T hybridoma [formula omitted] gene transfected in a murine T cell hybridoma: Role of CD4 molecule in vitro and in vivo—Engraftment in SCID mice induces T cell maturation

Abstract

In the present work, we tested in SCID and Balb/c mice the activity of T cell hybridoma transfected with T cell receptor (TCR) α β chain genes. A T cell hybridoma denoted D011107 was used as recipient for transfection of cytotoxic KB5C20 TCR α β heterodimer genes by protoplast fusion or electroporation. After transfection, the parental D011107 T cell line reexpressed CD5 and CD4 surface molecules. In vitro, we noted strong proliferation and unusual cytotoxic reactivities against H-2 k target cells although the transfected cell line does not express the CD8 molecule. The fate of parental and transfected cells was examined in severe combined immunodeficient (SCID) and Balb/c mice at Day 16 after intravenous injection. Cells from bone marrow, thymus, and spleen tissues were analyzed by immunofluorescence. The transfected T cell hybridoma was CD3 + Desire 1 + CD4 + Thy 1.2 +. The SCID mice grafted with the transfected T cell hybridoma presented a high percentage of CD3 + (15%), CD4 + (27%), Thy1.2 + (27.52%), and Desire 1 + (8.74%) cells in the spleen. The percentages of CD3 + (6.2%) and Thy1.2 + (5.06%) cells in the spleen from SCID mice grafted with parental T cell D011107 and from untreated SCID were similar and lower (CD3 +, 3.52%; Thy1.2 +, 4.34%). It seems that transfected T cells hybridoma grafted in the SCID mice induce significant expression of CD4 + Thy1.2 + Desire 1 − cells (17%) in the spleen. These results indicate that transfected T cells graft may allow T cell differentiation. In Balb/c mice, the percentage of different T cell subsets in bone marrow, thymus, or spleen cells in mice injected with transfected T cells was similar to that in untreated mice. We did not observe any cytotoxic or significant allogeneic proliferation in vitro.