Browsing by Author "Diamond, Michael S"

Now showing 1 - 5 of 5
  • Thumbnail Image
    ItemOpen Access
    A Prevalent Focused Human Antibody Response to the Influenza Virus Hemagglutinin Head Interface.
    (mBio, 2021-06) McCarthy, Kevin R; Lee, Jiwon; Watanabe, Akiko; Kuraoka, Masayuki; Robinson-McCarthy, Lindsey R; Georgiou, George; Kelsoe, Garnett; Harrison, Stephen C
    Novel animal influenza viruses emerge, initiate pandemics, and become endemic seasonal variants that have evolved to escape from prevalent herd immunity. These processes often outpace vaccine-elicited protection. Focusing immune responses on conserved epitopes may impart durable immunity. We describe a focused, protective antibody response, abundant in memory and serum repertoires, to a conserved region at the influenza virus hemagglutinin (HA) head interface. Structures of 11 examples, 8 reported here, from seven human donors demonstrate the convergence of responses on a single epitope. The 11 are genetically diverse, with one class having a common, IGκV1-39, light chain. All of the antibodies bind HAs from multiple serotypes. The lack of apparent genetic restriction and potential for elicitation by more than one serotype may explain their abundance. We define the head interface as a major target of broadly protective antibodies with the potential to influence the outcomes of influenza virus infection. IMPORTANCE The rapid appearance of mutations in circulating human influenza viruses and selection for escape from herd immunity require prediction of likely variants for an annual updating of influenza vaccines. The identification of human antibodies that recognize conserved surfaces on the influenza virus hemagglutinin (HA) has prompted efforts to design immunogens that might selectively elicit such antibodies. The recent discovery of a widely prevalent antibody response to the conserved interface between two HA "heads" (the globular, receptor-binding domains at the apex of the spike-like trimer) has added a new target for these efforts. We report structures of eight such antibodies, bound with HA heads, and compare them with each other and with three others previously described. Although genetically diverse, they all converge on a common binding site. The analysis here can guide immunogen design for preclinical trials.
  • Thumbnail Image
    ItemOpen Access
    An Evolutionary Insertion in the Mxra8 Receptor-Binding Site Confers Resistance to Alphavirus Infection and Pathogenesis.
    (Cell host & microbe, 2020-03) Kim, Arthur S; Zimmerman, Ofer; Fox, Julie M; Nelson, Christopher A; Basore, Katherine; Zhang, Rong; Durnell, Lorellin; Desai, Chandni; Bullock, Christopher; Deem, Sharon L; Oppenheimer, Jonas; Shapiro, Beth; Wang, Ting; Cherry, Sara; Coyne, Carolyn B; Handley, Scott A; Landis, Michael J; Fremont, Daved H; Diamond, Michael S
    Alphaviruses are emerging, mosquito-transmitted RNA viruses with poorly understood cellular tropism and species selectivity. Mxra8 is a receptor for multiple alphaviruses including chikungunya virus (CHIKV). We discovered that while expression of mouse, rat, chimpanzee, dog, horse, goat, sheep, and human Mxra8 enables alphavirus infection in cell culture, cattle Mxra8 does not. Cattle Mxra8 encodes a 15-amino acid insertion in its ectodomain that prevents Mxra8 binding to CHIKV. Identical insertions are present in zebu, yak, and the extinct auroch. As other Bovinae lineages contain related Mxra8 sequences, this insertion likely occurred at least 5 million years ago. Removing the Mxra8 insertion in Bovinae enhances alphavirus binding and infection, while introducing the insertion into mouse Mxra8 blocks CHIKV binding, prevents infection by multiple alphaviruses in cells, and mitigates CHIKV-induced pathogenesis in mice. Our studies on how this insertion provides resistance to CHIKV infection could facilitate countermeasures that disrupt Mxra8 interactions with alphaviruses.
