T-Cell-Specific Membrane Antigens in the Mexican Axolotl (Urodele Amphibian)

Comparative analysis of SDS-PAGE patterns of axolotl spleen cells membrane detergent lysates showed important discrepancies between control and thymectomized animals. Among these, a 38-kD protein band, which appeared as a major protein in controls, was not or poorly expressed after thymectomy. A rabbit antiserum (L12) raised against the 38-kD eluted band labeled in indirect immunofluorescence 80-86% of thymocytes and 40-46% of mIg(–) lymphoid cells in the spleen. The anti-38-kD antibodies stained in Western blotting two antigenically related polypeptides of 38- and 36-kD on splenocyte membrane lysates. Two-dimensional NEPHGE-PAGE analysis indicated that the anti-38-kD antibodies reacted in the spleen with several gathered spots in the 7.8–8.2 pI range, corresponding to 38–36-kD microheterogeneous polypeptides. Most of these spots are not further expressed in thymectomized animals. These results support evidence that the 38-kD surface antigens can be considered as specific surface markers of the axolotl thymus-derived lymphocytes.