Contribution of Invariant Natural Killer T Cells to the Clearance of Pseudomonas aeruginosa from Skin Wounds

Abstract

Chronic infections are considered one of the most severe problems in skin wounds, and bacteria are present in over 90% of chronic wounds. Pseudomonas aeruginosa is frequently isolated from chronic wounds and is thought to be a cause of delayed wound healing. Invariant natural killer T (iNKT) cells, unique lymphocytes with a potent regulatory ability in various inflammatory responses, accelerate the wound healing process. In the present study, we investigated the contribution of iNKT cells in the host defense against P. aeruginosa inoculation at the wound sites. We analyzed the re-epithelialization, bacterial load, accumulation of leukocytes, and production of cytokines and antimicrobial peptides. In iNKT cell–deficient (Jα18KO) mice, re-epithelialization was significantly decreased, and the number of live colonies was significantly increased, when compared with those in wild-type (WT) mice on day 7. IL-17A, and IL-22 production was significantly lower in Jα18KO mice than in WT mice on day 5. Furthermore, the administration of α-galactosylceramide (α-GalCer), a specific activator of iNKT cells, led to enhanced host protection, as shown by reduced bacterial load, and to increased production of IL-22, IL-23, and S100A9 compared that of with WT mice. These results suggest that iNKT cells promote P. aeruginosa clearance during skin wound healing.

A multi-study analysis enables identification of potential microbial features associated with skin aging signs

“…We found that samples from skin with lower grades of wrinkles were associated with some commensal taxa such as the genera Staphylococcus, Kocuria, Peptostreptococcus, and Lysobacter, (Figure 3A). (Tanno et al, 2021;Lebeer et al, 2022;Zanchetta et al, 2022) Our results also identified environment-related bacteria including Brevibacterium and Kaistella that are often associated with skin alterations and inflammatory conditions such as psoriasis and senile xerosis (Huang et al, 2021;Li et al, 2021). These taxa were enriched in the samples from subjects with higher grades of wrinkles (Figure 3A).…”

Topical Administration of Heat-Killed Enterococcus faecalis Strain KH2 Promotes Re-Epithelialization and Granulation Tissue Formation during Skin Wound-Healing

“…The wounded tissues were fixed with 4% paraformaldehyde-phosphate buffer solution and embedded in paraffin as previously described [ 17 , 18 , 19 ]. Sections were harvested from the central portion of the wound and stained with hematoxylin-eosin (HE) according to the standard method.…”

Features of the Local Immune Response in the Infectious Process of Acute and Chronic Wounds: Results of Immunohistochemical Studies of Cellular Immunity Factors

“…Отмечают значение натуральных киллеров в процессе заживления ран в условиях инфицирования P. aeruginosa. Увеличение этих клеток необходимо для элиминации бактерий из раны [27]. В эксперименте доказано, что, несмотря на повышение количества нейтрофилов и макрофагов, в условиях отсутствия натуральных киллеров элиминация P. aeruginosa из раны была нарушена, что определяет обязательное участие этих клеток в процессе выживания нейтрофилов, активации макрофагов и фагоцитоза [27][28][29].…”