Advantages of Cell-Based Assays for COVID-19 Drug Discovery
- Target Specific – Mechanism-of-action (MOA)-based, functional assays for drugs targeting proinflammatory cytokines such as IL-1, IL-6, IL-7, GM-CSF, and TNFα that are implicated in COVID-19 pathology
- Qualified Bioassays – Accelerate your drug release program into QC lot release with bioassays qualified using approved therapeutics like Actemra® (tocilizumab), Kineret® (anakinra), Leukine® (sargramostim), and Humira® (adalimumab)
- Complete Understanding – Evaluate both receptor-proximal and -distal responses for a comprehensive understanding of the biologic and small molecule therapeutics MOA
- Complete Solutions – Utilize Eurofins DiscoverX’s Custom Capabilities for the creation of other COVID-19-relevant receptor assays such as ACE2, TMPRSS2, and more
Implications of Cytokine Storm in COVID-19 Patients
CRS is a proinflammatory immune response that causes hyperinflammation and includes various cytokines such as interleukins (ILs), GM-CSF, chemokines, TNFα and more. This reaction remains one of the main reasons behind the severe implications of COVID-19. Even when the patients survive, there are long-lasting implications associated with tissue injury caused by the immune cells. Patients prone to getting secondary infections may suffer multiple organ failures leading to death.
Key Resources
Actemra is a registered trademark of Chugai Seiyaku Kabushiki Kaisha Corp., a member of the Roche Group; Kineret is a registered trademark, licensed by Swedish Orphan Biovitrum AB and marketed by Sobi, Inc.; Leukine is a registered trademark licensed to Genzyme Corporation; and Humira is a registered trademark AbbVie, Inc.
Eurofins DiscoverX offers a variety of cell-based assays for COVID-19 drug discovery and development programs. Contact custom assay development for additional assays or visit Eurofins Discovery to learn more about cell-based and phenotypic assay services.
Cell-Based Assays for COVID-19 Drug Discovery
Therapeutic Type or MOA |
Therapeutic |
Target |
Recommended Cell-Based Assay |
Monoclonal antibodies; to be used in combination with protease inhibitors |
Adalimumab |
TNFα |
PathHunter® Adalimumab Bioassay Kit (Cat. No. 93-0538B15-00132) |
Combination studies |
Adalimumab + Tocilizumab |
TNFα + IL-6 |
|
Varies |
Anakira |
IL-1β |
PathHunter Anakinra Bioassay Kit (Cat. No. 93-1032Y3-00106) |
Varies |
Angiotensin Converting Enzyme (ACE) inhibitors |
ACE2 |
Contact Custom Assay Development (Request Early Access) |
Varies |
Angiotensin receptor blockers |
AGTR1 |
PathHunter CHO-K1 AGTR1 Bioassay Kit (Cat. No. 93-0312Y2-00126) |
Monoclonal antibodies; to be used in combination with protease inhibitors |
Camrelizumab |
PD-1 |
- PathHunter Jurkat PD-1 (SHP1) Signaling Cell Line (Cat. No. 93-1104C19)
- PathHunter PD-1 (SHP1) Signaling Bioassay Kit (Cat. No. 93-1104Y19-00118)
|
Monoclonal antibodies; to be used in combination with protease inhibitors |
Eculizumab |
C5AR1 |
- PathHunter CHO-K1 C5AR1 β-Arrestin Cell Line (Cat. No. 93-0557C2)
- PathHunter C5AR1 Activated GPCR Internalization U2OS Cell Line (Cat. No. 93-0777C3)
- cAMP Hunter™ CHO-K1 C5R1 Gi Cell Line (Cat. No. 95-0079C2)
- PathHunter CHO-K1 C5AR1 Bioassay Kit (Cat. No. 93-0557Y2-0006)
|
Nonspecific anti-inflammatory and immunisuppressive drugs |
Fingolimod |
S1P1; EDG1 |
Sphingosine 1-phosphate receptor 1 (S1P1; EDG1)
- PathHunter CHO-K1 Eine (Cat. No. 93-0207C2)
- PathHunter EDG1 Total GPCR Internalization HEK 293 Cell Line (Cat. No. 93-0784C1)
- cAMP Hunter™ CHO-K1 EDG1 Gi Cell Line (Cat. No. 95-0142C2)DG1 β-Arrestin Cell L
|
Nonspecific anti-inflammatory and immunosuppressive drugs |
Fingolimod |
S1P2; EDG5 |
Sphingosine 1-phosphate receptor 2 (S1P2; EDG5)
- PathHunter CHO-K1 EDG5 β-Arrestin Cell Line (Cat. No. 93-0256C2)
- PathHunter EDG5 Activated GPCR Internalization U2OS Cell Line (Cat. No. 93-0735C3)
|
Nonspecifc anti-inflammatory and immunosuppressive drugs |
Fingolimod |
S1P3; EDG3 |
