Reconstitution of EBV-directed T cell immunity by adoptive transfer of peptide-stimulated T cells in a patient after allogeneic stem cell transplantation for AITL

Abstract

Reconstitution of the T cell repertoire after allogeneic stem cell transplantation is a long and often incomplete process. As a result, reactivation of Epstein-Barr virus (EBV) is a frequent complication that may be treated by adoptive transfer of donor-derived EBV-specific T cells. We generated donor-derived EBV-specific T cells by stimulation with peptides representing defined epitopes covering multiple HLA restrictions. T cells were adoptively transferred to a patient who had developed persisting high titers of EBV after allogeneic stem cell transplantation for angioimmunoblastic T-cell lymphoma (AITL). T cell receptor beta (TCRβ) deep sequencing showed that the T cell repertoire of the patient early after transplantation (day 60) was strongly reduced and only very low numbers of EBV-specific T cells were detectable. Manufacturing and in vitro expansion of donor-derived EBV-specific T cells resulted in enrichment of EBV epitope-specific, HLA-restricted T cells. Monitoring of T cell clonotypes at a molecular level after adoptive transfer revealed that the dominant TCR sequences from peptide-stimulated T cells persisted long-term and established an EBV-specific TCR clonotype repertoire in the host, with many of the EBV-specific TCRs present in the donor. This reconstituted repertoire was associated with immunological control of EBV and with lack of further AITL relapse.

Virus-specific T-cells from third party or transplant donors for treatment of EBV lymphoproliferative diseases arising post hematopoietic cell or solid organ transplantation

“…If the epitope specificities and HLA restrictions of the adoptively transferred EBV-specific T-cells are already identified EBV epitope specific T-cells expanding in the patient can also be measured by FACS-based quantitation of unstimulated T-cells binding the peptide epitope/HLA multimers ( 30 , 35 ). Furthermore, the use of such multimers can distinguish HLA partially matched 3 rd party T-cells-specific for EBV epitopes presented by shared HLA alleles from endogenous T-cells restricted by alleles unique to the patient, the HCT donor or 3 rd party donor and can provide estimates of their relative contributions to initial and long-term reconstitution of EBV-specific immunity ( 36 , 37 , 40 ).…”

“…However, responses to each of these immunodominant epitopes is polyclonal, each T-cell clone expressing a distinct T-cell receptor specific for the epitope bound to its presenting HLA allele. After sensitization with a pool of defined EBV peptides, these epitope-specific T-cells can be isolated by their binding to epitope-HLA multimers, and their T-cell receptors sequenced ( 40 , 42 ). The number of high frequency T-cell clonotypes expressing distinctive TCRs responding to a specific immunodominant epitope varies, but in one study ranged from 9-40 ( 40 ).…”

“…After sensitization with a pool of defined EBV peptides, these epitope-specific T-cells can be isolated by their binding to epitope-HLA multimers, and their T-cell receptors sequenced ( 40 , 42 ). The number of high frequency T-cell clonotypes expressing distinctive TCRs responding to a specific immunodominant epitope varies, but in one study ranged from 9-40 ( 40 ). Each of the epitope-specific T-cell clonotypes in this repertoire can be characterized as to phenotype and effector function.…”

“…Following adoptive transfer, the expansion of each epitope-specific T-cell can be sequentially quantitated. Differential expansions of specific clonotypes have also been correlated with clinical response ( 40 , 42 , 43 ). Ultimately, this may identify epitope-specific TCRs characterizing T-cell clonotypes with the most consistent and effective anti-viral activity.…”

The innate and T-cell mediated immune response during acute and chronic gammaherpesvirus infection

“…Direct contact-dependent killing of MHV68-or EBV-infected cells is an important mechanism how the adaptive immune system controls the viral spread in the host (Ressing et al, 2015). In light of this mechanism, adoptive T cell therapy in EBV-infected patients aims to selectively kill EBV-infected cells (Lammoglia Cobo et al, 2022). In ongoing trials, EBV-specific T cells are injected with the purpose to reduce numbers of EBV-infected B cells and thus lower overall disease severity.…”