Features of haemocyanin-induced suppression in vivo. Study of the fractionation of T lymphocytes involved in suppression over unsolubilized conjugated histamine columns.

Haemocyanin (KLH, 4 mg), given intraperitoneally, induces in mice a state of unresponsiveness related only to the activity of two independent pathways of suppression. The early pathway is characterized by the depression of the anti-trinitrophenyl response to TNP KLH within 24 h of KLH injection, and the ability of spleen cells from KLH-treated animals to transfer unresponsiveness in normal recipients. These features of suppression are stopped after fractionation of spleen cells from KLH-treated mice over insolubilized conjugated histamine columns. The late pathway of suppression is characterized by the nonspecificity of its effector phase, leading to a depressed anti-FLu antibody response after a challenge with TNP KLH + FLu OVA. These features, which are cyclophosphamide-resistant, are no longer active after passage through insolubilized conjugated histamine columns.