Interaction of Viruses with Neutralizing Antibodies

SUMMARYThe effect of rabbit anti-rubella virus (RV) serum on the course of RV infection of human lymphoid cells has been examined. The antibody was found to abolish viral replication such that no virus progeny could be detected either extracellularly (after removal of the antiserum) or intracellularly, in the treated cells. Viral protein synthesis was also found to be totally inhibited in the presence of anti-RV but resumed immediately on removal of the antibody block at levels suggesting that viral RNA had been accumulating in the cell. Infectious focus assays indicated that the effect could be explained in part by the restriction by antiviral antibody of cell-to-cell spread in the indicator monolayer. Thus by 48 h when 1009/oo of lymphoid cells infected with virus alone were capable of forming infectious foci, only 40 to 50~ of cells infected in the presence of antiviral antibody produced loci. However this restriction imposed by antibody did not adequately explain the total inhibition of viral protein synthesis that occurred under these conditions. Pretreatment of RV with excess neutralizing antiserum reduced the virus titre > 99.9 ~ but did not eliminate infectious virus. The

Section: Pretreatment Of R V With Neutralizing Antiserum Prior To Infsupporting

confidence: 61%

The Effect of Antibody on Rubella Virus Infection in Human Lymphoid Cells

Chantler

Davies

1987

“…The mechanisms involved in virus neutralization are still poorly understood (Mandel, 1979). It would appear that antibodies F7/3 and F7/101 are enhancing in nature but neutralize poorly, and may be 'non-protective'.…”

Section: Discussionmentioning

confidence: 99%

Monoclonal Antibodies Against the Flavivirus West Nile

Peiris

Porterfield

Roehrig

1982

SUMMARYMonoclonal antibodies having three different specificities have been prepared against the Egypt 101 strain of West Nile virus (WNV). All were reactive against the envelope glycoprotein in radioimmune precipitation tests, and all enhanced WNV replication in the mouse macrophage line P388D 1. One antibody, which is of IgG2a subclass, had strong neutralizing activity against the homologous virus, although it failed to neutralize a different WNV strain. The other two antibodies, both of IgG1 subclass, had little neutralizing activity, but one had strong reactivity with the haemagglutinin of the inducing virus and other flavivirus haemagglutinins.

“…Such data are of interest as they can be used to calculate the number of antibody molecules per virion that are required to mediate neutralization and hence give an insight into the mechanism of neutralization of each particular MAb. The data available on kinetics of neutralization are not extensive and have been reviewed by Mandel (1979). Neutralization which proceeds without any lag has been reported with both polyclonal antisera (Dulbecco et al, 1956;Rubin & Franklin, 1957;Mandel, 1960;Thormar, 1963;Granoff, 1965;Philipson, 1966;Keller, 1966;Wohlfart, 1988) and monoclonal IgG (Icenogle et al, 1983;Taylor et al, 1987;Sufi6 et al, 1990;Outlaw & Dimmock, 1991).…”

mentioning

confidence: 99%

“…However, demonstration of this usually requires special conditions such as an extremely low concentration of antibody and a reaction temperature of around 4 °C or was a particular property of IgM. There is no technical problem to investigating neutralization kinetics in itself, because the very low concentration of reactants normally used in such studies reduces the reaction rate to a measurable level (Mandel, 1979). In this report we have studied the neutralization of HIV-1 strain IIIB in human T cell leukaemia-derived C8166 cells by three rat IgG MAbs, using physiological temperatures and relatively high concentrations (11 to 210 pg/ml) of antibody.…”

mentioning

confidence: 99%

Single- and multi-hit kinetics of immunoglobulin G neutralization of human immunodeficiency virus type 1 by monoclonal antibodies

McLain

Dimmock

1994

A quantal assay, based on syncytium formation in the human T cell leukaemia-derived C8166 cell line, was used to determine the kinetics of human immunodeficiency virus type 1 (HIV-1) strain IIIB neutralization. Three rat monoclonal antibodies (MAbs) were used, under physiological conditions of temperature and antibody concentration. MAb ICR39.3b (IgG2b) neutralized virus with no lag period while the other two MAbs, ICR39.13g (IgG2b) and ICR41. li (IgG2a), neutralized with lag periods of 5 min and 15 min respectively. It was calculated that the latter two MAbs mediated neutralization by about two and three molecules of IgG per virion respectively. The highest neutralization rate constant (for MAb ICR 41. li) was over 300-fold less than that of MAbs specific for the haemagglutinin of the enveloped influenza virus type A and for poliovirus type 1.