Targeting Matrix Metalloproteinase-9 to Alleviate T Cell Exhaustion and Improve Sepsis Prognosis
Xuan Wang, Jingyuan Ning, Liang Zhou, Hongru Li, Jinlei Cui, Jiachao Wang, Xiangyang Liang, Jinquan Li, Miao Li, Xue Gao, Wenjian Li, Xing Chen, Fei Yu, Lin Wei, Cuiqing Ma
Abstract
Sepsis remains a leading global cause of death, with immune heterogeneity’s molecular mechanisms poorly understood. This study analyzed 1,862 human peripheral blood samples, constructing a molecular interaction disturbance network that first revealed the network biology underlying sepsis immune heterogeneity. We identified 3 sepsis subtypes with marked different prognostic characteristics, with the C1 subtype showing the worst prognosis characterized by severe CD4 + T cell exhaustion—validated across 10 independent cohorts. Integrating single-cell transcriptomics from over 450,000 cells, proteomics, and functional validation, we identified monocyte-derived matrix metalloproteinase-9 (MMP9) as a key regulator driving CD4 + T cell dysfunction. Mechanistically, MMP9 modulates T cell exhaustion through dual mechanisms: promoting leukocyte-associated immunoglobulin-like receptor-1 (Lair-1) aggregation on T cell membranes, directly inhibiting zeta chain of T cell receptor associated protein kinase 70 (ZAP70) phosphorylation in T cell receptor signaling, while impairing Ca 2+ -release-activated Ca 2+ channel function and intracellular calcium clearance, causing calcium dysregulation that blocks nuclear factor of activated T cells (NFAT) activation and nuclear translocation. The selective MMP9 inhibitor MMP9-in-1 effectively reversed T cell dysfunction, restored calcium homeostasis and NFAT nuclear translocation, markedly enhanced CD4 + T cell interleukin-2 and interferon-γ production, and reduced programmed cell death protein 1 expression. This work establishes a comprehensive translational framework from molecular network disturbances to clinical phenotypes, advancing sepsis immunopathophysiology understanding and providing effective targets for the treatment of sepsis patients.