scholarly journals Monoclonal Antibodies That Distinguish Antigenic Variants of Canine Parvovirus

2003 ◽  
Vol 10 (6) ◽  
pp. 1085-1089 ◽  
Author(s):  
Masato Nakamura ◽  
Kazuya Nakamura ◽  
Takayuki Miyazawa ◽  
Yukinobu Tohya ◽  
Masami Mochizuki ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Antigenic Site ◽  
Canine Parvovirus ◽  
The Other ◽  
Escape Mutants ◽  
Feline Parvovirus ◽  
Resistant Mutants ◽  
Selection Of

ABSTRACT Canine parvovirus (CPV) is classified as a member of the feline parvovirus (FPV) subgroup. CPV isolates are divided into three antigenic types: CPV type 2 (CPV-2), CPV-2a, and CPV-2b. Recently, new antigenic types of CPV were isolated from Vietnamese leopard cats and designated CPV-2c(a) or CPV-2c(b). CPV-2c viruses were distinguished from the other antigenic types of the FPV subgroup by the absence of reactivity with several monoclonal antibodies (MAbs). To characterize the antigenicity of CPV-2c, a panel of MAbs against CPV-2c was generated and epitopes recognized by these MAbs were examined by selection of escape mutants. Four MAbs were established and classified into three groups on the basis of their reactivities: MAbs which recognize CPV-2a, CPV-2b, and CPV-2c (MAbs 2G5 and 20G4); an MAb which reacts with only CPV-2b and CPV-2c(b) (MAb 21C3); and an MAb which recognizes all types of the FPV subgroup viruses (MAb 19D7). The reactivity of MAb 20G4 with CPV-2c was higher than its reactivities with CPV-2a and CPV-2b. These types of specificities of MAbs have not been reported previously. A mapping study by analysis of neutralization-resistant mutants showed that epitopes recognized by MAbs 21C3 and 19D7 belonged to antigenic site A. Substitution of the residues in site B and the other antigenic site influenced the epitope recognized by MAb 2G5. It was suggested that the epitope recognized by MAb 20G4 was related to antigenic site B. These MAbs are expected to be useful for the detection and classification of FPV subgroup isolates.

scholarly journals Occurrence of Canine Parvovirus Type 2c in the United States

2007 ◽  
Vol 19 (5) ◽  
pp. 535-539 ◽  
Author(s):  
Charles Hong ◽  
Nicola Decaro ◽  
Costantina Desario ◽  
Patrick Tanner ◽  
M. Camila Pardo ◽  
...  
Keyword(s):  
United States ◽  
Antigenic Site ◽  
The United States ◽  
Canine Parvovirus ◽  
Single Nucleotide ◽  
Diagnostic Assays ◽  
New Variant ◽  
Taqman Pcr ◽  
Polymerase Chain

Canine parvovirus (CPV) type 2 (CPV-2) emerged around 1978 as a major pathogen of dogs worldwide. In the mid-1980s, the original CPV-2 had evolved and was completely replaced by 2 variants, CPV-2a and CPV-2b. In 2000, a new variant of CPV (named CPV-2c) was detected in Italy and now cocirculates with types 2a and 2b in that country. The CPV-2c has also been reported from single outbreaks in Vietnam and Spain. This study was conducted to determine if CPV-2c occurs in the United States. Thirty-three fecal samples were collected from dogs in 16 states between April 2006 and April 2007 and were tested for CPV using real-time polymerase chain reaction (PCR). Positive samples were further tested using conventional PCR and minor-groove binding TaqMan PCR assays to determine the viral type and to differentiate vaccine strains from field strains. Twenty-seven samples were positive for CPV, 7 of which were CPV-2c from 5 states: Arizona, California, Georgia, Oklahoma, and Texas. Of the 7 isolates, 4 differed from European CPV-2c isolates by 2 additional single-nucleotide mutations at positions 4076 and 4104, the latter of which produces a ThrAla change at residue 440 located near a major antigenic site. The coast-to-coast geographic distribution of the states in which CPV-2c was detected strongly suggests that this new CPV variant is probably widespread in the United States. The continuous evolution of CPV requires that monoclonal antibody-based and nucleic acid-based diagnostic assays should be periodically checked for sensitivity on prevalent CPV strains.

