Use of lysates from pooled human mononuclear cells to activate CD3 T cells in humanized mice with low human cell engraftment efficiency.

In regenerative medicine, humanized mice (hu-mice) are extremely valuable for verifying the cross talk between immune cells and therapeutic cells. Given the highly dynamic nature of the activities of immune cells, the in vitro platform does not allow for screening of their exact interactions with different therapeutic cells. By contrast, hu-mice have been widely applied for in vivo studies, especially those on immune rejection. However, the full reconstitution of lymphoid lineage cells in hu-mice remains to be realized. In this study, we investigated whether lysates from healthy donor-derived pooled mononuclear cells (MNCs) can promote the increase of lymphoid lineage cells in hu-mice. The pooled MNC lysate treatment of hu-mice possessing a low proportion of CD45 cells resulted in significant increases in CD3 cells and CD45 cells with the RO phenotype. The diverse epitopes from the pooled MNC lysates significantly induced the proportion of lymphoid lineage cells in the thymus and spleen after therapeutic cells with mismatched HLAs were co-injected into the hu-mice. These findings demonstrate the technical benefits of using pooled MNC lysates for reconstituting lymphoid lineage cells in hu-mice, providing a valuable in vivo platform for investigating the cross talk between lymphoid immune cells and therapeutic cells.

Functional recovery by colon organoid transplantation in a mouse model of radiation proctitis.

Radiation proctitis is the collateral damage that occurs to healthy cells during radiation treatment of pelvic malignancies. Conservative treatment of radiation proctitis can mitigate inflammatory symptoms, but, to date, no therapeutic options are available for direct recovery of the damaged colonic epithelium. The present study assessed the ability of colon organoid-based regeneration to treat radiation proctitis. Radiation proctitis was induced in mice by irradiating their recta, followed by enema-based transplantation of mouse colon organoids. The transplanted colon organoids were found to successfully engraft onto the damaged rectal mucosa of the irradiated mice, reconstituting epithelial structure and integrity. Lgr5+ stem cells were shown to be pivotal to colon organoid mediated regeneration. Endoscopic examination showed the efficacy of localized transplantation of colon organoids with fibrin glue to irradiated sites. These findings provide useful insights into the use of colon organoid-based regenerative therapy for the treatment of radiation proctitis.

Distinct Repopulation Activity in Hu-Mice Between CB- and LPB-CD34＋ Cells by Enrichment of Transcription Factors.

BACKGROUND AND OBJECTIVES: Human CD34＋ hematopoietic stem cells can reconstitute the human hematopoietic system when transplanted into immunocompromised mice after irradiation. Human leukapheresis peripheral blood (LPB)- and cord blood (CB)-derived CD34＋ cells have a similar capacity to reconstitute myeloid lineage cells in a humanized mice (hu-mice) model. However, potent stem cells, such as CB-CD34＋ cells, efficiently reconstitute the lymphoid system in vivo compared to LPB-CD34＋ cells. Modeling the human hematolymphoid system is vital for studying immune cell crosstalk in human xenografted mice, with CB-CD34＋ cells used as an optimized cell source because they are essential in reconstituting lymphoid lineage cells. METHODS AND RESULTS: In this study, we established hu-mice that combined human characteristics with long-term survival and investigated the efficiency of the engraftment of lymphoid lineage cells derived from LPB- and CB-CD34＋ cells in the bone marrow, spleen, and LPB. We found an overall increase in the transcriptional activity of lymphoid lineage genes in CB-CD34＋ cells. Our results revealed that potent CB-CD34＋ cells displaying a general upregulation of the expression of genes involved in lymphopoiesis could contribute to the hematolymphoid system in the humanized mice model with longevity. CONCLUSIONS: Our data suggest that humanized mouse model by usage of CB-CD34＋ cells displaying high expression of TFs for lymphoid lineage cells can contribute to study the immune response against lymphocytes.

Esophageal tolerance to high-dose stereotactic radiosurgery.

PURPOSE: Esophageal tolerance is needed to guide the safe administration of stereotactic radiosurgery (SRS). We evaluated comprehensive dose-volume parameters of acute esophageal toxicity in patients with spinal metastasis treated with SRS. MATERIALS AND METHODS: From May 2008 to May 2011, 30 cases in 27 patients with spinal metastasis received single fraction SRS to targets neighboring esophagus. Endpoints evaluated include length (mm), volume (mL), maximal dose (Gy), and series of dose-volume thresholds from the dose-volume histogram (volume of the organ treated beyond a threshold dose). RESULTS: The median time from the start of irradiation to development of esophageal toxicity was 2 weeks (range, 1 to 12 weeks). Six events of grade 1 esophageal toxicity occurred. No grade 2 or higher events were observed. V15 of external surface of esophagus was found to predict acute esophageal toxicity revealed by multivariate analysis (odds radio = 1.272, p = 0.047). CONCLUSION: In patients with spinal metastasis who received SRS for palliation of symptoms, the threshold dose-volume parameter associated with acute esophageal toxicity was found to be V15 of external surface of esophagus. Restrict V15 to external surface of esophagus as low as possible might be safe and feasible in radiosurgery.

A comparison of preplan MRI and preplan CT-based prostate volume with intraoperative ultrasound-based prostate volume in real-time permanent brachytherapy.

PURPOSE: The present study compared the difference between intraoperative transrectal ultrasound (iTRUS)-based prostate volume and preplan computed tomography (CT), preplan magnetic resonance imaging (MRI)-based prostate volume to estimate the number of seeds needed for appropriate dose coverage in permanent brachytherapy for prostate cancer. MATERIALS AND METHODS: Between March 2007 and March 2011, among 112 patients who underwent permanent brachytherapy with (125)I, 60 image scans of 56 patients who underwent preplan CT (pCT) or preplan MRI (pMRI) within 2 months before brachytherapy were retrospectively reviewed. Twenty-four cases among 30 cases with pCT and 26 cases among 30 cases with pMRI received neoadjuvant hormone therapy (NHT). In 34 cases, NHT started after acquisition of preplan image. The median duration of NHT after preplan image acquisition was 17 and 21 days for cases with pCT and pMRI, respectively. The prostate volume calculated by different modalities was compared. And retrospective planning with iTRUS image was performed to estimate the number of (125)I seed required to obtain recommended dose distribution according to prostate volume. RESULTS: The mean difference in prostate volume was 9.05 mL between the pCT and iTRUS and 6.84 mL between the pMRI and iTRUS. The prostate volume was roughly overestimated by 1.36 times with pCT and by 1.33 times with pMRI. For 34 cases which received NHT after image acquisition, the prostate volume was roughly overestimated by 1.45 times with pCT and by 1.37 times with pMRI. A statistically significant difference was found between preplan image-based volume and iTRUS-based volume (p < 0.001). The median number of wasted seeds is approximately 13, when the pCT or pMRI volume was accepted without modification to assess the required number of seeds for brachytherapy. CONCLUSION: pCT-based volume and pMRI-based volume tended to overestimate prostate volume in comparison to iTRUS-based volume. To reduce wasted seeds and cost of the brachytherapy, we should take the volume discrepancy into account when we estimate the number of (125)I seeds for permanent brachytherapy.