Study on Antigen-presenting Function of Gamma Delta T Cells in Sepsis and Its Molecular Mechanisms

Study Overview
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Brief Summary
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Study on antigen-presenting function of gamma delta T cells in sepsis and its molecular mechanisms

Detailed Description
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The latest definition of sepsis highlights the role of dysregulated host response to infection in organ dysfunction aggravation. Maintenance of immune homeostasis of septic patients through immunotherapy is the key breakthrough to improve success rate. Antigen-presenting cell (APC) is the bridge that connects the innate and adaptive immunity. Decrease of count and function of APC has been shown to be associated with worsened clinical outcomes in patients with sepsis. Gamma-delta T cells (γδ T cells) are the newly identified population of T lymphocytes. Recent studies have found that γδ T cells possess unique and powerful antigen-presenting function, making them the hot topic in infection and cancer research. Based on the results, the investigator plan to evaluate the antigen-presenting function changes of γδ T cells in septic status by analyzing the antigen-presenting related molecules on γδ T cells, antigen protein uptake ability, and their function on the proliferation and activation of CD8+ T lymphocytes. Furthermore, the investigator will explore the mechanism and signal pathways for the APC function changes of γδ T cells. Findings from this research could help explain the mechanism of sepsis induced immune dysfunction, enrich our understanding of the important role of γδ T cells, and build a good foundation for immunotherapy in sepsis.

Official Title
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Study on Antigen-presenting Function of Gamma Delta T Cells in Sepsis and Its Molecular Mechanisms

Conditions
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Sepsis, Antigen-presenting Function, γδ T Cells

Intervention / Treatment
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* Other: Collect peripheral blood sample


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ≥18 year old; a known or suspected infection based on clinical data at the time of admission and sepsis-induced dysfunction of at least one organ. Exclusion Criteria: autoimmune disease, history of transplantation, acute tuberculosis, chronic hepatitis B or C infection, HIV infection, active malignancy, and long-term use of cortical steroids.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sepsis<br>Patient diagnosed with sepsis according to the new sepsis definition (infection+SOFA≥2). | Other: Collect peripheral blood sample<br>* Collect 20 ml heparinized blood from patients and controls strictly abiding by the principle of aseptic manipulation after informed consent.<br>|
| Control<br>Age-matched healthy control | Other: Collect peripheral blood sample<br>* Collect 20 ml heparinized blood from patients and controls strictly abiding by the principle of aseptic manipulation after informed consent.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 28-day clinical outcome | death | 28-day after ICU admission |