Browsing by Subject "Virion"

Now showing 1 - 5 of 5

Open Access
ADAP2 Is an Interferon Stimulated Gene That Restricts RNA Virus Entry.
(PLoS pathogens, 2015-09-15) Shu, Qian; Lennemann, Nicholas J; Sarkar, Saumendra N; Sadovsky, Yoel; Coyne, Carolyn B
Interferon stimulated genes (ISGs) target viruses at various stages of their infectious life cycles, including at the earliest stage of viral entry. Here we identify ArfGAP with dual pleckstrin homology (PH) domains 2 (ADAP2) as a gene upregulated by type I IFN treatment in a STAT1-dependent manner. ADAP2 functions as a GTPase-activating protein (GAP) for Arf6 and binds to phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) and PI(3,4)P2. We show that overexpression of ADAP2 suppresses dengue virus (DENV) and vesicular stomatitis virus (VSV) infection in an Arf6 GAP activity-dependent manner, while exerting no effect on coxsackievirus B (CVB) or Sendai virus (SeV) replication. We further show that ADAP2 expression induces macropinocytosis and that ADAP2 strongly associates with actin-enriched membrane ruffles and with Rab8a- and LAMP1-, but not EEA1- or Rab7-, positive vesicles. Utilizing two techniques--light-sensitive neutral red (NR)-containing DENV and fluorescence assays for virus internalization--we show that ADAP2 primarily restricts DENV infection at the stage of virion entry and/or intracellular trafficking and that incoming DENV and VSV particles associate with ADAP2 during their entry. Taken together, this study identifies ADAP2 as an ISG that exerts antiviral effects against RNA viruses by altering Arf6-mediated trafficking to disrupt viral entry.
Open Access
An enhanced isothermal amplification assay for viral detection.
(Nature communications, 2020-11) Qian, Jason; Boswell, Sarah A; Chidley, Christopher; Lu, Zhi-Xiang; Pettit, Mary E; Gaudio, Benjamin L; Fajnzylber, Jesse M; Ingram, Ryan T; Ward, Rebecca H; Li, Jonathan Z; Springer, Michael
Rapid, inexpensive, robust diagnostics are essential to control the spread of infectious diseases. Current state of the art diagnostics are highly sensitive and specific, but slow, and require expensive equipment. Here we report the development of a molecular diagnostic test for SARS-CoV-2 based on an enhanced recombinase polymerase amplification (eRPA) reaction. eRPA has a detection limit on patient samples down to 5 viral copies, requires minimal instrumentation, and is highly scalable and inexpensive. eRPA does not cross-react with other common coronaviruses, does not require RNA purification, and takes ~45 min from sample collection to results. eRPA represents a first step toward at-home SARS-CoV-2 detection and can be adapted to future viruses within days of genomic sequence availability.
Open Access
Anti-AIDS agents 81. Design, synthesis, and structure-activity relationship study of betulinic acid and moronic acid derivatives as potent HIV maturation inhibitors.
(J Med Chem, 2010-04-22) Qian, Keduo; Kuo, Reen-Yun; Chen, Chin-Ho; Huang, Li; Morris-Natschke, Susan L; Lee, Kuo-Hsiung
In our continuing study of triterpene derivatives as potent anti-HIV agents, different C-3 conformationally restricted betulinic acid (BA, 1) derivatives were designed and synthesized in order to explore the conformational space of the C-3 pharmacophore. 3-O-Monomethylsuccinyl-betulinic acid (MSB) analogues were also designed to better understand the contribution of the C-3' dimethyl group of bevirimat (2), the first-in-class HIV maturation inhibitor, which is currently in phase IIb clinical trials. In addition, another triterpene skeleton, moronic acid (MA, 3), was also employed to study the influence of the backbone and the C-3 modification toward the anti-HIV activity of this compound class. This study enabled us to better understand the structure-activity relationships (SAR) of triterpene-derived anti-HIV agents and led to the design and synthesis of compound 12 (EC(50): 0.0006 microM), which displayed slightly better activity than 2 as a HIV-1 maturation inhibitor.
Open Access
Infectious virion capture by HIV-1 gp120-specific IgG from RV144 vaccinees.
