E-MTAB-7483
Sepsis induces long-lasting impairments in T helper cell responses despite rapid numerical recovery of T-lymphocyte populations
Our experiments examined T-lymphocyte numbers and effector-functions in peritoneal contamination and infection (PCI) a mouse model of sepsis. One of our main questions was how T-lymphocytes reconstitute after sepsis-induced lymphopenia. We investigated the quantitative and qualitative recovery of T lymphocytes for 3.5 months after sepsis with or without IL-7 treatment. Sepsis is an immunological dysfunction against pathogens leading to inflammation with massive cytokine production. Simultaneously immunosuppression occurs e.g. lymphopenia, which is a hallmark of sepsis. The resulting immunosuppression is associated with secondary infections, which are often lethal. Moreover sepsis-survivors are burdened with increased morbidity and mortality for several years after the sepsis episode. The duration and clinical consequences of sepsis induced-immunosuppression are currently unknown.  More than 50% of T-cells undergo apoptosis shortly after sepsis-induction. However, 8 days after sepsis onset, surviving mice present normal lymphocyte counts. Theoretically, T-cells could reconstitute in two different ways. Firstly, the diminished pool of T-cells is replenished by newly in thymus produced T-cells with new diverse T-cell-receptors (TCRs). Alternatively, remaining T-cells start to proliferate until reaching normal cell count. If this was the case all divided cells shared the same TCRs as primary cells. This could lead to a narrowed TCR diversity within a quantitative normalized T-cell pool and would be an explanation for the long-lasting immune incompetence.  To address the question how T-cells recover from lymphopenia we applied next generation sequencing (NGS) to analyse TCR diversity in septic and healthy mice. One group of septic mice received Interleukin-7 (IL-7), an interleukin which regulates T-cell homeostasis and is a promising therapeutically approach for septic patients.  50000 sequences per mouse were analyzed and the three different groups (controls, sepsis, sepsis + IL-7 treatment) compared regarding their diversity. The sequenced raw data (fastq) are uploaded in this library.
Our experiments examined T-lymphocyte numbers and effector-functions in peritoneal contamination and infection (PCI) a mouse model of sepsis. One of our main questions was how T-lymphocytes reconstitute after sepsis-induced lymphopenia. We investigated the quantitative and qualitative recovery of T lymphocytes for 3.5 months after sepsis with or without IL-7 treatment. Sepsis is an immunological dysfunction against pathogens leading to inflammation with massive cytokine production. Simultaneously immunosuppression occurs e.g. lymphopenia, which is a hallmark of sepsis. The resulting immunosuppression is associated with secondary infections, which are often lethal. Moreover sepsis-survivors are burdened with increased morbidity and mortality for several years after the sepsis episode. The duration and clinical consequences of sepsis induced-immunosuppression are currently unknown.  More than 50% of T-cells undergo apoptosis shortly after sepsis-induction. However, 8 days after sepsis onset, surviving mice present normal lymphocyte counts. Theoretically, T-cells could reconstitute in two different ways. Firstly, the diminished pool of T-cells is replenished by newly in thymus produced T-cells with new diverse T-cell-receptors (TCRs). Alternatively, remaining T-cells start to proliferate until reaching normal cell count. If this was the case all divided cells shared the same TCRs as primary cells. This could lead to a narrowed TCR diversity within a quantitative normalized T-cell pool and would be an explanation for the long-lasting immune incompetence.  To address the question how T-cells recover from lymphopenia we applied next generation sequencing (NGS) to analyse TCR diversity in septic and healthy mice. One group of septic mice received Interleukin-7 (IL-7), an interleukin which regulates T-cell homeostasis and is a promising therapeutically approach for septic patients.  50000 sequences per mouse were analyzed and the three different groups (controls, sepsis, sepsis + IL-7 treatment) compared regarding their diversity. The sequenced raw data (fastq) are uploaded in this library.