Two distinct types of helper T cells involved in the secondary antibody response: independent and synergistic effects of Ia- and Ia+ helper T cells.

TLDR

Helper T cells are separable by passage through a nylon wool column. Two distinct helper T cell subsets, Th1 (nylon nonadherent, Ia‑negative, requiring cognate interaction) and Th2 (nylon adherent, Ia‑positive, enabling polyclonal interaction), act independently and synergistically to enhance B‑cell responses to hapten–carrier conjugates, revealing two separate T‑cell–B‑cell collaboration pathways.

Abstract

We have described here two distinct types of carrier-specific helper T cells which act independently and synergistically to augment the B-cell response to a hapten. They are separable by passage through a nylon wool column. The first type of helper T cell, which we designate as Th1, is nylon nonadherent, and can help the response of hapten-primed B cells only if the haptenic and carrier determinants are present on a single molecule (cognate interaction). The second type of helper T cell, Th2, adheres to the nylon wool column, and can help the B-cell response to a hapten coupled to a heterologous carrier upon stimulation with unconjugated relevant carrier (polyclonal interaction). The addition of a small number of Th2 to the mixture of Th1 and B cells significantly augmented the net response to the hapten carrier conjugate. Both Th1 and Th2 cells belong to the Lyt-1+,2-,3- subclass. Th1 has no detectable Ia antigen, whereas Th2 is killed by certain anti-Ia antisera and complement. The Ia antigen detected on Th2 was found to be controlled by a locus in the I-J subregion. The results clearly established the fact that there are two distinct pathways in the T- and B-cell collaboration, which involves two different subsets of carrier-specific helper T cells.