Adoptive immunotherapy with liver allograft–derived lymphocytes induces anti-HCV activity after liver transplantation in humans and humanized mice
Masahiro Ohira, … , Kazuaki Chayama, Hideki Ohdan
Masahiro Ohira, … , Kazuaki Chayama, Hideki Ohdan
Published October 1, 2009
Citation Information: J Clin Invest. 2009;119(11):3226-3235. https://doi.org/10.1172/JCI38374.
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Research Article

Adoptive immunotherapy with liver allograft–derived lymphocytes induces anti-HCV activity after liver transplantation in humans and humanized mice

Abstract

After liver transplantation in HCV-infected patients, the virus load inevitably exceeds pre-transplantation levels. This phenomenon reflects suppression of the host-effector immune responses that control HCV replication by the immunosuppressive drugs used to prevent rejection of the transplanted liver. Here, we describe an adoptive immunotherapy approach, using lymphocytes extracted from liver allograft perfusate (termed herein liver allograft–derived lymphocytes), which includes an abundance of NK/NKT cells that mounted an anti-HCV response in HCV-infected liver transplantation recipients, despite the immunosuppressive environment. This therapy involved intravenously injecting patients 3 days after liver transplantation with liver allograft–derived lymphocytes treated with IL-2 and the CD3-specific mAb OKT3. During the first month after liver transplantation, the HCV RNA titers in the sera of recipients who received immunotherapy were markedly lower than those in the sera of recipients who did not receive immunotherapy. We further explored these observations in human hepatocyte–chimeric mice, in which mouse hepatocytes were replaced by human hepatocytes. These mice unfailingly developed HCV infections after inoculation with HCV-infected human serum. However, injection of human liver–derived lymphocytes treated with IL-2/OKT3 completely prevented HCV infection. Furthermore, an in vitro study using genomic HCV replicon–containing hepatic cells revealed that IFN-γ–secreting cells played a pivotal role in such anti-HCV responses. Thus, our study presents what we believe to be a novel paradigm for the inhibition of HCV replication in HCV-infected liver transplantation recipients.

Authors

Masahiro Ohira, Kohei Ishiyama, Yuka Tanaka, Marlen Doskali, Yuka Igarashi, Hirotaka Tashiro, Nobuhiko Hiraga, Michio Imamura, Naoya Sakamoto, Toshimasa Asahara, Kazuaki Chayama, Hideki Ohdan

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Figure 4

The cultivation of liver lymphocytes with IL-2/OKT3 markedly promoted anti-HCV activity.

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The cultivation of liver lymphocytes with IL-2/OKT3 markedly promoted an...
(A) Activation by IL-2 and OKT3 significantly promoted the anti-HCV effect of the liver allograft–derived lymphocytes that were cultured in complete medium with and without IL-2 (100 JRU/ml) for 3 days. OKT3 (1 μg/ml) was then added 1 day before coculturing with HCV replicon cells, at the indicated time. The bar graphs indicate the luciferase activities of the cells in each group. Data are presented as mean ± SEM (n = 5). Statistical analyses were performed using the Mann-Whitney U test with Bonferroni correction after the Kruskal-Wallis H test. #P < 0.01 for OKT3 and IL-2/OKT3 treatment versus no treatment. (B) CD56+ fraction, including NK and NKT cells, strongly inhibited HCV replication. The culture conditions are described in A. By magnetic cell sorting, CD56+ and CD56– fractions were isolated from the activated lymphocytes and analyzed for anti-HCV activity. The bar graphs indicate the luciferase activities of the cells in each group (IL-2–treated group, white bars; IL-2 plus OKT3–treated group, black bars). Whole, whole lymphocytes. Data are presented as mean ± SEM (n = 5). Statistical analyses were performed using the Mann-Whitney U test. *P < 0.05 for CD56+ fraction versus CD56– fraction. (C) Anti-HCV effect of NK cells was almost identical to that of NKT cells after IL-2 activation. The liver allograft–derived lymphocytes were cultured in complete medium with IL-2 (100 JRU/ml) for 3 days. By magnetic sorting, CD3–CD56+ (NK) and CD3+CD56+ (NKT) fractions were isolated from the activated lymphocytes and analyzed for anti-HCV activity. Data are presented as mean ± SEM (n = 6).