Data from: Hemin treatment drives viral reactivation and plasma cell differentiation of EBV latently infected B cells

Epstein-Barr virus (EBV) and Plasmodium falciparum have a well described
role in the development of endemic Burkitt lymphoma (BL), yet the
mechanisms involved remain unknown. A major hallmark of malarial disease
is hemolysis and bystander eryptosis of red blood cells, which causes
release of free heme in large quantities into peripheral blood. We
hypothesized that heme released during malaria infection drives
differentiation of latently infected EBV-positive B cells, resulting in
viral reactivation and release of infectious virus. To test this
hypothesis, we used the EBV-positive Mutu I B-cell line and treated with
hemin (the oxidized form of heme) and evaluated for evidence of EBV
reactivation­. Hemin treatment resulted in the expression of EBV immediate
early, early and late lytic gene transcripts. In addition, expression of
CD138, a marker of plasma cells was co-expressed with the late lytic
protein gp350 on hemin treated Mutu I cells. Finally, DNase-resistant EBV
DNA indicative of virion production was detected in supernatant. To assess
the transcriptional changes induced by hemin treatment, RNA sequencing was
performed on mock- and hemin-treated Mutu I cells, and a shift from mature
B cell transcripts to plasma cell transcripts was identified. To identify
the mechanism of hemin-induced B cell differentiation, we measured levels
of the plasma cell transcriptional repressor, BACH2, that contains
specific heme binding sites. Hemin treatment caused significant
degradation of BACH2 by 24 hours post-treatment in four BL cell lines (two
EBV positive, two EBV negative). Knockdown of BACH2 in Mutu I cells using
siRNAs significantly increased CD138+gp350+ cells to levels similar to
treatment with hemin. This suggested that hemin induced BACH2 degradation
was responsible for plasma cell differentiation and viral reactivation.
Together, these data support a model where EBV reactivation can occur
during malaria infection via heme modulation, providing a mechanistic link
between malaria and EBV.