30 research outputs found

    Lectotypification of names in the genus Eragrostis Wolf (Poaceae)

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    In the present work 3 names within the genus Eragrostis viz, Eragrostis coarctata, E. plana and E. superba have been typified. Lectotypification has been performed for E. coarctata and Second-step lectotypification has been done for the names E. plana and E. superba. For lectotypification, rules and recommendations proposed by the International Code of Nomenclature for algae, fungi and plants (ICN), have been strictly followed. The selection of lectotypes are explained and the images of selected lectotypes are provided

    Typification and taxonomic notes on species of Muhlenbergia Schreb. (Poaceae, Muhlenbergiinae) in India

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    The present paper deals with typification for two names in the genus Muhlenbergia i.e. M. duthieana and M. himalayensis. Furthermore, taxonomy of all Indian species for the same has been provided along with taxonomic key for correct identification

    HIV-1 unmasks the plasticity of innate lymphoid cells [preprint]

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    Pharmaceuticals that suppress HIV-1 viremia preserve CD4+ T cells and prevent AIDS. Nonetheless, HIV-1 infected people taking these drugs have chronic inflammation attributable to persistent disruption of intestinal barrier function with increased rates of cardiovascular mortality. To better understand the etiology of this inflammation we examined the effect of HIV-1 infection on innate lymphoid cells (ILCs). These innate immune counterparts of T cells lack clonotypic antigen receptors, classify according to signature transcription factors and cytokines, and maintain homeostasis in inflamed tissues. ILCs have been defined, in part, by the IL-7Rα, CD127. Here we report that the vast majority of type 1 and 3 ILCs in human adult and placental cord blood are in fact CD127-, as are colon lamina propria ILC1s and many ILC3s. Among ILCs, CD127-ILC1s were the major producer of inflammatory cytokines. In contrast to CD127+ILC3s, CD127-ILC3s did not produce IL-22, a cytokine that maintains epithelial barrier function. In HIV-1+ people taking antivirals that preserve CD4+ T cells, CD127-ILC1s and all homeostatic cytokine-producing CD127+ILCs were decreased in blood and colon. Common γ-chain cytokines that are reported to be elevated in response to HIV-1 infection caused JAK3-dependent downregulation of CD127 and converted CD127-ILC1s into NK cells with heightened cytolytic activity. Consistent with the recent report that human blood CD117+ILCs give rise to both ILC1s and NK cells, pseudotemporal clustering of transcriptomes from thousands of individual cells identified a developmental trajectory from CD127-ILC1s to memory NK cells that was defined by WNT-transcription factor TCF7. WNT inhibition prevented the cytokine-induced transition of CD127-ILC1 cells into memory NK cells. In HIV-1+ people, effector NK cells and TCF7+ memory NK cells were elevated, concomitant with reduction in CD127-ILC1s. These studies describe previously overlooked human ILC subsets that are significant in number and function, identify profound abnormalities in homeostatic ILCs that likely contribute to ongoing inflammation in HIV-1 infection despite control of viremia, provide explanation for increased memory NK cells in HIV-1 infection, and reveal functional plasticity of ILCs

    Humanized Mice for the Generation of HIV-1 Human Monoclonal Antibodies

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    Background: Despite the length of time HIV has been wreaking havoc on its victims, improvements in the prevention and treatment of HIV are needed. Anti-retroviral therapy can be effective but is expensive and not entirely accessible for people infected in third world countries. Several promising broadly neutralizing antibodies have been isolated from infected individuals; we propose that generating antigen specific human monoclonal antibodies using humanized mice further represents a promising approach to engineer prophylactic antibodies to reduce spread and infection of HIV. Methods: Immunodeficient mice were engrafted with fetal liver and thymus (BLT) prior to infection with different HIV isolates. HIV infection of the mice was monitored by viral load and antibody response followed by ELISA using gp120, gp41 or gp120/CD4 complex as antigens. Approximately 8-12 weeks post infection, spleens were harvested and splenocytes fused with human fusion partner HMMA 2.5 to isolate antibody-expressing hybridomas. Lead clones were scaled and purified for testing in functional assays such as TZM-bl neutralization assays as well as ADCVI to determine neutralizing and cytotoxic ability of the antibodies. Antibody sequences were also determined for analysis. Results: A robust, specific antibody response, of both IgG and IgA isotypes, was generated in response to HIV infection. Over 60 hybridomas were created that were not only immunoreactive with env antigens, but also had neutralization activity. Moreover, variable family usage was not limited and somatic mutation was clearly evident. Conclusions: These findings suggest that humanized BLT mice are a novel source for well-characterized, stable human monoclonal antibodies to HIV

    Discovery and Development of Human Monoclonal Antibodies to Block RhD Alloimmunization During Pregnancy

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    Exposure of an Rh negative mother to red blood cells (RBCs) of an Rh positive fetus results in alloimmunization and development of anti-RhD antibodies. The anti-RhD antibodies cause hemolytic disease of the new born babies during subsequent pregnancies. Current prophylactic treatment involves polyclonal anti-RhD IgG purified from plasma of humans and is administered in approximately 20% of pregnancies. While the current prophylaxis is effective, it involves the use of human plasma and non-RhD specific antibodies, thus posing a risk of transmitting infections and undesired antibody reactions. Moreover, there is a serious scarcity of plasma donors to meet the requirement of anti-RhD antibodies. In this study we propose to discover and develop anti-RhD monoclonal human antibodies to replace the current polyclonal prophylaxis. We are using humanized BLT mice (fetal CD34+ stem cells, liver and thymus) reconstituted with RhD negative donor material and were immunized by using adenovirus containing RhD transgene. Serum samples were collected after 4-6 weeks of immunization. Our results show that the RhD immunized mice had considerably higher titer of IgG and IgA antibodies in the serum compared to the control, suggesting an immune response developed upon immunization. Splenocytes from antibody producing mice will be fused with a human fusion partner for the isolation of hybridomas producing human monoclonal antibodies. The immunoreactivity and functional activity of these antibodies will be discussed

