Open AccessExosomal PD‐L1 functions as an immunosuppressant to promote wound healing
Author(s) -
Su Dandan,
Tsai HsiangI,
Xu Zhanxue,
Yan Fuxia,
Wu Yingyi,
Xiao Youmei,
Liu Xiaoyan,
Wu Yanping,
Parvanian Sepideh,
Zhu Wangshu,
Eriksson John E.,
Wang Dongqing,
Zhu Haitao,
Chen Hongbo,
Cheng Fang
Publication year - 2020
Publication title -
journal of extracellular vesicles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.94
H-Index - 68
ISSN - 2001-3078
DOI - 10.1080/20013078.2019.1709262
Subject(s) - microvesicles , wound healing , inflammation , cancer research , immune system , cd8 , t cell , exosome , chemistry , microbiology and biotechnology , medicine , immunology , microrna , biology , biochemistry , gene
Excessive and persistent inflammation after injury lead to chronic wounds, increased tissue damage or even aggressive carcinogenic transformation. Effective wound repair could be achieved by inhibiting overactive immune cells to the injured site. In this study, we obtained high concentration of PD‐L1 in exosomes from either genetically engineered cells overexpressing PD‐L1 or IFN‐γ stimulated cells. We found that exosomal PD‐L1 is specially bound to PD‐1 on T cell surface, and suppressed T cell activation. Interestingly, exosomal PD‐L1 promoted the migration of epidermal cells and dermal fibroblasts when pre‐incubated with T cells. We further embedded exosomes into thermoresponsive PF‐127 hydrogel, which was gelatinized at body temperature to release exosomes to the surroundings in a sustained manner. Of importance, in a mouse skin excisional wound model, exosomal PD‐L1 significantly fastened wound contraction and reepithelialization when embedded in hydrogel during inflammation phase. Finally, exosomal PD‐L1 inhibited cytokine production of CD8+ T cells and suppressed CD8+ T cell numbers in spleen and peripheral lymph nodes. Taken together, these data provide evidence on exosomal PD‐L1 exerting immune inhibitory effects and promoting tissue repair.