scholarly journals Analysis of the host-specific haemagglutination of influenza A(H1N1) viruses isolated in the 1995/6 season

1997 ◽  
Vol 119 (3) ◽  
pp. 327-334 ◽  
Author(s):  
T. MORISHITA ◽  
E. NOBUSAWA ◽  
S. LUO ◽  
K. SATO ◽  
S. NAKAJIMA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Aspartic Acid ◽  
Influenza A ◽  
Mdck Cells ◽  
Amino Acid Sequences ◽  
The Other ◽  
Influenza A H1n1 ◽  
Group 2 ◽  
Ha Protein ◽  
Group 1

Two phenotypes of human influenza A(H1N1) virus are currently circulating in Japan. One (group 1) agglutinates both chicken and goose red blood cells (CRBC and GRBC), the other (group 2) agglutinates GRBC but not CRBC. In the 1995/6 season, group 2 viruses accounted for 70% of the H1N1 viruses isolated in MDCK cells. The 1995/6 viruses were located on two branches of the genetic tree. One branch contained both group 1 and group 2 viruses and the other branch contained only group 2 viruses. Group 2 viruses had aspartic acid at residue 225 in the haemagglutinin (HA) protein, the key amino acid residue for group 2 phenotype. The HA protein of group 1 viruses had a change from aspartic acid to asparagine at residue 225 and the expressed HA protein of these viruses adsorbed CRBC. Serial passage of group 2 viruses in MDCK cells or embryonated chicken eggs caused these viruses to gain the ability to agglutinate CRBC. MDCK-adapted viruses had the same amino acid sequences of HA polypeptide as the original ones, but egg-adapted viruses had changed amino acid sequences. The expressed HA protein from one egg-adapted virus that originally belonged to group 2 adsorbed CRBC.

scholarly journals Stereotyped B-cell response that counteracts antigenic variation of influenza viruses

2020 ◽  
Vol 32 (9) ◽  
pp. 613-621 ◽  
Author(s):  
Keisuke Tonouchi ◽  
Yu Adachi ◽  
Saya Moriyama ◽  
Kaori Sano ◽  
Koshiro Tabata ◽  
...  
Keyword(s):  
B Cells ◽  
Influenza A ◽  
Clonal Evolution ◽  
Influenza Viruses ◽  
Dependent Manner ◽  
Phylogenetic Distance ◽  
Native Form ◽  
Group 2 ◽  
Ha Protein ◽  
Group 1

Abstract Influenza A subtypes are categorized into group 1 and group 2 based on the hemagglutinin (HA) sequence. Owing to the phylogenetic distance of HAs in different groups, antibodies that bind multiple HA subtypes across different groups are extremely rare. In this study, we demonstrated that an immunization with acid-treated HA antigen elicits germinal center (GC) B cells that bind multiple HA subtypes in both group 1 and group 2. The cross-group GC B cells utilized mostly one VH gene (1S56) and exhibited a sign of clonal evolution within GCs. The 1S56-lineage IgGs derived from GC B cells were able to bind to HA protein on the infected cell surface but not to the native form of HA protein, suggesting the cryptic nature of the 1S56 epitope and its exposure in infected cells. Finally, the 1S56-lineage IgGs provided protection against lethal infection in an Fc-dependent manner, independent of the virus-neutralizing activity. Thus, we identified 1S56-lineage antibodies as a unique stereotype for achieving cross-group influenza specificity. The antigens exposing the 1S56 epitope may be good candidates for broadly protective immunogens.

scholarly journals A new member of the chalcone synthase (CHS) family in sugarcane

2001 ◽  
Vol 24 (1-4) ◽  
pp. 257-261 ◽  
Author(s):  
Miriam G.G. Contessotto ◽  
Claudia B. Monteiro-Vitorello ◽  
Pilar D.S.C. Mariani ◽  
Luiz L. Coutinho
Keyword(s):  
Amino Acid ◽  
Active Site ◽  
Chalcone Synthase ◽  
Expressed Sequence Tag ◽  
Consensus Sequence ◽  
Stilbene Synthase ◽  
Amino Acid Sequences ◽  
Group 2 ◽  
Expressed Sequence ◽  
Group 1

