Multiple B cell stimulation by individual antigen-specific T lymphocytes

Recently, an experimental system has been described which allows for the isolation and antigenic stimulation of individual antigen-specific helper T lymphocytes in collaboration with a nonlimiting number of primary B lymphocytes. In the studies presented in this report, this system has been employed to determine whether an individual T lymphocyte has the potential to interact with more than a single B lymphocyte, when the B cells are of different antigenic specificities. The results of these studies indicate that an individual influenza virus PR 8-specific T lymphocyte has the ability to promote antibody responses of both trinitrophenyl (TNP)- and PR8-specific B lymphocytes in response to the in vitro antigen TNP-PR8. Similar results were obtained when T cells specific for the hapten TNP were used in collaboration with TNP- and PR8-specific B cells. These results demonstrate that an individual T lymphocyte has the potential to collaborate with more than one B lymphocyte, and that these B cells may differ in their antibody receptor for antigen. These results do not rule out a role for idiotype or allotype-specific T cells in antibody responses but, rather, strongly argue that antigen-specific T cells are able to independently initiate primary B cell responses of B cells with distinct antibody receptors. In addition, under these conditions, hapten-specific helper T cells can be readily demonstrated and may facilitate the response of B cells specific for the same or different determinants.