Differential Inhibition of Nav1.7 and Neuropathic Pain by Hybridoma-Produced and Recombinant Monoclonal Antibodies that Target Nav1.7

Abstract

The voltage-gated Na channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.

GpTx‐1 and [Ala5, Phe6, Leu26, Arg28]GpTx‐1, two peptide NaV1.7 inhibitors: analgesic and tolerance properties at the spinal level

“…Based on this genetic evidence, Na V 1.7 is considered a novel target for pain management. Recently, a monoclonal antibody SVmab1 from a hybridoma has been shown to selectively inhibit Na V 1.7 and suppress inflammatory and neuropathic pain after spinal and systemic administrations (Lee et al ., ; Bang et al ., ). However, the recombinant monoclonal antibodies (arSVmab or rSVmab) that target Na V 1.7 had no or weak binding to Na V 1.7 and did not specifically inhibit Na V 1.7 currents in HEK293 cells (Liu et al ., ; Bang et al ., ), implying that the sources of monoclonal antibodies is a critical requirement for their efficacy.…”

“…Recently, a monoclonal antibody SVmab1 from a hybridoma has been shown to selectively inhibit Na V 1.7 and suppress inflammatory and neuropathic pain after spinal and systemic administrations (Lee et al, 2014;Bang et al, 2018). However, the recombinant monoclonal antibodies (arSVmab or rSVmab) that target Na V 1.7 had no or weak binding to Na V 1.7 and did not specifically inhibit Na V 1.7 currents in HEK293 cells (Liu et al, 2016;Bang et al, 2018), implying that the sources of monoclonal antibodies is a critical requirement for their efficacy. In addition, to systemically evaluate this proof-of-concept of analgesics targeting Na V 1.7, the antinociceptive profiles of potent Na V 1.7 inhibitors were also investigated in different pain models.…”

Long-lasting Analgesia via Targetedin vivoEpigenetic Repression of Nav1.7

“…Many small-molecule drugs targeting Na V 1.7 have accordingly failed due to side effects caused by lack of targeting specificity or their bioavailability by the systemic route 32 . Additionally, antibodies have faced a similar situation, since there is a tradeoff between selectivity and potency due to the binding of a specific (open or close) conformation of the channel, with binding not always translating into successful channel inhibition [33][34][35][36] . Further, it is not clear that such antibodies can gain access to the appropriate Na V 1.7 channels and yield a reliable block of their function.…”

Recent Progress in Understanding the Mechanisms of Pain and Itch: the Second Special Issue

“…currents in native sensory neurons and reduces neuropathic pain in mice. Furthermore, they revealed different activities of hybridoma-derived and recombinant SVmab, which will lead to new strategies for therapeutic development [22]. Latremoliere and Costigan discuss how a combination of human and mouse genetics helps to identify new pain targets and analgesics.…”