Sphingosine 1-phosphate receptor 3 (S1P3; EDG3)
- PathHunter HEK 293 EDG3 β-Arrestin Cell Line (Cat. No. 93-0217C1)
- PathHunter CHO-K1 EDG3 β-Arrestin Cell Line (Cat. No. 93-0217C2)
- PathHunter EDG3 Activated GPCR Internalization U2OS Cell Line (Cat. No. 93-0663C3)
- CHO-K1 EDG3 Gq Cell Line (Cat. No. 95-1007C2)
|
Nonspecific anti-inflammatory and immunosuppressive drugs |
Fingolimod |
S1P4; EDG6 |
Sphingosine 1-phosphate receptor 4 (S1P4; EDG6)
- PathHunter CHO-K1 EDG6 β-Arrestin Cell Line (Cat. No. 93-0227C2)
|
Antiviral drugs, non-specific |
Interleukin-2 |
IL-2 |
- PathHunter DLD1 IL7R/IL2RG Dimerization Cell Line (Cat. No. 93-0997C13)
- PathHunter HEK 293 IL9R/IL2RG Dimerization Cell Line (Cat. No. 93-1036C1)
- PathHunter U2OS IL21R/IL2RG Dimerization Cell Line (Cat. No. 93-1035C3)
- PathHunter U2OS IL2RB/IL2RG Dimerization Cell Line (Cat. No. 93-0998C3)
- PathHunter U2OS IL2RB/IL2RG/IL2RA Dimerization Cell Line (Cat. No. 93-1003C3)
- PathHunter U2OS IL4R/IL2RG Dimerization Cell Line (Cat. No. 93-0988C3)
- PathHunter U2OS IL2RB/IL2RG/IL2RA Dimerization Bioassay Kit (Cat. No. 93-1003Y3-00092)
|
Kinase inhibitors |
Jakotinib hydrochloride |
STAT3 |
PathHunter HepG2 STAT3 Pathway Reporter Cell Line (Cat. No. 93-1144C44) |
Nonspecifc anti-inflammatory and immunosuppresive drugs |
Leflunomide |
|
Contact Custom Assay Development |
Monoclonal antibodies; to be used in combination with protease inhibitors |
Meplazumab |
|
Contact Custom Assay Development |
Monoclonal antibodies; to be used in combination with protease inhibitors |
PD-1 mAb |
PD-1 |
- PathHunter Jurkat PD-1 (SHP1) Signaling Cell Line (Cat. No. 93-1104C19)
- PathHunter PD-1 (SHP1) Signaling Bioassay Kit (Cat. No. 93-1104Y19-00118)
|
Miscellaneous others |
Pirfenidone |
TGFBR1
PDGFRa
PDGFRb |
- PathHunter U2OS TGFBR1/TGFBR2 Dimerization Cell Line (Cat. No. 93-0889C3)
- PathHunter U2OS PDGFRa Functional Assay (Cat. No. 93-23C308)
- PathHunter U2OS PDGFRb Functional Assay (Cat. No. 93-0493C3)
- PathHunter U2OS PDGFRa Bioassay Kit (Cat. No. 93-0823Y3-00072)
- PathHunter U2OS PDGFRb Bioassay Kit (Cat. No. 93-0493Y3-00074)
|
Miscellaneous others |
rhGM-CSF |
GM-CSF |
PathHunter Sargramostim Bioassay Kit (Cat. No. 93-1078Y3-00112) |
Kinase inhibitors |
Ruxolitinib |
STAT3 |
PathHunter HepG2 STAT3 Pathway Reporter Cell Line (Cat. No. 93-1144C44) |
Nonspecific anti-inflammatory and immunosuppressive drugs |
Thalidomide |
Varies |
SPRINTer™ Protein Turnover Biosensor Platform Contact Custom Assay Development |
Monoclonal antibodies; to be used in combination with protease inhibitors |
Tocilizumab |
IL-6 |
PathHunter Tocilizumab Bioassay Kit (Cat. No. 93-1045B3-00110) |
Additional cell lines and kits (and alternative sizes) are available for the therapeutics indicated above. Please contact technical support for more information
Cell-based assays to study therapeutic candidates associated with COVID-19 research are based on Eurofins DiscoverX's Enzyme Fragment Complementation (EFC) technology. Figures below highlight select assay designs for some widely investigated therapeutic targets implicated in cytokine storm in COVID-19 patients.
PathHunter® Tocilizumab Bioassay Assay Principle
Measure IL-6 induced heterodimerization of IL-6 receptor (IL-6R) with the IL-6 Signal Transducer protein (IL-6ST; gp130) using the PathHunter Tocilizumab Bioassay (Cat. No. 93-1045B3-00110) qualified with the FDA approved therapeutic Actemra (tocilizumab, an anti-IL-6R antibody being evaluated as potential therapeutic for COVID-19). The assay principle involves the complementing of enzyme donor ProLink™ (PK) and enzyme acceptor (EA) EFC fragments tagged to IL-6ST and IL-6R, respectively. In presence of IL-6, the receptor units dimerize and there is an increase in signal detected upon substrate addition. However, in the presence of tocilizumab, the binding of IL-6 is inhibited and the signal decreases. Actemra® a registered trademark of Chugai Seiyaku Kabushiki Kaisha Corp., a member of the Roche Group.
