Anti-CDK20 monoclonal antibody, clone FQS8449(3)

The complete coding sequence of one pig gene, CDK20, was amplified by RT-PCR. Sequence analysis revealed that the porcine CDK20 gene encodes a protein of 343 amino acids which has high homology with the cyclin-dependent kinase 20 (CDK20) of eight species: cattle (96%), giant panda (96%), mouse (96%), rabbit (96%), rat (96%), dog (95%), human (93%) and Sumatran orangutan (93%). This novel porcine gene was then deposited into the GenBank database and finally assigned to GenelD: 100157041. This gene is structured in eight exons and seven introns as revealed by computer-assisted analysis. Polymorphism analysis revealed that there was a TIC substitution at the position of 96-bp of exon 4 and this led to the amino acid alteration from the Arg residue to the Cys residue. PCR-Alu I-RFLP analysis indicated that eight pig breeds displayed obvious genotype and allele frequency differences at this mutation locus. Association analysis showed that this polymorphic locus was significantly associated with the litter size of all parities in Large White and Landrace sows. Therefore, CDK20 gene could be a useful candidate gene for increasing the litter size of pigs. These data serve as a foundation for further insight into the porcine CDK20 gene.

Objective Myeloid-derived suppressor cells (MDSCs) contribute to tumour immunosuppressive microenvironment and immune-checkpoint blockade resistance. Emerging evidence highlights the pivotal functions of cyclin-dependent kinases (CDKs) in tumour immunity. Here we elucidated the role of tumour-intrinsic CDK20, or cell cycle-related kinase (CCRK) on immunosuppression in hepatocellular carcinoma (HCC). Design Immunosuppression of MDSCs derived from patients with HCC and relationship with CCRK were determined by flow cytometry, expression analyses and co-culture systems. Mechanistic studies were also conducted in liver-specific CCRK-inducible transgenic (TG) mice and Hepa1-6 orthotopic HCC models using CRISPR/Cas9-mediated Ccrk depletion and liver-targeted nanoparticles for interleukin (IL) 6 trapping. Tumorigenicity and immunophenotype were assessed on single or combined antiprogrammed death-1-ligand 1 (PD-L1) therapy. Results Tumour-infiltrating CD11b(+) CD33(+) HLA-DR- MDSCs from patients with HCC potently inhibited autologous CD8(+) T cell proliferation. Concordant overexpression of CCRK and MDSC markers (CD11b/CD33) positively correlated with poorer survival rates. Hepatocellular CCRK stimulated immunosuppressive CD11b(+) CD33(+) HLA-DR- MDSC expansion from human peripheral blood mononuclear cells through upregulating IL-6. Mechanistically, CCRK activated nuclear factor-kappa B (NF kappa B) via enhancer of zeste homolog 2 (EZH2) and facilitated NF-kappa B-EZH2 co-binding to IL-6 promoter. Hepatic CCRK induction in TG mice activated the EZH2/NF-kappa B/IL-6 cascade, leading to accumulation of polymorphonuclear (PMN) MDSCs with potent T cell suppressive activity. In contrast, inhibiting tumorous Ccrk or hepatic IL-6 increased interferon gamma(+) tumour necrosis factor-alpha(+) CD8(+) T cell infiltration and impaired tumorigenicity, which was rescued by restoring PMN-MDSCs. Notably, tumorous Ccrk depletion upregulated PD-L1 expression and increased intratumorous CD8(+) T cells, thus enhancing PD-L1 blockade efficacy to eradicate HCC. Conclusion Our results delineate an immunosuppressive mechanism of the hepatoma-intrinsic CCRK signalling and highlight an overexpressed kinase target whose inhibition might empower HCC immunotherapy.