Bone Marrow-Derived Cells as Target Cells for Polynucleotide Adjuvants

Abstract

Mice were immunized with 10⁷ sheep red blood cells (SRBC), with or without polyadenylic and polyuridylic acid adjuvant. Kinetics of the number of plaque-forming cells and cell units that could form hemolytic foci in recipient mice were studied. The adjuvant enhanced the number of plaque-forming cells on days 2 through 4 of the response but did not increase the number of hemolytic focus-forming units at any time. Since the limiting cell for the formation of hemolytic foci is probably the thymusderived cell, the adjuvant does not appear to act on cells of this type. The adjuvant appears to enhance the plaque-forming cell response at the level of the bone-marrow cell by a) increasing mitosis of bone marrow-derived cells, and/or b) by increasing the number of bone marrow-derived cells that interacted with thymus-derived cells.