An analysis of the uterine lymphocyte-derived hybridoma cell line GWM 1-2 for expression of receptors for estrogen, progesterone and interleukin 2

Characterisation of murine hybridoma cell lines derived from the fusion of lymphocytes migrating from explant cultures of early, pregnancy-associated metrial glands (days 6-8 of gestation) to SP 2/0 cells, has been extended (van den Heuvel et al., J; Reprod. Immunol., 27 (1994) 13-36). These hybridomas have been grown in culture for over 2 years and are thought to represent the only immortalized lines of murine pregnancy-associated, uterine natural killer (uNK) cells. Previous studies had shown that these hybridomas, known as GWM cells, lack uNK cell surface markers, but share with uNK cells the expression of the lytic protein perforin and the ability to lyse YAC cells, a natural killer cell target (van den Heuvel et al., J. Reprod. Immunol., 27 (1994) 13-36). We report here, the evaluation of the transcription and expression of genes encoding the estrogen receptor (ER), the progesterone receptor (PR) and the interleukin 2 receptor complex (IL 2R alpha, beta and gamma) by uNK cells at day 8 of gestation and by GWM 1-2 cells and SP 2/0 cells. Our investigations indicate that expression of these genes divides day 8 uNK cells into subsets, with the predominant population being ER(+), PR(-), IL 2R alpha(+), IL 2R beta(+) and IL 2R gamma(+). Like day 8 uNK cells, most GWM 1-2 cells expressed all three chains of the IL 2R complex. In addition, GWM 1-2 cells expressed the ER but the PR was not detected on this cell line. Only the IL 2R alpha was detected on the SP 2/0 myeloma cell line. These studies further validate the use of GWM hybridomas as models for pregnancy-associated uNK cells.