Immunodiffusion studies on the myxoviruses. III. Identification of the structural antigens of Myxovirus influenza A/PR8

1971 ◽  
Vol 17 (7) ◽  
pp. 915-920
Author(s):  
C. Margaret Johnson ◽  
John C. N. Westwood
Keyword(s):  
Biological Activity ◽  
Influenza A ◽  
Sodium Deoxycholate ◽  
Antigenic Structure ◽  
Structural Components ◽  
Dual Specificity

A comparison of the effect of several different virus disruption procedures on the biological activity and antigenic structure of the Myxovirus influenza A/PR8 virion has shown that sodium deoxycholate was the best disrupting agent. Six virus structural components were detected, of which one was classified as host specific, two were identified as virus specific, and three were found to possess dual specificity. These were classified as host-virus (HV) structural antigens.

scholarly journals Differential Role of Threonine and Tyrosine Phosphorylation in the Activation and Activity of the Yeast MAPK Slt2

2021 ◽  
Vol 22 (3) ◽  
pp. 1110
Author(s):  
Gema González-Rubio ◽  
Ángela Sellers-Moya ◽  
Humberto Martín ◽  
María Molina
Keyword(s):  
Cell Wall ◽  
Biological Activity ◽  
Biological Significance ◽  
Mitogen Activated Protein Kinase ◽  
Activation Loop ◽  
High Increase ◽  
Dual Specificity ◽  
Mitogen Activated Protein ◽  
Full Activation

The Mitogen-Activated Protein Kinase (MAPK) Slt2 is central to signaling through the yeast Cell Wall Integrity (CWI) pathway. MAPKs are regulated by phosphorylation at both the threonine and tyrosine of the conserved TXY motif within the activation loop (T190/Y192 in Slt2). Since phosphorylation at both sites results in the full activation of MAPKs, signaling through MAPK pathways is monitored with antibodies that detect dually phosphorylated forms. However, most of these antibodies also recognize monophosphorylated species, whose relative abundance and functionality are diverse. By using different phosphospecific antibodies and phosphate-affinity (Phos-tag) analysis on distinct Slt2 mutants, we determined that Y192- and T190-monophosphorylated species coexist with biphosphorylated Slt2, although most of the Slt2 pool remains unphosphorylated following stress. Among the monophosphorylated forms, only T190 exhibited biological activity. Upon stimulation, Slt2 is first phosphorylated at Y192, mainly by the MAPKK Mkk1, and this phosphorylation is important for the subsequent T190 phosphorylation. Similarly, dephosphorylation of Slt2 by the Dual Specificity Phosphatase (DSP) Msg5 is ordered, with dephosphorylation of T190 depending on previous Y192 dephosphorylation. Whereas Y192 phosphorylation enhances the Slt2 catalytic activity, T190 is essential for this activity. The conserved T195 residue is also critical for Slt2 functionality. Mutations that abolish the activity of Slt2 result in a high increase in inactive Y192-monophosphorylated Slt2. The coexistence of different Slt2 phosphoforms with diverse biological significance highlights the importance of the precise detection of the Slt2 phosphorylation status.

scholarly journals Characterization of an enhanced antigenic change in the pandemic 2009 H1N1 influenza virus haemagglutinin

2014 ◽  
Vol 95 (5) ◽  
pp. 1033-1042 ◽  
Author(s):  
Blanca García-Barreno ◽  
Teresa Delgado ◽  
Sonia Benito ◽  
Inmaculada Casas ◽  
Francisco Pozo ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Amino Acid ◽  
Influenza A ◽  
Point Mutations ◽  
Antigenic Site ◽  
Single Amino Acid ◽  
Antigenic Structure ◽  
Human Antibody ◽  
2009 H1n1

Murine hybridomas producing neutralizing mAbs specific to the pandemic influenza virus A/California/07/2009 haemagglutinin (HA) were isolated. These antibodies recognized at least two different but overlapping new epitopes that were conserved in the HA of most Spanish pandemic isolates. However, one of these isolates (A/Extremadura/RR6530/2010) lacked reactivity with the mAbs and carried two unique mutations in the HA head (S88Y and K136N) that were required simultaneously to eliminate reactivity with the murine antibodies. This unusual requirement directly illustrates the phenomenon of enhanced antigenic change proposed previously for the accumulation of simultaneous amino acid substitutions at antigenic sites of the influenza A virus HA during virus evolution (Shih et al., Proc Natl Acad Sci USA, 104 , 6283–6288, 2007). The changes found in the A/Extremadura/RR6530/2010 HA were not found in escape mutants selected in vitro with one of the mAbs, which contained instead nearby single amino acid changes in the HA head. Thus, either single or double point mutations may similarly alter epitopes of the new antigenic site identified in this work in the 2009 H1N1 pandemic virus HA. Moreover, this site is relevant for the human antibody response, as shown by competition of mAbs and human post-infection sera for virus binding. The results are discussed in the context of the HA antigenic structure and challenges posed for identification of sequence changes with possible antigenic impact during virus surveillance.

