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Research Interests: Biochemistry, Caenorhabditis elegans, Biology, Biological Chemistry, Medicine, and 13 moreBiological Sciences, RNA interference, Phylogeny, Animals, Phenotype, CHEMICAL SCIENCES, Molecular cloning, Time Factors, Veterinary Sciences, Amino Acid Sequence, Recombinant Proteins, Molecular Sequence Data, and Medical and Health Sciences
Among various metal-based nanoparticles, silver nanoparticles (AgNPs) manifest superior inhibitory effects against several microorganisms. In fact, the AgNP-based treatment has been reported to inhibit both sensitive and resistant... more
Among various metal-based nanoparticles, silver nanoparticles (AgNPs) manifest superior inhibitory effects against several microorganisms. In fact, the AgNP-based treatment has been reported to inhibit both sensitive and resistant isolates of bacteria and other disease-causing microbes with equal propensity. Keeping this fact into consideration, we executed bio-mediated synthesis of AgNPs employing extract of flower and various other parts (such as bud and leaf) of the Hibiscus rosa-sinensis plant. The physicochemical characterization of as-synthesized AgNPs was executed employing transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, Fourier transform infrared (FTIR) spectroscopy, and UV-Vis spectroscopy, etc. The as-synthesized AgNPs demonstrated strong antimicrobial activity against both Gram-positive and Gram-negative bacteria with equal propensity. The as-synthesized AgNPs successfully inhibited Streptococcus mutans (S. mutans), one of the main ...
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Diagnosis of visceral leishmaniasis (VL) is often hindered by cross-reactions with antigens from other related parasite infections. This study aimed to develop an immunochromatographic test (ICT) which can detect the antigen present in... more
Diagnosis of visceral leishmaniasis (VL) is often hindered by cross-reactions with antigens from other related parasite infections. This study aimed to develop an immunochromatographic test (ICT) which can detect the antigen present in circulating immune complexes (CICs) of VL patients using B-cell epitope-specific antibodies. MS analysis of six immunoreactive 2DE spots revealed two epitopes i.e. RFFVQGDGIGQHSLQEALERR (P<sub>1</sub>) and RRVAVLVLLDRL (P<sub>2</sub>) (From a hypothetical protein [Acc No: XP_003861458.1]). The epitope conservancy analysis suggested that the linear epitope (P<sub>1</sub>P<sub>2</sub>) is 97–100% conserved among <i>Leishmania</i> species and diverged from <i>Homo sapiens</i> (61% query coverage and 80% identity). Further, immunoinformatics analysis of hydrophilicity and flexibility confirmed the antigenicity of the peptide fragment. The linear epitope (P<sub>1</sub>P<...
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During the last 2 years, the entire world has been severely devastated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic (COVID-19) as it resulted in several million deaths across the globe. While the virus... more
During the last 2 years, the entire world has been severely devastated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic (COVID-19) as it resulted in several million deaths across the globe. While the virus infects people indiscriminately, the casualty risk is higher mainly in old, and middle-aged COVID-19 patients. The incidences of COVID-19 associated co-morbidity and mortality have a great deal of correlation with the weakened and malfunctioning immune systems of elderly people. Presumably, due to the physiological changes associated with aging and because of possible comorbidities such as diabetes, hypertension, obesity, cardiovascular, and lung diseases, which are more common in elderly people, may be considered as the reason making the elderly vulnerable to the infection on one hand, and COVID-19 associated complications on the other. The accretion of senescent immune cells not only contributes to the deterioration of host defense, but also results i...
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Protein Profiling of Rice for Drought under Stress and Recovery Regimes by Two-Dimensional Electrophoresis
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Tuberculosis (TB) is a significant and continuing problem worldwide, with a death toll of around 1.5 million human lives annually. BCG, the only vaccine against TB, offers a varied degree of protection among human subjects in different... more
Tuberculosis (TB) is a significant and continuing problem worldwide, with a death toll of around 1.5 million human lives annually. BCG, the only vaccine against TB, offers a varied degree of protection among human subjects in different regions and races of the world. The majority of the population living near the tropics carries a varying degree of tolerance against BCG due to the widespread prevalence of non-tuberculous mycobacteria (NTM). Interestingly, ≈90% of the Mycobacterium tuberculosis (Mtb) infected population restrain the bacilli on its own, which strengthens the notion of empowering the host immune system to advance the protective efficacy of existing mycobacterial vaccines. In general, Mtb modulates IL-10/STAT3 signaling to skew host mononuclear phagocytes toward an alternatively activated, anti-inflammatory state that helps it thrive against hostile immune advances. We hypothesized that modulating the IL-10/STAT3 driven anti-inflammatory effects in mononuclear cells may...
