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Dharmendra P.S. Sengar Daphne B. Hyslop Abdur Rashid Jules E. Harris 《Cellular immunology》1975,20(1):92-97
Subcellular fractions, isolated from the lymphoid cell line IM-1, are capable of stimulating a weak proliferative response in allogeneic lymphocytes. They also stimulate the generation of cytotoxic effector lymphocytes. The proliferative response to subcellular fractions, as measured by 3H-thymidine incorporation, is only one-fourth to one-sixth as great as that to intact IM-1 cells, suggesting that a component(s) synthesized during the mixed lymphocyte reaction (MLR), or a short-lived cellular constituent, may be responsible for the ability of intact cells to stimulate a lymphocyte proliferative response. This component appears to be lacking or in limiting quantity in subcellular fractions, including the soluble fractions. In contrast to the decreased proliferative response to subcellular fractions, the cytotoxic capacity of the stimulated lymphocytes is comparable to that after stimulation by intact IM-1 cells. The data demonstrate that, in this system, cytotoxic effector lymphocytes can be generated in the absence of the extensive proliferative response normally observed in the MLR. The antigenic stimulus responsible for the generation of cytotoxic effector cells appears to reside on intracellular components as well as on plasma membrane. In these reactions, specificity is shown by the failure of the cytotoxic cells to release 51Cr from autologous target cells. In fact, reactivity of lymphocytes stimulated by subcellular fractions is more specific than the reactivity of cells stimulated by intact IM-1 as judged by their lytic capacity for another target cell, RPMI 4265. 相似文献
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Tanuja?Singh Ratul?Saikia Tarakanta?Jana Dilip?K.?AroraEmail author 《Mycological Progress》2004,3(3):219-228
The present investigation was done to understand the fungal-fungal interactions mechanisms based on level of nonspecific adhesion
of a potential fungal mycoparasite (Trichoderma) to their fungal host (Macrophomina phaseolina). The relative cell surface hydrophobicity (CSH) and cell surface electrostatic charge (CSEC) of 29 isolates of Trichoderma species, analyzed by bacterial adhesion to hydrocarbon (BATH), hydrophobic interaction chromatography (HIC), microelectrophoresis
and contact angle, revealed a large degree of variability. CSH and CSEC of conidia depended on culture age, pH and temperature.
Maximum CSH and CSEC were recorded in 25–28 °C range, and both declined significantly with increasing temperature. Isolate
Trichoderma hazianum (Th)-23/98 expressed surface hydrophobicity at 25–28 °C and hydrophilicity at 40 °C. Surface hydrophobicity of the isolate was
susceptible to various proteases (trypsin, pepsin, proteinase k and a-chymotrypsin) and inhibitors (SDS, mercaptoethanol and
Triton X-100) and a significant reduction in CSH was recorded in hydrophobic conidia. Hydrophilic conidia remained more or
less unaffected by such treatments. SDS-PAGE analysis of the hydrophobic and hydrophilic conidia exhibited several protein
bands in the 25 to 61 kDa range. However, each protein population contained one protein that was not observed in the other
population. For hydrophobic conidia, the unique protein had an apparent molecular mass of 49 kDa, while the unique protein
associated with hydrophilic conidia had a molecular mass of 61 kDa. Our findings suggest that CSH and CSEC of mycoparasitic
Trichoderma may contribute to non-specific adhesion on to the sclerotial surfaces of Macrophomina phaseolina that may be influenced by growth and environmental conditions. 相似文献
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Mridusmita Saikia Ye Fu Mariana Pavon-Eternod Chuan He Tao Pan 《RNA (New York, N.Y.)》2010,16(7):1317-1327
The N1-methyl-Adenosine (m1A58) modification at the conserved nucleotide 58 in the TΨC loop is present in most eukaryotic tRNAs. In yeast, m1A58 modification is essential for viability because it is required for the stability of the initiator-tRNAMet. However, m1A58 modification is not required for the stability of several other tRNAs in yeast. This differential m1A58 response for different tRNA species raises the question of whether some tRNAs are hypomodified at A58 in normal cells, and how hypomodification at A58 may affect the stability and function of tRNA. Here, we apply a genomic approach to determine the presence of m1A58 hypomodified tRNAs in human cell lines and show how A58 hypomodification affects stability and involvement of tRNAs in translation. Our microarray-based method detects the presence of m1A58 hypomodified tRNA species on the basis of their permissiveness in primer extension. Among five human cell lines examined, approximately one-quarter of all tRNA species are hypomodified in varying amounts, and the pattern of the hypomodified tRNAs is quite similar. In all cases, no hypomodified initiator-tRNAMet is detected, consistent with the requirement of this modification in stabilizing this tRNA in human cells. siRNA knockdown of either subunit of the m1A58-methyltransferase results in a slow-growth phenotype, and a marked increase in the amount of m1A58 hypomodified tRNAs. Most m1A58 hypomodified tRNAs can associate with polysomes in varying extents. Our results show a distinct pattern for m1A58 hypomodification in human tRNAs, and are consistent with the notion that this modification fine tunes tRNA functions in different contexts. 相似文献
