Gonococcal interactions with polymorphonuclear neutrophils: importance of the phagosome for bactericidal activity.

Abstract

A B S T R A C T Gonococci are capable of attaching to the surface of polymorphonuclear leukocytes (PMN). In this location they resist phagocytosis and are not killed by PMN. To delineate the factors involved in the survival of these gonococci, we investigated the interaction of virulent gonococci, which adhere to cells and resist phagocytosis, and avirulent gonococci, which are phagocytized and killed by PMN. In the presence of serum, both virulent and avirulent gonococci associate equally well with PMN and stimulate increases in oxidative metabolism. In the absence of serum virulent gonococci attached to PMN and stimulated PMN oxidative metabolism to a greater extent than avirulent gonococci which did not attach to PMN (P = 0.0009). Therefore, the survival of virulent gonococci attached to the PMN surface is not a result of failure to activate oxidative and bactericidal mechanisms.Both virulent and avirulent gonococci stimulated equivalent PMN specific granule release as measured by the appearance of lactoferrin in the media. Phagocytosis of avirulent gonococci stimulated significantly greater,/3-glucuronidase release (P = 0.01) and myeloperoxidase-mediated iodination of protein (P = 0.001) by PMN

Pathology of Liver Granulomas in Turkeys

“…Resistance of the bacteria to degradation may have been due to innate properties of the bacterial cell wall or the failure of host cells to form closed phagolysosomes. Some virulent gonococci attach to the surface of neutrophils but resist phagocytosis [4]. Such surface-attached gonococci are believed to resist the bactericidal effects of neutrophils because of the failure of neutrophils to enclose the gonococci in phagosomes.…”

“…Such surface-attached gonococci are believed to resist the bactericidal effects of neutrophils because of the failure of neutrophils to enclose the gonococci in phagosomes. The phagosome may be critical in providing a closed space in which bactericidal secretions of phagocytes can exert optimal killing of bacteria [4]. A gram-positive, anaerobic, filamentous bacterium identified as E. tortuosum was demonstrated consistently by microscopy and culture in naturally occurring and experimentally induced lesions.…”

Oxygen-independent intracellular and oxygen-dependent extracellular killing of Escherichia coli S15 by human polymorphonuclear leukocytes.

“…Hence, effective bacterial killing by PMN is generally presumed to require intracellular sequestration of bacteria (4). We now provide evidence that human PMN do kill extracellular Escherichia coli (S15).…”

The Importance of Hydrogen Peroxide in Phagocytic Bactericidal Activity of Japanese Eel Neutrophils.

“…Many researchers have reported the importance of phagosome formation for bacterial killing by mammalian phagocytes (Zigmond and Hirsch, 1972;Densen and Mandell, 1978;Root et al, 1981). To further assess the contribution of phagosome formation to bacterial killing by fish phagocytes, we also examined the bactericidal activity of eel neutrophils treated with cytochalasin B, which suppresses the phagosome formation of phagocytes.…”