OBJECTIVE: This study aimed to compare the mean percentages and absolute counts of CD4+ memory T cell subsets between: (i) non-allergic controls and AR patients; (ii) mild AR patients and moderate-severe AR patients.
METHODS: Sensitization to Dermatophagoides farinae and Dermatophagoides pteronyssinus were determined in 33 non -allergic controls, 28 mild AR and 29 moderate-severe AR patients. Flow cytometry was used to determine the percentage of CD4+ na?ve (TN; CD45RA+CCR7+), central memory (TCM; CD45RA-CCR7+), effector memory (TEM; CD45RA-CCR7-) and TEMRA (CD45RA+CCR7-) T cells from the peripheral blood. The absolute counts of CD4+ T cell subsets were obtained by dual platform method from flow cytometer and hematology analyzer.
RESULTS: There were no significant differences in the mean percentages and absolute counts of CD4+ T cell subsets between non-allergic controls and AR patients sensitized to HDMs. However, there were significant reduction in the mean percentage (p=0.0307) and absolute count (p=0.0309) of CD4+ TEMRA cells in moderate-severe AR patients compared to mild AR patients sensitized to HDMs and 13/24 (54.2%) moderate-severe AR patients sensitized to HDMs had persistent symptoms.
CONCLUSION: Reduction in the mean percentage and absolute count of CD4+CD45RA+CCR7- TEMRA cells were observed in moderate-severe AR patients compared to mild AR patients in our population of AR patients sensitized to HDMs.
METHODS: MSCs and Oh-LAAO were isolated and characterized by standard methodologies. The effects of the experimental therapies were evaluated in C57/BL6 mice. The animal study groups consisted of full-thickness uninfected and MRSA-infected wound models which received Oh-LAAO, MSCs, or both. Oh-LAAO was administered directly on the wound while MSCs were delivered via intradermal injections. The animals were housed individually with wound measurements taken on days 0, 3, and 7. Histological analyses and bacterial enumeration were performed on wound biopsies to determine the efficacy of each treatment.
RESULTS: Immunophenotyping and differentiation assays conducted on isolated MSCs indicated expression of standard cell surface markers and plasticity which corresponds to published data. Characterization of Oh-LAAO by proteomics, enzymatic, and antibacterial assays confirmed the identity, purity, and functionality of the enzyme prior to use in our subsequent studies. Individual treatments with MSCs and Oh-LAAO in the infected model resulted in reduction of MRSA load by one order of magnitude to the approximate range of 6 log10 colony-forming units (CFU) compared to untreated controls (7.3 log10 CFU). Similar wound healing and improvements in histological parameters were observed between the two groups. Co-administration of MSCs and Oh-LAAO reduced bacterial burden by approximately two orders of magnitude to 5.1 log10 CFU. Wound closure measurements and histology analysis of biopsies obtained from the combinational therapy group indicated significant enhancement in the wound healing process compared to all other groups.
CONCLUSIONS: We demonstrated that co-administration of MSCs and Oh-LAAO into a mouse model of MRSA-infected wounds exhibited a synergistic antibacterial effect which significantly reduced the bacterial count and accelerated the wound healing process.