Expression of an Immunoglobulin Heavy Chain Gene Transfected into Lymphocytes

We determined that mouse lymphoid cell lines can be transfected at high efficiencies (10-70%) by a polyoma virus shuttle vector. With this vector, we obtained expression of a cloned mouse α heavy chain gene transfected into cell lines representative of all stages in B-lymphocyte development, a T-cell lymphoma line, and 3T3 fibroblasts. Heavy chain gene expression in transfected light chain-producing myeloma cells occurred at levels comparable to those in IgA-secreting myeloma cells. Heavy chains produced in transfected myeloma cells were associated with light chains in membrane-bound and secreted IgA. While T-lymphoma cells and fibroblasts were transfected at similar efficiencies to B cells, significantly lower levels of α heavy chains were produced. This immunoglobulin gene transfection system provides a powerful approach for defining important regulatory regions in immunoglobulin genes and for identifying lymphoid cell factors involved in immunoglobulin gene expression in B-lymphocyte development.