Association of Chlamydia trachomatis with mammalian and cultured insect cells lacking putative chlamydial receptors.

The association of radiolabelled Chlamydia trachomatis (strains DK-20 and 434) with cultured cell monolayers has been examined. Previously, N-acetyl neuraminic acid and N-acetyl-glucosamine had been suggested to be involved in the association of certain strains of C. trachomatis with cultured cell monolayers. We have now studied the association of non-LGV (DK-20) and LGV (434) strains of C. trachomatis with cultured cells lacking these putative receptor components. Comparison of the association of strain DK-20 with McCoy or HeLa cells (containing sialic acids), with neuraminidase-treated McCoy or HeLa or with Aedes aegypti cells (all lacking sialic acids), surprisingly, showed enhanced binding to cells lacking the putative receptor component. Similarly, comparison of the association of chlamydial strain 434 with BHK-21 wild-type (containing N-linked N-acetylglucosamine) and BHK-21 RicR14 mutant cells (lacking this component) showed enhanced binding to the mutant cells.