Sequences from the sugarcane expressed sequence tag (SUCEST) database were analyzed based on their identities to genes encoding chalcone-synthase-like enzymes. The sorghum (Sorghum bicolor) chalcone-synthase (CHS, EC 2.3.1.74) protein sequence (gi|12229613) was used to search the SUCEST database for clusters of sequencing reads that were most similar to chalcone synthase. We found 121 reads with homology to sorghum chalcone synthase, which we were then able to sort into 14 clusters which themselves were divided into two groups (group 1 and group 2) based on the similarity of their deduced amino acid sequences. Clusters in group 1 were more similar to the sorghum enzyme than those in group 2, having the consensus sequence of the active site of chalcone and stilbene synthase. Analysis of gene expression (based on the number of reads from a specific library present in each group) indicated that most of the group 1 reads were from sugarcane flower and root libraries. Group 2 clusters were more similar to the amino acid sequence of an uncharacterized pathogen-induced protein (PI1, gi|9855801) from the S. bicolor expressed sequence tag (EST) database. The group 2 clusters sequences and PI1 proteins are 90% identical, having two amino acid changes at the chalcone and stilbene synthase consensi but conserving the cysteine residue at the active site. The PI1 EST has not been previously associated with chalcone synthase and has a different consensus sequence from the previously described chalcone synthase of sorghum. Most of the group 2 reads were from libraries prepared from sugarcane roots and plants infected with Herbaspirillum rubrisubalbicans and Gluconacetobacter diazotroficans. Our results indicate that we have identified a sugarcane chalcone synthase similar to the pathogen-induced PI1 protein found in the sorghum cDNA libraries, and it appears that both proteins represent new members of the chalcone and stilbene synthase super-family.

scholarly journals Structural and antigenic variance between novel influenza A/H1N1/2009 and influenza A/H1N1/2008 viruses

2009 ◽  
Vol 4 (01) ◽  
pp. 001-006 ◽  
Author(s):  
Shailendra K Saxena ◽  
Niraj Mishra ◽  
Rakhi Saxena ◽  
ML Arvinda Swamy ◽  
Pranshu Sahgal ◽  
...  
Keyword(s):  
Amino Acid ◽  
Influenza A ◽  
Vaccine Development ◽  
Amino Acid Sequences ◽  
Host Cells ◽  
Antigenic Analysis ◽  
Amino Acid Homology ◽  
Viral Attachment ◽  
Influenza A H1n1 ◽  
Significant Difference

Background: The emergence of influenza A/H1N1/2009 is alarming. The severity of previous epidemics suggests that the susceptibility of the human population to H1N1 is directly proportional to the degree of changes in hemagglutinin/HA and neuraminidase/NA; therefore, H1N1/2009 and H1N1/2008 were analyzed for their sequence as well as structural divergence. Methodology: The structural and sequence divergence of H1N1/2009 and H1N1/2008 strains were analyzed by aligning HA and NA amino acid sequences by using ClustalW and ESyPred3D software. To determine the variations in sites of viral attachment to host cells, a comparison between amino acid sequences of HA and NA glycosylation sites was performed with NetNGlyc software. The antigenic divergence was executed by CTL epitope prediction method.  Results: The amino acid homology levels of H1N1/2009 were 20.32% and 18.73% compared to H1N1/2008 for HA and NA genes, respectively.  In spite of the high variation in HA and NA amino acid composition, there was no significant difference in their structures. Antigenic analysis proposes that great antigenic differences exist between both the viral strains, but no addition of a new site of glycosylation was observed. Conclusions: To our knowledge, this is the first report suggesting that the circulating novel influenza virus A/H1N1/2009 attaches to the same glycosylation receptor sites as its predecessor influenza A/H1N1/2008 virus, but is antigenically different and may have the potential for initiating a significant pandemic. Our study may facilitate the development of better therapeutics and preventive strategies, as well as impart clues for novel H1N1 diagnostic and vaccine development.

scholarly journals Comparative Analysis of Evolutionary Mechanisms of the Hemagglutinin and Three Internal Protein Genes of Influenza B Virus: Multiple Cocirculating Lineages and Frequent Reassortment of the NP, M, and NS Genes

1999 ◽  
Vol 73 (5) ◽  
pp. 4413-4426 ◽  
Author(s):  
Stephen E. Lindstrom ◽  
Yasuaki Hiromoto ◽  
Hidekazu Nishimura ◽  
Takehiko Saito ◽  
Reiko Nerome ◽  
...  
Keyword(s):  
Amino Acid ◽  
Influenza A ◽  
Amino Acid Sequences ◽  
Evolutionary Rates ◽  
Influenza B Virus ◽  
Influenza B ◽  
Evolutionary Analysis ◽  
Human Influenza ◽  
Evolutionary Mechanisms ◽  
Ha Protein

