33 research outputs found

    Cross-Reactive T Cells Are Involved in Rapid Clearance of 2009 Pandemic H1N1 Influenza Virus in Nonhuman Primates

    Get PDF
    In mouse models of influenza, T cells can confer broad protection against multiple viral subtypes when antibodies raised against a single subtype fail to do so. However, the role of T cells in protecting humans against influenza remains unclear. Here we employ a translational nonhuman primate model to show that cross-reactive T cell responses play an important role in early clearance of infection with 2009 pandemic H1N1 influenza virus (H1N1pdm). To “prime” cellular immunity, we first infected 5 rhesus macaques with a seasonal human H1N1 isolate. These animals made detectable cellular and antibody responses against the seasonal H1N1 isolate but had no neutralizing antibodies against H1N1pdm. Four months later, we challenged the 5 “primed” animals and 7 naive controls with H1N1pdm. In naive animals, CD8+ T cells with an activated phenotype (Ki-67+ CD38+) appeared in blood and lung 5–7 days post inoculation (p.i.) with H1N1pdm and reached peak magnitude 7–10 days p.i. In contrast, activated T cells were recruited to the lung as early as 2 days p.i. in “primed” animals, and reached peak frequencies in blood and lung 4–7 days p.i. Interferon (IFN)-γ Elispot and intracellular cytokine staining assays showed that the virus-specific response peaked earlier and reached a higher magnitude in “primed” animals than in naive animals. This response involved both CD4+ and CD8+ T cells. Strikingly, “primed” animals cleared H1N1pdm infection significantly earlier from the upper and lower respiratory tract than the naive animals did, and before the appearance of H1N1pdm-specific neutralizing antibodies. Together, our results suggest that cross-reactive T cell responses can mediate early clearance of an antigenically novel influenza virus in primates. Vaccines capable of inducing such cross-reactive T cells may help protect humans against severe disease caused by newly emerging pandemic influenza viruses

    Cross‐cultural assessment of HIV‐associated cognitive impairment using the Kaufman assessment battery for children: a systematic review

    Get PDF
    Introduction: Despite improved efficacy of, and access to, combination antiretroviral therapy (cART), HIV‐associated cognitive impairments remain prevalent in both children and adults. Neuropsychological tests that detect such impairment can help clinicians formulate effective treatment plans. The Kaufman Assessment Battery for Children (KABC), although developed and standardized in the United States, is used frequently in many different countries and cultural contexts to assess paediatric performance across various cognitive domains. This systematic review investigated the cross‐cultural utility of the original KABC, and its 2nd edition (KABC‐II), in detecting HIV‐associated cognitive impairment in children and adolescents.Methods: We entered relevant keywords and MeSH terms into the PubMed, PsycInfo, EBSCOHost, ProQuest, and Scopus databases, with search limits set from 1983–2017. Two independent reviewers evaluated the retrieved abstracts and manuscripts. Studies eligible for inclusion in the review were those that (a) used the KABC/KABC‐II to assess cognitive function in children/adolescents aged 2–18 years, (b) featured a definition of cognitive impairment (e.g. >2 SD below the mean) or compared the performance of HIV‐infected and uninfected control groups, and (c) used a sample excluded from population on which the instruments were normed.Results and discussion: We identified nine studies (eight conducted in African countries, and one in the United Kingdom) to comprise the review’s sample. All studies detected cognitive impairment in HIV‐infected children, including those who were cART‐naïve or who were cART treated and clinically stable. KABC/KABC‐II subtests assessing simultaneous processing appeared most sensitive. Evaluation of the methodological quality of the selected studies by two independent reviews suggested that shortcomings included reporting and selection biases.Conclusions: This systematic review provides evidence for the cross‐cultural utility of the KABC/KABC‐II, particularly the simultaneous processing subtests, in detecting cognitive impairment in HIV‐infected children (including those who are clinically stable). Although the current results suggest there is justification for using the KABC/KABC‐II primarily in East Africa, further investigation is required to explore the instrument’s utility in other HIV‐prevalent regions of the globe.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138351/1/jia21412.pd

    Coquillettidia (Culicidae, Diptera) mosquitoes are natural vectors of avian malaria in Africa

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The mosquito vectors of <it>Plasmodium </it>spp. have largely been overlooked in studies of ecology and evolution of avian malaria and other vertebrates in wildlife.</p> <p>Methods</p> <p><it>Plasmodium </it>DNA from wild-caught <it>Coquillettidia </it>spp. collected from lowland forests in Cameroon was isolated and sequenced using nested PCR. Female <it>Coquillettidia aurites </it>were also dissected and salivary glands were isolated and microscopically examined for the presence of sporozoites.</p> <p>Results</p> <p>In total, 33% (85/256) of mosquito pools tested positive for avian <it>Plasmodium </it>spp., harbouring at least eight distinct parasite lineages. Sporozoites of <it>Plasmodium </it>spp. were recorded in salivary glands of <it>C. aurites </it>supporting the PCR data that the parasites complete development in these mosquitoes. Results suggest <it>C. aurites</it>, <it>Coquillettidia pseudoconopas </it>and <it>Coquillettidia metallica </it>as new and important vectors of avian malaria in Africa. All parasite lineages recovered clustered with parasites formerly identified from several bird species and suggest the vectors capability of infecting birds from different families.</p> <p>Conclusion</p> <p>Identifying the major vectors of avian <it>Plasmodium </it>spp. will assist in understanding the epizootiology of avian malaria, including differences in this disease distribution between pristine and disturbed landscapes.</p