PathHunter Anakinra Bioassay Assay Principle
Measure IL-1β induced heterodimerization of IL-1R1 and IL-1RAP receptors using the PathHunter Anakinra Bioassay (Cat. No. 93-1032Y3-00106) qualified with the FDA approved therapeutic Kineret (anakinra, an IL-1R antagonist being evaluated as potential therapeutic for COVID-19). The assay principle involves the complementing of PK and EA EFC fragments tagged to IL-1RAP and IL-R1, respectivitly. In presence of IL-1β, the receptors dimerize and there is an increase in signal detected upon substrate addition. However, in the presence of anakinra, the binding of IL-1β is inhibited and the signal decreases. Kineret® is a registered trademark, licensed by Swedish Orphan Biovitrum AB and marketed by Sobi, Inc.
PathHunter Sargramostim Bioassay Assay Principle
Measure GM-CSF induced heterodimerization of CSF2RA with CSF2RB PathHunter Sargramostim Bioassay Kit (Cat. No. 93-1078Y3-00112) qualified with the FDA approved therapeutic Leukin (sargramostim), which is being evaluated as potential therapeutic for COVID-19. The assay principle involves the complementing of PK and EA EFC fragments tagged to CSF2RB and CSF2RA, respectivitly. In presence of GM-CSF or sargramostim, the receptors dimerize and there is an increase in signal detected upon substrate addition. Leukine® is a registered trademark licensed to Genzyme Corporation.
PathHunter Adalimumab Bioassay Assay Principle
Detect IkB protein degradation as a result of TNFα-mediated activation of the NF-kB signaling pathway using PathHunter Adalimumab Bioassay Kit (Cat. No. 93-0538B15-00132) qualified with the FDA approved therapeutic Humira (adalimumab), which is being evaluated as potential therapeutic for COVID-19. The assay principle involves the enzyme donor ProLabel® (PL) tagged to phosphorylated IkB, and the IκB levels can then be measured by the addition of EA, which forces complementation of the two EFC fragments. The resulting active enzyme hydrolyzes the substrate to generate the signal that is proportional to the degree of IκB stabilization. In presence of TNFα, which activates the NF-kB signaling pathway, proteasome-mediated IκB degradation occurs and there is a loss of signal. In the presence of both TNFα and adalimumab, which blocks the binding of TNFα, degradation of IκB is avoided, and the EFC complementation occurs leading to an increase in signal upon substrate addition. Humira® is a registered trademark AbbVie, Inc.
Qualify COVID-19 Therapeutics with Receptor Dimerization Bioassays
Reproducibly measure ligand-mediated receptor dimerization for potency and stability testing of therapeutics such as Kineret® (anakinra) implemented in QC lot release programs.
The PathHunter Anakinra Bioassay (Cat. No. 93-1032Y3-00106) was used to quantify an inhibitory response from Kineret (anakinra, an IL-1R antagonist being evaluated as potential therapeutic for COVID-19). [A.] In the presence of anakinra, there is a dose dependent inhibition (signal-to-background (S/B) 4.2; IC50 302 ng/mL) of IL-R1 and IL-1RAP dimerization. In comparison with agonist IL-1β, the receptors dimerize and there is an increase in signal detected (S/B 5.3; EC50 4.2 ng/mL). [B.] Dilutional linearity derived from the relative potency experiments performed over a range of 50-150%. Overall, the bioassay measures a robust response to both anakinra and IL-1β with a high accurate potency of over 99.4%. Kineret is a registered trademark, licensed by Swedish Orphan Biovitrum AB and marketed by Sobi, Inc.
Measure TNFα-Mediated Activation of the NF-κB Signaling Pathway with MOA-Reflective, IkB Protein Degradation Bioassays
The PathHunter Adalimumab Bioassay Kit (Cat. No. 93-0538B15-00132) was used to measure IκB protein degradation as a result of TNFα-mediated activation of the NF-kB signaling pathway. [A.] In the presence of adalimumab (Humira®), there is a dose dependent inhibition of TNFα-mediated activation IkB protein degradation and an increased signal (S/B 6.5; IC50 5.45 ng/mL). In comparison with TNFα alone, a decrease in signal detected (S/B 10.3; IC50 53.9 ng/mL). [B.] Dilutional linearity derived from the relative potency experiments performed over a range of 50-150%. Overall, the bioassay measures a robust response to both Humira and TNFα with an excellent accurate potency of over 99.99%. Humira is a registered trademark AbbVie, Inc.