Journal of Dental Research, Vol 61, 636-639, Copyright © 1982 by International & American Associations for Dental Research Online Journals
Phagocytic and killing activity of human blood, gingival crevicular, and salivary polymorphonuclear leukocytes for oral streptococci
C. Scully
The phagocytosis and killing of oral streptococci by blood, crevicular, and
salivary polymorphonuclear leukocytes (PMNL) were examined using a visual
assay based on differential staining of viable and non-viable
microorganisms by acridine orange. Crevicular PMNL were 83% viable, 19%
contained bacteria on collection, and phagocytosis occurred in vitro in 66%
of glass-adherent leukocytes. Salivary PMNL were 56% viable, 11% contained
bacteria on collection, and 44% phagocytosed streptococci in vitro.
Crevicular and salivary PMNL were capable of phagocytosis and killing of
oral streptococci, but both were impaired. Crevicular fluid was not
significantly leukotoxic; mixed saliva caused a significant reduction in
PMNL viability and in phagocytic and killing activity for oral
streptococci. Crevicular PMNL may be actively functional phagocytes, but
salivary PMNL are unlikely to be significant in oral defenses.