Lysozyme-dependent Proliferation Switch: Hematopoietic and Hybridoma Cell Growth Control with the Use of Antibody/GP130 Chimera

Abstract

Proliferation and differentiation of factor-dependent animal cells are controlled by cytokines, which activate their specific receptors expressed on the cell surface. However, cytokines are often so expensive that the use of factor-dependent cells for the industrial applications such as protein production is not practical. In our previous study, a pair of chimeric erythropoietin receptors (EpoR) whose part of the extracellular region was replaced with either VH or VL, region of anti-hen egg lysozyme (HEL) antibody HyHEL-10 (VH-EpoR or VL-EpoR, respectively) transduced a growth signal through heterodimer formation between VH-EpoR and VL-EpoR in response to an inexpensive protein, HEL. In this study, the intracellular domain of VH-EpoR and VL-EpoR was replaced with that of gp130 (VH-gp130 and VL-gp130, respectively). When VH-gp130 and VL-gp130 genes were co-transfected into an interleukin-3 (IL-3) dependent pro-B cell line Ba/F3, the transfectant also proliferated in a HEL dose-dependent manner without IL-3. When VH-gp130 and VL-gp130 genes were co-transfected into an IL-6 dependent hybridoma cell line 7TD1, the transfectant showed clear HEL dose-dependent cell growth and monoclonal antibody production both in serum-containing and serum-free media without IL-6, resulting in significant medium cost reduction. The results further suggest the possibility of applying this technology for the control of many other cell functions by exchanging the chimeric receptor intracellular domain.