Are V_H framework antigenic determinants expressed on both rabbit B and T lymphocytes?

Abstract

Abstract The extent to which V H framework determinants are represented on T cell receptors is unresolved and controversial. We have studied this question in the rabbit using antia (V H framework) allotype antisera and a goat anti‐rabbit V H antiserum. Flow micro‐ fluorometric analysis of spleen lymphocytes from hyperimmune animals (Freund's adjuvant plus picryl chloride) demonstrated closely similar frequencies of cells stained with the anti‐V H framework antisera compared to anti‐light chain antisera. To search for potentially hidden molecules, additional studies were performed with radioiodinated, detergent‐solubilized plasma membranes derived from immune spleen and lymph node cells. The membranes were analyzed by standard immunoprecipitation techniques. Absorption with anti‐Ig constant region immunoabsorbents removed all radioactivity precipitable by specific anti‐V H framework antisera compared to controls, whereas after absorption with control (normal goat globulin) immunosorbents, V H ‐bearing surface IgM and putative surface IgD (presumably of B cell origin) were readily demonstrated by immunoprecipitation. Thus, no evidence for a population of cells or a class of molecule(s) bearing V H in the absence of light or heavy chain constant region determinants was obtained. Although these studies do not support the concept of similar V H framework determinants on T and B cell receptors, they do not exclude a much more limited sharing of determinants or a very minor T cell subpopulation which expresses V H framework that would not be detectable by the methods used in these studies.