Taigo Kato

Adipose tissue-derived stem cells suppress acute cellular rejection by TSG-6 and CD44 interaction in rat kidney transplantation.

Background In addition to its abundance and easy accessibility, adipose tissue yields more potent immunoregulatory stem cells (adipose tissue-derived stem cells, ADSCs) than does bone marrow. However, the beneficial effects of ADSCs on alloreactivity are scarcely known. This study evaluated the beneficial effects of ADSCs in rat kidney transplantation and analyzed the underlying molecular mechanism. Methods Dark Agouti rat kidneys were transplanted into Lewis rats. Autologous ADSCs (2×106) were injected through the left renal artery of the donors before the nephrectomy (ADSCs group). Graft survival, histologic changes, and the expression of several cytokines and proteins were assessed. In an in vitro experiment, the immunosuppressive capacity of ADSCs was tested in a mixed lymphocyte reaction. Results Histologic findings of the ADSCs group revealed a reduced rejection grade, whereas the number of infiltrated CD4+/CD8+ T cells was also significantly decreased as compared to the control. Relative to these findings, injection of ADSCs led to a significantly prolonged mean graft survival compared with the control. In vitro, autologous ADSCs dose-dependently suppressed alloreactive lymphocytes. Moreover, ADSCs increased the level of tumor necrosis factor-inducible gene 6 protein (TSG-6) in mixed lymphocyte reaction, which has an anti-inflammatory capacity. Recombinant TSG-6 markedly suppressed alloreactive T cells through downregulating CD44, which may lead to the suppression of T-cell activation and infiltration into allografts. Conclusion Our findings clearly showed that ADSCs attenuated acute rejection by secreting TSG-6 as well as through direct cell interaction. These findings contribute to the clinical application of these cells in solid organ transplantation.

Tacrolimus and angiotensin receptor blockers associated with changes in serum adiponectin level in new-onset diabetes after renal transplantation: single-center cross-sectional analysis

We analysed whether pre‐ and post‐transplant serum adiponectin levels in renal transplant patients were associated with new‐onset diabetes after transplantation (NODAT). The mean post‐transplant follow‐up duration was 47.9 months. Of 98 previously non‐diabetic renal transplant patients, 12 were diagnosed with NODAT and 86 without (non‐NODAT). There was a significant inverse correlation between mean post‐transplant serum adiponectin level and homeostasis model assessment for insulin resistance (HOMA‐IR) (r = −0.22, P = 0.03), and a positive correlation between follow‐up duration after transplantation and HOMA‐IR (r = 0.28, P = 0.005). The mean pre‐ and post‐transplant serum adiponectin levels in NODAT patients were significantly lower than those in non‐NODAT patients (13.3 vs. 21.0 μg/ml and 13.0 vs. 16.4 μg/ml, P = 0.01 and 0.03 respectively). In addition, the post‐transplant serum adiponectin level in patients treated with tacrolimus (TAC) was significantly lower than that in patients with cyclosporine (14.3 vs. 18.7 μg/ml, P = 0.01), while, that level in patients treated with angiotensin receptor blockers (ARB) was significantly higher than that in patients without treatment of ARB (17.9 vs. 14.7 μg/ml, P = 0.01). Our results indicate that post‐transplant serum adiponectin levels are decreased after transplantation in association with insulin resistance in the development of NODAT, and that TAC and ARB influence the level of adiponectin in serum.

Depression of Complement Regulatory Factors in Rat and Human Renal Grafts Is Associated with the Progress of Acute T-Cell Mediated Rejection

Background The association of complement with the progression of acute T cell mediated rejection (ATCMR) is not well understood. We investigated the production of complement components and the expression of complement regulatory proteins (Cregs) in acute T-cell mediated rejection using rat and human renal allografts. Methods We prepared rat allograft and syngeneic graft models of renal transplantation. The expression of Complement components and Cregs was assessed in the rat grafts using quantitative real-time PCR (qRT-PCR) and immunofluorescent staining. We also administered anti-Crry and anti-CD59 antibodies to the rat allograft model. Further, we assessed the relationship between the expression of membrane cofactor protein (MCP) by immunohistochemical staining in human renal grafts and their clinical course. Results qRT-PCR results showed that the expression of Cregs, CD59 and rodent-specific complement regulator complement receptor 1-related gene/protein-y (Crry), was diminished in the rat allograft model especially on day 5 after transplantation in comparison with the syngeneic model. In contrast, the expression of complement components and receptors: C3, C3a receptor, C5a receptor, Factor B, C9, C1q, was increased, but not the expression of C4 and C5, indicating a possible activation of the alternative pathway. When anti-Crry and anti-CD59 mAbs were administered to the allograft, the survival period for each group was shortened. In the human ATCMR cases, the group with higher MCP expression in the grafts showed improved serum creatinine levels after the ATCMR treatment as well as a better 5-year graft survival rate. Conclusions We conclude that the expression of Cregs in allografts is connected with ATCMR. Our results suggest that controlling complement activation in renal grafts can be a new strategy for the treatment of ATCMR.

