Construction of Rat-Mouse T-Cell Hybridomas That Constitutively Produce Rat IL-2

We have established rat-mouse T-cell hybridomas that constitutively produce rat Interleukin-2 (IL-2). T-cell hybridomas cannot be boosted to a higher level of IL-2 production by Con A stimulation. IL-2 prepared from T-cell hybridomas and from Con A activated rat spleen cells was partially purified using Ultrogel AcA 54 chromatography and ion exchange chromatography on Mono Q or chromatofocusing on Mono P. When analyzed on Mono P, IL-2 activity derived from IA2-B10 T-cell hybridoma eluted as a single peak with pH range 6.9-7.1, whereas IL-2 derived from Con A activated spleen cells resolved into four peaks within the following pH range: 7.1-7.2, 6.5-6.6, 6.1-6.2, and 5.6-5.7. Neuraminidase-treated IL-2 derived from Con A activated spleen cells resolved into single peaks appearing in the pH range 7.1-7.2. In contrast, neuraminidase treatment did not change the elution profile of IL-2 derived from the IA2-B10 hybridoma. IL-2 activity derived from the 3D6-B1 T-cell hybridoma also eluted as a single peak with the pH range 7.1-7.2. Neuraminidase treatment did not change the elution profile of IL-2. These data demonstrate that heterogeneity of IL-2 might be due to differences in the degree of glycosylation of IL-2 and differences in the sources of T-cells from which the IL-2 has derived.