A novel pre-B cell precursor: phenotypic characterization and differentiation induction by dendritic cell-T cell mixtures.

Abstract

We have derived from spleens of nude mice early B lineage cell lines that are dependent upon factor(s) in supernatants of the WEHI-3B cell line. The cells are phenotypically at the pre-pre-B cell stage of differentiation. These cells are large and have basophilic granules in the cytoplasm. They are negative for cytoplasmic and surface immunoglobulin heavy or light chain, surface B220, surface Thy 1.2 and surface Ia but are positive for cytoplasmic B220. These cells at this early stage of maturation can be induced by mixtures of DC-T cells to express B220 on their surfaces and later to synthesize and ultimately to secrete immunoglobulin. These events are associated with morphologic changes in the cells to a lymphoblastoid appearance. Different pattern of immunoglobulin secretion were induced by DC-T from different tissues. The inductive event appears to occur during cell contact of pre-pre-B cells with the inducing DC-T cell mixture, but it does not appear to require IL-3. These data indicate that DC-T cell mixtures can provide signals for B cell differentiation at pre-pre-B cell stage as well as pre-B and mature B cell stage.