to develop the digital transformation of health and care in rhinitis. It strengthens the ARIA change management strategy in the prevention and management of airway disease. The MASK strategy is based on validated digital tools. Using the MASK digital tool and the CARAT online enhanced clinical framework, solutions for practical steps of digital enhancement of care are proposed

Nonviral Transfection Strategies for Keratinocytes, Fibroblasts, and Endothelial Progenitor Cells for Ex Vivo Gene Transfer to Skin Wounds

In a search for the optimal nonviral gene transfer technique in epidermal and dermal supportive extracellular matrix studies, we investigated the efficiency of late generation liposomal transfection reagents and nucleofection of fibroblasts (FBs), endothelial progenitor cells (EPCs), and keratinocytes (KCs) as essential indicators of healing skin wounds. FBs, KCs, and EPCs were grown under serum-reduced conditions and manipulated according to optimized in vitro manufacturer protocols. Fugene HD, Effectene, PEI, and Lipofectin were compared to Amaxa Nucleofection. A green fluorescent protein (GFP)-encoded reporter gene plasmid was transfected, and transfection efficiencies were determined by green-fluorescence-activated cell sorting. Normal cell morphologies were observed after either transfection or nucleofection. For KC cell cultures, Fugene HD resulted in the highest transfection efficiency in human (41%) and porcine (42%) KCs. For EPCs, Effectene was optimal for human-derived cells (42%), whereas nucleofection was optimal (32%) for porcine cells. For FBs, however, nucleofection resulted in the highest transfection rates in human (46%) and porcine (60%) FBs. For specific epidermal cell studies, Fugene HD was the preferred gene transfer method, whereas Effectene appeared to be the optimal reagent for pro-angiogenic studies. Nucleofection in combination with FBs is the best combination to achieve the highest overall transfection rate and is thus the optimal combination for use in ex vivo gene transfer strategies of wound healing or skin tissue engineering.status: publishe