ABSTRACT Phylogenetic profiles of the genes coding for the hemagglutinin (HA) protein, nucleoprotein (NP), matrix (M) protein, and nonstructural (NS) proteins of influenza B viruses isolated from 1940 to 1998 were analyzed in a parallel manner in order to understand the evolutionary mechanisms of these viruses. Unlike human influenza A (H3N2) viruses, the evolutionary pathways of all four genes of recent influenza B viruses revealed similar patterns of genetic divergence into two major lineages. Although evolutionary rates of the HA, NP, M, and NS genes of influenza B viruses were estimated to be generally lower than those of human influenza A viruses, genes of influenza B viruses demonstrated complex phylogenetic patterns, indicating alternative mechanisms for generation of virus variability. Topologies of the evolutionary trees of each gene were determined to be quite distinct from one another, showing that these genes were evolving in an independent manner. Furthermore, variable topologies were apparently the result of frequent genetic exchange among cocirculating epidemic viruses. Evolutionary analysis done in the present study provided further evidence for cocirculation of multiple lineages as well as sequestering and reemergence of phylogenetic lineages of the internal genes. In addition, comparison of deduced amino acid sequences revealed a novel amino acid deletion in the HA1 domain of the HA protein of recent isolates from 1998 belonging to the B/Yamagata/16/88-like lineage. It thus became apparent that, despite lower evolutionary rates, influenza B viruses were able to generate genetic diversity among circulating viruses through a combination of evolutionary mechanisms involving cocirculating lineages and genetic reassortment by which new variants with distinct gene constellations emerged.

Myeloid neoplasms in the setting of chronic lymphocytic leukaemia/chronic lymphocytic leukaemia-like disease: a clinicopathological study of 66 cases comparing cases with prior history of treatment to those without

2021 ◽  
pp. jclinpath-2020-207334
Author(s):  
Catherine Luedke ◽  
Yue Zhao ◽  
Jenna McCracken ◽  
Jake Maule ◽  
Lian-He Yang ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Lymphocytic Leukaemia ◽  
The Other ◽  
Prior History ◽  
Myeloid Neoplasm ◽  
Myeloid Neoplasms ◽  
History Of ◽  
Cytogenetic Profile ◽  
Group 2 ◽  
Group 1

AimsMyeloid neoplasms occur in the setting of chronic lymphocytic leukaemia (CLL)/CLL-like disease. The underlying pathogenesis has not been elucidated.MethodsRetrospectively analysed 66 cases of myeloid neoplasms in patients with CLL/CLL-like disease.ResultsOf these, 33 patients (group 1) had received treatment for CLL/CLL-like disease, while the other 33 patients (group 2) had either concurrent diagnoses or untreated CLL/CLL-like disease before identifying myeloid neoplasms. The two categories had distinct features in clinical presentation, spectrum of myeloid neoplasm, morphology, cytogenetic profile and clinical outcome. Compared with group 2, group 1 demonstrated a younger age at the diagnosis of myeloid neoplasm (median, 65 vs 71 years), a higher fraction of myelodysplastic syndrome (64% vs 36%; OR: 3.1; p<0.05), a higher rate of adverse unbalanced cytogenetic abnormalities, including complex changes, −5/5q- and/or −7/7q- (83% vs 28%; OR: 13.1; p<0.001) and a shorter overall survival (median, 12 vs 44 months; p<0.05).ConclusionsMyeloid neoplasm in the setting of CLL/CLL-like disease can be divided into two categories, one with prior treatment for CLL/CLL-like disease and the other without. CLL-type treatment may accelerate myeloid leukaemogenesis. The risk is estimated to be 13-fold higher in patients with treatment than those without. The causative agent could be attributed to fludarabine in combination with alkylators, based on the latency of myeloid leukaemogenesis and the cytogenetic profile.

scholarly journals Whole-Genome Sequences of Influenza A(H1N1)pdm09 Virus Isolates from Kerala, India

2017 ◽  
Vol 5 (28) ◽  
Author(s):  
Sara Jones ◽  
Raji Prasad ◽  
Anjana S. Nair ◽  
Sanjai Dharmaseelan ◽  
Remya Usha ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Analysis ◽  
Influenza A ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
H1n1 Pandemic ◽  
Genome Sequences ◽  
Influenza A H1n1 ◽  
Virus Isolates ◽  
New Mutations

ABSTRACT We report here the whole-genome sequence of six clinical isolates of influenza A(H1N1)pdm09, isolated from Kerala, India. Amino acid analysis of all gene segments from the A(H1N1)pdm09 isolates obtained in 2014 and 2015 identified several new mutations compared to the 2009 A(H1N1) pandemic strain.

scholarly journals A novel giant secretion polypeptide in Chironomus salivary glands: implications for another Balbiani ring gene.

