Hepatitis C Virus-Specific T Cell Receptor mRNA-Engineered Human T Cells: Impact of Antigen Specificity on Functional Properties

Abstract

Therapy with genetically modified autologous T cells has shown great promise in cancer therapy. For an efficient control of hepatitis C virus (HCV) infection, cytotoxic T cells (CTL) are pivotal, but persistence of activated T cells may lead to liver toxicity. Here, anti-HCV T cell receptors (TCRs) recognizing the HCV nonstructural (NS) NS3 or NS5 viral peptide target were examined by mRNA transfection of human peripheral blood lymphocytes (PBLs) derived from healthy donors as well as chronically infected HCV patients. Immunological analysis shows that while the CTLs expressing the NS5-specific TCR reduced HCV RNA replication by a noncytotoxic mechanism, the NS3-specific TCR-redirected CTLs were polyfunctional and inhibited HCV RNA replication through antigen-specific cytotoxicity. Transcriptome signatures from these two types of CTL responses revealed uniquely expressed gene clusters upon encountering hepatoma target cells presenting endogenously expressed HCV proteins. The NS3 TCR induced a rapid expression of apoptotic signaling pathways and formation of embryonic gene clusters, whereas the NS5A TCR activation induced extended proliferative and metabolic pathways as the HCV target cells survived. Our results provide detailed insights into basic HCV T cell immunology and have clinical relevance for redirecting T cells to target virally infected hepatoma cells.IMPORTANCE Due to the protective ability of HCV-specific T cells and the hepatotoxic potential that they possess, there is a great need for the understanding of the functional aspects of HCV-specific T cells. To circumvent the low level of precursor frequency in patients, we engineered primary CD8 ϩ T cells by mRNA TCR vectors to confer HCV specificity to new T cells. HCV TCRs that differ in antigen specificity and polyfunctionality were examined. mRNA TCR engineering of peripheral blood lymphocytes from healthy donors or chronically infected HCV patients resulted in strikingly high levels of HCV TCR expression and HCV-specific responses. While a cytotoxicity response from a polyfunctional T cell activation caused hepatotoxicity and the rapid induction of apoptotic signaling pathways, the noncytotoxic T cell activation showed extended proliferative, metabolic pathways and persistence of HCV target cells. Our results provide detailed insights into basic HCV T cell immunology and have clinical relevance for immune protection of HCV-associated diseases.

Hepatitis E Virus (HEV)-Specific T Cell Receptor Cross-Recognition: Implications for Immunotherapy

“…Based on the TCR repertoire sequencing data, mRNA encoding the TCRs was synthesized and transfected into recipient effector T cells by electroporation. Gene optimization of TCR constant regions is done to prevent mispairing between the introduced and endogenous TCRs (26), and the TCR-redirected cells were used for analysis on day 1 post-transfection, as described (27).…”

Chronic Viral Liver Diseases: Approaching the Liver Using T Cell Receptor-Mediated Gene Technologies

“…Characterized by strong cytolytic and proinflammatory cytokine responses, particularly in terms of IFN-γ production, they are noted of being of high-avidity and preferentially control the viral infection [62]. TCR redirection of human T cells toward these antigens renders them responsive to HCV-bearing hepatocytes and inhibits viral replication in vitro, proving their potential in TCR therapy [53][54][55]. In Soon et al [57], TCRs targeting epitopes at HEV RdRp and helicase domains were suggested as immunotherapeutics for immunosuppressed patients.…”

HBV Immune-Therapy: From Molecular Mechanisms to Clinical Applications

“…Recent reports indicate that adoptive cell transfer currently comprised of TCR-engineered and chimeric Ag receptor (CAR)-T cells have the potential to treat a variety of other diseases including multiple sclerosis, inflammatory intestinal diseases and autoimmune diseases [97,98,99]. Moreover, in the last few years researchers have also considered extending T cell engineering to therapies for virus infections such as HIV-1, CMV, HBV, HCV and SARS [100,101,102,103,104,105,106,107]. In this regard, clinical evidence of the potential effectiveness of immune-modulatory strategies designed to strengthen HBV-specific T-cell responses by adoptive transfer of engineered antigen-specific T lymphocytes are based on the observation that virus-specific T cell administration through a bone marrow transplant from subjects who cleared HBV infection spontaneously, to patients with chronic HBV infection, led to virus control [108].…”

“…Similarly, liver transplantation in a patient with resolved HBV infection receiving a HBsAg positive graft resulted in viral clearance [109]. Thus, adoptive T-cell therapy using autologous T cells genetically engineered to express a canonical HLA class I restricted TCR, or a chimeric antigen receptor (CAR), targeting both HBV and HCV chronic viral infections has been attempted [103,104,105,106,107]. In HBV infection, the re-directed specificity of existing T cells by transfer of HBV-TCR genes has so far been tried in HBV transgenic mice and in patients with relapses of HBV-related HCC [110,111].…”