Project description:Interleukin-21 treatment during ART was able to decrease residual immune activation and viral burden in SIV-infected rhesus macaques Overall design: total PBMCs at pre-ART and during ART treatment were used to generate RNA-seq data
Project description:BACKGROUND Interferon alpha (IFNalpha) exerts its anti-proliferative effect on many human cancers. Among the 13 subtypes of human IFNalpha, IFNalpha-1 subtype has 2 variants, named IFNalpha-1a and IFNalpha-1b, that differ from each other in only 1 amino acid, at residue 114. However, the mechanism by which IFNalpha-1a mediates growth inhibition is still unclear. MATERIAL AND METHODS Human laryngeal carcinoma HEp2 cells were treated with IFNalpha-1a by either transient transfection or exogenous delivery. Western blot and RT-PCR analysis were carried out to assess apoptotic pathways active in IFNalpha-1a-treated HEp2 cells. Microarray analysis was conducted to uncover the differential gene expressions after IFNalpha-1a treatment. KEGG pathway enrichment analysis was also performed. RESULTS IFNalpha-1a markedly inhibited the proliferation and significantly promoted the apoptosis of HEp-2 cells. Mechanistic studies indicate that IFNalpha-1a-mediated cell apoptosis is directly linked to intrinsic and endoplasmic reticulum (ER) stress-related apoptosis, but is independent of extrinsic apoptosis. The top 40 differentially expressed genes discovered by microarray analysis included 20 upregulated genes (e.g., IFI6, IFI27, IFI44L, and MIR548X) and 20 downregulated genes (e.g., PRKDC, HIST1H3B, DYNC1H1, and HIST1H2AM). KEGG pathway enrichment analysis revealed that 4 out of 6 pathways are TP53-related. CONCLUSIONS We demonstrated a detailed mechanism involved in IFNalpha-1a-mediated anti-proliferation activity in human laryngeal carcinoma cells.
Project description:Despite successful control of viremia, many HIV-infected individuals given antiretroviral therapy (ART) exhibit residual inflammation, which is associated with non-AIDS-related morbidity and mortality and may contribute to virus persistence during ART. Here, we investigated the effects of IL-21 administration on both inflammation and virus persistence in ART-treated, SIV-infected rhesus macaques (RMs). Compared with SIV-infected animals only given ART, SIV-infected RMs given both ART and IL-21 showed improved restoration of intestinal Th17 and Th22 cells and a more effective reduction of immune activation in blood and intestinal mucosa, with the latter maintained through 8 months after ART interruption. Additionally, IL-21, in combination with ART, was associated with reduced levels of SIV RNA in plasma and decreased CD4(+) T cell levels harboring replication-competent virus during ART. At the latest experimental time points, which were up to 8 months after ART interruption, plasma viremia and cell-associated SIV DNA levels remained substantially lower than those before ART initiation in IL-21-treated animals but not in controls. Together, these data suggest that IL-21 supplementation of ART reduces residual inflammation and virus persistence in a relevant model of lentiviral disease and warrants further investigation as a potential intervention for HIV infection.
Project description:The induction of type I interferons during acute viral infections drives local and systemic anti-viral responses. However, in chornic virus infection these type I interferon driven responses can be detrimental and can be characterized impaired immune responses (greater T cell exhaustion) and an overall decline in health outcomes. To parse out the role of type I IFN and assess the therapeutic impact of blocking type I IFN, we administered IFN-a blocking antibody to a cohort of SIV-infected ART treated Maccaca mulata. After 9 weeks of treatment (1 injection per week), we observed a significant reduction in the SIV-DNA levels in the lymphnode. This reduced SIV reservoir was seem with a systemic increase in immune cell subset signatures associated with better CD8 T cell function and lower plasma levels of TGF-beta. In addition, upon interruption of ART (16 weeks after ART initiation and after 16 rounds of anti-IFNa infusion), we observed that the non-human primates that underwent type I interferon blockade maintained better overall health and hemoglobin levels. Overall design: 12 female Rhesus Macaques (4-5 years of age) were intravenously challenged with SIVmac251 after testing negative for simian retrovirus, simian T-lymphotropic virus, hepatitis B, and helminthic infections. At 8 weeks p.i., NHPs commenced an ART treatment regimen of L-612 (RAL, 150 mg PO BID, Merck), emtricitabine (FTC, 30 mg/kg/day, Gilead), tenofovir (PMPA, 20 mg/kg/day, Gilead), and darunavir (DRV, 400 mg PO BID, Tibotec) until ATI at 36 weeks p.i. After 12 weeks of ART (20 weeks p.i.), 6 NHPs received anti-IFN humanized Ab AGS-009 i.v. at 10-11 mg/kg and the other 6 control NHPs received an irrelevant Ab (an anti-hepatitis B antibody, prepared by Keith Reimann) weekly for 16 weeks. AGS-009 and control Ab were administered i.v. in 50 ml saline solution, with an injection rate of 2.5-8 ml/min. Peripheral blood, rectal pinch biopsies, and peripheral lymph node biopsies were sampled to evaluate VL, CD4+ T cell counts, immune phenotype and function, and transcriptional and serological signatures.
