Peripheral blood mononuclear cell transplantation to treat no-option critical limb ischaemia: effectiveness and safety.

OBJECTIVE: Local intramuscular transplantation of granulocyte colony-stimulating factor (G-CSF)-mobilised peripheral blood mononuclear cells (PB-MNC) has been shown to be effective for treating patients with no-option critical limb ischaemia (CLI) who are not considered suitable to undergo surgical bypass or percutaneous transluminal angioplasty. The aim of this study was to investigate the effectiveness and safety of PB-MNCs as a treatment for no-option CLI patients. METHOD: This prospective cohort study was conducted between April 2013 and December 2017. Patients with no-option CLI were treated with G-CSF 5-10 µg/kg/day for 3 days. PB-MNCs (7.1±2.2×1010) with CD34+ cells (2.1±1.2×108) were collected by blood cell separator and then injected into the calf or thigh of ischaemic limbs. Ankle-brachial index, toe-brachial index and transcutaneous oxygen tension were recorded at 1 and 3 months after injection. The amputation rate and the wound healing rate were also recorded. RESULTS: Eight patients took part in the study. Two patients experienced rest pain relief 1 month after PB-MNC therapy. Five patients had healed ulcer at 6 months after PB-MNC therapy. Limb ischaemia did not improve after PB-MNC therapy in one patient. Below-knee amputation was performed in that patient due to extension of gangrene. Two patients required reinjection of PB-MNCs because of recurrence of ischaemic ulcer. The limb salvage rate after 1 year was 87.5%. CONCLUSION: Local intramuscular transplantation of G-CSF-mobilised PB-MNCs might be a safe and effective treatment for no-option CLI patients.

Characterization and functional analysis of novel circulating NK cell sub-populations.

Natural killer (NK) cells are innate lymphoid cells having potent cytolytic function that provide host defense against microbial infections and tumors. Using our generated monoclonal antibody (mAb), named FE-1H10, new NK cell sub-populations in peripheral blood were identified. The molecules recognized by mAb FE-1H10 were expressed on a sub-population of CD3-CD56dim NK cells. The epitope recognized by mAb FE-1H10 was demonstrated to be N-glycan and proven to be different from CD57. Upon K562 stimulation, the CD56dimFE-1H10+ NK cell sub-population exhibited significantly lower cytolytic function with low ability to degranulate and release cytolytic granules compared to the CD56dimFE-1H10- NK cell sub-population. Moreover, the CD56dimFE-1H10+ NK cells produced less IFN-γ and TNF-α than the CD56dimFE-1H10- NK cells. We demonstrated here that mAb FE-1H10 could identify two sub-populations of circulating CD56dim NK cells with different functions. Our discovery of new sub-populations of NK cells improves our understanding of NK cell biology and may lead to the development of new approaches for NK cell therapy.

Involvement of CD147 on multidrug resistance through the regulation of P-glycoprotein expression in K562/ADR leukemic cell line.

The relationship between P-gp and CD147 in the regulation of MDR in leukemic cells has not been reported. This study aimed to investigate the correlation between CD147 and P-gp in the regulation of drug resistance in the K562/ADR leukemic cell line. The results showed that drug-resistant K562/ADR cells expressed significantly higher P-gp and CD147 levels than drug-free K562/ADR cells. To determine the regulatory effect of CD147 on P-gp expression, anti-CD147 antibody MEM-M6/6 significantly decreased P-gp and CD147 mRNA and protein levels. This is the first report to show that CD147 mediates MDR in leukemia through the regulation of P-gp expression.

Identification of a T cell surface molecule using a monoclonal antibody produced by TCR/CD3 complex immunization.

BACKGROUND: Several molecules are known to be involved in T-cell activation via the TCR/CD3 complex and while the mechanisms of late T cell signaling have been well characterized, the very early events are still not fully understood. OBJECTIVE: The aim of this study was to identify yet unknown molecules associated with the TCR/CD3 complex. RESULTS: To identify new molecules associated with the TCR/CD3 complex, a monoclonal antibody termed MT3 was produced by immunoprecipitated beads immunization. Colocalization of the MT3 mAb recognizing molecules with the TCR/CD3 complexes was verified by confocal microscopic analysis. The surface antigen recognized by MT3 antibody was expressed on a subpopulation of CD3+ T cells, and on both CD4+ and CD8+ lymphocytes. The antigen was also expressed on na?ve CD4+ T cells and on a subset of memory CD4+ T cells. In contrast, in the CD8 population, the majority of MT3+ cells were found in the na?ve population. The MT3 mAb recognizing molecules were also expressed on red blood cells but only in particular subjects. Similar to peripheral blood leukocytes, MT3 mAb recognizing molecules are exclusively expressed on T cell lines. CONCLUSIONS: Based on the cellular distribution patterns and confocal microscopic analysis, the MT3 mAb recognizing molecule that we investigated is proposed to be a TCR/CD3 associated molecule and might be involved in the antigen recognition of T cells.

ß3 subunit of Na,K ATPase regulates T cell activation with no involvement of Na,K ATPase activity.

