RESUMEN
Herpesviruses, including human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), and Kaposi's sarcoma-associated herpesvirus, establish latency by modulating or mimicking antiapoptotic Bcl-2 proteins to promote survival of carrier cells. BH3 profiling, which assesses the contribution of Bcl-2 proteins towards cellular survival, was able to globally determine the level of dependence on individual cellular and viral Bcl-2 proteins within latently infected cells. Moreover, BH3 profiling predicted the sensitivity of infected cells to small-molecule inhibitors of Bcl-2 proteins.
Asunto(s)
Herpesviridae/fisiología , Herpesviridae/patogenicidad , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Secuencia de Aminoácidos , Apoptosis , Línea Celular , Supervivencia Celular , Citomegalovirus/patogenicidad , Citomegalovirus/fisiología , Infecciones por Herpesviridae/metabolismo , Infecciones por Herpesviridae/patología , Infecciones por Herpesviridae/virología , Herpesvirus Humano 4/patogenicidad , Herpesvirus Humano 4/fisiología , Herpesvirus Humano 8/patogenicidad , Herpesvirus Humano 8/fisiología , Interacciones Huésped-Patógeno , Humanos , Datos de Secuencia Molecular , Análisis por Matrices de Proteínas , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Virales/metabolismo , Latencia del VirusRESUMEN
Human cytomegalovirus (HCMV) spreads and establishes a persistent infection within a host by stimulating the survival of carrier myeloid cells via the upregulation of Mcl-1, an antiapoptotic member of the Bcl-2 family of proteins. However, the lack of potent Mcl-1-specific inhibitors and a targetable delivery system has limited the ability to exploit Mcl-1 as a therapeutic strategy to eliminate HCMV-infected monocytes. In this study, we found a lead compound from a novel class of Mcl-1 small-molecule inhibitors rapidly induced death of HCMV-infected monocytes. Moreover, encapsulation of Mcl-1 antagonists into myeloid cell-targeting nanoparticles was able to selectively increase the delivery of inhibitors into HCMV-activated monocytes, thereby amplifying their potency. Our study demonstrates the potential use of nanotechnology to target Mcl-1 small-molecule inhibitors to HCMV-infected monocytes.
Asunto(s)
Antivirales/farmacología , Monocitos/efectos de los fármacos , Monocitos/virología , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/antagonistas & inhibidores , Nanopartículas , Citomegalovirus/efectos de los fármacos , Descubrimiento de Drogas , Humanos , Monocitos/patología , NanotecnologíaRESUMEN
Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with B-cell lymphomas including primary effusion lymphoma and multicentric Castleman's disease. KSHV establishes latency within B cells by modulating or mimicking the antiapoptotic Bcl-2 family of proteins to promote cell survival. Our previous BH3 profiling analysis, a functional assay that assesses the contribution of Bcl-2 proteins towards cellular survival, identified two Bcl-2 proteins, cellular Mcl-1 and viral KsBcl-2, as potential regulators of mitochondria polarization within a latently infected B-cell line, Bcbl-1. In this study, we used two novel peptide inhibitors identified in a peptide library screen that selectively bind KsBcl-2 (KL6-7_Y4eK) or KsBcl-2 and Mcl-1 (MS1) in order to decipher the relative contribution of Mcl-1 and KsBcl-2 in maintaining mitochondrial membrane potential. We found treatment with KL6-7_Y4eK and MS1 stimulated a similar amount of cytochrome c release from mitochondria isolated from Bcbl-1 cells, indicating that inhibition of KsBcl-2 alone is sufficient for mitochondrial outer membrane permiabilzation (MOMP) and thus apoptosis during a latent B cell infection. In turn, this study also identified and provides a proof-of-concept for the further development of novel KsBcl-2 inhibitors for the treatment of KSHV-associated B-cell lymphomas via the targeting of latently infected B cells.