Antigen-induced non-specific suppressor factor in sheep efferent lymph is prostaglandin E2.

Efferent lymph from the popliteal node of sheep challenged with antigen was found to suppress the in vitro transformation of sheep peripheral blood lymphocytes to a variety of antigens. The suppressor factor appeared 6-20 hr after challenge of the node and was shown to bc prostaglandin E₂, probably complexed to albumin. [ABSTRACT FROM AUTHOR]