    Methamphetamine Causes Differential Alterations in Gene Expression and Patterns of Histone Acetylation/Hypoacetylation in the Rat Nucleus Accumbens

    Get PDF
    Methamphetamine (METH) addiction is associated with several neuropsychiatric symptoms. Little is known about the effects of METH on gene expression and epigenetic modifications in the rat nucleus accumbens (NAC). Our study investigated the effects of a non-toxic METH injection (20 mg/kg) on gene expression, histone acetylation, and the expression of the histone acetyltransferase (HAT), ATF2, and of the histone deacetylases (HDACs), HDAC1 and HDAC2, in that structure. Microarray analyses done at 1, 8, 16 and 24 hrs after the METH injection identified METH-induced changes in the expression of genes previously implicated in the acute and longterm effects of psychostimulants, including immediate early genes and corticotropin-releasing factor (Crf). In contrast, the METH injection caused time-dependent decreases in the expression of other genes including Npas4 and cholecystokinin (Cck). Pathway analyses showed that genes with altered expression participated in behavioral performance, cell-to-cell signaling, and regulation of gene expression. PCR analyses confirmed the changes in the expression of c-fos, fosB, Crf, Cck, and Npas4 transcripts. To determine if the METH injection caused post-translational changes in histone markers, we used western blot analyses and identified METH-mediated decreases in histone H3 acetylated at lysine 9 (H3K9ac) and lysine 18 (H3K18ac) in nuclear sub-fractions. In contrast, the METH injection caused time-dependent increases in acetylated H4K5 and H4K8. The changes in histone acetylation were accompanied by decreased expression of HDAC1 but increased expression of HDAC2 protein levels. The histone acetyltransferase, ATF2, showed significant METH-induced increased in protein expression. These results suggest that METH-induced alterations in global gene expression seen in rat NAC might be related, in part, to METH-induced changes in histone acetylation secondary to changes in HAT and HDAC expression. The causal role that HATs and HDACs might play in METH-induced gene expression needs to be investigated further

    T-cell recognition of chemicals, protein allergens and drugs: towards the development of in vitro assays

    Get PDF
    Chemicals can elicit T-cell-mediated diseases such as allergic contact dermatitis and adverse drug reactions. Therefore, testing of chemicals, drugs and protein allergens for hazard identification and risk assessment is essential in regulatory toxicology. The seventh amendment of the EU Cosmetics Directive now prohibits the testing of cosmetic ingredients in mice, guinea pigs and other animal species to assess their sensitizing potential. In addition, the EU Chemicals Directive REACh requires the retesting of more than 30,000 chemicals for different toxicological endpoints, including sensitization, requiring vast numbers of animals. Therefore, alternative methods are urgently needed to eventually replace animal testing. Here, we summarize the outcome of an expert meeting in Rome on 7 November 2009 on the development of T-cell-based in vitro assays as tools in immunotoxicology to identify hazardous chemicals and drugs. In addition, we provide an overview of the development of the field over the last two decades

    Malicious MXit? South African adolescents’ use of mobile-based communication applications

    Full text link
    Across the globe, and particularly in the high-income countries of the developed world, adolescents are resorting in increasing numbers to the virtual world for peer interaction and socialisation (Subrahmanyam, Smahel and Greenfield 2006). This new and popular way of relating through virtual mediums such as the Internet has sparked public concern, and has been a focus of academic debate. Ongoing debate in psychology literature discusses the notion of compulsive usage of online communication platforms (commonly termed Internet addiction), particularly among adolescents (Kim et al. 2006, Fu et al. 2010, Israelashvili, Kim and Bukobza 2012).Journal of Child &amp; Adolescent Mental Health 2012, 24(2): 117&#8211;13

    Cradling bias is absent in children with autism spectrum disorders

    Full text link
    Objective: This study investigated relations among empathy and cradling bias in children diagnosed with autism spectrum disorders (ASDs).Method: Twenty children with ASDs and 20 typically developing (TD) children, aged 5–15 years old, cradled a doll as if it were an infant s/he was putting to sleep on three separate occasions. We recorded side preference on each occasion.Results: Children with ASDs showed no preference for cradling side whereas TD children showed a strong left-sided preference. To the best of our knowledge, children with ASDs are the only population that does not exhibit cradling bias.Conclusion: An absence of cradling bias and empathy deficits in ASD may be related. If so, these data support the hypothesis that leftward cradling is a characteristic of enhanced quality of caregiver-infant interaction and bonding.Journal of Child and Adolescent Mental Health 2013, 25(1): 55–6
    corecore