The Experts below are selected from a list of 67212 Experts worldwide ranked by ideXlab platform
Maria M E De Bracco - One of the best experts on this subject based on the ideXlab platform.
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increased lymphocyte viability after non Stimulated peripheral blood mononuclear cell pbmc Culture in patients with x linked lymphoproliferative disease xlp
Clinical Immunology, 2009Co-Authors: Liliana Belmonte, Cecilia Parodi, Mariela Baston, Ana Coraglia, M Felippo, Patricia Bare, Alejandro Malbran, B Ruibalares, Maria M E De BraccoAbstract:Abstract Survival of lymphocytes after prolonged Culture was studied in two asymptomatic XLP patients. Viability of XLP PBMC after 30 days of non-Stimulated Culture was higher than that of normal controls (N), mainly due to the persistence of CD8 memory lymphocytes. IFNγ high CD8 T lymphocytes remained higher in XLP than in N after 30 days. The number of perforin+ CD8 lymphocytes was markedly reduced after 30 days in XLP and in N. Increased viability was not related to CD127, PD-1, CD27, or CD62L expression. Concerning B lymphocytes, memory CD27+ CD19+ cells prevailed over CD27− cells after 30 days in both XLP and N, with far more surviving cells in XLP. In N, few CD19+ B lymphocytes were viable after prolonged Culture. In XLP, these cells were also IgD+, IgM+ and EBNA2+. These results demonstrate that IFNγ-positive memory CD8 T cells persist in XLP after prolonged Culture in association with a subset of viable memory CD27+ B cells expressing latent EBV antigens. The survival advantage of XLP cells might be related to increased frequency of extranodal lymphoma in XLP patients.
Lloyd H. Kasper - One of the best experts on this subject based on the ideXlab platform.
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impairment of the cellular immune response in acute murine toxoplasmosis regulation of interleukin 2 production and macrophage mediated inhibitory effects
Infection and Immunity, 1994Co-Authors: Sakhina Haque, Im Khan, Ashanul Haque, Lloyd H. KasperAbstract:Depression of the cellular immune response to Toxoplasma gondii has been reported in both mice and humans. The present study was undertaken to determine the kinetics and mechanism of the observed downregulation of interleukin 2 (IL-2) production during experimental murine toxoplasmosis. For these investigations, the cell-mediated immune response to the wild type (PTg) was compared with that to the less-virulent mutant parasite (PTgB), which is deficient in the major surface antigen, p30 (SAG-1). Spleen cells from infected A/J mice failed to proliferate in response to Toxoplasma antigens during the first week of infection. Both PTg- and PTgB-infected A/J mice exhibited a significant reduction in the concanavalin A (Con A)-induced lymphoproliferative response. Further, the response of splenocytes from mice infected with the wild-type parasite was significantly diminished compared with that of mice infected with PTgB. The lymphoproliferative response to Con A reached its nadir at day 7 and remained below control levels for at least 14 days postinfection. By day 21 postinfection, the response to Con A and to Toxoplasma antigens was restored to the level observed prior to day 7. Con A-Stimulated Culture supernatants of spleen cells from mice on day 7 postinfection contained significantly less IL-2 than normal mice. There was no significant difference in the numbers of binding sites or capacity of high-affinity IL-2 receptors between infected and normal mouse splenocytes as determined by Scatchard analysis. Exogenous IL-2 at different concentrations failed to restore the proliferative response of lymphocytes from infected mice to Con A. Adherent macrophages from 7-day-infected mice were able to suppress IL-2 production by normal splenocytes following stimulation with Con A. The inhibitory activity mediated by infected cells was reversed by the antibody to IL-10 but not transforming growth factor beta. There were insignificant levels of nitric oxide production in both infected and normal splenocytes. These results indicate that during acute murine toxoplasmosis, there is a well-defined period (day 7) during which both the T-cell mitogen and parasite antigen-associated lymphoproliferative response are reduced. Further, there is a reduction in the production of IL-2 and an increase in IL-10, which appear to mediate, in part, the observed downregulation of immunity to T. gondii.
Liliana Belmonte - One of the best experts on this subject based on the ideXlab platform.
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increased lymphocyte viability after non Stimulated peripheral blood mononuclear cell pbmc Culture in patients with x linked lymphoproliferative disease xlp
Clinical Immunology, 2009Co-Authors: Liliana Belmonte, Cecilia Parodi, Mariela Baston, Ana Coraglia, M Felippo, Patricia Bare, Alejandro Malbran, B Ruibalares, Maria M E De BraccoAbstract:Abstract Survival of lymphocytes after prolonged Culture was studied in two asymptomatic XLP patients. Viability of XLP PBMC after 30 days of non-Stimulated Culture was higher than that of normal controls (N), mainly due to the persistence of CD8 memory lymphocytes. IFNγ high CD8 T lymphocytes remained higher in XLP than in N after 30 days. The number of perforin+ CD8 lymphocytes was markedly reduced after 30 days in XLP and in N. Increased viability was not related to CD127, PD-1, CD27, or CD62L expression. Concerning B lymphocytes, memory CD27+ CD19+ cells prevailed over CD27− cells after 30 days in both XLP and N, with far more surviving cells in XLP. In N, few CD19+ B lymphocytes were viable after prolonged Culture. In XLP, these cells were also IgD+, IgM+ and EBNA2+. These results demonstrate that IFNγ-positive memory CD8 T cells persist in XLP after prolonged Culture in association with a subset of viable memory CD27+ B cells expressing latent EBV antigens. The survival advantage of XLP cells might be related to increased frequency of extranodal lymphoma in XLP patients.