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Saikia Banashree Singh Sanjay Debbarma Johni Velmurugan Natarajan Dekaboruah Hariprasanna Arunkumar Kallare P. Chikkaputtaiah Channakeshavaiah 《Physiology and Molecular Biology of Plants》2020,26(5):857-869
Physiology and Molecular Biology of Plants - The recent global climate change has directly impacted major biotic and abiotic stress factors affecting crop productivity worldwide. Therefore, the... 相似文献
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Jayanta Kumar Nath Minakshi Kalita Anu Saikia Hrishikesh Choudhury D. Khlur B. Mukhim Dandadhar Sarma 《Zeitschrift fur angewandte Ichthyologie》2021,37(2):268-277
The present study provides the first detailed early embryonic development of the Shalyni barb, Pethia shalynius (Yazdani & Talukdar, 1975), a vulnerable cyprinid fish occurring in streams and lentic waters of Meghalaya, northeast India. Induced spawning by synthetic hormone injection in May 2019 was conducted to a pair of mature female and male P. shalynius under controlled conditions in a well-aerated aquarium. Fertilized eggs were spherical, 0.75–0.80 mm (approx.) in diameter, transparent, unpigmented and non-adhesive. A total of 22 developmental stages could be categorized under seven broad periods, viz. the zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatchling. The first cleavage occurred at 15 min post fertilization (mpf), followed by blastulation at 01:23 hr post-fertilization (hpf), gastrulation at 04:20 hpf, initial somite formation at 07:00 hpf, and pharyngula period at 19:20 hpf, respectively. Embryos hatched between 26–27 hpf and the newly-hatched larvae ranged 2.2–2.5 mm in total length. For naturally-declining populations of this vulnerable fish species, inferences drawn from the present study will help provide a baseline data for its conservation and management, and aid the research fields of developmental biology, biotechnology, molecular biology as well as taxonomy of this species. 相似文献
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Saikia Snigdha Pal Uttariya Kalita Deep Jyoti Rai Avdhesh Kumar Sarma Anupam Kataki Amal Chandra Limaye Anil Mukund 《Molecular biology reports》2021,48(7):5399-5409
Molecular Biology Reports - RUNX1T1 is extensively studied in the context of AML1-RUNX1T1 fusion protein in acute myeloid leukemia. Little is known about the function of RUNX1T1 itself, although... 相似文献
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Dharmendra Puri Keerthana Ponniah Kasturi Biswas Atrayee Basu Swagata Dey Erik A. Lundquist Anindya Ghosh-Roy 《The Journal of cell biology》2021,220(9)
Neuronal polarization is facilitated by the formation of axons with parallel arrays of plus-end-out and dendrites with the nonuniform orientation of microtubules. In C. elegans, the posterior lateral microtubule (PLM) neuron is bipolar with its two processes growing along the anterior–posterior axis under the guidance of Wnt signaling. Here we found that loss of the Kinesin-13 family microtubule-depolymerizing enzyme KLP-7 led to the ectopic extension of axon-like processes from the PLM cell body. Live imaging of the microtubules and axonal transport revealed mixed polarity of the microtubules in the short posterior process, which is dependent on both KLP-7 and the minus-end binding protein PTRN-1. KLP-7 is positively regulated in the posterior process by planar cell polarity components of Wnt involving rho-1/rock to induce mixed polarity of microtubules, whereas it is negatively regulated in the anterior process by the unc-73/ced-10 cascade to establish a uniform microtubule polarity. Our work elucidates how evolutionarily conserved Wnt signaling establishes the microtubule polarity in neurons through Kinesin-13. 相似文献
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Dharmendra Kumar Thirumala R Talluri Naresh L Selokar Iqbal Hyder Wilfried A Ku 《World journal of stem cells》2021,13(1):1-29
The recent progress in derivation of pluripotent stem cells(PSCs)from farm animals opens new approaches not only for reproduction,genetic engineering,treatment and conservation of these species,but also for screening novel drugs for their efficacy and toxicity,and modelling of human diseases.Initial attempts to derive PSCs from the inner cell mass of blastocyst stages in farm animals were largely unsuccessful as either the cells survived for only a few passages,or lost their cellular potency;indicating that the protocols which allowed the derivation of murine or human embryonic stem(ES)cells were not sufficient to support the maintenance of ES cells from farm animals.This scenario changed by the innovation of induced pluripotency and by the development of the 3 inhibitor culture conditions to support na?ve pluripotency in ES cells from livestock species.However,the long-term culture of livestock PSCs while maintaining the full pluripotency is still challenging,and requires further refinements.Here,we review the current achievements in the derivation of PSCs from farm animals,and discuss the potential application areas. 相似文献