The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform

Nivedita Shankar - One of the best experts on this subject based on the ideXlab platform.

  • highly functional virus specific Cellular Immune Response in asymptomatic sars cov 2 infection
    Journal of Experimental Medicine, 2021
    Co-Authors: Nina Le Bert, Hannah E Clapham, Anthony T Tan, Wan Ni Chia, Christine Y L Tham, Jane M Lim, Kamini Kunasegaran, Linda Wei Lin Tan, Charlesantoine Dutertre, Nivedita Shankar
    Abstract:

    The efficacy of virus-specific T cells in clearing pathogens involves a fine balance between antiviral and inflammatory features. SARS-CoV-2-specific T cells in individuals who clear SARS-CoV-2 without symptoms could reveal nonpathological yet protective characteristics. We longitudinally studied SARS-CoV-2-specific T cells in a cohort of asymptomatic (n = 85) and symptomatic (n = 75) COVID-19 patients after seroconversion. We quantified T cells reactive to structural proteins (M, NP, and Spike) using ELISpot and cytokine secretion in whole blood. Frequencies of SARS-CoV-2-specific T cells were similar between asymptomatic and symptomatic individuals, but the former showed an increased IFN-I³ and IL-2 production. This was associated with a proportional secretion of IL-10 and proinflammatory cytokines (IL-6, TNF-α, and IL-1s) only in asymptomatic infection, while a disproportionate secretion of inflammatory cytokines was triggered by SARS-CoV-2-specific T cell activation in symptomatic individuals. Thus, asymptomatic SARS-CoV-2-infected individuals are not characterized by weak antiviral immunity; on the contrary, they mount a highly functional virus-specific Cellular Immune Response.

  • highly functional virus specific Cellular Immune Response in asymptomatic sars cov 2 infection
    bioRxiv, 2020
    Co-Authors: Nina Le Bert, Hannah E Clapham, Anthony T Tan, Wan Ni Chia, Christine Y L Tham, Jane M Lim, Kamini Kunasegaran, Linda Wei Lin Tan, Charlesantoine Dutertre, Nivedita Shankar
    Abstract:

    The efficacy of virus-specific T cells in clearing pathogens involves a fine balance between their antiviral and inflammatory features. SARS-CoV-2-specific T cells in individuals who clear SARS-CoV-2 infection without symptoms or disease could reveal non-pathological yet protective characteristics. We therefore compared the quantity and function of SARS-CoV-2-specific T cells in a cohort of asymptomatic individuals (n=85) with that of symptomatic COVID-19 patients (n=76), at different time points after antibody seroconversion. We quantified T cells reactive to structural proteins (M, NP and Spike) using ELISpot assays, and measured the magnitude of cytokine secretion (IL-2, IFN-{gamma}, IL-4, IL-6, IL-1{beta}, TNF- and IL-10) in whole blood following T cell activation with SARS-CoV-2 peptide pools as a functional readout. Frequencies of T cells specific for the different SARS-CoV-2 proteins in the early phases of recovery were similar between asymptomatic and symptomatic individuals. However, we detected an increased IFN-{gamma} and IL-2 production in asymptomatic compared to symptomatic individuals after activation of SARS-CoV-2-specific T cells in blood. This was associated with a proportional secretion of IL-10 and pro-inflammatory cytokines (IL-6, TNF- and IL-1{beta}) only in asymptomatic infection, while a disproportionate secretion of inflammatory cytokines was triggered by SARS-CoV-2-specific T cell activation in symptomatic individuals. Thus, asymptomatic SARS-CoV-2 infected individuals are not characterized by a weak antiviral immunity; on the contrary, they mount a robust and highly functional virus-specific Cellular Immune Response. Their ability to induce a proportionate production of IL-10 might help to reduce inflammatory events during viral clearance.

Dan Hultmark - One of the best experts on this subject based on the ideXlab platform.

  • jak stat signaling in drosophila muscles controls the Cellular Immune Response against parasitoid infection
    EMBO Reports, 2015
    Co-Authors: Hairu Yang, Jesper Kronhamn, Jens-ola Ekström, Gül Gizem Korkut, Dan Hultmark
    Abstract:

    The role of JAK/STAT signaling in the Cellular Immune Response of Drosophila is not well understood. Here, we show that parasitoid wasp infection activates JAK/STAT signaling in somatic muscles of the Drosophila larva, triggered by secretion of the cytokines Upd2 and Upd3 from circulating hemocytes. Deletion of upd2 or upd3, but not the related os (upd1) gene, reduced the Cellular Immune Response, and suppression of the JAK/STAT pathway in muscle cells reduced the encapsulation of wasp eggs and the number of circulating lamellocyte effector cells. These results suggest that JAK/STAT signaling in muscles participates in a systemic Immune defense against wasp infection.