  • Thumbnail Image
    ItemOpen Access
    Dengue virus selectively annexes endoplasmic reticulum-associated translation machinery as a strategy for co-opting host cell protein synthesis
    (Journal of Virology, 2018-01-10) Reid, DW; Campos, RK; Child, JR; Zheng, T; Chan, KWK; Bradrick, SS; Vasudevan, SG; Garcia-Blanco, MA; Nicchitta, CV
    A primary question in Dengue virus (DENV) biology is the molecular strategy for recruitment of host cell protein synthesis machinery. Here we combined cell fractionation, ribosome profiling, and RNA-seq to investigate the subcellular organization of viral genome translation and replication as well as host cell translation and its response to DENV infection. We report that throughout the viral life cycle, DENV (+) and (-) strand RNAs were highly partitioned to the endoplasmic reticulum (ER), identifying the ER as the primary site of DENV translation. DENV infection was accompanied by an ER compartment-specific remodeling of translation, where ER translational capacity was subverted from host transcripts to DENV (+) strand RNA, particularly at late stages of infection. Remarkably, translation levels and patterns in the cytosol compartment were only modestly affected throughout the experimental time course of infection. Comparisons of ribosome footprinting densities of the DENV (+) strand RNA and host mRNAs indicated that DENV (+) strand RNA was only sparsely loaded with ribosomes. Combined, these observations suggest a mechanism where ER-localized translation and translational control mechanisms, likely cis-encoded, are used to repurpose the ER for DENV virion production. Consistent with this view, we found ER-linked cellular stress response pathways commonly associated with viral infection, namely the interferon response and unfolded protein response, to be only modestly activated during DENV infection. These data support a model where DENV reprograms the ER protein synthesis and processing environment to promote viral survival and replication, while minimizing the activation of anti-viral and proteostatic stress response pathways.ImportanceDENV, a prominent human health threat with no broadly effective or specific treatment, depends on host cell translation machinery for viral replication, immune evasion, and virion biogenesis. The molecular mechanism by which DENV commandeers the host cell protein synthesis machinery and the subcellular organization of DENV replication and viral protein synthesis is poorly understood. Here we report that DENV has an almost exclusively ER-localized life cycle, with viral replication and translation largely restricted to the ER. Surprisingly, DENV infection largely affects only ER-associated translation, with relatively modest effects on host cell translation in the cytosol. DENV RNA translation is very inefficient, likely representing a strategy to minimize disruption of ER proteostasis. Overall these findings demonstrate that DENV has evolved an ER-compartmentalized life cycle and thus targeting the molecular signatures and regulation of the DENV-ER interaction landscape may reveal strategies for therapeutic intervention.
  • Thumbnail Image
    ItemOpen Access
    Gestational Stage and IFN-λ Signaling Regulate ZIKV Infection In Utero.
    (Cell host & microbe, 2017-09) Jagger, Brett W; Miner, Jonathan J; Cao, Bin; Arora, Nitin; Smith, Amber M; Kovacs, Attila; Mysorekar, Indira U; Coyne, Carolyn B; Diamond, Michael S
    Although Zika virus (ZIKV)-induced congenital disease occurs more frequently during early stages of pregnancy, its basis remains undefined. Using established type I interferon (IFN)-deficient mouse models of ZIKV transmission in utero, we found that the placenta and fetus were more susceptible to ZIKV infection at earlier gestational stages. Whereas ZIKV infection at embryonic day 6 (E6) resulted in placental insufficiency and fetal demise, infections at midstage (E9) resulted in reduced cranial dimensions, and infection later in pregnancy (E12) caused no apparent fetal disease. In addition, we found that fetuses lacking type III IFN-λ signaling had increased ZIKV replication in the placenta and fetus when infected at E12, and reciprocally, treatment of pregnant mice with IFN-λ2 reduced ZIKV infection. IFN-λ treatment analogously diminished ZIKV infection in human midgestation fetal- and maternal-derived tissue explants. Our data establish a model of gestational stage dependence of ZIKV pathogenesis and IFN-λ-mediated immunity at the maternal-fetal interface.
  • Thumbnail Image
    ItemOpen Access
    Vaccines in 2017: Closing in on a Zika virus vaccine.
    (Nature reviews. Immunology, 2018-02) Diamond, Michael S; Coyne, Carolyn B