Cell-to-Cell Transfer of M. tuberculosis Antigens Optimizes CD4 T Cell Priming

SummaryDuring Mycobacterium tuberculosis and other respiratory infections, optimal T cell activation requires pathogen transport from the lung to a local draining lymph node (LN). However, the infected inflammatory monocyte-derived dendritic cells (DCs) that transport M. tuberculosis to the local lymph node are relatively inefficient at activating CD4 T cells, possibly due to bacterial inhibition of antigen presentation. We found that infected migratory DCs release M. tuberculosis antigens as soluble, unprocessed proteins for uptake and presentation by uninfected resident lymph node DCs. This transfer of bacterial proteins from migratory to local DCs results in optimal priming of antigen-specific CD4 T cells, which are essential in controlling tuberculosis. Additionally, this mechanism does not involve transfer of the whole bacterium and is distinct from apoptosis or exosome shedding. These findings reveal a mechanism that bypasses pathogen inhibition of antigen presentation by infected cells and generates CD4 T cell responses that control the infection

Morpho-Anatomical Adaptation against Salinity

Plants tolerant of NaCl, implement several adjustments to acclimate to salt stress, such as biochemical, physiological, and morphological modifications. Besides, plants also adjust to saline circumstances by altering their anatomical structure of roots, leaves, and morphological modifications. The leaf and roots are among the essential plant organs and are involved in the transport of water and minerals used for photosynthesis. From a plant physiology perspective, water use efficiency in the quantity of CO2 fixed in photosynthesis compared to the leaf anatomy. In this review, we provide a comparative account of the morphology of the leaf and root under normal and salt stress circumstances. There is little information on the ultrastructure changes elicited in response to salt stress. The analysis expands our knowledge of how salt may impact the leaves and root anatomy

Clastogenic Effects of Glyphosate in Bone Marrow Cells of Swiss Albino Mice

Glyphosate (N-(phosphonomethyl) glycine, C3H8NO5P), a herbicide, used to control unwanted annual and perennial plants all over the world. Nevertheless, occupational and environmental exposure to pesticides can pose a threat to nontarget species including human beings. Therefore, in the present study, genotoxic effects of the herbicide glyphosate were analyzed by measuring chromosomal aberrations (CAs) and micronuclei (MN) in bone marrow cells of Swiss albino mice. A single dose of glyphosate was given intraperitoneally (i.p) to the animals at a concentration of 25 and 50 mg/kg b.wt. Animals of positive control group were injected i.p. benzo(a)pyrene (100 mg/kg b.wt., once only), whereas, animals of control (vehicle) group were injected i.p. dimethyl sulfoxide (0.2 mL). Animals from all the groups were sacrificed at sampling times of 24, 48, and 72 hours and their bone marrow was analyzed for cytogenetic and chromosomal damage. Glyphosate treatment significantly increases CAs and MN induction at both treatments and time compared with the vehicle control (P < .05). The cytotoxic effects of glyphosate were also evident, as observed by significant decrease in mitotic index (MI). The present results indicate that glyphosate is clastogenic and cytotoxic to mouse bone marrow

Sequencing of 28SrRNA Gene for Identification of Trichoderma longibrachiatum 28CP/7444 Species in Soil Sample

Most of the Trichoderma species are morphologically very similar and were considered for many years as a single species. Since new species were discovered, a consolidated taxonomical scheme was needed and proposed and defined nine morphological species aggregates. DNA methods brought additional valuable criteria to the taxonomy of Trichoderma which are being used today for studies that include identification and phylogenetic classification. Most isolates of the genus Trichoderma that were found to act as mycoparasites of many economically important aerial and soil-borne plant pathogens. Trichoderma has attained importance for substitute of chemical pesticides and hence an attempt was intended to corroborate the positive relatedness of molecular and morphological characters. A fungal strain of Trichoderma longibrachiatum 28CP/7444 was isolated from a soil sample collected from Barabanki district of Uttar Pradesh, India. The universal primers were used for amplification of the 28S rRNA gene fragment and strain characterized by using 28S rRNA gene sequence with the help of ITS marker. It is proposed that the identified strain Trichoderma longibrachiatum 28CP be assigned as the type strain of a species of the genus Trichoderma based on phylogenetic tree analysis together with the 28S rRNA gene sequence search in Ribosomal Database Project, small subunit rRNA and large subunit rRNA databases. The sequence was deposited in GenBank with the accession number JX978541. Thus an integrated approach of morphological and molecular markers can be employed to identify a superior strain of Trichoderma for its commercial exploitation