Bernadeta Nowak - One of the best experts on this subject based on the ideXlab platform.
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suppression of allergic reaction by λ carrageenan toll like receptor 4 myd88 dependent and independent modulation of immunity
Clinical & Experimental Allergy, 2003Co-Authors: R F Tsuji, N M Tsuji, T Kurokawa, Katsuaki Hoshino, Yasuhiro Noro, Shizuo Akira, T Masuda, Bernadeta NowakAbstract:Summary Background Recognition of foreign substances by innate immunity through pattern recognition receptors (PRRs) regulates acquired immunity such as allergic reaction. Because PRRs recognize heterogeneous ligands, daily food intake can potentially regulate immune allergic reaction. Objective Elucidation of the effect of λ-carrageenan on allergic reactions was aimed. Method IFN-γ and IL-4 was measured in in vitro T cell-Stimulated Culture. Cytokine production from macrophages in response to λ-carrageenan was measured as indicator for innate immunity activation. Mice were immunized with OVA in alum to induce specific IgE, and then histamine release was induced by systemic injection of OVA. Results Activation of innate immunity by λ-carrageenan is dependent on Toll-like receptor-4 (TLR4) and MyD88, in which induction of pro-inflammatory cytokines such as TNF-α and IL-6 was largely impaired in macrophages from TLR4- and MyD88-deficient mice. Footpad oedema, a model for in vivo inflammatory reactions, was significantly reduced in these mice. Similar to recent evidence showing a preference for the stimulation of Th1 via TLR/MyD88 signalling, λ-carrageenan showed enhanced IFN-γ and decreased IL-4 in Stimulated T cell Cultures. Interestingly, increased IFN-γ production was still seen in TLR4- and MyD88-deficient splenocytes. Oral administration of λ-carrageenan to immunized mice successfully decreased OVA-specific IgE, and λ-carrageenan was also effective in previously immunized mice. Further, serum histamine release upon systemic challenge of OVA was significantly inhibited. Neither OVA-specific IgG1/IgG2a nor cytokine secretion from in vitro Cultures were altered, suggesting the involvement of multiple PRRs as demonstrated by TLR4/MyD88-independent IFN-γ up-regulation. The simultaneous feeding of OVA with lipopolysaccharide abrogated oral tolerance, but λ-carrageenan was not only devoid of such an effect but was also found to promote oral tolerance in the absence of TLR4. Conclusion λ-Carrageenan was suggested to be a useful dietary supplement to ameliorate allergic reactions while maintaining oral tolerance-dependent intestinal homeostasis.
Vijay Kothari - One of the best experts on this subject based on the ideXlab platform.
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Investigation on the effect of sonic stimulation on Xanthomonas campestris at the whole transcriptome level
2019Co-Authors: Pooja Patel, Chinmayi Joshi, Vijay KothariAbstract:Abstract A gram-negative bacterium Xanthomonas campestris was subjected to sonic stimulation with sound pertaining to 1000 Hz at three different sound intensities. The X. campestris Culture subjected to sonic stimulation at 66 dB produced 1.69 fold higher exopolysaccharide. Whole transcriptome analysis of this sonic-Stimulated Culture revealed a total of 115 genes expressed differentially in the sonic-Stimulated Culture, majority of which were coding for different proteins including enzyme. This study demonstrates the property of the test bacterium of being responsive to sonic/vibrational stimulation.
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frequency dependent response of chromobacterium violaceum to sonic stimulation and altered gene expression associated with enhanced violacein production at 300 hz
Current Science, 2018Co-Authors: Chinmayi Joshi, Pooja Patel, Abhishek Singh, Jinal Sukhadiya, Vidhi Shah, Vijay KothariAbstract:In this study, Chromobacterium violaceum was subjected to sonic (100–2000 Hz) stimulation. Sound waves of 300 Hz frequency promoted bulk production of the quorum-regulated pigment, violacein. Whole transcriptome analysis indicated that a total of 342 genes (i.e. 4.63% of the whole genome) were significantly upregulated in the sonic Stimulated Culture. Enhanced violacein production in the sound-Stimulated Culture seems to have stemmed from enhanced expression of the genes involved in pentose phosphate pathway, resulting in an increased availability of erythrose-4-phosphate to be used in the synthesis of tryptophan – the precursor of violacein synthesis. This study is a good demonstration of the ability of sound waves to alter bacterial metabolism.
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frequency dependent response of chromobacterium violaceum to sonic stimulation and altered gene expression associated with enhanced violacein production at 300 hz
bioRxiv, 2017Co-Authors: Chinmayi Joshi, Pooja Patel, Abhishek Singh, Jinal Sukhadiya, Vidhi Shah, Vijay KothariAbstract:Chromobacterium violaceum was subjected to sonic (100-2000 Hz) stimulation, and the effect on its cell yield and quorum sensing regulated pigment (violacein) production was investigated. Sound corresponding to the 300 Hz was found to promote (by 1.52 fold) violacein production the most, with only marginal impact on cell yield. Whole transcriptome analysis revealed that a total of 342 genes (i.e. 4.63% of whole genome) were significantly up-regulated in the sonic Stimulated Culture. Enhanced violacein production in the sound Stimulated Culture seems to have stemmed from enhanced expression of the genes involved in glucose metabolism through pentose phosphate pathway, resulting in increased availability of erythrose-4-phosphate, to be used for synthesis of tryptophan, the precursor for violacein synthesis. Multiple ribosomal subunit genes, enzyme coding genes, and those associated with secretion/transport were up-regulated owing to sonic stimulation. This study is a good demonstration of the ability of sound waves to alter bacterial metabolism.