Plasmacytic differentiation of circulating Epstein-Barr virus-infected B lymphocytes during acute infectious mononucleosis.

Abstract

During the acute phase (1 wk of symptoms or less) of infectious mononucleosis (IM), 70--80% of circulating Epstein-Barr virus nuclear antigen (EBNA)-positive cells have differentiated toward plasma cells. Thus the characteristics of the infected cells in the majority of IM patients during early disease are indistinguishable from EBNA-positive tumor cells of a previously reported child who developed lymphoma during IM. IgA and IgG were the most frequent and IgM the least frequent immunoglobulin isotypes detected in EBNA-positive cells. In acute disease EBNA was present in 5.5--20% of T cell-depleted blood lymphocytes but in the 2nd or 3rd wk of illness the number of EBNA-positive cells sharply decreased to 0.4--1.4%. At the same time the fraction of antigen-positive cells containing cytoplasmic immunoglobulins also diminished, suggesting either that differentiation of infected cells was altered during the disease or that nondifferentiated antigen-positive cells had a survival advantage. Both the high proportion of plasmacytic EBNA-positive cells seen during acute disease and the apparent loss of differentiation by these cells later in disease may be regulated by host immunologic factors. Immunoglobulin-producing EBNA-positive cells may be the source of heterophile antibodies and other seemingly inappropriate antibodies usually found in serum during IM; however, increased numbers of noninfected plasma cells were present in some patients and may also be a potential source of these unusual antibodies.

Acute Infection with Epstein-Barr Virus Targets and Overwhelms the Peripheral Memory B-Cell Compartment with Resting, Latently Infected Cells

“…It is apparent that the EBV-infected cells do not have the same cell cycle distribution as the cell line but closely resemble the bulk population of B cells: 3.4 to 10% of the infected cells and 2.2 to 9% of the bulk B cells are in S/G 2 /M. These numbers are similar to what have been reported for healthy carriers (32) but are not consistent with previous claims that the infected cells in AIM blood are transformed, proliferating lymphoblasts (39,40,47). We conclude that the latently infected B cells in the peripheral blood of AIM patients are resting cells that divide with the bulk B cells presumably as part of the homeostatic regulation of B-cell levels.…”

Distribution and phenotype of Epstein–Barr virus-infected cells in human pharyngeal tonsils

“…17 Also, it has been reported that up to 80% of the EBER-positive cells in the peripheral blood exhibit features of plasmacytoid differentiation. 18 In the present study, numerous BZLF1-positive cells were detected within the tonsils, primarily within the lymphocyterich crypt epithelium. This result is consistent with previous reports documenting EBV replication in IM tonsils.…”

Abnormally elevated frequency of Epstein-Barr virus-infected B cells in the blood of patients with rheumatoid arthritis.

“…Since our patients with (22), and spontaneous outgrowth of EBV-infected cells occurs with a frequency of -300/106 mononuclear cells (23). After primary infection with EBV, viral nucleic acid sequences can be found to persist within the infected B cells, probably for the lifetime ofthe host.…”