Tumor delayed hypersensitivity reactions. "In vivo" functional differences between spleen and peripheral blood lymphocytes.

In a syngeneic BALB/c transplantable tumor model, specific delayed hypersensitvity reaction, detected by foot-pad swelling test appeared specifically suppressed or "eclipsed" in advanced tumor bearing mice. This "eclipsed" response could not be reversed after tumor resection. Unresponsiveness was analyzed by local adoptive transfer of lymphocytes from two different sources. When spleen cells (SC) from advanced tumor bearing and advanced tumor resected mice were locally transferred into normal recipients, a positive cutaneous delayed hypersensitivity (CDH) reaction was observed. While when peripheral blood lymphocytes (PBL) from the same anergic donors were transferred, no CDH reactivity was elicited. Functional differences between SC and PBL populations are suggested to explain these findings.