ENHANCEMENT OF DELAYED-TYPE HYPERSENSITIVITY TO SHEEP RED-BLOOD-CELLSIN MICE BY GRANULOCYTE-COLONY-STIMULATING FACTOR ADMINISTRATION AT THE ELICITATION PHASE

We previously demonstrated that selective depletion of polymorphonucle ar neutrophils by a mAb inhibits both the priming and effector phases of delayed-type hypersensitivity (DTH) to SRBC. To better understand t he role of polymorphonuclear neutrophils in DTH, we examined the effec t of granulocyte CSF (G-CSF) on DTH to SRBC in mice, G-CSF administere d at the elicitation phase enhanced a DTH response that was weak in co ntrol G-CSF-untreated mice. This treatment also augmented mononuclear leukocyte recruitment in DTH in these mice. However, G-CSF administrat ion failed to augment priming of DTH to SRBC under any conditions exam ined.