Search

Mucosal-associated invariant T (MAIT) cells are innate-like, unconventional T cells that are present in peripheral blood and mucosal surfaces. A clear understanding of how MAIT cells in the mucosae function and their role in host immunity is still lacking. Therefore, our aim was to investigate MAIT cell distribution and their characteristics in the gastrointestinal (GI) mucosal tissue based on Vα7.2 + CD161 hi identification. We showed that Vα7.2 + CD161 hi T cells are present in both intraepithelial layer and lamina propriae of the GI mucosa, but have different abundance at each GI site. Vα7.2 + CD161 hi T cells were most abundant in the duodenum, but had the lowest reactivity to MR1-5-OP-RU tetramers when compared with Vα7.2 + CD161 hi T cells at other GI tissue sites. Striking discrepancies between MR1-5-OP-RU tetramer reactive cells and Vα7.2 + CD161 hi T cells were observed along each GI tissue sites. Vα7.2 + CD161 hi TCR repertoire was most diverse in the ileum. Similar dominant profiles of TRBV usage were observed among peripheral blood, duodenum, ileum, and colon. Some TRBV chains were detected at certain intestinal sites and not elsewhere. The frequency of peripheral blood Vα7.2 + CD161 hi T cells correlated with mucosal Vα7.2 + CD161 hi T cells in lamina propriae ileum and lamina propriae colon. The frequency of peripheral blood Vα7.2 + CD161 hi T cells in Helicobacter pylori-infected individuals was significantly lower than uninfected individuals, but this was not observed with gastric Vα7.2 + CD161 hi T cells. This study illustrates the biology of Vα7.2 + CD161 hi T cells in the GI mucosa and provides a basis for understanding MAIT cells in the mucosa and MAIT-related GI diseases., (©2022 Society for Leukocyte Biology.)

We compared two and four intra-articular injections of platelet-rich plasma (PRP) in terms of changes of synovial cytokines and clinical outcomes. One hundred twenty-five patients having knee osteoarthritis (OA) underwent PRP injections at a 6-week interval. Before each PRP injection, synovial fluid aspiration was collected for investigation. Patients were divided into two or four intra-articular PRP injections (group A and B, respectively). Changes in synovial biomarkers were compared with the baseline levels of both groups, and clinical outcomes were evaluated until one year. Ninety-four patients who had completed synovial fluid collection were included for final evaluation, 51 in group A and 43 in group B. There were no differences in mean age, gender, body mass index (BMI), and radiographic OA grading. The average platelet count and white blood cell count in PRP were 430,000/µL and 200/ µL, respectively. There were no changes of synovial inflammatory cytokines (IL-1β, IL-6, IA-17A, and TNF-alpha), anti-inflammatory cytokines (IL-4, IL-10, IL-13, and IL-1RA), and growth factors (TGF-B1, VEGF, PDGF-AA, and PDGF-BB) between baseline levels and six weeks in group A, and 18 weeks in group B. Both groups had significantly improved clinical outcomes from six weeks including visual analog scale (VAS), patient-reported outcome measures [PROMs; Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index and Short Form-12 (SF-12)], with a significant delayed improvement of performance-based measures [PBMs; time up and go (TUG), 5-time sit to stand test (5 × SST), and 3-min walk test (3-min WT)]. In conclusion, two- or four-PRP intra-articular injection at a 6-week interval for knee OA demonstrated no changes of synovial cytokines and growth factors but similarly improved clinical outcomes from 6 weeks until 1 year., (© 2021. The Author(s).)