Rosette-forming ability of thymus-derived lymphocytes in humoral and cell-mediated immunity. II. Helper cell activity.

Abstract

The technique of velocity sedimentation at unit gravity was used to determine the size and rosette-forming ability of helper cells in nonimmune and immune C57BL/6 mice. Helper T cells were assayed by the ability to cooperate with bone barrow (B) cells in the antibody response to sheep erythrocytes (SRBC) in vivo. 19S helper cells in nonimmune animals were nonrosette-forming small lymphocytes; after immunization with SRBC in complete Freund's adjuvant, 19S helper cells were nonrosette-forming medium lymphocytes. 7S helper cells in immune animals were small lymphocytes which did not form rosettes. No SRBC binding by helper cells was observed under the conditions of rosette formation used.

The nature of allorosette-forming cells in rats

“…The T-lymphocyte subpopulation involved in rosette formation is controversial. Using sheep red blood cells as antigen, some authors could not detect helper cell activity among rosette-forming T cells [10,11]. In other experiments, T cells forming rosettes with sheep red blood cells exhibit helper cell function [3,23,37].…”

Antigen-binding T cells as helper cells. Separation of helper cells by immune rosette formation.

“…The T-cell nature of the helper cells is shown by their sensitivity to anti-T serum and complement, and by the fact that the majority of the B cells were removed by filtration through the nylon wool column . Although T cells binding a variety of antigens like sheep red blood cells, synthetic polypeptides, and keyhole limpet hemocyanin (13)(14)(15) have been demonstrated, the efforts to recover helper cells by specific rosetting have so far been unsuccessful (5)(6)(7) . The discrepancies between previous reports and this work may perhaps be explained by a number of differences .…”