RESUMEN
OBJECTIVE: The combined combination antiretroviral therapy (cART) and anti-α4ß7 RM-Act-1 antibody therapy allows macaques to durably control simian immunodeficiency virus (SIV) rebound after withdrawal of the interventions. Here, we aimed to investigate whether vedolizumab (VDZ), a clinical-grade humanized anti-α4ß7 antibody, would have similar effects in controlling live HIV-1 infection in humanized mice. DESIGN AND METHODS: The integrin α4ß7 blockade by VDZ was evaluated on human primary memory CD4+ T (MEMT) cells and retinoic acid-induced gut-homing α4ß7+MEMT cells (α4ß7+MEMT) in vitro. The antiretroviral activity of VDZ was determined using pseudotyped R5-tropic HIV-1SF162, which displays binding activity to α4ß7. The preventive and immunotherapeutic efficacies of VDZ were further investigated in humanized mice using the live HIV-1SF162 strain compared with RM-Act-1. RESULTS: VDZ effectively and dose-dependently blocked the binding of mucosal vascular addressin cell adhesion molecule-1 (MAdCAM-1), the native ligand of α4ß7, to α4ß7+MEMT cells. HIV-1SF162 not only displayed binding capacity to α4ß7-expressing cells, but also showed an increased infectivity in retinoic acid-induced α4ß7+MEMT cells pretreated with VDZ. Moreover, VDZ failed to prevent live HIV-1SF162 infection and did not reduce the peak viral load when administrated prior to viral challenge in humanized mice. Lastly, in immunotherapeutic settings, the withdrawal of combined cART with either VDZ or RM-Act-1 resulted in an uncontrolled HIV-1SF162 rebound in humanized mice, whereas the α4ß7 molecules remained significantly blocked on circulating CD4+ T cells. CONCLUSION: VDZ neither prevents nor controls HIV-1SF162 infection both in vitro and in humanized mice. Our findings have significant implications to the clinical application of VDZ in HIV-1 preventive and immunotherapeutic interventions.
Asunto(s)
Antirretrovirales/administración & dosificación , Anticuerpos Monoclonales Humanizados/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Factores Inmunológicos/administración & dosificación , Integrinas/antagonistas & inhibidores , Animales , Terapia Antirretroviral Altamente Activa/métodos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/virología , Células Cultivadas , VIH-1/aislamiento & purificación , Humanos , Ratones SCID , Resultado del Tratamiento , Carga ViralRESUMEN
We report here that human monocytic/macrophage THP-1 cells express the neurokinin 1 receptor (NK-1R), and that exposure of these cells to the proinflammatory cytokine IL-1 beta increased the expression of the NK-1R gene at the mRNA and protein levels. Because IL-1 beta function involves nuclear factor kappa B (NF-kappa B) activation, these data suggest that this increase in the expression of the NK-1R gene is mediated by the NF-kappa B transcription factor. An earlier report noted that the promoter region of the human NK-1R gene contains a putative binding site for NF-kappa B [Takahashi, K., Tanaka, A., Hara, M. & Nakanishi, S. (1992) Eur. J. Biochem. 204, 1025-1033]. Here we demonstrate that this is indeed a functional NF-kappa B-binding site, and that NF-kappa B is responsible for regulating the expression of the NK-1R gene by binding to the promoter region of the NK-1R gene. To further substantiate that the observed NF-kappa B-dependent IL-1 beta induction of the human NK-1R gene is regulated via a transcriptional event through this NF-kappa B site on the NK-1R gene promoter, we transfected THP-1 cells with a luciferase promoter-reporter construct containing the 5' promoter region of the human NK-1R gene. Exposure of these cells to IL-1 beta or overexpression of NF-kappa B cDNAs resulted in a significant increase in the amount of luciferase activity that was diminished greatly in cells transfected with I kappa B alpha, the NF-kappa B inhibitor. These results directly implicate NF-kappa B in the regulation of the NK-1R gene and provide a molecular mechanism for the increase in expression of the NK-1R gene in responsive cells.