scholarly journals Immunogenetic and structural analysis of a class of HCV broadly neutralizing antibodies and their precursors

2018 ◽  
Vol 115 (29) ◽  
pp. 7569-7574 ◽  
Author(s):  
Fernando Aleman ◽  
Netanel Tzarum ◽  
Leopold Kong ◽  
Kenna Nagy ◽  
Jiang Zhu ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Structural Analysis ◽  
Neutralizing Antibodies ◽  
Antigenic Site ◽  
The Other ◽  
Maturation Process ◽  
Broadly Neutralizing Antibodies ◽  
Vaccine Candidates ◽  
Rational Vaccine Design ◽  
Hairpin Conformation

Elicitation of broadly neutralizing antibodies (bnAbs) is a leading strategy in rational vaccine design against antigenically diverse pathogens. Here, we studied a panel of monoclonal antibodies (mAbs) from mice immunized with the hepatitis C virus (HCV) envelope glycoproteins E1E2. Six of the mAbs recognize the conserved E2 antigenic site 412–423 (AS412) and cross-neutralize diverse HCV genotypes. Immunogenetic and structural analysis revealed that the antibodies originated from two different germline (GL) precursors and bind AS412 in a β-hairpin conformation. Intriguingly, the anti-HCV activity of one antibody lineage is associated with maturation of the light chain (LC), whereas the other lineage is dependent on heavy-chain (HC) maturation. Crystal structures of GL precursors of the LC-dependent lineage in complex with AS412 offer critical insights into the maturation process of bnAbs to HCV, providing a scientific foundation for utilizing the mouse model to study AS412-targeting vaccine candidates.

scholarly journals Molecular characterisation and genetic diversity of canine parvovirus type 2 prevalent in Central China

2020 ◽  
Vol 64 (3) ◽  
pp. 347-354 ◽  
Author(s):  
Wen Hu ◽  
Xin Xu ◽  
Qiang Liu ◽  
Jun Ji ◽  
Yunchao Kan ◽  
...  
Keyword(s):  
Structural Model ◽  
Canine Parvovirus ◽  
Central China ◽  
Clinical Samples ◽  
The Common ◽  
Wild Dogs ◽  
Canine Parvovirus Type 2 ◽  
Reference Strains ◽  
Selection Of

AbstractIntroductionCanine parvovirus (CPV) disease is one of the most threatening to domestic and wild dogs.Material and MethodsA total of 132 clinical samples were isolated from domestic dogs with diarrhoea from Henan, Hubei, Jiangsu, and Anhui provinces from 2016 to 2017, and 56 were positive for CPV-2 by PCR. A phylogenetic tree was constructed for the isolate sequences incorporating 53 non-Chinese reference strains.ResultsVP2 sequences showed the strains mainly to be new CPV-2a/2b and CPV-2c genotypes. The Ala5Gly, Phe267Tyr, Ser297Ala, Tyr324Ile, Gln370Arg, Asn426Asp or Asn426Glu, and Thr440Ala sites in the VP2 protein antigenic region were found to have high mutation rates. The VP2 tertiary structural model shows that the change at these mutation points is a factor for the changes in the protein structure. Significant differences between the Central Chinese strains and others were found, indicating that evolution is geographically related and extended in major regions. The homology between the identified strains confirmed their relationship. Phylogenetic analysis indicated that the common genotypes in the same clusters differ slightly in homology and evolutionary history.ConclusionThis epidemiological study enriches the available data and serves as an important reference for studies on the evolution of CPV and selection of vaccines in China.

scholarly journals Evidence for evolution of canine parvovirus type 2 in Italy

2001 ◽  
Vol 82 (12) ◽  
pp. 3021-3025 ◽  
Author(s):  
Canio Buonavoglia ◽  
Vito Martella ◽  
Annamaria Pratelli ◽  
Maria Tempesta ◽  
Alessandra Cavalli ◽  
...  
Keyword(s):  
Antigenic Site ◽  
Canine Parvovirus ◽  
Antigenic Specificity ◽  
Antigenic Analysis ◽  
Antigenic Variant ◽  
Protein Encoding ◽  
Typing Methods ◽  
Canine Parvovirus Type 2 ◽  
Haemorrhagic Diarrhoea

