Dynamic CD8 T-cell responses to tumor-associated Epstein-Barr virus antigens in patients with Epstein-Barr virus-negative Hodgkin's disease

Abstract

In almost half of patients diagnosed with Hodgkin's disease (HD), the malignant Reed-Sternberg (RS) cells express Epstein-Barr virus (EBV) antigens. Multiple translational efforts are actively investigating antitumor immune strategies by stimulating cytotoxic T lymphocytes (CTL) against tumor-associated EBV antigens. It has previously been believed that this therapeutic strategy and presence of EBV-specific CTLs are limited to EBV-positive HD. In an effort to explore the EBV-specific immune response, here we characterize EBV-specific CTL responses to lytic and latent EBV antigens in 12 consecutive EBV carriers with EBV-negative HD. Compared to healthy donors, we detected weak, baseline EBV-specific responses to both lytic and latent antigens by IFN-gamma ELISPOT in patients with EBV-negative HD at diagnosis. Chemoradiotherapy was associated temporally with a decrease EBV-specific responses. At final follow-up (24 months), recovery of EBV-specific CTL responses was observed with robustness of lytic-specific response equivalent to healthy controls. We confirm evidence of EBV-specific CTLs in patients with EBV-negative HD and provide the first report of dynamic variance in this population during treatment. Our observation challenges prior belief that patients with HD remain immunodeficient following therapy and argues that the clinical significance of the EBV-specific immune response in EBV-negative HD should be further investigated.

Figure 1

Profile of the immune response to EBV peptides in EBV-negative HD patients (white bars) and healthy donors (black bars). (A) Baseline: release of IFN-γ by ELISPOT following peptide stimulation. (B) Baseline: percent of CD8⁺ cells and tetramer⁺ cells following peptide stimulation. (C) Changes in IFN-γ by ELISPOT following peptide stimulation throughout the study follow-up period.