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The shift of macrophage and T-cell repertoires towards proinflammatory cytokine signalling ensures the generation of host-protective machinery that is otherwise compromised in cases of the intracellular Leishmania parasite. Different... more
The shift of macrophage and T-cell repertoires towards proinflammatory cytokine signalling ensures the generation of host-protective machinery that is otherwise compromised in cases of the intracellular Leishmania parasite. Different groups have attempted to restore host protective immunity. These vaccine candidates showed good responses and protective effects in murine models, but they generally failed during human trials. In the present study, we evaluated the effect of 97 kDa recombinant nucleoporin-93 of Leishmania donovani (rLd-NUP93) on mononuclear cells in healthy and treated visceral leishmaniasis (VL) patients and on THP-1 cell lines. rLd-NUP93 stimulation increased the expression of the early lymphocyte activation marker CD69 on CD4 and CD8 T cells. The expression of the host protective pro-inflammatory cytokines IFN-γ, IL-12 and TNF-α was increased, with a corresponding down-regulation of IL-10 and TGF-β upon rLd-NUP93 stimulation. This immune polarization resulted in the...
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Visceral leishmaniasis (VL) is a disease caused by protozoan species of the genus Leishmania and is transmitted through bites from the Phlebotomus sand fly; it is associated with considerable morbidity and mortality in many parts of... more
Visceral leishmaniasis (VL) is a disease caused by protozoan species of the genus Leishmania and is transmitted through bites from the Phlebotomus sand fly; it is associated with considerable morbidity and mortality in many parts of world, including India. Reports on the protective role played by saliva proteins of Lutozomyia longipalpis, Phlebotomus papatasi and Phlebotomus duboscqi. are available. However, no studies have explored the salivary proteins of P. argentipes, which is the known proven vector for the transmission of VL in the Indian sub-continent. Herein we revealed the presence of two proteins of 14.2 and one protein of 13.6 kDa in Indian strain P. argentipes which is absolute identical to previously reported protein of SP15 family (PagSP01, PagSP02 and PagSP07) of P. argentipes of NIH colony, USA. In an experimental study on P. argentipes from Bihar, India, we demonstrated that a strong humoral and cellular immune response was triggered to reduce the concomitant Leishm...
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Sterile cure from visceralized Leishmania donovani (L. donovani) needs Th1 cell support along with the assistance from innate immune cells, NK cells and NKT cells. NKT cells play as a connecting link between innate and adaptive immune... more
Sterile cure from visceralized Leishmania donovani (L. donovani) needs Th1 cell support along with the assistance from innate immune cells, NK cells and NKT cells. NKT cells play as a connecting link between innate and adaptive immune cell and support T helper cell function. Earlier, a categorical function of CD56 positive CD4 or CD8 NKT cells was reported in visceral leishmaniasis (VL). It was observed in in vitro that CD4CD56NKT cells, but not CD8CD56NKT cells, were accumulated at the L. donovani infection site. Therefore, in vitro experiments have been carried out to decipher the mechanism behind preferential accumulation of CD4CD56NKT cells at infection site. In this study, 1.89 fold higher expression of CCL4/MIP-1β was noticed in infected macrophages. The higher expression of CCL4 was correlated with preferential accumulation of CCR5CD4CD56NKT cells and apoptosis of CD8CD56NKT cells at in vitro infection site. The CD4CD56NKT cells were also observed expressing TGF-β dominantly....
