Epstein-Barr virus-transformed human precursor B cell lines: altered growth phenotype of lines with germline or rearranged but nonexpressed heavy chain genes

Publisher Website
Google Scholar
Abstract
A series of lymphoblastoid cell lines (LCLs) have been established by in vitro infection of fetal bone marrow and fetal liver cells with Epstein‐Barr virus (EBV). While most lines showed the usual mature B cell phenotype, a small proportion were cytoplasmic and surface immunoglobulin (Ig) heavy and light chain negative. Analysis of gene rearrangements indicated that the Ig lines were either germ‐line or nonproductively rearranged when probed for JH and were in germ‐line configuration for Cx; no μ or χ mRNA could be detected in such cells. Precursor B cell lines were indistinguishable from their normal Ig+ counterparts in their expression of a wide variety of cell surface markers including “activation” antigens usually associated with the lymphoblastoid state; even the single LCL showing germ‐line heavy and light chain genes expressed B lineage‐specific cell surface antigens. However, the Ig− lines were distinct from their Ig+ counterparts in three important respects: (a) they grew much more slowly and achieved lower saturation densities, (b) they showed unusually high proportions (8–16%) of cells in EBV‐productive cycle, and (c) they contained unusually high proportions (up to 40%) of cells expressing free joining (J) chain. These results suggest that precursor B cells differ in their response to the growth‐transforming effects of EBV such that the virus‐cell interaction in precursor B cell lines is inherently less stable than in conventional LCL. In particular there may be a greater movement of cells out of cycle and along the B cell maturation pathway. It is possible that such movement leads in individual cells either to virus replication or to a “sterile” plasmacytoid differentiation with J chain expression in the absence of Ig synthesis.
Keywords