Neighborhood responses to abandonment & gentrification : a case study of the Lower East Side

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1989.Includes bibliographical references (leaves 100-103).by Shampa Chanda.M.C.P

Surveillance in eastern India (2007-2009) revealed reassortment event involving ns and PB1-F2 gene segments among co-circulating influenza a subtypes

<p>Abstract</p> <p>Background</p> <p>Influenza A virus encodes for eleven proteins, of which HA, NA, NS1 and PB1-F2 have been implicated in viral pathogenicity and virulence. Thus, in addition to the HA and NA gene segments, monitoring diversity of NS1 and PB1-F2 is also important.</p> <p>Methods</p> <p>55 out of 166 circulating influenza A strains (31 H1N1 and 24 H3N2) were randomly picked during 2007-2009 and NS and PB1-F2 genes were sequenced. Phylogenetic analysis was carried out with reference to the prototype strains, concurrent vaccine strains and other reference strains isolated world wide.</p> <p>Results</p> <p>Comparative analysis of both nucleotide and deduced amino acid sequences, revealed presence of NS gene with A/PR/8/34(H1N1)-like mutations (H4N, Q21R, A22V, K44R, N53D, C59R, V60A, F103S and M106I) in both RNA-binding and effector domain of NS1 protein, and G63E, the HPAI-H5N1-like mutation in NEP/NS2 of five A/H1N1 strains of 2007 and 2009. NS1 of other A/H1N1 strains clustered with concurrent A/H1N1 vaccine strains. Of 31 A/H1N1 strains, five had PB1-F2 similar to the H3N2 strains; six had non-functional PB1-F2 protein (11 amino acids) similar to the 2009 pandemic H1N1 strains and rest 20 strains had 57 amino acids PB1-F2 protein, similar to concurrent A/H1N1 vaccine strain. Interestingly, three A/H1N1 strains with H3N2-like PB1-F2 protein carried primitive PR8-like NS gene. Full gene sequencing of PB1 gene confirmed presence of H3N2-like PB1 gene in these A/H1N1 strains.</p> <p>Conclusion</p> <p>Overall the study highlights reassortment event involving gene segments other than HA and NA in the co-circulating A/H1N1 and A/H3N2 strains and their importance in complexity of influenza virus genetics. In contrast, NS and PB1-F2 genes of all A/H3N2 eastern India strains were highly conserved and homologous to the concurrent A/H3N2 vaccine strains suggesting that these gene segments of H3N2 viruses are evolutionarily more stable compared to H1N1 viruses.</p

NSP1 inhibits IFN-β induction irrespective of IRF3 degradation.

<p><b>A)</b> HEK293 cells were transfected with FLAG-MAVS and pcD-OSU-NSP1 vector in order to assess the MAVS mediated inhibition of IRF3 phosphorylation. Cell lysates were analyzed for pIRF3, IRF3, Anti-His, Anti-FLAG and GAPDH specific antibodies. <b>B)</b> Fold change of IFN-β transcripts was assessed in cells overexpressing human TBK1 and pFLAG-MAVS vectors, in presence or absence of pcD-NSP1. The data shown are means ± the SD (n = 3). * Significantly different in comparison to human TBK1 and NSP1 transfected and pFLAG-MAVS untransfected condition. P<0.05 <b>C)</b> Activation of IRF3 was assessed in absence or presence of pcD-NSP1 in cells transfected with TBK1 and FLAG-MAVS. <b>D)</b> Association of MAVS with TBK1 was studied by Co-IP in presence or absence of pcD-NSP1 in cells overexpressing TBK1 and MAVS. The MAVS degradation was controlled by proteosomal inhibitor MG132 Results reveal reduced interaction between MAVS-TBK1 in presence of NSP1.</p

Correction: MAVS Protein Is Attenuated by Rotavirus Nonstructural Protein 1

<p>Correction: MAVS Protein Is Attenuated by Rotavirus Nonstructural Protein 1</p

MAVS Protein Is Attenuated by Rotavirus Nonstructural Protein 1

<div><p>Rotavirus is the single, most important agent of infantile gastroenteritis in many animal species, including humans. In developing countries, rotavirus infection attributes approximately 500,000 deaths annually. Like other viruses it establishes an intimate and complex interaction with the host cell to counteract the antiviral responses elicited by the cell. Among various pattern recognition receptors (PAMPs) of the host, the cytosolic RNA helicases interact with viral RNA to activate the Mitochondrial Antiviral Signaling protein (MAVS), which regulates cellular interferon response. With an aim to identify the role of different PAMPs in rotavirus infected cell, MAVS was found to degrade in a time dependent and strain independent manner. Rotavirus non-structural protein 1 (NSP1) which is a known IFN antagonist, interacted with MAVS and degraded it in a strain independent manner, resulting in a complete loss of RNA sensing machinery in the infected cell. To best of our knowledge, this is the first report on NSP1 functionality where a signaling protein is targeted unanimously in all strains. In addition NSP1 inhibited the formation of detergent resistant MAVS aggregates, thereby averting the antiviral signaling cascade. The present study highlights the multifunctional role of rotavirus NSP1 and reinforces the fact that the virus orchestrates the cellular antiviral response to its own benefit by various back up strategies.</p></div

List of primers designed and used in the study.

<p>List of primers designed and used in the study.</p

Mechanistic model for rotavirus NSP1-mediated attenuation of cellular proteins for improved infection.

<p>The model summarizes all the NSP1 mediated inhibitory effects during RV infection. In brief, it shows the critical role of MAVS in RLR mediated activation of type I IFN and immune response. By degrading MAVS, NSP1 can directly inhibit IRF3 and NF-κB signaling. Other cellular proteins like IRFs and β-TrCP are targeted selectively but MAVS degradation was observed in all RV strains with functional NSP1.</p

NSP1 interacts with MAVS protein during infection and transfection.

<p><b>A)</b> NSP1 interacts with MAVS during SA11 infection. HT29 cells were infected with SA11 for increasing time points and cell extracts were immunoprecipitated with either NSP1 or MAVS antibody followed by immunoblotting with reciprocal antibody. Whole cell lysates were immunoblotted with anti-MAVS and anti-NSP1 antibody. CO-IP revealed positive interaction between NSP1 and MAVS. <b>B)</b> HEK293 cells were co-transfected with pFLAG-MAVS and pcD-NSP1. After 24 hours, cell extracts were immunoprecipitated using FLAG Ab or His Ab followed by immunoblotting by reciprocal antibodies. NSP1 was found to co-immunoprecipitate with MAVS in absence of other viral protein.</p