Activation of peripheral phagocytes in BCG-vaccinated subjects

The role of polymorphonuclear leukocytes (PMNs) in the immune defence against intracellular bacteria has long been neglected. Only recently have studies begun to address this issue. In this study the behavior of peripheral PMNs in Bacillus Calmette-Guerin (BCG) vaccinated subjects was investigated. Twenty healthy and purified protein derivative-negative adults were studied before, and two and four months after, BCG administration. Luminol-amplified chemiluminescence (CL) emission was evaluated in whole blood phagocytes using a soluble stimulus, such as phorbol mirystate acetate, or particulates such as zymosan opsonized with homologous (OZH) or autologous (OZA) serum. Specific IgG, IgA and IgM against antigen -60 by ELISA, total immunoglobulin, C3 and C4 components of complement, were assessed by immunochemical tests. The results revealed a late heightened production of reactive oxygen intermediates in vaccinated subjects in presence of OZA and OZH. Our findings confirm that the role of PMNs and their mediators in immunoregulation of intracellular diseases needs to be re-evaluated.