Epstein-Barr virus type 2 infection is associated with higher viral loads in pediatric tonsils from western Kenya

Abstract

Epstein-Barr virus (EBV) is an etiologic agent of endemic Burkitt lymphoma (BL), a prevalent pediatric cancer in sub-Saharan Africa. There are two known types of EBV, EBV Type-1 (EBV-1) and EBV Type-2 (EBV-2), both found in eBL patients. To determine the EBV load and type dynamics within the tonsils, saliva, whole blood, and plasma, we enrolled 102 children aged 1–14 undergoing tonsillectomy in a malaria holoendemic region of western Kenya. Additionally, we investigated EBV-2 cell type preference in tonsillar mononuclear cells (TMCs). Saliva, whole blood, and tonsillar tissue were collected at the time of enrollment. Whole blood was centrifuged to separate plasma from red blood cells, and tonsillar mononuclear cells (TMCs) were isolated from tonsils using a ficoll gradient. Using qPCR, we assessed EBV load and type in TMCs, plasma, whole blood, and saliva. Additionally, a subset of samples was subject to cell sorting to determine the infected cell population. We found that EBV loads were significantly higher in TMCs compared to whole blood (P < 0.01) and in saliva compared to plasma (P < 0.01). Children with EBV-2 exhibited higher EBV loads in TMCs (P = 0.016) than those with EBV-1. Both EBV types were detected in T-cells isolated from TMCS and were also observed in different compartments within the same individual. Our findings indicate that EBV-2 infection in tonsils is associated with higher viral loads, consistent with a model where EBV-2 has more lytic replication compared to EBV-1.