The Potential of O’nyong-nyong Virus Strain SG650 Murine Monoclonal Antibodies for Detection of O’nyong-nyong and Chikungunya Viruses

Abstract

O’nyong-nyong virus (ONNV) and Chikungunya virus (CHIKV) are antigenically related alphaviruses responsible for febrile illnesses common to the tropics and associated with relatively high morbidity and mortality. Murine monoclonal antibodies (mAbs) targeting alphaviruses like Chikungunya have been developed and used to make commercially available kits. However, few studies have been conducted to develop antibodies specific to ONNV and no commercial kits are available for use in endemic regions where outbreak potential is high. We demonstrate the potential of in-house generated monoclonal antibodies against ONNV to detect both ONNV and CHIKV. The objective of this study was to generate mAbs using hybridoma technology, characterize the developed mAbs, determine their specificity against selected alphaviruses and check their diagnostic potential using an indirect IgG enzyme-linked immunosorbent assay (ELISA) and focus neutralization assay (FRNT50). BALB/c mice were immunized with ONNV purified proteins from ONNV infectious culture fluid. After four rounds of booster injections, the mice were sacrificed, spleen cells harvested and fused with parental myeloma cells then cultured in selective media and the successful hybrid clones with antibody-producing ability purified to yield the desired mAbs. Five monoclonal antibodies targeting the ONNV E1 protein of isotypes IgG2a/kappa, IgG2b/kappa and IgM/kappa (P1B12, P1E9, P1G11, P1B4 and P1G6) demonstrated a potential to detect both ONNV and CHIKV isolates by indirect IgG ELISA but no potential for neutralization of the viruses by FRNT50. This study demonstrates the potential efficacy of in-house serological tools as an alternative in the absence of commercial assays in screening and diagnosis of ONN and CHIK viruses which are often co-circulating. It is our recommendation that this work may be pursued further to design and optimize ELISA assays, using the developed mAbs, for the detection of both ONN and CHIK viruses in the research laboratory set-up.