Value of FOXP3 expression in peripheral blood as rejection marker after miniature swine lung transplantation

Swine used in the medical university: overview of 20 years of experience

Center for Development of Advanced Medical Technology (CDAMTec) in Jichi Medical University was established in 2009. It is the first educational research facility specialized for medical research and training using swine in Japan. Preclinical studies on large animals are essential prior to clinical trials to develop regenerative medical products and medical equipment. We have continued comprehensively considering using miniature swine for experiments to develop advanced medical technologies and train physicians with advanced clinical abilities, while paying attention to animal welfare. The center plays a pioneering role in this field by accumulating know-how such as (1) Construction and effective utilization of research facilities, (2) Procurement of quality animal resources, (3) Education and training of technical staff, (4) Establishment of support system for physicians and researchers. We now open up widely these expertise and foundation for medical research and training not only within our university but also outside the university, so as to move faster to practical use of advanced medical technology and contribute to human health and welfare.

Time elapsed after transplantation influences the relationship between the number of regulatory T cells in lung allograft biopsies and subsequent acute rejection episodes

BACKGROUND

Regulatory T lymphocytes (Tregs) play an important role in acute rejection after lung transplantation. However, the importance of the time elapsed after transplantation on the Treg response requires further investigation. We aim to evaluate the change over time in the frequency of Tregs in lung allograft biopsies and to assess how Tregs relate to simultaneous and subsequent acute cellular rejection.

MATERIALS AND METHODS

A total of 258 biopsy samples obtained 0.5, 1, 3, 12 and 24 months after transplantation from 58 consecutive lung transplant patients were included. The biopsies were scored for acute rejection according to the ISHLT criteria (A0-A4) and immunohistochemically stained with antibodies against FoxP3.

RESULTS

There was a tendency for a decrease in the number of Tregs/mm2 with time. However, the previous levels of Tregs/mm2 did not have any significant effect on future levels of Tregs/mm2. For biopsies taken 0.5 and 1 month after transplantation, a significant correlation between Tregs/mm2 and the degree of acute rejection was found, and logistic regression analysis using updated values for Tregs/mm2 showed a significant relationship between Tregs/mm2 at 2 weeks and an A-score≥2 after 1 and 3 months. At later time points, this correlation disappeared.

DISCUSSION AND CONCLUSION

Our data indicate that the time elapsed after transplantation is an important parameter influencing the Treg response after lung transplantation. This observation is in accordance with studies indicating a narrow therapeutic window for induction of tolerance by specifically targeting T-cells. The results also indirectly indicate that Tregs early after transplantation could have an impact on the long-term outcome.

The pig as a model for translational research: overview of porcine animal models at Jichi Medical University

To improve the welfare of experimental animals, investigators seek to respect the 3R principle (Replacement, Reduction, and Refinement). Even when large animal studies are essential before moving to clinical trials, it is important to look for ways to reduce the number of experimental animals used. At the Center for the Development of Advanced Medical Technology, we consider ‘medical’ pigs to be ideal preclinical model systems.

We have been using both wild-type and genetically modified pigs. We began using this approach about 10 years ago with a ‘total pig system’ to model human health and disease for the purposes of both medical skill education and the development of new devices and therapeutic strategies.

At our Center, medical students and residents use pigs to gain experience with surgical skills and train for emergency procedures after appropriate simulation training. Senior clinicians have also used these models to advance the development of innovative tools for endo- and laparoscopic procedures. The Center focuses on translational research for organ transplantation and stem cell therapy. Several pig models have been established for liver, intestine, kidney, pancreas, and lung transplantation. Mesenchymal stromal cells have been established in green fluorescent protein- and red fluorescent protein-transgenic pigs and tested to trans-differentiate organogenesis. A program to establish induced pluripotent stem cells in the pig is ongoing at our Center.

Here, we review our 10 years of activity in this field. Based on our experience in surgical education and research, experimental pigs are valuable models in translational research.

Lung function early after lung transplantation is correlated with the frequency of regulatory T cells

PURPOSES

Outcomes following lung transplantation are limited by bronchiolitis obliterans syndrome (BOS). As the number of circulating regulatory T cells (Treg) is lower in lung recipients with BOS than in stable lung recipients, we hypothesized that Treg is also correlated with lung function in the early post-transplantation period.

METHODS

This prospective study included 18 consecutive patients whose lung function parameters were recorded 3 weeks and 3 months after transplantation, between February and July 2007. Peripheral blood mononuclear cells were stained with anti-CD3, -CD4, -CD8, -CD19, -CD25, -CD28, -CD45RA, -CD45RO, -CD69, -CD127, -CTLA4, and -Foxp3 antibodies and FACS assays were performed. In addition, intracellular cytokines were stained for FACS.

RESULTS

Treg-specific markers (Foxp3, CD127(lo), and CTLA4) in the CD25+ CD4+ population were correlated with both forced expiratory volume in 1 s and forced vital capacity. Th1-cytokine secretion was more dominant in CD4+ CD25+ T cells than in CD4+ CD25- T cells. In contrast, Th2 and Treg cytokine secretion was the dominant response in stable recipients.

CONCLUSIONS

The frequency of Treg cells was positively correlated with good lung function in the early period after lung transplantation.

A census of human transcription factors: function, expression and evolution

Transcription factors are key cellular components that control gene expression: their activities determine how cells function and respond to the environment. Currently, there is great interest in research into human transcriptional regulation. However, surprisingly little is known about these regulators themselves. For example, how many transcription factors does the human genome contain? How are they expressed in different tissues? Are they evolutionarily conserved? Here, we present an analysis of 1,391 manually curated sequence-specific DNA-binding transcription factors, their functions, genomic organization and evolutionary conservation. Much remains to be explored, but this study provides a solid foundation for future investigations to elucidate regulatory mechanisms underlying diverse mammalian biological processes.