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This study reports a structural and functional heterogeneity of CD8CD56NKT cells, which usually decrease quantitatively during visceral leishmaniasis. Based on fluorescence intensity of CD8 receptors on CD56NKT cells, two populations of... more
This study reports a structural and functional heterogeneity of CD8CD56NKT cells, which usually decrease quantitatively during visceral leishmaniasis. Based on fluorescence intensity of CD8 receptors on CD56NKT cells, two populations of CD8CD56NKT cells have been identified. These cells were recognized as CD8CD56NKT and CD8CD56NKT cells. We further analyzed the functional nature of CD8 and CD8 positive CD56NKT cells. In comparison to CD8CD56NKT cells, a significantly higher percentage of CD8CD56NKT cells expressed KIR during VL. The percentage of CD8CD56NKT cells expressing KIR was found 4 fold higher in VL as compared to healthy subjects. But, the difference was insignificant in case of CD8CD56NKT cells. CD8CD56NKT cells release granzyme B to kill the infected cells. A categorical difference was also observed in the function of CD8CD56NKT and CD8CD56NKT cells during visceral leishmaniasis. The percentage of granzyme B expressing CD8CD56NKT cells was 2.83 fold higher in VL compared ...
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Visceral leishmaniasis (VL) is one of the most neglected tropical diseases for which no vaccine exists. In spite of extensive efforts, no successful vaccine is available against this dreadful infectious disease. To support vaccine... more
Visceral leishmaniasis (VL) is one of the most neglected tropical diseases for which no vaccine exists. In spite of extensive efforts, no successful vaccine is available against this dreadful infectious disease. To support vaccine development, an immunoinformatics approach was applied to screen potential MHC class-II-restricted epitopes that can activate the immune cells. Initially, 37 epitopes derived from six stage-dependent, overexpressed antigens were predicted, which were presented by at least 26 diverse MHC class-II allele. Based on a population coverage analysis and human leukocyte antigen cross-presentation ability, six of the 37 epitopes were selected for further analysis. Stimulation with synthetic peptide alone or as a cocktail triggered intracellular IFN-γ production. Moreover, specific IgG antibodies were detected in the serum of active VL cases against P1, P4, P5, and P6 in order to evaluate the peptide effect on the humoral immune response. Additionally, most of the p...
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Diagnosis of visceral leishmaniasis (VL) is often hindered by cross-reactions with antigens from other related parasite infections. This study aimed to develop an immunochromatographic test (ICT) which can detect the antigen present in... more
Diagnosis of visceral leishmaniasis (VL) is often hindered by cross-reactions with antigens from other related parasite infections. This study aimed to develop an immunochromatographic test (ICT) which can detect the antigen present in circulating immune complexes (CICs) of VL patients using B-cell epitope-specific antibodies. MS analysis of six immunoreactive 2DE spots revealed two epitopes i.e. RFFVQGDGIGQHSLQEALERR (P1) and RRVAVLVLLDRL (P2) (From a hypothetical protein [Acc No: XP_003861458.1]). The epitope conservancy analysis suggested that the linear epitope (P1P2) is 97-100% conserved among Leishmania species and diverged from Homo sapiens (61% query coverage and 80% identity). Further, immunoinformatics analysis of hydrophilicity and flexibility confirmed the antigenicity of the peptide fragment. The linear epitope (P1P2) was synthesized (98% purity) and the purity was confirmed by high-performance liquid chromatography and MS. The indirect Enzyme linked immunosorbent assay...
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Research Interests: Microbiology, Immunology, Biology, Ecology, Response, and 15 moreInfectious Diseases, Medicine, Multidisciplinary, Visceral Leishmaniasis, TNF, ROS, PLoS one, IL, IFN, Immune system, Arsenic Exposure, VL, Thiol, As, and Host
Among various metal-based nanoparticles, silver nanoparticles (AgNPs) manifest superior inhibitory effect against several microorganisms. In fact, the AgNPs based therapy has been reported to inhibit both sensitive as well resistant... more
Among various metal-based nanoparticles, silver nanoparticles (AgNPs) manifest superior inhibitory effect against several microorganisms. In fact, the AgNPs based therapy has been reported to inhibit both sensitive as well resistant isolates of bacteria and other disease causing microbes with equal propensity. Keeping this fact into consideration, we executed bio-mediated synthesis of AgNPs employing Hibiscus rosa sinensis flower extract. The as-synthesized AgNPs were evaluated for their potential to inhibit Streptococcus mutans (S. mutans), one of the main causative bacteria for dental caries. Beside several other reasons, orthodontic appliances have also been reported to facilitate infliction of oral cavity with a range of microbes including S. mutans. To determine the growth inhibitory and anti-adherence activity of AgNPs on orthodontic appliance, we performed microbiological assays employing AgNPs adsorbed on to the orthodontic wires. Topographic analysis of orthodontic wires wa...