Sensitive antiproliferative neutralization assay for the detection of neutralizing IFN-alpha and IFN-beta antibodies.
Antibodies to interferon (IFN) may compromise IFN treatment in some patients. In tumor therapy, a critical function of type I IFNs is their antiproliferative effect. For the quantification of neutralizing IFN antibodies we have developed an antiproliferative neutralization assay (APA) based on the reduction of IFN-mediated growth inhibition of Daudi cells by IFN-alpha and IFN-beta antibodies. Proliferation was quantified by [3H]thymidine incorporation, and the neutralizing potency of IFN antibody-positive sera was expressed as the neutralizing titer inhibiting 50% of the antiproliferative activity of 10 IU/ml of IFN (NT50). The APA is easy to perform, reproducible, and more sensitive than a well-established antiviral neutralization assay (AVA). All 30 sera with recombinant IFN-alpha 2a-binding antibodies proved to be neutralizing antibody-positive in the APA whereas seven were scored antibody-negative or uninterpretable in the AVA. The APA is recommended as a second or third line assay for the estimation of the neutralizing potency of spontaneous or treatment-induced IFN-alpha and IFN-beta-specific antibodies.
Prümmer
O
O
Department of Medicine III, University of Ulm, Germany.
Streichan
U
U
Heimpel
H
H
Porzsolt
F
F
D000818:Animals; D000906:Antibodies / Q000097:blood* / Q000276:immunology; D000918:Antibody Specificity; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D006801:Humans; D007370:Interferon Type I / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000494:pharmacology; D016899:Interferon-beta / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000494:pharmacology; D007700:Kinetics; D009500:Neutralization Tests / Q000379:methods*; D010865:Pilot Projects; D011994:Recombinant Proteins; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000906:Antibodies; D007370:Interferon Type I; D011994:Recombinant Proteins; D016899:Interferon-beta