title: Attachment and internalization of a Chlamydia trachomatis lymphogranuloma venereum strain by McCoy cells: kinetics of infectivity and effect of lectins and carbohydrates.
abstract: The kinetics of attachment and ingestion of Chlamydia trachomatis serotype L1 by monolayers of McCoy cells were studied by using a method that discriminated between attachment and uptake. When about 1% of the McCoy cells was infected, the proteinase K-resistant chlamydial fraction, regarded as ingested chlamydiae, reached a constant value after about 3 h of incubation at 37 degrees C. Uptake of chlamydiae at 4 degrees C could not be demonstrated. The attached and ingested chlamydial fractions were constant over an eightfold increase in chlamydial inoculum. Chitobiose and chitotriose, the di- and trisaccharides of N-acetyl-D-glucosamine, reduced the association of C. trachomatis serotype L1 with McCoy cells. Higher concentrations of chitobiose also selectively inhibited ingestion of chlamydiae. A corresponding effect of chitobiose was also observed on the number of chlamydial inclusions. Wheat germ agglutinin, specific for N-acetyl-D-glucosamine residues, reduced the association of chlamydiae when incubated at 4 degrees C, but not at 37 degrees C. A small inhibiting effect of concanavalin A on association of chlamydiae, but no effect of the corresponding carbohydrates, indicates a nonspecific effect on chlamydial attachment of this lectin. These results suggest that beta 1 leads to 4-linked oligomers of N-acetyl-D-glucosamine are important in the specificity of attachment of C. trachomatis to McCoy cells.
mesh_terms: D002241:Carbohydrates / Q000494:pharmacology*; D002478:Cells, Cultured; D002692:Chlamydia trachomatis / Q000472:pathogenicity*; D004705:Endocytosis / Q000187:drug effects*; D007700:Kinetics; D037102:Lectins / Q000494:pharmacology*; D008219:Lymphogranuloma Venereum / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors
chemical_list: D002241:Carbohydrates; D037102:Lectins