Project description:A major involvement of IFNalpha in the etiopathogenesis of systemic lupus erythematosus has been suggested by clinical observations, including the increase of serum levels of this cytokine in patients with active disease. Supporting this hypothesis, we have shown that expression of IFNalpha from a recombinant adenovirus (IFNalpha Adv) precipitates lupus manifestations in genetically susceptible New Zealand Black (NZB) x New Zealand White (NZW)F(1) mice (NZB/W) but not in BALB/c mice. In the present investigation, we have prepared an IFNalpha immunogen, termed IFNalpha kinoid, which, appropriately adjuvanted, induces transient neutralizing antibodies (Abs) but no cellular immune response to the cytokine and without apparent side effects. Using this preparation, we also showed that, in kinoid-vaccinated NZB/W mice, lupus manifestations, including proteinuria, histological renal lesions, and death triggered by IFNalpha Adv challenge were delayed/prevented as long as an effective threshold of anti-IFNalpha inhibitory capacity was present in the serum.
Project description:Objective: To evaluate the effect of short-term type I IFN treatment on the latent viral reservoir in SIV-infected rhesus macaques on ART; Methods: We infected twelve RMs intrarectally with 10,000 TCID of SIVmac239. After 6 weeks of infection, all RMs started a three-class, four-drug ART regimen. Once viral loads were consistently undetectable, six animals were administered 1 dose of pegylated IFN-α2a per week for 4 weeks with each weekly intramuscular application being 6 µg/kg. Overall design: We infected twelve RMs intrarectally with 10,000 TCID of SIVmac239. After 6 weeks of infection, all RMs started a three-class, four-drug ART. Once viral loads were consistently undetectable, six animals were administered 1 dose of pegylated IFN-α2a per week for 4 weeks with each weekly intramuscular application being 6 µg/kg.
Project description:Rotaviruses are the leading cause of severe dehydrating diarrhea in children worldwide. Rotavirus-induced immune responses, especially the T and B cell responses, have been extensively characterized; however, little is known about innate immune mechanisms involved in the control of rotavirus infection. Although increased levels of systemic type I interferon (IFNalpha and beta) correlate with accelerated resolution of rotavirus disease, multiple rotavirus strains, including rhesus rotavirus (RRV), have been demonstrated to antagonize type I IFN production in a variety of epithelial and fibroblast cell types through several mechanisms, including degradation of multiple interferon regulatory factors by a viral nonstructural protein. This report demonstrates that stimulation of highly purified primary human peripheral plasmacytoid dendritic cells (pDCs) with either live or inactivated RRV induces substantial IFNalpha production by a subset of pDCs in which RRV does not replicate. Characterization of pDC responses to viral stimulus by flow cytometry and Luminex revealed that RRV replicates in a small subset of human primary pDCs and, in this RRV-permissive small subset, IFNalpha production is diminished. pDC activation and maturation were observed independently of viral replication and were enhanced in cells in which virus replicates. Production of IFNalpha by pDCs following RRV exposure required viral dsRNA and surface proteins, but neither viral replication nor activation by trypsin cleavage of VP4. These results demonstrate that a minor subset of purified primary human peripheral pDCs are permissive to RRV infection, and that pDCs retain functionality following RRV stimulus. Additionally, this study demonstrates trypsin-independent infection of primary peripheral cells by rotavirus, which may allow for the establishment of extraintestinal viremia and antigenemia. Importantly, these data provide the first evidence of IFNalpha induction in primary human pDCs by a dsRNA virus, while simultaneously demonstrating impaired IFNalpha production in primary human cells in which RRV replicates. Rotavirus infection of primary human pDCs provides a powerful experimental system for the study of mechanisms underlying pDC-mediated innate immunity to viral infection and reveals a potentially novel dsRNA-dependent pathway of IFNalpha induction.