The benefits of cancer screening in kidney transplant recipients: a single‐center experience

The frequency of malignancy is increasing in kidney transplant recipients. Posttransplant malignancy (PTM) is a major cause of long‐term graft survival inhibition. In this study, we evaluated the frequency and prognosis of PTM at our center and examined the efficacy of cancer screening. Between 1972 and 2013, 750 patients were followed‐up at our center. Annual physical examinations and screenings were performed to detect PTM. We investigated the detail of two distinctive cancer groups: screening‐detected cancers and symptom‐detected cancers. Seventy‐seven PTM were identified during the follow‐up period. The mean age at the initial PTM detection was 43.6 ± 12.8 years. The mean interval from transplantation to cancer diagnosis was 134.5 ± 11.3 months. Among the 77 patients, posttransplant lymphoproliferative disease (PTLD) was the most common cancer (19.5%, 15/77), followed by renal cell carcinoma (15.6%, 12/77). Of the cancer cases, 46.8% (36/77) were detected via screening. The most frequently screening‐detected cancer was renal cell carcinoma of the native kidney and breast cancer (22.2%, 8/36). However, it was difficult to detect PTLD, urothelial carcinoma, and colorectal cancer via screening. Interestingly, Cox proportional regression analyses revealed nonscreened recipients to be a significant prognostic factor for PTM (P < 0.001). This study is the first to report that appropriate screening tests play a key role in early PTM diagnosis and lead to reduce the mortality rate in kidney transplant recipients. These findings support the provision of long‐term appropriate screening for kidney transplant recipients.

Risk factors and incidence for lipid abnormalities in kidney transplant patients.

BACKGROUND Lipid abnormalities (LA) are related to an increased risk for cardiovascular diseases in kidney transplantation patients. PATIENTS AND METHODS Multivariable logistic regression models were used to estimate the risk of LA associated with potential risk factors, including immunosuppressant use, patient background characteristics, and laboratory data. RESULTS In total, 386 patients who were undergoing kidney transplantation were included in the study. Statins were prescribed to 43% of patients. The LA composite outcome was defined as statin use and/or low density lipoprotein cholesterol level ≥120 mg/dL, and 229 patients (59.3%) developed LA as a result. LA was significantly related to everolimus, corticosteroid, age, and estimated glomerular filtration ratio in the multiple logistic regression analysis. The odds ratios were 2.264, 3.119, 1.186, and 0.870, respectively. Mycophenolate mofetil, mizoribine, azathioprine, cyclosporine (CYA), tacrolimus, proteinuria, body mass index, and male sex were not related to LA. DISCUSSION CYA influenced lipid metabolism but was not related to LA in our study. The mean post transplantation period was 8.4 years, and the CYA dose decreased over time. The CYA blood concentration was 70.0 ng/mL, which is relatively low, but it decreased the susceptibility to LA. Serum lipid levels were well controlled by statins, and the estimated glomerular filtration rate was maintained stably. CONCLUSIONS Everolimus and corticosteroid use, as well as a lower estimated glomerular filtration rate and higher age, were significant risk factors for LA. CYA is known for its adverse LA effects, but it was not a significant risk factor for LA in patients undergoing maintenance phase kidney transplantation.

Early diagnosis and treatment of breast cancer in Japanese kidney transplant recipients: a single center experience

BackgroundThe incidence of malignancies in kidney transplant recipients is increasing. Breast cancer is a common malignancy after kidney transplantation and can be more aggressive in kidney transplant recipients than in the general population. In this study, we evaluated the incidence and prognosis of breast cancer in kidney transplant recipients.FindingsBetween 1993 and 2013, 750 kidney transplant patients were followed-up at our center. Since 1999, annual physical examination, mammography, and breast ultrasonography have been performed for such patients. Diagnostic studies, including core needle or mammotome biopsy, were performed for suspected malignancies. Patients with malignant neoplasm were administered the appropriate treatment and followed-up to assess tumor response and symptoms.Nine patients were diagnosed with breast cancer during the follow-up period. The mean age at the initial detection of the breast cancer was 47.7 ± 8.4 years. The mean interval from transplantation to diagnosis was 148.7 ± 37.1 months. Of the 9 patients, 8 were detected through the screening test; 7 were treated with breast conservative surgery and 1 was treated with modified radical mastectomy. The cancer stages were 0 (n = 2), I (n = 6), and II (n = 1). The incidence of breast cancer tended to be unchanged with time between transplantation and diagnosis, inconsistent with the increase in the duration of immunosuppression.ConclusionAnnual screening tests are crucial in the early diagnosis of breast cancer. Early treatment of breast cancer can result in an excellent prognosis in kidney transplant recipients.

