Sanofi Pasteur Vaxdesign Corporation

Olga Kachurina

Anatoly Kachurin

Vaughan Wittman

Tenekua Tapia

Mike Nguyen

Vipra Dhir

Alexander Karol

The present invention comprises rugged, inexpensive, reliable, and sensitive laboratory assays of antibody-based viral neutralization activity and antibody-based viral adherence inhibition activity. The assays use inactivated, fluorescently-labeled virus, allowing the tests to be performed without extensive safety precautions. The interaction of the labeled virus with target cells is monitored using flow cytometric methods. A preferred embodiment uses simple and inexpensive flow cytometry methodologies and equipment, such as bead array readers used as simplified flow cytometers. The assays are rapid, taking no longer than a few hours and are readily conducted by a trained technician. The assays are sensitive because they use labeled viruses at low concentrations and determine neutralizing and blocking capacity of sera and antibody at low concentrations. The methods are appropriate for high-throughput screening of large panels of samples.

Fluorescent neutralization and adherence inhibition assays

Hemagglutination (HA) and hemagglutination inhibition (HAI) functional assays remain important instruments of analysis of virus-cell interaction and protecting efficacy of virus-specific antibodies and sera. However, they demonstrate limited sensitivity towards many viruses, and require significant volumes of viruses, erythrocytes, sera, and antibodies. The present invention comprises new and significantly more sensitive versions of the HA and HAI assays based on observing agglutination on activated surfaces of specifically opsonized plates and ELISA plates rather than in solution. A version of the new assay that uses ELISA plates additionally allows characterizing the affinity of functional antibodies in the tested sera and fluids, which is not possible in the classical HAI assay. The methods of the present invention can also be used to improve the sensitivity of agglutination methods based on latex beads and to develop agglutination methods using target cells other than erythrocytes.

Surface-assisted hemagglutination and hemagglutination inhibition assays

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Orlando, FL, United States of America

Olga Kachurina