Differentiation antigens in rat lymphocyte subpopulations recognized by rabbit antisera against electrophoretically separated cells.

Abstract

AbstractRat lymphocytes of high (H cells) and low (L cells) electrophoretic mobility (EPM) from lymph node (LN), spleen (Spl) and thymus (Thy) were separated by free flow electrophoresis and antisera against these cells raised in rabbits. Eight distinct lymphocyte‐specific xenoantigens could be characterized by appropriate cross‐absorption of three antisera: anti‐Thy‐L cell IgG, anti‐LN/‐Spl‐H cell IgG and anti‐LN/Spl‐L cell IgG. Cross‐absorption of anti‐Thy‐L cell IgG with unseparated LN or Spl cells revealed a thymus‐specific antigen complex which was absent from peripheral rat lymphocytes but present on mouse thymocytes and peripheral T cells. This complex could be further separated into brain‐associated and nonassociated antigens. The brain‐associated antigens consisted of a rat‐specific component, a component shared by the rat and all mice which carry the Thy‐1.1 and Thy‐1.2 allogenic specificity, and a third component shared by rat and Thy‐1.1 mice. This Thy‐1 antigen complex showed a 26‐fold larger antibody‐binding capacity to thymocytes of low EPM than to those of high EPM. The thymic antigens which were not absorbed by brain tissue showed similar antibody‐binding capacity to all thymocytes whether of low or high EPM. Anti‐LN/Spl‐H cell IgG cross‐absorbed with LN/Spl‐L cells detected antigens which were localized on all rat peripheral H cells and thymocytes but which were absent from peripheral L cells. Further absorption with Thy‐L cells revealed a distinct subclass of antigens present on peripheral H cells and Thy‐H cells but absent from Thy‐L cells. On the other hand, cross‐absorption of anti‐LN/Spl‐L cell IgG with peripheral H cells provided specificities which were directed against all peripheral L cells but which did not react with peripheral H cells and thymocytes. The relationship of these different xenoantigens to known lymphocyte subpopulations is discussed.