Yasuhiro Tsuneyoshi

Targeting tumor-associated macrophages in an experimental glioma model with a recombinant immunotoxin to folate receptor β

Tumor-associated macrophages (TAMs) are frequently found in glioblastomas and a high degree of macrophage infiltration is associated with a poor prognosis for glioblastoma patients. However, it is unclear whether TAMs in glioblastomas promote tumor growth. In this study, we found that folate receptor β (FRβ) was expressed on macrophages in human glioblastomas and a rat C6 glioma implanted subcutaneously in nude mice. To target FRβ-expressing TAMs, we produced a recombinant immunotoxin consisting of immunoglobulin heavy and light chain Fv portions of an anti-mouse FRβ monoclonal antibody and Pseudomonas exotoxin A. Injection of the immunotoxin into C6 glioma xenografts in nude mice significantly depleted TAMs and reduced tumor growth. The immunotoxin targeting FRβ-expressing macrophages will provide a therapeutic tool for human glioblastomas.

Functional folate receptor beta-expressing macrophages in osteoarthritis synovium and their M1/M2 expression profiles

Objective: The distribution of folate receptor (FR)-β+ macrophages and their M1/M2 expression profiles were examined in osteoarthritis (OA) synovial tissues, and compared to those in rheumatoid arthritis (RA) synovial tissues and CD163+ macrophages in both OA and RA synovial tissues. Method: The phenotypes and fluorescein isothiocyanate (FITC)–folate uptake of FR-β+ synovial macrophages were analysed by flow cytometry. The distribution of FR-β+ macrophages in OA and RA synovial tissues was examined by immunofluorescent microscopy. Tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), interleukin (IL)-10, and transforming growth factor (TGF)-β expression in FR-β+ macrophages was detected by double-immunostaining in both OA and RA synovial tissues. Results: FR-β+ macrophages were predominantly present in the synovial lining layer in OA patients. The proportion of CD163–FR-β+ cells in synovial mononuclear cells (MNCs) was increased in OA compared to RA synovial tissues. FR-βhigh macrophages from OA synovial tissues represented the majority of folic acid-binding cells. Although FR-β+ or CD163+ macrophages in the synovial tissues of OA and RA patients expressed a mixed pattern of M1 and M2 macrophage markers, there were more M2 markers expressing synovial macrophages in OA than in RA patients. Conclusions: The distribution and M1/M2 expression profiles of FR-β+ synovial macrophages were different between OA and RA synovial tissues. Thus, the findings underscore that the M1/M2 paradigm using surface markers FR-β and CD163 is an oversimplification of macrophage subsets. Functional FR-β present on OA synovial macrophages provides a potential tool for the diagnosis and treatment of OA.

Expansion of a unique macrophage subset in rheumatoid arthritis synovial lining layer

The Z39Ig protein (complement receptor for C3b and iC3b) is expressed on resident tissue macrophages in various tissues. This study was undertaken to examine the distribution of Z39Ig+cells and their phenotypic features in rheumatoid arthritis (RA) synovium, in comparison with those of osteoarthritis (OA) and psoriatic arthritis (PsA) synovium. Monoclonal anti‐Z39Ig antibody was produced by immunizing Z39Ig transfected murine pre B cells and used for the identification of Z39Ig+cells. Z39Ig+cells were further stained with antibodies to macrophages, fibroblast‐like synoviocytes, complement receptors and dendritic cells by using the double immunostaining method in normal, RA, OA and PsA synovium. RA synovial mononuclear cells were double‐stained using anti‐Z39Ig and anti‐CD11c antibodies and sorted into Z39Ig+CD11c+cells and Z39Ig+CD11c−cells. These cell populations were then analysed by electron microscopy. The expression of the Z39Ig protein was limited to intimal macrophages in normal, RA, OA and PsA synovium. The numbers of Z39Ig+CD11c+cells and the ratios of Z39Ig+CD11c+cells to Z39Ig+cells were increased in the synovial lining layer of RA as compared with those of OA and PsA. The ultrastructural analysis of Z39Ig+CD11c+cells showed the character of macrophages with many secondary lysosomes and swelling of mitochondria. Z39Ig+ cells appeared to be useful for identification of resident tissue macrophages in normal synovium and the corresponding macrophages in the synovial lining layer of inflammatory arthritis. Expansion of Z39Ig+CD11c+cells was characteristic of RA synovial lining layer.

Risk Factors for Venous Thromboembolism After Spine Surgery

AbstractThe efficacy and safety of chemical prophylaxis to prevent the development of deep venous thrombosis (DVT) or pulmonary embolism (PE) following spine surgery are controversial because of the possibility of epidural hematoma formation. Postoperative venous thromboembolism (VTE) after spine surgery occurs at a frequency similar to that seen after joint operations, so it is important to identify the risk factors for VTE formation following spine surgery. We therefore retrospectively studied data from patients who had undergone spinal surgery and developed postoperative VTE to identify those risk factors.We conducted a retrospective clinical study with logistic regression analysis of a group of 80 patients who had undergone spine surgery at our institution from June 2012 to August 2013. All patients had been screened by ultrasonography for DVT in the lower extremities. Parameters of the patients with VTE were compared with those without VTE using the Mann–Whitney U-test and Fisher exact probability test. Logistic regression analysis was used to analyze the risk factors associated with VTE. A value of P < 0.05 was used to denote statistical significance.The prevalence of VTE was 25.0% (20/80 patients). One patient had sensed some incongruity in the chest area, but the vital signs of all patients were stable. VTEs had developed in the pulmonary artery in one patient, in the superficial femoral vein in one patient, in the popliteal vein in two patients, and in the soleal vein in 18 patients. The Mann–Whitney U-test and Fisher exact probability test showed that, except for preoperative walking disability, none of the parameters showed a significant difference between patients with and without VTE. Risk factors identified in the multivariate logistic regression analysis were preoperative walking disability and age.The prevalence of VTE after spine surgery was relatively high. The most important risk factor for developing postoperative VTE was preoperative walking disability. Gait training during the early postoperative period is required to prevent VTE.

Suppurative Arithritis of Facet Joint of Rheumatoid Arthritis Patient Using Human Monoclonal Antibody Rheumatoid Arthritis

腰痛を主訴として発症したまれなL2/3化膿性椎間関節炎に対し，外科的治療により良好な成績を得たので報告する．（症例）51歳女性．RA罹患歴5年．RA治療として生物学的製剤使用中．平成20年12月4日より左腰殿部痛出現．高熱出現し近医受診．炎症所見認めた為，抗菌薬投与開始．翌1月3日当科紹介入院．左優位の大腿部以下の筋力低下，左大腿内側より足先まで知覚鈍麻認めた．MRIで左L2/3椎間関節付近に造影効果を有するT1低信号，T2高信号の膿腫を認めた．診断確定の為，L2/3椎間関節より穿刺，培養結果でMSSA検出．抗菌薬投与としたが，症状改善認められず．そのため内視鏡下膿腫摘出術実施．術後症状消失，MRIで膿腫の消失が確認．外科的治療により症状改善を得た．