Current treatments for diabetic ulcers (DUs) remain unsatisfactory due to the risk of bacterial infection and impaired angiogenesis during the healing process. The increased degradation of polyubiquitinated hypoxia‐inducible factor‐1α (HIF‐1α) compromises wound healing efficacy. Therefore, the maintenance of HIF‐1α protein stability might help treat DU. Nitric oxide (NO) is an intrinsic biological messenger that functions as a ubiquitination flow repressor and antibacterial agent; however, its clinical application in DU treatment is hindered by the difficulty in controlling NO release. Here, an intelligent near‐infrared (NIR)‐triggered NO nanogenerator (SNP@MOF‐UCNP@ssPDA‐Cy7/IR786s, abbreviated as SNP@UCM) is presented. SNP@UCM represses ubiquitination‐mediated proteasomal degradation of HIF‐1α by inhibiting its interaction with E3 ubiquitin ligases under NIR irradiation. Increased HIF‐1α expression in endothelial cells by SNP@UCM enhances angiogenesis in wound sites, promoting vascular endothelial growth factor (VEGF) secretion and cell proliferation and migration. SNP@UCM also enables early detection of wound infections and ROS‐mediated killing of bacteria. The potential clinical utility of SNP@UCM is further demonstrated in infected full‐thickness DU model under NIR irradiation. SNP@UCM is the first reported HIF‐1α‐stabilizing advanced nanomaterial, and further materials engineering might offer a facile, mechanism‐based method for clinical DU management.
Candida auris is a multidrug-resistant human fungal pathogen responsible for nosocomial outbreaks worldwide. Although considerable progress has increased our understanding of the biological and clinical aspects of C. auris, its interaction with the host immune system is only now beginning to be investigated in-depth. Here, we compare the innate immune responses induced by C. auris BJCA001 and Candida albicans SC5314 in vitro and in vivo. Our results indicate that C. auris BJCA001 appears to be less immunoinflammatory than C. albicans SC5314, and this differential response correlates with structural features of the cell wall.
Highlights d Fever promotes a4-integrin-mediated T cell adhesion and transmigration d Hsp90 binds to a4 tails and activates a4 integrins via insideout signaling d Hsp90 triggers dimerization and clustering of a4 integrins to activate FAK-RhoA d Disruption of Hsp90-a4 interaction impairs fever-induced T cell trafficking SUMMARYFever is an evolutionarily conserved response that confers survival benefits during infection. However, the underlying mechanism remains obscure. Here, we report that fever promoted T lymphocyte trafficking through heat shock protein 90 (Hsp90)induced a4 integrin activation and signaling in T cells. By inducing selective binding of Hsp90 to a4 integrins, but not b2 integrins, fever increased a4-integrin-mediated T cell adhesion and transmigration. Mechanistically, Hsp90 bound to the a4 tail and activated a4 integrins via inside-out signaling. Moreover, the N and C termini of one Hsp90 molecule simultaneously bound to two a4 tails, leading to dimerization and clustering of a4 integrins on the cell membrane and subsequent activation of the FAK-RhoA pathway. Abolishment of Hsp90-a4 interaction inhibited fever-induced T cell trafficking to draining lymph nodes and impaired the clearance of bacterial infection. Our findings identify the Hsp90-a4-integrin axis as a thermal sensory pathway that promotes T lymphocyte trafficking and enhances immune surveillance during infection.
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