A COMPARATIVE-ASSESSMENT OF TLC OVERLAY TECHNIQUE AND MICROWELL ADSORPTION ASSAY IN THE EXAMINATION OF INFLUENZA-A AND SENDAI VIRUS SPECIFICITIES TOWARDS OLIGOSACCHARIDES AND SIALIC-ACID LINKAGES OF GANGLIOSIDES

Influenza A and Sendai viruses bind to neolacto-series gangliosides is olated from human granulocytes. Differences in receptor specificity of influenza viruses A/PR/8/34 (H1N1), A/X-31 (H3N2), and parainfluenza Sendai virus (HNF1, Z-strain) were determined by two direct solid phas e binding assays: the overlay technique, which combines high-resolutio n in the separation of gangliosides on thin-layer chromatograms with d irect binding; and the microwell adsorption assay as a convenient bind ing assay which is performed in microtitre wells to estimate the avidi ty of binding to an isolated ganglioside. Both methods were applied fo r comparative binding studies. Viruses were found to exhibit specifici ty for oligosaccharides and sialic acids as well as for chain length o f the neutral carbohydrate backbone, whereas differing fatty acids (C- 24:1 and C-16:0) in the ceramide portion had no impact on virus adsorp tion. Terminal sialyloligosaccharides Neu5Ac alpha 2-3Gal beta 1-4Glc- R of G(M3), and Neu5Ac alpha 2-3Gal beta 1-4GlcNAc-R as well as Neu5Ac alpha 2-6Gal beta 1-4GlcNAc-R of neolacto-series gangliosides with nL cOse(4)Cer and nLcOse(6)Cer backbone, exhibited significant specific r eceptor activity towards the different viruses. To compare the data re vealed from both test systems, values of virus binding were ascertaine d by a non-parametric statistical approach based on rank correlation. The rank correlation coefficient r(s) was calculated according to Spea rman from each virus binding towards G(M3), IV(3)Neu5Ac-nLcOse(4)Cer, IV(6)Neu5Ac-nLcOse(4)Cer and VI(3)Neu5Ac-nLcOse(6)SCer. The rank corre lation coefficients 0.74, 0.95 and 0.92, which were determined for A/P R/8/34 (H1N1), A/X-31 (H3N2) and Sendai virus (HNF1, Z-strain), respec tively, indicated that both assays generate highly correlated experime ntal data. Based on these results, analyses of virus binding on thin-l ayer chromatograms as well as in microwells were found equivalent tool s for ganglioside receptor studies.