Abstract / Summary
ABSTRACT Epstein-Barr virus (EBV) is a ubiquitous human gammaherpesvirus causally linked to several malignancies, including lymphomas and solid tumors. Despite its high global prevalence, a comprehensive profile of humoral responses to EBV is yet to be described. Moreover, how HIV-1 co-infection influences this response can reveal new insights into how cancer risk increases in people with HIV-1 (PWH). Here, we employed phage immunoprecipitation and sequencing (PhIP-Seq) using the VirScan phage-display library to map antibody responses against the EBV proteome in 115 adults from sub-Saharan Africa, with and without HIV-1 co-infection (43 HIV-positive and 72 HIV-negative) at peptide-level resolution. We identified EBNA1, EBNA2, EBNA3B, and the viral capsid antigen protein BFRF3 as the most immunodominant EBV proteins. Differential antibody reactivities between EBV Type 1 and Type 2 were observed against EBNA2, with increased antibody recognition near the C-terminal transactivation domain (C-TAD) observed for Type 1. A specific region of EBNA1 containing the nuclear localization sequence (NLS) was the most frequently targeted epitope of the EBV proteome. Our comprehensive and high-resolution analysis identified several immunodominant EBV proteins that are targeted by most individuals regardless of HIV-1 status. HIV-1 co-infected individuals (PWH) had increased antibody recognition against most EBV proteins compared to HIV-uninfected individuals, but the magnitudes of those responses varied across the proteome. Overall, our findings suggest that HIV-1 co-infection alters both the breadth and magnitude of anti-EBV responses, potentially reflecting increased viral reactivation and HIV-driven mechanisms of immunosuppression that may impact the magnitude of antibody responses in EBV. IMPORTANCE This study employs the first comprehensive high-resolution antibody profiling against Epstein-Barr virus (EBV) among healthy adults and people with HIV-1 (PWH). Our results indicated that HIV-1 has a considerable influence on the anti-EBV repertoire that may provide further evidence of how HIV-1 significantly increases the risk of EBV-associated malignancies such as lymphoma. We showed evidence that HIV-1 co-infection leads to higher exposure to viral antigens, likely due to viral reactivation, reflected by a higher percentage of patients with antibodies reactive to the majority of EBV proteins when compared to people without HIV-1. Since PWH are known to be more susceptible to EBV-associated cancers, whether these changes in humoral immune response can be used as prognostic biomarkers for cancer risks should be further investigated with longitudinal studies.