Reactivation of persistent Epstein–Barr virus (EBV) causes secretion of thyrotropin receptor antibodies (TRAbs) in EBV-infected B lymphocytes with TRAbs on their surface

Abstract

antibodies (TRAbs). We have reported that Graves' disease patients and healthy controls have EBV-infected lymphocytes that have TRAbs on their surface (TRAb(+)EBV(+) cells) in peripheral blood mononuclear cells (PBMCs). EBV reactivation is known to be associated with plasma cell differentiation and antibody production of B cells. In this study, we investigated whether TRAb(+)EBV(+) cells really produce TRAbs or not when persistent EBV is reactivated. We cultured PBMCs from 12 Graves' disease patients and 12 healthy controls for several days with cyclosporine A to expand the EBV-infected cell population, and then compared TRAb levels between EBV reactivation by 33 C culture and EBV nonreactivation by 37 C culture of PBMCs. Flow cytometry confirmed that all samples at day 0 (reactivation starting point) contained TRAb(+)EBV(+) cells. During 33 C culture, EBV-reactivated cells with EBV-gp350/220 expression increased from about 1 to 4%. We quantified TRAb levels in culture fluids by radio-receptor assay, and detected an increased concentration for at least one sampling point at 33 C (from days 0 to 12) for all patients and healthy controls. TRAb levels were significantly higher in supernatants of 33 C culture than of 37 C culture, and also significantly higher in supernatants from patients than those from controls. This study revealed TRAb production from TRAb(+)EBV(+) cells in response to reactivation induction of persistent EBV in different efficiencies between patients and controls.

Epstein–Barr Virus Lytic Reactivation Activates B Cells Polyclonally and Induces Activation-Induced Cytidine Deaminase Expression: A Mechanism Underlying Autoimmunity and Its Contribution to Graves' Disease

“…EBV reactivation and plasma cell differentiation occur in the same period (10,18,19). We examined Ig secretion during EBV reactivation induction and observed significant biphasic variations in IgG, IgM, and IgE with peaks on days 0 and 10 or 12 (Fig.…”

“…PBMCs were cultured for 2 days in RPMI 1640/10% FBS with 0.1 μg/mL cyclosporin A at 37°C, as described in our previous study (18,19), to suppress T cell function and enrich the B cell population. They were then transferred to a culture at 33°C to induce EBV reactivation and were regarded as day 0 samples.…”

“…They were then transferred to a culture at 33°C to induce EBV reactivation and were regarded as day 0 samples. Culture at 33°C is a physiological way to induce EBV reactivation (6,19,24,25). …”

“…Then we showed that patients with Graves' disease and healthy controls had EBV-infected B cells with TRAbs on their surface (TRAb+EBV+ cells) (18). We also demonstrated that peripheral blood mononuclear cells (PBMCs) containing these double-positive cells released TRAbs during the induction of EBV reactivation (19). …”

A possible link between the Epstein-Barr virus infection and autoimmune thyroid disorders

“…Nagata has shown that in vitro reactivation of the EBV infection causes the production of thyrotropin receptor antibodies (TRAbs) in EBV-infected B-cells with TRAbs on their surface [48]. Moreover, Nagata has also reported increased TRAb titres in children with infectious mononucleosis due to EBV primary infection [23].…”