Immune competent mouse models of CHB

PI: Gabriel Birkuš, co-PIs: Radim Nencka, Ivan Rosenberg, Jiří Brynda, Lubomír Rulíšek, Evžen Bouřa, Miroslav Hájek

We have successfully established mouse models of chronic hepatitis B (CHB) by hydrodynamic injection of pAAV-HBV gt A plasmid or minicircle plasmids encoding HBV gt A and gt D. HBsAg and HBeAg are detectable in plasma and HBcAg in livers of >90% of the injected animals for up to 7 month. The models were used to test anti-HBV activity of a novel STING agonist, developed during the first phase of the project, anti-mouse PD-1 and anti-mouse CTLA-4 mAbs. The STING agonist induced a dose dependent, statistically significant (p <0.01) decrease in the levels of HBcAg, HBsAg and HBeAg in the treated animals. Moreover, one animal in each treatment group induced expression of anti-HBsAbs. The follow-up study showed that the blockage of mouse INF α/β receptor results in a significant reduction of the STING agonist activity. Even though B and T cells from the treated animals expressed activation markers, ELISPOT assay did not show a difference between the treated and control animals. Anti-mouse PD-1 mAb induced response in three out of nineteen treated animals; however, anti-CTLA-4 mAbs were inactive.

The program is an example of a multidisciplinary collaboration of medicinal chemists, computational chemists, virologists, immunologists, and biochemists, and shares a common goal with our colleagues from Gilead to cure CHB.

Selected publications

Molecular dynamics simulations provide structural insight into binding of cyclic dinucleotides to human STING protein
Journal of Biomolecular Structure and Dynamics 2021: Early View
Conformational energies and equilibria of cyclic dinucleotides in vacuo and in solution: computational chemistry vs. NMR experiments
Physical Chemistry Chemical Physics 23 (12): 7280-7294 (2021)
Protein–Ligand Interactions in the STING Binding Site Probed by Rationally Designed Single-Point Mutations: Experiment and Theory
Biochemistry 60 (8): 607–620 (2021)
Ligand Strain and Its Conformational Complexity Is a Major Factor in the Binding of Cyclic Dinucleotides to STING Protein
Angewandte Chemie International Edition 60 (18): 10172-10178 (2021)
Synthesis and Biological Evaluation of Phosphoester and Phosphorothioate Prodrugs of STING Agonist 3′,3′-c-Di(2′F,2′dAMP)
Journal of Medicinal Chemistry 64 (11): 7596–7616 (2021)
Enzymatic Preparation of 2′–5′,3′–5′-Cyclic Dinucleotides, Their Binding Properties to Stimulator of Interferon Genes Adaptor Protein, and Structure/Activity Correlations
Journal of Medicinal Chemistry 62 (23): 10676-10690 (2019)