1.Antigenic differentiation of avian pneumovirus isolates using polyclonal antisera and mouse monoclonal antibodies.
Collins MS;Gough RE;Alexander DJ Avian Pathol. 1993 Sep;22(3):469-79.
Avian pneumovirus (AVP) isolates F83, CC220 and 1260 from Great Britain and 1556, 657/4, 2119 and 872/S from France, Hungary, Italy and Spain, respectively, were compared in ELISA and virus neutralization (VN) tests for reactions with chicken polyclonal sera against each of the viruses and monoclonal antibodies (MAbs) against two British isolates. ELISA test results using the polyclonal antisera indicated that all seven viruses were antigenically related, but some variation between strains could be detected, especially when antigens were prepared from infected cells using Nonidet P40 (NP40) rather than freezing and thawing. In VN tests results also showed that all viruses tested were related but there was evidence that the three British isolates showed closer relationships with each other than with the viruses from Italy, Hungary and Spain. In ELISA tests, isolates F83 and 1556 bound all 11 MAbs and 1260 reacted with 10/11 MAbs. Isolate CC220 showed reaction with all the MAbs but for 8/11 MAbs the optical density differences were low. Isolates 2119 and 872/S both reacted only with MAb 4 and none of the MAbs reacted with 657/4.
2.A Cereblon Modulator (CC-220) with Improved Degradation of Ikaros and Aiolos.
Matyskiela ME;Zhang W;Man HW;Muller G;Khambatta G;Baculi F;Hickman M;LeBrun L;Pagarigan B;Carmel G;Lu CC;Lu G;Riley M;Satoh Y;Schafer P;Daniel TO;Carmichael J;Cathers BE;Chamberlain PP J Med Chem. 2018 Jan 25;61(2):535-542. doi: 10.1021/acs.jmedchem.6b01921. Epub 2017 Apr 20.
The drugs lenalidomide and pomalidomide bind to the protein cereblon, directing the CRL4-CRBN E3 ligase toward the transcription factors Ikaros and Aiolos to cause their ubiquitination and degradation. Here we describe CC-220 (compound 6), a cereblon modulator in clinical development for systemic lupus erythematosis and relapsed/refractory multiple myeloma. Compound 6 binds cereblon with a higher affinity than lenalidomide or pomalidomide. Consistent with this, the cellular degradation of Ikaros and Aiolos is more potent and the extent of substrate depletion is greater. The crystal structure of cereblon in complex with DDB1 and compound 6 reveals that the increase in potency correlates with increased contacts between compound 6 and cereblon away from the modeled binding site for Ikaros/Aiolos. These results describe a new cereblon modulator which achieves greater substrate degradation via tighter binding to the cereblon E3 ligase and provides an example of the effect of E3 ligase binding affinity with relevance to other drug discovery efforts in targeted protein degradation.
3.Recent topics in IMiDs and cereblon.
Ito T;Handa H Rinsho Ketsueki. 2017;58(10):2067-2073. doi: 10.11406/rinketsu.58.2067.
Immunomodulatory drugs (IMiDs) are a new class of anticancer compounds that are derived from thalidomide. Lenalidomide and pomalidomide are well-known IMiDs, and they have already been approved by FDA for the treatment of several diseases, including multiple myeloma. Cereblon (CRBN) is a common primary target for IMiDs. It works as a substrate receptor of CRL4. Accumulating evidence has shown that the substrate specificity of CRL4;CRBN; is altered by ligands such as IMiDs. Recently, novel CRBN-binding compounds have been developed and are called "cereblon modulators". Among these, CC-122 and CC-220 are currently under clinical development for the treatment of diffuse large B-cell lymphoma and systemic lupus erythematosus, respectively. Another new cereblon modulator CC-885 is shown to induce degradation of the translation termination factor GSPT1, resulting in an antiproliferative effect in acute myeloid leukemia. Structural analyses have revealed that CC-885 provides an interaction hotspot between CRBN and GSPT1. On the other hand, several groups have been investigating linker-based approaches for targeted protein degradation via CRBN. Several proteins, such as BRD4 and BCR-ABL, have been successfully degraded by CRL4;CRBN; using these technologies.