A non-lectin-like mechanism by which Fusobacterium nucleatum 10953 adheres to and activates human lymphocytes.
Most (approximately 80%) strains of Fusobacterium nucleatum adhere to human erythrocytes in a lectin-like manner that is strongly inhibited by N-acetyl-D-galactosamine (GalNAc). In this study, we investigated the capacity of F. nucleatum 10953, a strain that is weakly inhibited by GalNAc, to adhere to and activate human lymphocytes in vitro. Experiments using [3H]-labeled bacteria and scanning electron microscopy clearly showed that 10953 adhered to lymphocytes and that adherence was blocked by L-arginine+GalNAc greater than L-arginine much greater than GalNAc. Adherence was Ca(2+)-dependent, inhibited by pretreatment of the bacteria with proteases or heat, and unaffected by paraformaldehyde fixation of the bacteria. Strain 10953 induced lymphocyte mitogenesis that was blocked by L-arginine but not by GalNAc. These results suggest that certain strains of F. nucleatum, such as 10953, express a distinct, non-lectin-like mechanism by which they adhere to and activate lymphocytes. Activation of lymphocytes may be an important mechanism in the pathogenesis of periodontal diseases associated with these bacteria.
Tuttle
R S
RS
University of Rochester School of Medicine and Dentistry.
Strubel
N A
NA
Mourad
J
J
Mangan
D F
DF
D000116:Acetylgalactosamine / Q000494:pharmacology*; D001120:Arginine; D001422:Bacterial Adhesion / Q000502:physiology*; D002118:Calcium; D002478:Cells, Cultured; D016967:Fusobacterium nucleatum / Q000472:pathogenicity / Q000502:physiology*; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D037102:Lectins; D008213:Lymphocyte Activation / Q000187:drug effects; D008854:Microscopy, Electron; D010518:Periodontitis / Q000382:microbiology
D037102:Lectins; D001120:Arginine; D000116:Acetylgalactosamine; D002118:Calcium