935 NORMAL LYMPHOCYTE-DERIVED CHEMOTACTIC FACTOR PRODUCTION BY NEONATAL LYMPHOCYTES

Abstract

This study measured production of the lymphokine, lymphocytederived chemotactic factor by neonatal peripheral blood lymphocytes. Previous lymphokine studies of cord lymphocytes have yielded conflicting results with normal or deficient function found. Comparing cord and neonatal lymphocytes, some investigators have reported that neonatal lymphocytes are more deficient than cord lymphocytes in lymphokine production. Since one prior study reports normal LDCF production by cord lymphocytes, we studied LDCF production by peripheral blood lymphocytes from 7 healthy newborns 2 to 5 days of age. Seven healthy adult donors were also studied. Lymphocytes were incubated for 48 hours with or without phytohemagglutinin (PHA). Supernatants from these cell cultures were assayed for monocyte chemotactic activity in chemotaxis chambers using adult monocytes. Results were expressed as the difference in chemotactic activity between stimulated and nonstimulated culture supernatants. Each supernatant from a neonatal culture was assayed with the supernatant from a paired adult control culture. Six of the 7 neonatal lymphocyte cultures produced LDCF, and 5 of the 7 adult lymphocyte cultures produced LDCF. Neonatal lymphocytes were not deficient in LDCF production compared to adult lymphocytes. These results show that neonatal lymphocytes are functionally competent producers of LDCF in response to the mitogen PHA.