  • JAK/STAT signaling in Drosophila muscles controls the Cellular Immune Response against parasitoid infection
    EMBO reports, 2015
    Co-Authors: Hairu Yang, Jesper Kronhamn, Jens-ola Ekström, Gül Gizem Korkut, Dan Hultmark
    Abstract:

    The role of JAK/STAT signaling in the Cellular Immune Response of Drosophila is not well understood. Here, we show that parasitoid wasp infection activates JAK/STAT signaling in somatic muscles of the Drosophila larva, triggered by secretion of the cytokines Upd2 and Upd3 from circulating hemocytes. Deletion of upd2 or upd3, but not the related os (upd1) gene, reduced the Cellular Immune Response, and suppression of the JAK/STAT pathway in muscle cells reduced the encapsulation of wasp eggs and the number of circulating lamellocyte effector cells. These results suggest that JAK/STAT signaling in muscles participates in a systemic Immune defense against wasp infection.

  • the rhogef zizimin related acts in the drosophila Cellular Immune Response via the rho gtpases rac2 and cdc42
    Developmental and Comparative Immunology, 2012
    Co-Authors: Christopher Sampson, Dan Hultmark, Susanna Valanne, Marieodile Fauvarque, Mika Ramet, Michael Williams
    Abstract:

    Zizimin-related (Zir), a Rho guanine nucleotide exchange factor (RhoGEF) homologous to the mammalian Dock-C/Zizimin-related family, was identified in a screen to find new genes involved in the Drosophila melanogaster Cellular Immune Response against eggs from the parasitoid wasp Leptopilina boulardi. RhoGEFs activate Rho-family GTPases, which are known to be central regulators of cell migration, spreading and polarity. When a parasitoid wasp is recognized as foreign, multiple layers of circulating immunosurveillance cells (haemocytes) should attach to the egg. In Zir mutants this process is disrupted and lamellocytes, a haemocyte subtype, fail to properly encapsulate the wasp egg. Furthermore, macrophage-like plasmatocytes exhibit a strong reduction in their ability to phagocytise Escherichia coli and Staphylococcus aureus bacteria. During encapsulation and phagocytosis Zir genetically interacts with two Rho-family GTPases, Rac2 and Cdc42. Finally, Zir is dispensable for the humoral Immune Response against bacteria. We propose that Zir is necessary to activate the Rho-family GTPases Rac2 and Cdc42 during the Drosophila Cellular Immune Response.

Nina Le Bert - One of the best experts on this subject based on the ideXlab platform.

  • highly functional virus specific Cellular Immune Response in asymptomatic sars cov 2 infection
    Journal of Experimental Medicine, 2021
    Co-Authors: Nina Le Bert, Hannah E Clapham, Anthony T Tan, Wan Ni Chia, Christine Y L Tham, Jane M Lim, Kamini Kunasegaran, Linda Wei Lin Tan, Charlesantoine Dutertre, Nivedita Shankar
    Abstract:

    The efficacy of virus-specific T cells in clearing pathogens involves a fine balance between antiviral and inflammatory features. SARS-CoV-2-specific T cells in individuals who clear SARS-CoV-2 without symptoms could reveal nonpathological yet protective characteristics. We longitudinally studied SARS-CoV-2-specific T cells in a cohort of asymptomatic (n = 85) and symptomatic (n = 75) COVID-19 patients after seroconversion. We quantified T cells reactive to structural proteins (M, NP, and Spike) using ELISpot and cytokine secretion in whole blood. Frequencies of SARS-CoV-2-specific T cells were similar between asymptomatic and symptomatic individuals, but the former showed an increased IFN-I³ and IL-2 production. This was associated with a proportional secretion of IL-10 and proinflammatory cytokines (IL-6, TNF-α, and IL-1s) only in asymptomatic infection, while a disproportionate secretion of inflammatory cytokines was triggered by SARS-CoV-2-specific T cell activation in symptomatic individuals. Thus, asymptomatic SARS-CoV-2-infected individuals are not characterized by weak antiviral immunity; on the contrary, they mount a highly functional virus-specific Cellular Immune Response.

  • highly functional virus specific Cellular Immune Response in asymptomatic sars cov 2 infection
    bioRxiv, 2020
    Co-Authors: Nina Le Bert, Hannah E Clapham, Anthony T Tan, Wan Ni Chia, Christine Y L Tham, Jane M Lim, Kamini Kunasegaran, Linda Wei Lin Tan, Charlesantoine Dutertre, Nivedita Shankar
    Abstract:

