Effect of Polycations, Polyanions, and Neuraminidase on the Infectivity of Trachoma-Inclusion Conjunctivitis and Lymphogranuloma Venereum Organisms in HeLa Cells: Sialic Acid Residues as Possible Receptors for Trachoma-Inclusion Conjunctivitis

The infectivity of trachoma-inclusion conjunctivitis (TRIC) organisms (TW-5) was enhanced by pretreatment of HeLa cell monolayers before inoculation with diethylaminoethyl (DEAE)-dextran (30 μg/ml) and poly-l-lysine (10 μg/ml) and inhibited by dextran sulphate (250 μg/ml), fetuin (4%), ovomucoid (5%), N-acetyl neuraminic acid (0.5%), and Cholera vibrio neuraminidase (100 U/ml). The infectivity of lymphogranuloma venereum organisms (434) was not affected by DEAE-dextran, fetuin, and neuraminidase, was slightly inhibited by poly-l-lysine, and was inhibited by dextran-sulphate, ovomucoid, and N-acetyl neuraminic acid. The study suggested that sialic acid residues on the cell surface may be specific receptors for TRIC organisms. The receptors for TRIC organisms (TW-5 and TW-3) could be specifically blocked with inactivated (56 C for 30 min) TRIC organisms at the ratio of one live to 100 inactivated TRIC organisms, but not by inactivated lymphogranuloma venereum (434) or influenza virus (A2/Jap 305).