(J Virol, 2013-07) Liu, Pinghuang; Yates, Nicole L; Shen, Xiaoying; Bonsignori, Mattia; Moody, M Anthony; Liao, Hua-Xin; Fong, Youyi; Alam, S Munir; Overman, R Glenn; Denny, Thomas; Ferrari, Guido; Ochsenbauer, Christina; Kappes, John C; Polonis, Victoria R; Pitisuttithum, Punnee; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Rerks-Ngarm, Supachai; Montefiori, David C; Gilbert, Peter; Michael, Nelson L; Kim, Jerome H; Haynes, Barton F; Tomaras, Georgia D
The detailed examination of the antibody repertoire from RV144 provides a unique template for understanding potentially protective antibody functions. Some potential immune correlates of protection were untested in the correlates analyses due to inherent assay limitations, as well as the need to keep the correlates analysis focused on a limited number of endpoints to achieve statistical power. In an RV144 pilot study, we determined that RV144 vaccination elicited antibodies that could bind infectious virions (including the vaccine strains HIV-1 CM244 and HIV-1 MN and an HIV-1 strain expressing transmitted/founder Env, B.WITO.c). Among vaccinees with the highest IgG binding antibody profile, the majority (78%) captured the infectious vaccine strain virus (CM244), while a smaller proportion of vaccinees (26%) captured HIV-1 transmitted/founder Env virus. We demonstrated that vaccine-elicited HIV-1 gp120 antibodies of multiple specificities (V3, V2, conformational C1, and gp120 conformational) mediated capture of infectious virions. Although capture of infectious HIV-1 correlated with other humoral immune responses, the extent of variation between these humoral responses and virion capture indicates that virion capture antibodies occupy unique immunological space.
Open Access
Phenotypic properties of transmitted founder HIV-1.
(Proc Natl Acad Sci U S A, 2013-04-23) Parrish, Nicholas F; Gao, Feng; Li, Hui; Giorgi, Elena E; Barbian, Hannah J; Parrish, Erica H; Zajic, Lara; Iyer, Shilpa S; Decker, Julie M; Kumar, Amit; Hora, Bhavna; Berg, Anna; Cai, Fangping; Hopper, Jennifer; Denny, Thomas N; Ding, Haitao; Ochsenbauer, Christina; Kappes, John C; Galimidi, Rachel P; West, Anthony P; Bjorkman, Pamela J; Wilen, Craig B; Doms, Robert W; O'Brien, Meagan; Bhardwaj, Nina; Borrow, Persephone; Haynes, Barton F; Muldoon, Mark; Theiler, James P; Korber, Bette; Shaw, George M; Hahn, Beatrice H
Defining the virus-host interactions responsible for HIV-1 transmission, including the phenotypic requirements of viruses capable of establishing de novo infections, could be important for AIDS vaccine development. Previous analyses have failed to identify phenotypic properties other than chemokine receptor 5 (CCR5) and CD4+ T-cell tropism that are preferentially associated with viral transmission. However, most of these studies were limited to examining envelope (Env) function in the context of pseudoviruses. Here, we generated infectious molecular clones of transmitted founder (TF; n = 27) and chronic control (CC; n = 14) viruses of subtypes B (n = 18) and C (n = 23) and compared their phenotypic properties in assays specifically designed to probe the earliest stages of HIV-1 infection. We found that TF virions were 1.7-fold more infectious (P = 0.049) and contained 1.9-fold more Env per particle (P = 0.048) compared with CC viruses. TF viruses were also captured by monocyte-derived dendritic cells 1.7-fold more efficiently (P = 0.035) and more readily transferred to CD4+ T cells (P = 0.025). In primary CD4+ T cells, TF and CC viruses replicated with comparable kinetics; however, when propagated in the presence of IFN-α, TF viruses replicated to higher titers than CC viruses. This difference was significant for subtype B (P = 0.000013) but not subtype C (P = 0.53) viruses, possibly reflecting demographic differences of the respective patient cohorts. Together, these data indicate that TF viruses are enriched for higher Env content, enhanced cell-free infectivity, improved dendritic cell interaction, and relative IFN-α resistance. These viral properties, which likely act in concert, should be considered in the development and testing of AIDS vaccines.