    QlicRice: a web interface for abiotic stress responsive QTL and loci interaction channels in rice

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    The QlicRice database is designed to host publicly accessible, abiotic stress responsive quantitative trait loci (QTLs) in rice (Oryza sativa) and their corresponding sequenced gene loci. It provides a platform for the data mining of abiotic stress responsive QTLs, as well as browsing and annotating associated traits, their location on a sequenced genome, mapped expressed sequence tags (ESTs) and tissue and growth stage-specific expressions on the whole genome. Information on QTLs related to abiotic stresses and their corresponding loci from a genomic perspective has not yet been integrated on an accessible, user-friendly platform. QlicRice offers client-responsive architecture to retrieve meaningful biological information—integrated and named ‘Qlic Search’—embedded in a query phrase autocomplete feature, coupled with multiple search options that include trait names, genes and QTL IDs. A comprehensive physical and genetic map and vital statistics have been provided in a graphical manner for deciphering the position of QTLs on different chromosomes. A convenient and intuitive user interface have been designed to help users retrieve associations to agronomically important QTLs on abiotic stress response in rice

    Dengue Virus Infection and Virus-Specific HLA-A2 Restricted Immune Responses in Humanized NOD-scid IL2rγnull Mice

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    BACKGROUND:The lack of a suitable animal model to study viral and immunological mechanisms of human dengue disease has been a deterrent to dengue research. METHODOLOGY/PRINCIPAL FINDINGS:We sought to establish an animal model for dengue virus (DENV) infection and immunity using non-obese diabetic/severe combined immunodeficiency interleukin-2 receptor gamma-chain knockout (NOD-scid IL2rgamma(null)) mice engrafted with human hematopoietic stem cells. Human CD45(+) cells in the bone marrow of engrafted mice were susceptible to in vitro infection using low passage clinical and established strains of DENV. Engrafted mice were infected with DENV type 2 by different routes and at multiple time points post infection, we detected DENV antigen and RNA in the sera, bone marrow, spleen and liver of infected engrafted mice. Anti-dengue IgM antibodies directed against the envelope protein of DENV peaked in the sera of mice at 1 week post infection. Human T cells that developed following engraftment of HLA-A2 transgenic NOD-scid IL2rgamma(null) mice with HLA-A2(+) human cord blood hematopoietic stem cells, were able to secrete IFN-gamma, IL-2 and TNF-alpha in response to stimulation with three previously identified A2 restricted dengue peptides NS4b 2353((111-119)), NS4b 2423((181-189)), and NS4a 2148((56-64)). CONCLUSIONS/SIGNIFICANCE:This is the first study to demonstrate infection of human cells and functional DENV-specific T cell responses in DENV-infected humanized mice. Overall, these mice should be a valuable tool to study the role of prior immunity on subsequent DENV infections

    Enhanced humoral and hla-a2-restricted dengue virus-specific t cell responses in humanized blt nsg mice

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    Dengue is a mosquito borne viral disease of humans, and animal models that recapitulate human immune responses and/or dengue pathogenesis are needed to understand the pathogenesis of the disease. We recently described an animal model for dengue virus (DENV) infection using humanized NOD-scid IL2rgamma(null) mice (NSG) engrafted with cord blood hematopoietic stem cells (HSC). We sought to further improve this model by co-transplantation of human fetal thymus and liver tissues into NSG (BLT-NSG) mice. Enhanced DENV-specific antibody titers were found in the sera of BLT-NSG mice compared to human cord blood HSC-engrafted NSG mice. Furthermore, B cells generated during the acute phase and in memory from splenocytes of immunized BLT-NSG mice secreted DENV-specific IgM antibodies with neutralizing activity. Human T cells in engrafted BLT-NSG mice secreted IFN-gamma in response to overlapping DENV peptide pools and HLA-A2 restricted peptides. BLT-NSG mice will provide a much-needed platform to assess human immune responses to DENV vaccines and the effects of prior immunity on subsequent DENV infections. (c) 2012 The Authors. Immunology (c) 2012 Blackwell Publishing Ltd, Immunology

    Replication-Defective Adenoviral Vaccine Vector for the Induction of Immune Responses to Dengue Virus Type 2

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    A recombinant replication-defective adenovirus vector that can overexpress the ectodomain of the envelope protein of dengue virus type 2 (NGC strain) has been constructed. This virus was immunogenic in mice and elicited dengue virus type 2 specific B- and T-cell responses. Sera from immunized mice contained neutralizing antibodies that could specifically recognize dengue virus type 2 and neutralize its infectivity in vitro, indicating that this approach has the potential to confer protective immunity. In vitro stimulation of splenocytes (from immunized mice) with dengue virus type 2 resulted in a significant proliferative response accompanied by the production of high levels of gamma interferon but did not show significant changes in interleukin-4 levels. This is suggestive of a Th1-like response (considered to be important in the maturation of cytotoxic T lymphocytes that are essential for the elimination of virus-infected cells). The data show that adenovirus vectors offer a promising alternative strategy for the development of dengue virus vaccines
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