Phylogenetic diversity analysis of Trichoderma species based on internal transcribed spacer (ITS) marker

The phylogeny of Trichoderma and the phylogenetic relationships of its species was investigated by maximum parsimony analysis and distance analysis of DNA sequences from multiple genetic loci 18S rDNA sequence analysis suggests that the genus Trichoderma evolved at the same time as Hypomyces and Fusarium and thus about 110 Myr ago 28S rDNA sequence analysis shows that the genus Trichoderma is part of a monophyletic branch within the Hypocreaceae. Most isolates of the genus Trichoderma were found to act as mycoparasites of many economically important aerial and soil-borne plant pathogens. Trichoderma has attained importance as a substitute for chemical pesticides and hence an attempt was intended to corroborate the positive relatedness of molecular and morphological characters. Two fungal strains, Trichoderma koningii Tk-5201/CSAU and Trichoderma virens Tvi-4177/CSAU were isolated from a soil sample collected from CSA Farm, Kanpur district of Uttar Pradesh, India. The universal primers (internal transcribed spacer, ITS) were used for the amplification of 18S rRNA gene fragment and strains were thus characterized with the help of ITS marker. It is proposed that the identified strains T. koningii Tk-5201/CSAU and T. virens Tvi-4177/CSAU be assigned as the type strains of a species of genus Trichoderma based on phylogenetic tree analysis together with the 18S rRNA gene sequence search in Ribosomal Database Project, small subunit rRNA and large subunit rRNA databases. The sequence was deposited in GenBank with the accession numbers KC800923 and KC800924, respectively. Thus an integrated approach of morphological and molecular markers can be employed to identify a superior strain of Trichoderma for its commercial exploitation.Keywords: 18S ribosomal RNA gene, Trichoderma, phylogenetic analysis, internal transcribed spacer (ITS), DNA sequencing, GenBankAfrican Journal of Biotechnology, Vol. 13(3), pp. 449-455, 15 January, 201

Growth, yield and economic potential of rice (Oryza sativa) as influenced by different age of seedlings, cultivars and weed management under system of rice intensification

A field experiment was conducted to study the growth, yield and economic potential of rice as influenced by different age of seedlings, cultivars and weed management under system of rice intensification on sandy-clay-loam soil at Agricultural Research Farm of Institute of Agricultural Sciences, Banaras Hindu University during the two consecutive kharif (rainy) seasons of 2010 and 2011. The experiment was laid out in split-plot design with two ages of seedlings with two cultivars assigned to main plots and seven weed management treatments were allocated as sub- plot treatments has replicated thrice. Transplanting of younger age seedling (10 days) of PHB 71 recorded significantly higher growth attributes, viz. plant height, no. of green leaves/hill and dry matter accumulation with yield attributing characters. Similarly, ten days old seedlings of PHB 71 also produced significantly higher yield (grain and straw) that fetched maximum benefit in respect to gross return, net return and B: C ratio over old aged seedling (15 days) of NDR 359 during 2010 and 2011. Among weed management, cono-weeding 4 times at 10, 20, 30 and 40 days after transplanting (DAT) recorded significantly higher growth attributes, yield attributes and yield, but sequential application of pre and post-emergence herbicides, i e pretilachlor + bispyribac-Na was found economically feasible under SRI due to lesser labour requirement

A role for apoptosis-inducing factor in T cell development

Apoptosis-inducing factor (Aif) is a mitochondrial flavoprotein that regulates cell metabolism and survival in many tissues. We report that aif-hypomorphic harlequin (Hq) mice show thymic hypocellularity and a cell-autonomous thymocyte developmental block associated with apoptosis at the β-selection stage, independent of T cell receptor β recombination. No abnormalities are observed in the B cell lineage. Transgenes encoding wild-type or DNA-binding–deficient mutant Aif rectify the thymic defect, but a transgene encoding oxidoreductase activity–deficient mutant Aif does not. The Hq thymic block is reversed in vivo by antioxidant treatment, and Hq T but not B lineage cells show enhanced oxidative stress. Thus, Aif, a ubiquitous protein, serves a lineage-specific nonredundant antiapoptotic role in the T cell lineage by regulating reactive oxygen species during thymic β-selection