Evidence for peripheral release of a lymphokine following transplantation in mice.

: Mouse sera obtained 14-18 h after transplantation of skin or spleen cells from H-2-disparate donors contain a "lymph node activating factor". They activate the draining lymph nodes of syngeneic recipients or F1 hybrids of the mouse strains, which have served as graft donors and recipients, and give specific precipitation lines with the antibody against LNAF. LNAF can be determined in the sera of mice, which have been sensitized with spleen cells prior to transplantation, from 7 to 48 h after transplantation.