Abelson virus-infected cells can exhibit restricted in vitro growth and low oncogenic potential

Abstract

We have designed a method for growing bone marrow cells infected with Abelson murine leukemia virus which permits examination of target cell growth early after infection. This culture system increases the efficiency of target cell growth by favoring rapid growth of a mixed population of adherent cells in the primary culture. The nonadherent Abelson virus-infected cell populations expressed pre-B-cell differentiation markers characteristic of Abelson virus-transformed cells (i,-heavy chains of immunoglobulin M and terminal deoxynucleotidyltransferase). Early after infection, these cell populations exhibited restricted in vitro and in vivo growth properties which differed from those of an established Abelson virus-transforned cell line, 2M3. These included a marked dependency upon the adherent cell layer for growth and viability, a lower efficiency of agar colony formation, and a lower capacity for tumor production in syngeneic animals. Growth of the early populations could be maintained in the absence of the adherent cell layer by using conditioned medium from long-tern adherent cell cultures established in the absence of viral infection. After passage of the populations for several weeks, the in vitro growth properties gradually shifted toward that of the 2M3 cell line. Twelve-week-old populations grew independently of the adherent cell layer and showed an increased efficiency of agar colony formation. These data indicate that many lymphoid target cells exhibit an intermediate transformed phenotype when infected with Abelson virus. Growth of these cells in culture is mediated via a synergistic interaction between intracellular expression of the viral transforming gene and an exogenous growth-promoting activity which can be provided by cultures of adherent bone marrow cells.

G protein-coupled receptor kinase-3-deficient mice exhibit WHIM syndrome features and attenuated inflammatory responses

“…Ableson virus-immortalized pre-B cells [21] were derived from GRK3Ϫ/Ϫ, GRK5Ϫ/Ϫ, and WT BM. To quantitate internalization, we adapted from previously published protocols [2].…”

“…CXCL12-activated CXCR4 signaling is turned off by GRKs via homologous desensitization; the final step is receptor internalization [5,6]. To test the specific role of GRK3 in internalization of activated CXCR4 by primary immune cells, we created BM-derived pre-B cell lines from GRK3Ϫ/Ϫ and WT mice using Abelson virus immortalization [21]; GRK5Ϫ/Ϫ pre-B cell lines were also generated as an additional control, as this kinase is not thought to regulate the CXCR4 receptor [8,9]. The cells were stimulated ex vivo with CXCL12, and the expression of surface CXCR4 over time was analyzed by flow cytometry.…”

A temperature-sensitive mutant of Abelson murine leukemia virus confers inducibility of IgM expression to transformed lymphoid cells.

“…Subcloning could restore the initial state but noninducible variants gradually appeared again (T.T., unpublished observations). In support of the concept that v-abl is mainly needed for the initiation of transformation is the finding by Whitlock and Witte (1981) that A-MuLV-transformed lymphoid cell clones progressively become more feeder (factor) independent and tumorigenic as they are maintained in culture. In addition, certain lymphomas induced by transformation with A-MuLV were observed to lose expression of v-abl but to retain their oncogenic phenotype (Grunwald et al, 1982).…”

“…In all cell lines examined the level of staining with antibody AF-6 was at least 20 times lower than that of cells stained with the goat anti-IgM serum. LPS stimulation 1 x 106 cells were precultured at 35.5 or 39.5°C for 6 days in conditioned medium as described by Whitlock and Witte (1981). 4 x 105 cells /ml were then treated with 10 Ag/ml of LPS (Escherichia coli 055:B5, DIFCO, USA) at 35.5 or 37°C.…”

Expression of a monoclonal antibody-defined, B-lineage transformation antigen specifically identifies Abelson-diseased animals. Genetically determined resistance to Abelson murine leukemia virus acts before induction of gp160(6C3).

“…After integration of A-MuLV into host cells, viral-encoded gag-abl fusion protein is expressed as a cytoplasmic, plasma membrane-associated tyrosine kinase . This expression of the v-abl oncogene is not sufficient for full neoplastic transformation in vitro in liquid cultures, as proliferation of cells expressing gag-abl is dependent on bone marrow-derived stromal feeder cells characteristic of the Whitlock-Witte in vitro pre-B culture system (6) . These gag-abl + cells are 6C3Ag at this stage of development (2).…”