Retrospective Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Sep 28, 2017; 9(27): 1115-1124
Published online Sep 28, 2017. doi: 10.4254/wjh.v9.i27.1115
T-cell allorecognition of donor glutathione S-transferase T1 in plasma cell-rich rejection
María José Martínez-Bravo, Berta Sánchez, José Manuel Sousa, María José Acevedo, Miguel Angel Gómez-Bravo, Antonio Núñez-Roldán, Isabel Aguilera
María José Martínez-Bravo, Berta Sánchez, María José Acevedo, Antonio Núñez-Roldán, Isabel Aguilera, Immunology Service, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Seville, Spain
José Manuel Sousa, Digestive Diseases Service, Hospital Universitario Virgen del Rocío, 41013 Seville, Spain
Miguel Angel Gómez-Bravo, Liver Transplant Unit, Hospital Universitario Virgen del Rocío, 41013 Seville, Spain
Author contributions: Martínez-Bravo MJ designed and performed the research and contributed to the analysis; Acevedo MJ performed the experiments and acquired the data; Sousa JM and Gómez-Bravo MA provided samples and the clinical information of the patients; Sánchez B contributed to the analysis and revised the manuscript; Núñez-Roldán A critically reviewed the manuscript; Aguilera I designed the study, analyzed the data and wrote the manuscript.
Supported by The Spanish Ministry of Economy, Instituto de Salud Carlos III, Nos. 10/2332 and 11/857; and the Andalusian government, No. PI-0332-2007, for which Martinez-Bravo MJ was a pre-doctoral fellow. Aguilera I is a senior researcher from the Nicolás Monardes program.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the University Hospital Virgen del Rocío, Seville, Spain.
Informed consent statement: Patients were not required to give informed consent to this study because they have been enrolled in previous projects and this was a continuation of the research for which they gave a general consent.
Conflict-of-interest statement: The authors have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Isabel Aguilera, PhD, Immunology Service, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot s/n, 41013 Seville, Spain. iaguilera-ibis@us.es
Telephone: +34-95-5923120
Received: January 26, 2017
Peer-review started: February 8, 2017
First decision: March 27, 2017
Revised: April 6, 2017
Accepted: June 12, 2017
Article in press: June 13, 2017
Published online: September 28, 2017
Processing time: 242 Days and 9.8 Hours
Abstract
AIM

To investigate the role of glutathione S-transferase T1 donor-specific T lymphocytes in plasma cell-rich rejection of liver allografts.

METHODS

The study group included 22 liver transplant patients. Among them, 18 patients were mismatched for the glutathione S-transferase T1 (GSTT1) alleles (don+/rec-), and 4 were matched (don+/rec+). Seven of the mismatched patients produced anti-GSTT1 antibodies and developed plasma cell-rich rejection (former de novo immune hepatitis). For the detection of specific T lymphocytes, peripheral blood mononuclear cells were collected and stored in liquid nitrogen. The memory T cell response was studied by adding to the cell cultures to a mix of 39 custom-made, 15-mer overlapping peptides, which covered the entire GSTT1 amino acid sequence. The specific cellular response to peptides was analyzed by flow cytometry using the markers CD8, CD4, IL-4 and IFNγ.

RESULTS

Activation of CD8+ T cells with different peptides was observed exclusively in the group of patients with plasma-cell rich rejection (3 out of 7), with production of IL-4 and/or IFNγ at a rate of 1%-4.92% depending on the peptides. The CD4+ response was most common and not exclusive for patients with the disease, where 5 out of 7 showed percentages of activated cells from 1.24% to 31.34%. Additionally, two patients without the disease but with the mismatch had cells that became stimulated with some peptides (1.45%-5.18%). Highly unexpected was the finding of a double positive CD4+CD8low T cell population that showed the highest degree of activation with some of the peptides in 7 patients with the mismatch, in 4 patients with plasma cell-rich rejection and in 3 patients without the disease. Unfortunately, CD4+CD8low cells represent 1% of the total number of lymphocytes, and stimulation could not be analyzed in 9 patients due to the low number of gated cells. Cells from the 4 patients included as controls did not show activation with any of the peptides.

CONCLUSION

Patients with GSTT1 mismatch can develop a specific T-cell response, but the potential role of this response in the pathogenesis of plasma cell-rich rejection is unknown.

Keywords: Donor-specific glutathione S-transferase T1 antibodies; Indirect presentation; Glutathione S-transferase T1-memory T cells; De novo immune hepatitis; Donor/recipient mismatch

Core tip: In solid organ transplants, donor recipient mismatch of glutathione S-transferase T1 (GSTT1) alleles triggers a specific immune response with the production of IgG antibodies. In a proportion of mismatched liver and kidney transplants, the clinical outcome is rejection. However, detection of GSTT1-specific T lymphocytes has not been documented. We provide the first evidence of T cells able to become activated by GSTT1 peptides in patients who develop plasma cell-rich (PC-rich) rejection after GSTT1-mismatch liver transplantation. Interestingly, not only CD8+ or CD4+ cells but also double positive CD4+CD8low cells reacted to the antigenic stimulation in vitro.