Archives of Virology

Kostolansky, F.; Russ, G.; Mucha, V.; Styk, B.

doi: 10.1007/bf01314648pmid: 2458086

SummaryMonoclonal antibodies (Mabs) specific to the HA 1 and HA 2 subunits of the influenza virus haemagglutinin (HA) were used to show that changes in the antigenicity of the HA molecule at acid pH involve both HA subunits. In solid phase RIA (intact virus adsorbed) the acid-induced change was detected in the form of greatly increased binding of anti-HA 1 Mabs (IVA 1 and IVG 6) and anti-HA 2 Mab (IIF 4). This increased binding could be most probably explained by alterations in accessibility of epitopes to the corresponding Mabs. Other Mabs examined (including 7 anti-HA 2 Mabs specific to 3 independent antigenic sites) had either similar reactivities with both untreated and pH 5-treated virus or slightly but significantly increased binding to pH 5-treated virus. No effect of pH 5 treatment on antibody binding was observed with purified BHA in solid phase RIA. Nevertheless a similar pH 5-induced conformational change in the isolated BHA (like in intact viral HA in solid phase RIA) was detected in competitive binding assay carried out in liquid phase.

Cusi, M. G.; Rossolini, G. M.; Cellesi, C.; Valensin, P. E.

doi: 10.1007/bf01314649pmid: 3046563

SummaryAntibody response to individual structural proteins (E 1, E 2, and C) of the M-33 wild rubella virus strain was assayed by an immunoblot technique in 12 girls, following immunization with RA 27/3 live attenuated rubella vaccine. Of the 12 immunized subjects, before vaccination 9 had no demonstrable rubella specific antibodies while the remaining 3 had a low level of rubella specific antibodies, reacting only with the E 1 protein. At one month after vaccination all the immunized subjects presented anti-E 1, anti-E 2, and anti-C specific antibodies. However, at 1–2 weeks after vaccination the 9 girls who were seronegative before immunization still had no detectable antibodies to any of the rubella virus structural proteins, while the 3 subjects whose preimmunization sera had reacted with the E 1 protein presented an accelerated immune response, showing anti-E 2 and anti-C specific antibodies and a more intensely marked anti-E 1 specific band.

Heinz, B. A.; Cliver, D. O.

doi: 10.1007/bf01314650pmid: 2843148

SummaryCoxsackievirus B 5 (CB 5) labeled with tritiated uridine was used to trace the interaction of the virus with explant cultures of porcine ileum. Similarly labeled human poliovirus 1 (PO 1), which is not specifically retained by porcine tissue, was used as a control. The explant procedure employed could maintain ileal tissue in a differentiated state for up to 48 hours. Porcine ileum was acquired from both young (4–6 week-old) and adult (9–11 month-old) animals. Inoculated explants of either absorptive or lymphoid tissue were incubated at temperatures selected to permit either viral adsorption or penetration and elution to occur. Retention of radioactive virus was quantitated by liquid scintillation counting and localized by autoradiography. Only in absorptive tissue explants from young animals did adsorption of CB 5 at 6°C exceed penetration at 37°C. This suggested that incubation at 6°C may not be an appropriate condition for studying enterovirus adsorption in explants. CB 5 penetrated most efficiently into lymphoid tissue explants from young animals, indicating that these tissues could discriminate between CB 5 and PO 1. In explants from adults, CB 5 penetrated equally well into lymphoid and absorptive tissues. Virus penetrated into the absorptive epithelial cells and, possibly, the lamina propria near the villous tips. Low efficiency of penetration, and the non-critical function of these target cells, may help account for the characteristic lack of gastrointestinal symptoms in enterovirus infections.