scholarly journals The importance of antineuraminidase antibodies in resistance to influenza A and immunologic memory for their synthesis

1983 ◽  
Vol 91 (1) ◽  
pp. 131-138 ◽  
Author(s):  
A. N. Naikhin ◽  
I. M. Tsaritsina ◽  
E. V. Oleinikova ◽  
L. G. Syrodoeva ◽  
N. L. Korchanova ◽  
...  
Keyword(s):  
Protective Effect ◽  
Influenza A ◽  
Natural Infection ◽  
Haemagglutination Inhibition ◽  
Surface Antigens ◽  
Antigenic Structure ◽  
Immunologic Memory ◽  
Antibody Synthesis ◽  
Influenza A H1n1 ◽  
Simplified Method

SUMMARYEight hundred and seventy-seven sera from 360 adults aged 18–50 who were under permanent observation from October 1980 to March 1981 have been studied by haemagglutination-inhibition (HI) and erythrocyte elution-inhibition (EI) tests – a simplified method of antineuraminidase antibody titration. It was demonstrated in some subjects infected with influenza A H1N1 and H3N2 viruses that the antibody rise was to one of the surface antigens only – haemagglutinin or neuraminidase. These subjects made up 5·2–25·8% of all examinees. The protective effect of antibodies to neuraminidase was similar to that of antihaemagglutinins. Interaction of both types of antibodies was observed in protection against the disease. Data have been obtained on the influence of antineuraminidase antibodies in decreasing the severity of natural infection with influenza A.A study of heterologous immunologic responses to haemagglutinin and neuraminidase among persons immunized with live influenza A H1N1 and H3N2 vaccines and among children naturally infected with influenza A H3N2 demonstrated the presence of immunologic memory for antineuraminidase antibody synthesis. Thus, the suggestion of a common antigenic structure for neuraminidase Nl and N2 is made.

scholarly journals Location of antigenic sites recognized by monoclonal antibodies in the influenza A virus nucleoprotein molecule

2009 ◽  
Vol 90 (7) ◽  
pp. 1730-1733 ◽  
Author(s):  
Natalia L. Varich ◽  
Konstantin S. Kochergin-Nikitsky ◽  
Evgeny V. Usachev ◽  
Olga V. Usacheva ◽  
Alexei G. Prilipov ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Amino Acid ◽  
Influenza A Virus ◽  
Influenza A ◽  
Antigenic Variation ◽  
Strain Differences ◽  
Antigenic Structure ◽  
Amino Acid Residues ◽  
Mutant Proteins ◽  
Antigenic Sites

The locations of amino acid positions relevant to antigenic variation in the nucleoprotein (NP) of influenza virus are not conclusively known. We analysed the antigenic structure of influenza A virus NP by introducing site-specific mutations at amino acid positions presumed to be relevant for the differentiation of strain differences by anti-NP monoclonal antibodies. Mutant proteins were expressed in a prokaryotic system and analysed by performing ELISA with monoclonal antibodies. Four amino acid residues were found to determine four different antibody-binding sites. When mapped in a 3D X-ray model of NP, the four antigenically relevant amino acid positions were found to be located in separate physical sites of the NP molecule.

scholarly journals Synthesis of alkyl derivatives of 3,7,10-trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane and evaluation of their biological activity

2021 ◽  
Vol 101 (1) ◽  
pp. 19-26
Author(s):  
А.А. Sinitsyna ◽  
◽  
S.G. Il’yasov ◽  
Keyword(s):  
Biological Activity ◽  
Influenza A ◽  
Bacillus Pumilus ◽  
Maximum Yield ◽  
Methyl Derivative ◽  
Tert Butyl ◽  
Alkyl Derivatives ◽  
Derivatives Of ◽  
And Staphylococcus Aureus ◽  
Moderate Yield

Today 3,7,10-trioxo-2,4,6,8,9,11-hexaaaza[3.3.3]propellane (THAP) has not yet received widespread re-search attention due to the complexity of the synthesis. This work is devoted to the development of a method for the THAP derivatives synthesis, as well as to the study of their biological activity in comparison with al-kyl-substituted glycolurils (subject of comparison). ТНАРwas N-alkylated to furnish novel hexaalkyl deriva-tives of ТНАРwith methyl, ethyl and propyl substituents. The conditionsfor obtaining the maximum yield of the target productwere optimizedon the base of methyl derivative. The reaction proceeded in DMSO/КОНat 75–80ºC for 13hours in a moderate yield of 56%. The ethyl and propyl derivatives of ТНАРwere synthe-sized under the same conditions. The biological activity of the obtained ТНАРalkyl derivatives and glycoluril alkyl derivatives was evaluated against Sporosarcina ureae, Bacillus pumilus, Salmonella typhimurium and Staphylococcus aureus bacteria and influenza A virus. All the samples were found to exhib-it antibacterial activity against Staphylococcus aureus.It was shown that 2,4,6,8,9,11-hexapropyl-ТНАР, di-tert-butyl-diphenyl-, di-tert-butyl-dibenzyl-, di-tert-butyl-dimethyl-and di-isopropyl-dibenzylglycoluril, have exhibited also toxicity to living cells besides antiviral activity