    The efficacy of virus-specific T cells in clearing pathogens involves a fine balance between their antiviral and inflammatory features. SARS-CoV-2-specific T cells in individuals who clear SARS-CoV-2 infection without symptoms or disease could reveal non-pathological yet protective characteristics. We therefore compared the quantity and function of SARS-CoV-2-specific T cells in a cohort of asymptomatic individuals (n=85) with that of symptomatic COVID-19 patients (n=76), at different time points after antibody seroconversion. We quantified T cells reactive to structural proteins (M, NP and Spike) using ELISpot assays, and measured the magnitude of cytokine secretion (IL-2, IFN-{gamma}, IL-4, IL-6, IL-1{beta}, TNF- and IL-10) in whole blood following T cell activation with SARS-CoV-2 peptide pools as a functional readout. Frequencies of T cells specific for the different SARS-CoV-2 proteins in the early phases of recovery were similar between asymptomatic and symptomatic individuals. However, we detected an increased IFN-{gamma} and IL-2 production in asymptomatic compared to symptomatic individuals after activation of SARS-CoV-2-specific T cells in blood. This was associated with a proportional secretion of IL-10 and pro-inflammatory cytokines (IL-6, TNF- and IL-1{beta}) only in asymptomatic infection, while a disproportionate secretion of inflammatory cytokines was triggered by SARS-CoV-2-specific T cell activation in symptomatic individuals. Thus, asymptomatic SARS-CoV-2 infected individuals are not characterized by a weak antiviral immunity; on the contrary, they mount a robust and highly functional virus-specific Cellular Immune Response. Their ability to induce a proportionate production of IL-10 might help to reduce inflammatory events during viral clearance.

Kiron M. Das - One of the best experts on this subject based on the ideXlab platform.

Hannah E Clapham - One of the best experts on this subject based on the ideXlab platform.

  • highly functional virus specific Cellular Immune Response in asymptomatic sars cov 2 infection
    Journal of Experimental Medicine, 2021
    Co-Authors: Nina Le Bert, Hannah E Clapham, Anthony T Tan, Wan Ni Chia, Christine Y L Tham, Jane M Lim, Kamini Kunasegaran, Linda Wei Lin Tan, Charlesantoine Dutertre, Nivedita Shankar
    Abstract:

    The efficacy of virus-specific T cells in clearing pathogens involves a fine balance between antiviral and inflammatory features. SARS-CoV-2-specific T cells in individuals who clear SARS-CoV-2 without symptoms could reveal nonpathological yet protective characteristics. We longitudinally studied SARS-CoV-2-specific T cells in a cohort of asymptomatic (n = 85) and symptomatic (n = 75) COVID-19 patients after seroconversion. We quantified T cells reactive to structural proteins (M, NP, and Spike) using ELISpot and cytokine secretion in whole blood. Frequencies of SARS-CoV-2-specific T cells were similar between asymptomatic and symptomatic individuals, but the former showed an increased IFN-I³ and IL-2 production. This was associated with a proportional secretion of IL-10 and proinflammatory cytokines (IL-6, TNF-α, and IL-1s) only in asymptomatic infection, while a disproportionate secretion of inflammatory cytokines was triggered by SARS-CoV-2-specific T cell activation in symptomatic individuals. Thus, asymptomatic SARS-CoV-2-infected individuals are not characterized by weak antiviral immunity; on the contrary, they mount a highly functional virus-specific Cellular Immune Response.

  • highly functional virus specific Cellular Immune Response in asymptomatic sars cov 2 infection
    bioRxiv, 2020
    Co-Authors: Nina Le Bert, Hannah E Clapham, Anthony T Tan, Wan Ni Chia, Christine Y L Tham, Jane M Lim, Kamini Kunasegaran, Linda Wei Lin Tan, Charlesantoine Dutertre, Nivedita Shankar
    Abstract:

    The efficacy of virus-specific T cells in clearing pathogens involves a fine balance between their antiviral and inflammatory features. SARS-CoV-2-specific T cells in individuals who clear SARS-CoV-2 infection without symptoms or disease could reveal non-pathological yet protective characteristics. We therefore compared the quantity and function of SARS-CoV-2-specific T cells in a cohort of asymptomatic individuals (n=85) with that of symptomatic COVID-19 patients (n=76), at different time points after antibody seroconversion. We quantified T cells reactive to structural proteins (M, NP and Spike) using ELISpot assays, and measured the magnitude of cytokine secretion (IL-2, IFN-{gamma}, IL-4, IL-6, IL-1{beta}, TNF- and IL-10) in whole blood following T cell activation with SARS-CoV-2 peptide pools as a functional readout. Frequencies of T cells specific for the different SARS-CoV-2 proteins in the early phases of recovery were similar between asymptomatic and symptomatic individuals. However, we detected an increased IFN-{gamma} and IL-2 production in asymptomatic compared to symptomatic individuals after activation of SARS-CoV-2-specific T cells in blood. This was associated with a proportional secretion of IL-10 and pro-inflammatory cytokines (IL-6, TNF- and IL-1{beta}) only in asymptomatic infection, while a disproportionate secretion of inflammatory cytokines was triggered by SARS-CoV-2-specific T cell activation in symptomatic individuals. Thus, asymptomatic SARS-CoV-2 infected individuals are not characterized by a weak antiviral immunity; on the contrary, they mount a robust and highly functional virus-specific Cellular Immune Response. Their ability to induce a proportionate production of IL-10 might help to reduce inflammatory events during viral clearance.