1985 ◽  
Vol 101 (3) ◽  
pp. 1044-1051 ◽  
Author(s):  
W Y Kao ◽  
S T Case
Keyword(s):  
Amino Acid ◽  
Nucleotide Sequence ◽  
Salivary Glands ◽  
Cyanogen Bromide ◽  
Tryptic Peptide ◽  
Amino Acid Sequences ◽  
The Other ◽  
Balbiani Ring ◽  
Sequence Organization ◽  
Peptide Maps

Chironomus salivary glands contain a family of high Mr (approximately 1,000 X 10(3)) secretion polypeptides thought to consist of three components: sp-Ia, sp-Ib, and sp-Ic. The use of a new extraction protocol revealed a novel high Mr component, sp-Id. Results of a survey of individual salivary glands indicated that sp-Id was widespread in more than a dozen strains of C. tentans and C. pallidivittatus. Sp-Id was phosphorylated at Ser residues, and a comparison of cyanogen bromide and tryptic peptide maps of 32P-labeled polypeptides suggested that sp-Ia, sp-Ib, and sp-Id are comprised of similar but nonidentical tandemly repeated amino acid sequences. We concluded that sp-Id is encoded by an mRNA whose size and nucleotide sequence organization are similar to Balbiani ring (BR) mRNAs that code for the other sp-I components. Furthermore, parallel repression of sp-Ib and sp-Id synthesis by galactose led us to hypothesize that both of their genes exist within Balbiani ring 2.

A Neutralizing Antibody Selected from Plasma Cells That Binds to Group 1 and Group 2 Influenza A Hemagglutinins

Science ◽  
2011 ◽  
Vol 333 (6044) ◽  
pp. 850-856 ◽  
Author(s):  
D. Corti ◽  
J. Voss ◽  
S. J. Gamblin ◽  
G. Codoni ◽  
A. Macagno ◽  
...  
Keyword(s):  
Influenza A ◽  
Plasma Cells ◽  
Neutralizing Antibody ◽  
Group 2 ◽  
Group 1

scholarly journals Functional Analysis of PA Binding by Influenza A Virus PB1: Effects on Polymerase Activity and Viral Infectivity

2001 ◽  
Vol 75 (17) ◽  
pp. 8127-8136 ◽  
Author(s):  
Daniel R. Perez ◽  
Ruben O. Donis
Keyword(s):  
Amino Acids ◽  
Influenza Virus ◽  
Amino Acid ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Influenza A ◽  
Amino Acid Sequences ◽  
Influenza Viruses ◽  
Virus Growth ◽  
Transcription And Replication

ABSTRACT Influenza A virus expresses three viral polymerase (P) subunits—PB1, PB2, and PA—all of which are essential for RNA and viral replication. The functions of P proteins in transcription and replication have been partially elucidated, yet some of these functions seem to be dependent on the formation of a heterotrimer for optimal viral RNA transcription and replication. Although it is conceivable that heterotrimer subunit interactions may allow a more efficient catalysis, direct evidence of their essentiality for viral replication is lacking. Biochemical studies addressing the molecular anatomy of the P complexes have revealed direct interactions between PB1 and PB2 as well as between PB1 and PA. Previous studies have shown that the N-terminal 48 amino acids of PB1, termed domain α, contain the residues required for binding PA. We report here the refined mapping of the amino acid sequences within this small region of PB1 that are indispensable for binding PA by deletion mutagenesis of PB1 in a two-hybrid assay. Subsequently, we used site-directed mutagenesis to identify the critical amino acid residues of PB1 for interaction with PA in vivo. The first 12 amino acids of PB1 were found to constitute the core of the interaction interface, thus narrowing the previous boundaries of domain α. The role of the minimal PB1 domain α in influenza virus gene expression and genome replication was subsequently analyzed by evaluating the activity of a set of PB1 mutants in a model reporter minigenome system. A strong correlation was observed between a functional PA binding site on PB1 and P activity. Influenza viruses bearing mutant PB1 genes were recovered using a plasmid-based influenza virus reverse genetics system. Interestingly, mutations that rendered PB1 unable to bind PA were either nonviable or severely growth impaired. These data are consistent with an essential role for the N terminus of PB1 in binding PA, P activity, and virus growth.

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