Phenotypic restriction of antigen-binding specificity on immunized amphibian spleen cells

Abstract

Antigen-binding studies have been used to determine the specificity of immunized splenocytes of adult representatives in three groups of Amphibia, the American common newt, Triturus viridescens, the South African clawed toad, Xenopus laevis, and the American leopard frog, Rana pipiens. At question is the basis for organismal response diversity available to lower vertebrates. In vivo immunization with horse erythrocytes (HRBC) followed by trinitrophenylated (TNP) HRBC was effected. Dissociated splenic lymphocytes capable of binding TNP-HRBC and HRBC were counted after preincubation with glycine or TNP-glycine. Since TNP-glycine blocked Triturus immunocytes from binding TNP-HRBC and HRBC equally, while only binding to TNP-HRBC was blocked in the other two species, we have concluded that immunized cells from Triturus, but not Xenopus or Rana, appear to bear surface receptor molecules capable of binding TNP and a determinant of HRBC.