Development of heterotopic transplantation of the testis with the epididymis to evaluate an aspect of testicular immunology in rats.

Kai Yi,Munekazu Naito,Shinichi Kawata,Naoyuki Hatayama,Kenta Nagahori,Masahiro Itoh,Ning Qu,Shogo Hayashi,Shuichi Hirai

doi:10.1371/journal.pone.0177067

Kai Yi, Munekazu Naito + Show 7 more

Open Access

https://doi.org/10.1371/journal.pone.0177067

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Journal: PloS one	Publication Date: May 5, 2017
Citations: 4	License type: CC BY 4.0

Affiliation: Tokyo Medical University, Aichi Medical University

Abstract

Transplantation of testicular cells and tissues has been studied for the investigation of immunology of the testis, which is an immunologically privileged organ. However, reports of transplant of the testis at organ level have been extremely limited because of technical difficulties of the orthotopic testis transplantation (OTT) in experimental animals. In the present study, we developed a new and simple model of the heterotopic testis transplantation (HTT), which is donor testis transplantation into the cervical region of recipients, in a syngeneic model in rats [donor Lewis (LEW) graft to LEW recipient]. The duration of HTT was significantly shorter and success rate higher than that of OTT. To histologically evaluate HTT, the local immune responses were compared among the syngeneic model, an acute rejection allogeneic model [donor Augustus Copenhagen Irish (ACI) graft to LEW recipient] and a chronic rejection allogeneic model (donor F344 graft to LEW recipient) at postoperative day 3. We found that allogeneic ACI grafts resulted in mild and not severe orchitic lesions, whereas immune responses of allogeneic F344 grafts seemed intact and were not significantly different from those of syngeneic LEW grafts. These results suggest that our new operative procedure will be useful in future for the investigation of the testicular immunology.

Highlights

The testis is an immunologically unique site because new differentiation autoantigens-bearing spermatids and spermatozoa that appear in the seminiferous tubules long after the establishment of immune tolerance survive with no rejection by self-immunity under healthy conditions [1, 2]
With regard to whole testis transplantation, Lee et al were the first to formulate a model for orthotopic testis transplantation (OTT), which is characterized by an end-to-side anastomosis between the graft’s great arteriovenous segments with testicular arteriovenous vessels and the recipient’s great arteriovenous vessels that is subsequently retracted into the scrotum [8]
Histological examination of the arterioles inside the testis revealed that the sham, heterotopic testis transplantation (HTT), OTT, Vx, and CR groups were normal, including numerous red blood cells

Summary

Introduction

The testis is an immunologically unique site because new differentiation autoantigens-bearing spermatids and spermatozoa that appear in the seminiferous tubules long after the establishment of immune tolerance survive with no rejection by self-immunity under healthy conditions [1, 2]. Heron et al were the first to report heterotopic heart transplantation to the recipient’s cervical region using the cuff technique in rodents [17]. This operation technique has many benefits, such as complete anastomosis through ligation on only one occasion, less bleeding from anastomosis sites, shorter ischemic time of the graft, and improved success rate compared with orthotopic transplantation using the general suture technique. Nunes et al attempted to transplant a whole testis into the greater omentum without vascular anastomosis in rats with resultant failure of graft survival [18]. We performed heterotopic testis transplantation (HTT) with blood vessel anastomosis in the present study. The present study aimed to introduce a new and simple method of HTT for future elucidation of testicular immunology in rats

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