scholarly journals Synthesis of Stilbene and Chalcone Inhibitors of Influenza A Virus by SBA-15 Supported Hoveyda-Grubbs Metathesis

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 983 ◽  
Author(s):  
Bruno Mattia Bizzarri ◽  
Angelica Fanelli ◽  
Davide Piccinino ◽  
Marta De Angelis ◽  
Camilla Dolfa ◽  
...  
Keyword(s):  
Biological Activity ◽  
Influenza A Virus ◽  
Influenza A ◽  
Early Stage ◽  
Active Species ◽  
The Novel ◽  
Santa Barbara ◽  
Ring Closing Metathesis ◽  
Experimental Conditions ◽  
Mesoporous Silicate

Stilbene and chalcone derivatives with biological activity against influenza A virus have been synthesized by self-, cross-, and ring-closing metathesis procedures. The reactions were performed under environmentally friendly conditions using the second generation Hoveyda-Grubbs catalyst Aquamet SiPr after immobilization on Santa Barbara Amorphous mesoporous silicate SBA-15. Irrespective from the experimental conditions, the heterogeneous catalyst showed activity and selectivity comparable than the homogeneous counterpart for at least six successive runs without appreciable leaching of the active species. An appreciable antiviral activity against influenza A virus for some of the novel derivatives were observed, mainly involving the early stage of the virus-replication life-cycle.

scholarly journals Encephalopathy During H1N1 Influenza a Virus Infection / Encefalopatija Kod Infekcije Virusom Influence A Podtip H1N1

2016 ◽  
Vol 17 (1) ◽  
pp. 71-75
Author(s):  
Ljiljana Nesic ◽  
Biljana Popovska-Jovicic ◽  
Ivana Rakovic ◽  
Sara Petrovic ◽  
Dusan Todorovic ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Clinical Picture ◽  
Influenza A ◽  
Neurological Diseases ◽  
Epidemiological Data ◽  
H1n1 Influenza ◽  
Antigenic Structure ◽  
Radiographic Examination ◽  
Upper Respiratory Tract ◽  
Reye's Syndrome

Abstract Influenza virus type A is known for its capacity to transform its antigenic structure and create new viral subtypes. The clinical picture varies from non-febrile, mild upper respiratory tract infection to severe or fatal pneumonia. Neurological complications include encephalitis, encephalopathy, Reye’s syndrome and other neurological diseases. Patients with encephalopathy exhibit a disturbed state of consciousness lasting more than 24 hours, and patients with encephalitis exhibit high temperature, focal neurological signs and pathological CSF results in addition to disturbed state of consciousness. A 54-year old, previously healthy male farmer was hospitalized at the Clinic for Infectious Diseases of the Clinical Centre Kragujevac on the fifth day of disease. In addition to general symptoms of the disease, the clinical picture was dominated by a disturbed state of consciousness (Glasgow Coma Scale score <8). The aetiological agent was an H1N1 influenza A virus, which was isolated from nasopharyngeal secretions. No other causes of infection were demonstrated from both serum and cerebrospinal fluid specimens. Interstitial pneumonia was detected by radiographic examination of the chest. There were also some changes present in the EEG. The patient was cured without consequences. Because our country is in a whirlwind of pandemic H1N1 virus activity, we should think of all the possible complications that this virus can produce regardless of the epidemiological data and the clinical picture.

scholarly journals Biophysical and immunological studies on the differential effect of guanidine hydrochloride on type A and type B influenza viruses

1974 ◽  
Vol 72 (1) ◽  
pp. 31-39
Author(s):  
Tam. S. David-West
Keyword(s):  
Biological Activity ◽  
Differential Effect ◽  
Influenza A ◽  
Guanidine Hydrochloride ◽  
Type A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Type B

SUMMARYGuanidine hydrochloride selectively inactivated both the biological activity and the immunogenicity of the haemagglutinin of influenza A/X-7 (H0N2). The residual neuraminidase was fully active biologically and immunologically. The reverse was observed with influenza B/ROB; with this virus the haemagglutinin was resistant, and was immunogenic; while the neuraminidase was selectively inactivated, and was not immunogenic.

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