Hapten‐specific helper T cells. I. Collaboration with B cells to which the hapten has been directly coupled

摘要

AbstractA new system to obtain large numbers of functionally competent hapten‐specific effector helper T cells has been developed. Mice were primed in the tail with syngeneic spleen cells derivatized with one of three different haptens: 2,4,6‐trinitrophenyl, fluorescein isothiocyanate and 3‐(p‐sulfophenyldiazo)‐4‐hydroxyphenyl. Draining lymph node cells were subsequently restimulated in culture with the homologous antigen for periods up to 6 weeks. More than 99 and 90 of the cells recovered from these preparative cultures, expressed Thy‐1 and Lyt‐1 antigens, respectively. These cells proliferated specifically in response to the homologous stimulation by haptenated syngeneic spleen cells, and they were found to display very high levels of hapten‐specific helper activity, as assayed in a new, universal method for testing T ‐ B cell cooperation, where every B cell can potentially respond to specific T cell help. Coculture of hapten‐derivatized, functionally competent B cells with hapten‐specific T cells obtained from the preparative cultures, resulted in the appearance, and exponential increase with time, of very large numbers of IgM and IgG plaque‐forming cells. This helper activity could be shown to be: specific for the immunizing hapten and to increase with the time ofin vitrohelper cell enrichment, which also resulted in higher average avidities expressed by the helper cell populations. This methodology appears valuable for structural studies on hapten‐specific helper cells, as well as for the functional analysis of effector h