THE EX-VIVO FUNCTION AND EXPRESSION OF FUNCTION-ASSOCIATED ANTIGENS OF PERIPHERAL-BLOOD NEUTROPHILS AND MONOCYTES

The availability of recombinant human granulocyte and granulocyte-macr ophage colony-stimulating factors (rhG-CSF and rhGM-CSF) has prompted many studies of the analysis of antigen expression and function of mon ocytes and neutrophils from patients receiving these factors as therap eutic agents. Preparatory procedures for leukocytes are known to alter antigen expression and so function. We therefore investigated the use of a novel procedure in which live leukocytes are analyzed by now cyt ometry without isolation from blood. The expression levels of CD11b, C D13, CD14, CD16, and CD18 antigens and L-selectin (TQ1 and Leu-8 epito pes) on neutrophils and monocytes from 15 normal individuals were dete rmined and compared with a previously used method in which the leukocy tes were fixed and the erythrocytes lysed before analysis. Significant differences for the apparent expression of CD11b, CD18, and L-selecti n were observed between the two methods. The reasons for this were inv estigated. Since the new method allowed analysis of live cells, we als o investigated whether modulation of antigen expression could be deter mined following receptor agonist interaction. This was found to be eas ily achievable, and we advocate using the new procedure where possible for the ex vivo analysis of function and function-associated antigens on monocytes and neutrophils.