Modulation of in vivo immune response by selective depletion of neutrophils using a monoclonal antibody, RP-3. II. Inhibition by RP-3 treatment of mononuclear leukocyte recruitment in delayed-type hypersensitivity to sheep red blood cells in rats.

We demonstrated in our previous paper that treatment of rats with RP-3, a mAb that depletes in vivo neutrophils selectively, resulted in inhibition of both the priming and effector phases of delayed type hypersensitivity (DTH) to SRBC. In order to clarify the mechanisms of this phenomenon, we examined the effect of RP-3 treatment on mononuclear leukocyte (MNL) recruitment in DTH. When rats had been treated with RP-3 at the time of Ag priming, MNL migration, which accompanies DTH, was inhibited. The prior infiltration of neutrophils was also partially required for MNL recruitment because migration was inhibited when the immune rats were treated with RP-3 at the time of DTH elicitation.