Na,K ATPase plays an important role in the regulation of Na(+) and K(+) ions that are required for normal resting membrane potential and various cellular functions. Na,K ATPase is composed of two subunits, α and ß subunits. Engagement of the ß subunit by an agonistic monoclonal antibody (mAb) P-3E10 inhibited T cell activation and induced the G0/G1 cell cycle arrest. In addition, mAb P-3E10 decreased CD25 expression. The mAb P-3E10, however, did not inhibit the proliferation of cell lines and the phagocytosis activity of phagocytes, and did not interfere with the Na,K ATPase activity. These results indicate that mAb P-3E10 reacts to the ß subunit and, as a consequence, brings about the regulation of the T cell activation without disturbing the Na,K pump activity. By sequential immunoprecipitation, we demonstrated the expression of the ß3 subunit free form apart from the α subunit. In this study, we propose that the ß3 subunits of Na,K ATPase are expressed separately from the α subunit, and play a role in regulation of the immune response.

Favorable interleukin-8 induction in human gingival epithelial cells by the antimicrobial peptide LL-37.

BACKGROUND: LL-37, the only member of the antimicrobial peptide cathelicidin family in humans, exerts a variety of biological activities, especially immunomodulation through either direct chemotactic activity or up-regulation of several cytokines and chemokines in various cell types. In this study, we aimed to determine the immunoregulatory effect of LL-37 on Th1/Th2 cytokine expression and production in human gingival epithelial cells (HGECs). METHODS: Cultured HGECs were treated with different concentrations of LL-37 for different numbers of times. The cytotoxicity of LL-37 was determined by an MTT assay. Total RNA was isolated for RT-PCR and real-time PCR analyses of cytokine expression. Cell-free culture supernatants were assayed for Th1/Th2 cytokine levels by a cytokine bead array. RESULTS: Out of eleven Th1/Th2 cytokines tested, treatment of HGECs with non-toxic doses of LL-37 (2-6 µM) significantly raised only IL-8 levels in the cell-free culture supernatants, when compared to control untreated cells (P <0.05). Consistent with the elevated IL-8 levels, IL-8 mRNA expression was remarkably and significantly induced by LL-37 treatment (P < 0.05), when compared to the modest mRNA induction of other three cytokines, including IL-1ß, IL-6, and TNF-α. The time-course study demonstrated a cumulative IL-8 mRNA induction by LL-37 treatment within a 24-hour interval. CONCLUSIONS: These findings indicate that LL-37 favorably induces IL-8 expression and secretion in HGECs, suggesting both direct and indirect involvement of LL-37 in neutrophil recruitment into an inflammatory site within diseased periodontal tissues.

CD99 ligation induces intercellular cell adhesion molecule-1 expression and secretion in human gingival fibroblasts.

OBJECTIVE: To examine CD99 expression and its functional role in ICAM-1 induction in human gingival fibroblasts (HGFs) and human gingival epithelial cells (HGECs) by activating cells with anti-CD99 monoclonal antibody, MT99/3. BACKGROUND: Engagement of CD99 with agonistic antibodies has been shown to regulate immune responses, cell adhesion and migration, and cell death in several studies. Particularly, this engagement results in transendothelial migration of leukocytes mediated by intercellular adhesion molecule-1 (ICAM-1) induction in endothelial cells. METHODS: Total mRNA and protein were isolated from HGFs and HGECs for analyses of CD99 and ICAM-1 expression. Surface expression of CD99 and ICAM-1 was analysed by flow cytometry, and the detection of soluble ICAM-1 was assayed by immunoprecipitation and ELISA. RESULTS: CD99 surface expression was constitutive on HGFs to a greater extent than that on HGECs. CD99 ligation with MT99/3 induced ICAM-1 mRNA expression in HGFs, but not in HGECs. Interestingly, CD99 ligation led to an increased level of soluble ICAM-1 detected in culture supernatant, whereas interleukin-1ß (IL-1ß) treatment induced expression of membrane-bound ICAM-1. Furthermore, ICAM-1 induction by CD99 engagement was demonstrated to involve the activation of the p50 subunit of nuclear factor-kappaB (NF-κB), extracellular signal-regulated kinase, and p46 c-Jun N-terminal kinase that differed from that by IL-1ß treatment. CONCLUSION: Our study has shown the involvement of CD99 ligation in the up-regulation of ICAM-1 expression and its secretion in gingival fibroblasts, which may be essential for better understanding of the pathogenesis of periodontal disease.

Production of monoclonal antibodies to P-glycoprotein: its application in detection of soluble and surface P-glycoprotein of leukemia patients.

Multidrug resistance (MDR) in leukemia is commonly associated with the expression of a transmembrane protein, P-glycoprotein (P-gp). In this study, two monoclonal antibodies (mAbs) specific for the extracellular domain of P-gp were generated. By employing the generated mAbs, a two-color lysed whole blood flow cytometric method for surface P-gp and an efficient sandwich ELISA for soluble P-gp determinations were established. By using the established methods, surface and soluble P-gp were detected in several leukemia patients. The presence of soluble P-gp could be used to identify the P-gp surface expression patients. Detection of soluble P-gp reported provides a new basis that may lead to a better understanding of the MDR mechanism in leukemia.