Identification and characterization of rabbit-mouse hybridomas secreting rabbit immunoglobulin chains

Standard cell-fusion techniques have been used to generate hybrid cells from rabbit spleen cells and mouse myeloma cell lines. The hybrids were selected for secretion of rabbit immunoglobulin. Detailed allotype analyses were carried out for 189 cell lines found to be immunoglobulin positive: 1 produced an intact immunoglobulin molecule with antibody activity, 143 produced rabbit light (L) chains, 36 produced rabbit heavy (H) chains, and 9 cell lines gave negative results in tests for group a and b allotypes. Fusions with a nonproducing murine myeloma cell line (SP-2) yielded only L chain-secreting hybrids, whereas 27% of hybrids resulting from fusion with an L chain-producing line (PU) secreted rabbit H chains paired with mouse L chains. Several of the hybridomas have maintained the ability to produce rabbit immunoglobulin chains in culture for almost 1 year and can be propagated as ascites tumors in athymic (nude) mice. Cytogenetic analyses have detected no rabbit chromosomes in the stable hybrid cell lines.