BACKGROUND: Mononuclear cells contain progenitor cells including haematopoietic and mesenchymal stem cells, endothelial progenitor cells and fibroblasts which facilitate wound healing through cytokines, growth factor secretions, cell-cell interactions and provision of extracellular matrix scaffolding. Clinical applications of autologous mononuclear cells therapy in wound healing in non-malignant patients with critical limb ischaemia have been reported with remarkable outcome.
METHODS: We report three patients with haematological malignancies undergoing chemotherapy, who received autologous mononuclear cells implantation to treat non-healing wound after optimum conventional wound care. The sources of mononuclear cells (MNC) were from bone marrow (BM), peripheral blood (PB) and mobilised PB cells (mPB-MNC) using granulocyte colony stimulating factor (G-CSF). The cells were directly implanted into wound and below epidermis. Wound sizes and adverse effects from implantation were assessed at regular intervals.
RESULTS: All patients achieved wound healing within three months following autologous mononuclear cells implantation. No implantation adverse effects were observed.
CONCLUSIONS: Autologous mononuclear cells therapy is a feasible alternative to conventional wound care to promote complete healing in non-healing wounds compounded by morbid factors such as haematological malignancies, chemotherapy, diabetes mellitus (DM), infections and prolonged immobility.
METHODS: This study belongs to a part of an ongoing Singapore/Malaysia cross-sectional genetics and epidemiological study (SMCSGES). We performed population genotyping on n = 2,880 individuals from the SMCSGES cohort to assess the associations of SNPs in the AA pathway genes with asthma and allergic rhinitis (AR). Spirometry assessments were performed to identify associations between SNPs and lung function among n = 74 pediatric asthmatic patients from the same cohort. Allergy-associated SNPs were functionally characterized using in vitro promoter luciferase assay, along with DNA methylome and transcriptome data of n = 237 peripheral blood mononuclear cell (PBMC) samples collected from a subset of the SMCSGES cohort.
RESULTS: Genetic association analysis showed 5 tag-SNPs from 4 AA pathway genes were significantly associated with asthma (rs689466 at COX2, rs35744894 at hematopoietic PGD2 synthase (HPGDS), rs11097414 at HPGDS, rs7167 at CRTH2, and rs5758 at TBXA2R, p < 0.05), whereas 3 tag-SNPs from HPGDS (rs35744894, rs11097414, and rs11097411) and 2 tag-SNPs from PTGDR (rs8019916 and rs41312470) were significantly associated with AR (p < 0.05). The asthma-associated rs689466 regulates COX2 promoter activity and associates with COX2 mRNA expression in PBMC. The allergy-associated rs1344612 was significantly associated with poorer lung function, increased risks of asthma and AR, and increased HPGDS promoter activity. The allergy-associated rs8019916 regulates PTGDR promoter activity and DNA methylation levels of cg23022053 and cg18369034 in PBMC. The asthma-associated rs7167 affects CRTH2 expression by regulating the methylation level of cg19192256 in PBMC.
CONCLUSIONS: The present study identified multiple allergy-associated SNPs that modulate the transcript expressions of key genes in the AA pathway. The development of a "personalized medicine" approach with consideration of genetic influences on the AA pathway may hopefully result in efficacious strategies to manage and treat allergic diseases.
METHODS: Circulating CD8+ T cells were analysed for differentiation status (CD45RO, CCR7), markers of activation (CD69 and CD25) and proliferation (Ki-67) in 14 newly diagnosed GCA patients and 18 healthy controls by flow cytometry. Proliferative capacity of CD8+ T cells upon anti-CD3 and anti-CD3/28 in vitro stimulation was assessed. Single-cell RNA sequencing of peripheral blood mononuclear cells of patients and controls (n = 3 each) was performed for mechanistic insight. Immunohistochemistry was used to detect CD3, CD8, Ki-67, TNF-α and IFN-γ in GCA-affected tissues.
RESULTS: GCA patients had decreased numbers of circulating effector memory CD8+ T cells but the percentage of Ki-67-expressing effector memory CD8+ T cells was increased. Circulating CD8+ T cells from GCA patients demonstrated reduced T cell receptor activation thresholds and displayed a gene expression profile that is concurrent with increased proliferation. CD8+ T cells were detected in GCA temporal arteries and aorta. These vascular CD8+ T cells expressed IFN-γ but not Ki-67.
CONCLUSION: In GCA, circulating effector memory CD8+ T cells demonstrate a proliferation-prone phenotype. The presence of CD8+ T cells in inflamed arteries seems to reflect recruitment of circulating cells rather than local expansion. CD8+ T cells in inflamed tissues produce IFN-γ, which is an important mediator of local inflammatory responses in GCA.