Demonstration by immunoelectro-osmophoresis of precipitating antibodies to a purified rubella virus antigen

Production of antiserum to respiratory syncytial virus polypeptides: application in enzyme-linked immunosorbent assay

By use of crossed immunoelectrophoresis techniques, respiratory syncytial (RS) virus-specific precipitates were produced between RS virus cellular antigen [solubilized in tris(hydroxymethyl)aminomethane-glycine buffer, pH 9] and antiserum raised in rabbits against semipurified RS virus. When these precipitates were employed as antigens for further immunizations in rabbits, antibodies (anti-RSV-precip.I) were produced which reacted with only one RS virus antigen when tested by the crossed immunoelectrophoresis technique. Precipitates obtained between RS virus cellular antigen (labeled with L-[35S]methionine) and anti-RSV-precip.I were examined by polyacrylamide gel electrophoresis, which showed that anti-RSV-precip.I precipitated RS virus polypeptides of molecular weights 28,000 to 84,000. Anti-RSV-precip.I was employed as capture antibodies in the enzyme-linked immunosorbent assay, in which RS virus cellular antigen was used as the second layer. Determination of human RS virus immunoglobulin G antibodies by this enzyme-linked immunosorbent assay technique showed a high degree of sensitivity, specificity, and reproducibility.

Production of rabbit antibodies against the viral capsid antigen (VCA) of the Epstein-Barr virus (EBV)

Rabbits were immunized with nuclear or cytoplasmic extracts of the Epstein-Barr virus (EBV)-producing marmoset cell line B95-8. Following extensive absorption with human EBV-negative cells (HeP-2, Ramos and BJAB), sera were obtained that no longer reacted with cellular or serum proteins of human origin, but gave a single precipitin band with extracts of the human EBV-producing line, P3HR-1. Immunofluorescence tests performed with appropriate parallel human serum controls showed that the rabbit serum contained no activity against EBNA + EA - VCA - Raji cells, or against P3HR-1 virus superinfected, cytosine arabinoside-treated Raji cells that contained EBNA and EA, but not VCA. The sera gave a brilliant indirect immunofluorescence reaction with the virus-producing (EBNA+ EA+ VCA+) P3HR-1 lines. Two-color fluorescence tests, performed with a direct TRITC-labelled VCA conjugate and indirect FITC-staining with the rabbit serum, showed that the same cells reacted in both red and green fluorescence, confirming that the rabbit serum was directed specifically against some antigen formed in the virus-producer cells. Since the synthesis of the relevant antigen was prevented by cytosine arabinoside it cannot be EA and must be a late antigen. The morphology and localization of the antigen support the conclusion that the antigen is VCA or some part of the VCA complex.

Antibody responses in patients with rubella infection determined by passive hemagglutination, hemagglutination inhibition, complement fixation, and solid-phase radioimmunoassay tests

Antibody responses in serial serum specimens collected from 31 patients with an acute rubella infection were determined by passive hemagglutination (PHA), hemagglutination inhibition (HI), complement fixation (CF), radioimmunoassay (RIA) immunoglobulin G (IgG), and RIA immunoglobulin M (IgM) tests to evaluate the effectiveness of these tests in diagnosing a recent infection. The HI, RIA IgG, and RIA IgM antibodies appeared almost simultaneously and reached the maximum level about 1 week after the onset of rash. Compared to these, the CF antibodies developed only slightly later, whereas the development of the PHA antibodies was much more delayed. The RIA IgM response was shown to be transient, lasting approximately 1.5 to 2.5 months postinfection. The results of this study indicate that demonstration of specific IgM antibodies is the best method for diagnosing a recent infection, one within 2 months after the onset of the illness. If an IgM test is not available, a combination of the HI and PHA tests is recommended.

Titration of herpes simplex virus antibodies in human sera by the enzyme-linked immunosorbent assay (ELISA)

100 sera from healthy adults were titrated simultaneously for herpes simplex virus (HSV) antibodies by ELISA and neutralization. The ELISA was performed on microtitre plates where approximately 100 ng of detergent solubilized and chromatographically purified HSV glycoproteins was bound covalently to the plastic bottom of each well. The optical density (OD) values obtained by the use of the peroxidase-1.2phenylendiamindihydrochloride system showed good correlation with the neuratlizing antibody titres. Sera with very low neutralizing titres were clearly positive in ELISA.

Crossed immunoelectrophoretic studies of the solubility immunogenicity of herpes simplex virus antigens

The nonionic detergent Triton X-100 was capable of solubilizing 90% of the protein content in herpes simplex virus (HSV)-infected rabbit cornea cells. The solubilized HSV antigens formed well-characterized precipitates by crossed immunoelectrophoresis in Triton X-100-containing agarose gel, allowing both identification and relative quantitation. Water-soluble and detergent-requiring HSV antigens were identified by different solubilization procedures in buffer with and without detergent. Five glycoprotein antigens were solubilized only in the presence of detergent, indicating their membrane-bound state. One non-glycosylated antigen was present in both a water-soluble and a membrane-bound form. Based upon the crossed immunoelectrophoretic precipitating patterns of Triton X-100-solubilized HSV antigens, it has been estimated that infected cells yield an amount of virus-specific protein equivalent to 2,000 enveloped virions per cell. Rabbits inoculated intracutaneously with Triton X-100-solubilized HSV antigens developed neutralizing antibodies against HSV almost as effectively as rabbits with an active HSV infection. Precipitins against individual HSV antigens in sera from rabbits infected with HSV and immunized with the Triton X-100-solubilized HSV antigens were assayed by the crossed immunoelectrophoretic technique. Sera from infected rabbits reacted more strongly and with a higher number of HSV antigens than sera from immunized rabbits.

Development of a modified immunoelectroosmophoresis method for Uukuniemi and Runde virus serology

In search for a suitable method for sero-ecological screenings for arboviruses in Norway, efforts were undertaken to make the immunoelectroosmophoresis technique more sensitive than here to fare in detection of antibodies. The aim was to make it comparable to haemagglutination inhibition test in sensitivity, retaining the advantages in specificity, simplicity and capacity. This has been achieved by: 1. Using concentrated virus as antigen. 2. Performing electrophoresis in a gel consisting of an agar-agarose mixture in optimal concentrations. 3. "Sandwiching" the first specific electrophoretic run with an anti-species antiserum to the tested sample.