Nonspecific factors in monkey tissues and serum causing inhibition of plaque formation and hemagglutination by dengue viruses.

Detection of flavivirus antibodies in human serum by epitope-blocking immunoassay.

Human flavivirus group-reactive, dengue complex-reactive, and encephalitis virus complex-reactive antibodies were detected using epitope-blocking immunoassays in which the binding of selected mouse monoclonal antibodies to flavivirus antigens was blocked by human serum. When late (greater than 6 months after illness) convalescent sera were tested, the epitope-blocking immunoassays were superior...

Method for extracting viral hemagglutination-inhibiting antibodies from the nonspecific inhibitors of serum.

Various methods are used to remove nonspecific inhibitors from sera before titering viral hemagglutination-inhibiting antibodies. These methods have several undesirable features; some are tedious and time-consuming, some remove antibody along with nonspecific inhibitors, and different techniques are usually required to remove the nonspecific inhibitors for different viruses. This communication ...

The Formation of Plaques by African Horse Sickness Viruses and Factors Affecting Plaque Size

Dengue viruses and mononuclear phagocytes. I. Infection enhancement by non-neutralizing antibody

Cultured mononuclear peripheral blood leukocytes (PBL) from nonimmune human beings and monkeys are nonpermissive to dengue 2 virus (D2V) infection at multiplicities of infection of 0.001-0.1, but become permissive when non-neutralizing dengue antibody is added to medium. D2V infection occurred in PBL prepared from anti-coagulated but not from defibrinated plasma. Infection enhancement was produ...

Assay of dengue virus in monkey kidney cells by detection of hemagglutinin in the culture medium.

Tissue culture methods for the isolation and assay of the dengue viruses have been developed in a number of laboratories (1-7). Their aim has been to find an in vitro substitute for the suckling mouse (the usual host for these procedures). This study introduces a new method for the assay of mouse-adapted dengue viruses. Titrations and neutralization tests for serotypes 1, 2 and 4 have been cond...