Effective screening of T cells recognizing neoantigens and construction of T-cell receptor-engineered T cells

Neoantigens are the main targets of tumor-specific T cells reactivated by immune checkpoint-blocking antibodies or when using tumor-infiltrating T cells for adoptive therapy. While cancers often accumulate hundreds of mutations and harbor several immunogenic neoantigens, the repertoire of mutation-specific T cells in patients might be restricted. To bypass suboptimal conditions, which impede the reactivation of existing T cells or the priming of neoantigen-specific T cells in a patient, we employ T cells of healthy donors with an overlapping HLA repertoire to target cancer neoantigens. In this study, we focus on streamlining the process of in vitro-induction of neoantigen-specific T cells and isolating their T cell receptors (TCRs) to establish a time-efficient protocol that will allow the patient to benefit from subsequent therapy. We first optimized the priming of T cells to omit multiple restimulations and extended culturing. Neoantigen-specific T cells were enriched using specific dextramers and next-generation sequencing was applied to determine the TCR repertoire. This allowed us to circumvent the laborious process of expanding T cell clones. Using this protocol, we successfully identified HLA-A-restricted TCRs specific for neoantigens found in an esophageal cancer cell line (TE-8) and a primary ovarian cancer. To verify TCR specificity, we generated TCR-engineered T cells and confirmed recognition of the tumor-derived neoantigens. Our results also emphasize the importance of neoepitope selection in order to avoid cross-reactivity to corresponding wild-type peptide sequences. In conclusion, we established a 2-week protocol for generating and identifying neoantigen-specific TCRs from third-party donors making this strategy applicable for clinical use.

High-Fat Diet-Induced Inflammation Accelerates Prostate Cancer Growth via IL6 Signaling

Purpose: High-fat diet (HFD) could induce prostate cancer progression. The aim of this study is to identify mechanisms of HFD-induced prostate cancer progression, focusing on inflammation. Experimental Design: We administered HFD and celecoxib to autochthonous immunocompetent Pb-Cre+;Pten(fl/fl) model mice for prostate cancer. Tumor growth was evaluated by tumor weight and Ki67 stain, and local immune cells were assessed by flow cytometry at 22 weeks of age. Cytokines which correlated with tumor growth were identified, and the changes of tumor growth and local immune cells after inhibition of the cytokine signals were evaluated in the mice. IHC analyses using prostatectomy specimens of obese patients were performed. Results: HFD accelerated tumor growth and increased the myeloid-derived suppressor cells (MDSCs) fraction and M2/M1 macrophage ratio in the model mice. Celecoxib-suppressed tumor growth, and decreased both local MDSCs and M2/M1 macrophage ratio in HFD-fed mice. HFD-induced tumor growth was associated with IL6 secreted by prostatic macrophages, as were phosphorylated STAT3 (pSTAT3)-positive tumor cells. Anti-IL6 receptor antibody administration suppressed tumor growth, and decreased local MDSCs and pSTAT3-positive cell fractions in HFD-fed mice. The tumor-infiltrating CD11b-positive cell count was significantly higher in prostatectomy specimens of obese than those of nonobese patients with prostate cancer. Conclusions: HFD increased MDSCs and accelerated prostate cancer tumor growth via IL6/pSTAT3 signaling in the mice. This mechanism could exist in obese patients with prostate cancer. IL6-mediated inflammation could be a therapeutic target for prostate cancer. Clin Cancer Res; 24(17); 4309–18. ©2018 AACR.

Similarity and difference in tumor-infiltrating lymphocytes in original tumor tissues and those of in vitro expanded populations in head and neck cancer

Though adoptive tumor-infiltrating lymphocyte (TIL) therapy has been explored in clinical trials for many years, there is little information for the clonotype composition between TILs in original tumor tissues and TILs that were in vitro expanded and infused to cancer patients. To investigate the similarity/difference in TILs in original tumor tissues and those of in vitro expanded populations in squamous cell carcinoma of head and neck (SCCHN) as well as their correlation with somatic mutations in cancer cells, we performed whole exome analysis, expression profile analysis of immune-related genes, and T cell receptor (TCR) analysis of original TILs and in vitro expanded TILs in 8 surgically-resected HPV-negative fresh tumors with SCCHN. We found an unusually high number of non-synonymous somatic mutations (4290, 1779 and 901 mutations) in three SCCHN tumors, in which we identified mutations in mismatch repair genes, MSH2 or MSH4, or a DNA polymerase gene, POLE. Interestingly, dominant TCR clonotypes of expanded CD8+ TILs derived from these three tumors revealed high similarity to those in original tumors while for remaining tumors with the lower mutational load, we found that T cell clonotypes between TILs in original tumor tissues and those expanded in vitro were almost entirely different. Our findings might provide clinically useful information for identification of tumor-antigen-specific T cell clones that may lead to further improvement of adoptive TIL therapy for SCCHN patients.

Selective arterial embolization for uncontrollable urethral hemorrhage in a patient with a left ventricular assist device

Selective arterial embolization for uncontrollable urethral hemorrhage in a patient with a left ventricular assist device Yujiro Hayashi , Atsunari Kawashima a, , Kazutoshi Fujita , Taigo Kato , Toyofumi Abe , Takeshi Ujike , Akira Nagahara , Shinichiro Fukuhara , Motohide Uemura , Hiroshi Kiuchi , Ryoichi Imamura , Tetsuya Saito , Koichi Toda , Yoshiki Sawa , Kentaro Kishimoto c, , Keigo Osuga , Norio Nonomura a