Two isolates of canine parvovirus (CPV) were obtained from dogs affected with severe haemorrhagic diarrhoea. Type 2b antigenic specificity was predicted by both antigenic analysis with monoclonal antibodies and PCR characterization with type-specific primers. Nevertheless, sequence analysis of the capsid protein-encoding gene revealed two amino acid changes. One of the changes affected position 426 (Asp to Glu), in a major antigenic site of the viral capsid, determining the replacement of a residue unique to CPV type 2b. The failure of established typing methods to distinguish this antigenic variant was overcome by the development of an RFLP assay.

Analisis Kapasitas Galangan Kapal Ikan Untuk Memenuhi Rencana Pengadaan Kapal Ikan Hibah

2019 ◽  
Vol 13 (1) ◽  
pp. 25-36
Author(s):  
Agus Lubis Fitriansyah ◽  
Heri Supomo
Keyword(s):  
Fishing Vessel ◽  
Fishing Vessels ◽  
Score Method ◽  
The Government ◽  
The Right ◽  
Type 3 ◽  
Selection Of

The government through the Ministry of Marine and Fisheries offers assistance of fishing vessel to achieve fisheries production targets. This procurement plan must be supported by the ability and selection of the right shipyard. Beacuse the information of the capability and capacity of fiber shipyards in Indonesia is unclear, so the realization of the procurement of fishing vessel in previous years did not met the planned targets. The purpose of this study was to analyze shipyard capacity to meet the planned procurement of KKP fishing vessels grant in 2019. First classification of fishing vessels is based on the size of each GT, which is 5 GT (type 1), 5-10 GT (type 2), and 20-30 GT (type 3). The second is the minimum shipyard criteria for building fishing boats. Third, an assessment of the shipyard is based on the criteria that have been made. Fourth, shipyard selection was carried out on each WPPN-RI using the load score method. The fifth calculates the number of ships that can be built by the shipyard. The results of the shipyard assessment found that 43% of shipyards have the ability to build type 1 vessels, around 38% of shipyards have the ability to build type 2 vessels, and around 19% of shipyards have the ability to build type 3 vessels. is 1625 units / period. Referring to shipyard capacity, it can be said that the entire shipyard is able to fulfill the plan to procure assistance for KKP fishing vessels in the 2019 budget year.

Intelligent Classifier for Atrial Fibrillation (ECG)

2011 ◽  
pp. 910-916
Author(s):  
O. Valenzuela ◽  
I. Rojas ◽  
F. Rojas ◽  
A. Guillen ◽  
L. J. Herrera ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cardiac Pace ◽  
Heart Beat ◽  
The Other ◽  
Cardiac Diseases ◽  
Electrical Impulses ◽  
Electrocardiogram Ecg ◽  
The Waves ◽  
Selection Of

This chapter is focused on the analysis and classification of arrhythmias. An arrhythmia is any cardiac pace that is not the typical sinusoidal one due to alterations in the formation and/or transportation of the impulses. In pathological conditions, the depolarization process can be initiated outside the sinoatrial (SA) node and several kinds of extra-systolic or ectopic beatings can appear. Besides, electrical impulses can be blocked, accelerated, deviated by alternate trajectories and can change its origin from one heart beat to the other, thus originating several types of blockings and anomalous connections. In both situations, changes in the signal morphology or in the duration of its waves and intervals can be produced on the ECG, as well as a lack of one of the waves. This work is focused on the development of intelligent classifiers in the area of biomedicine, focusing on the problem of diagnosing cardiac diseases based on the electrocardiogram (ECG), or more precisely on the differentiation of the types of atrial fibrillations. First of all we will study the ECG, and the treatment of the ECG in order to work with it, with this specific pathology. In order to achieve this we will study different ways of elimination, in the best possible way, of any activity that is not caused by the auriculars. We will study and imitate the ECG treatment methodologies and the characteristics extracted from the electrocardiograms that were used by the researchers that obtained the best results in the Physionet Challenge, where the classification of ECG recordings according to the type of Atrial Fibrillation (AF) that they showed, was realised. We will extract a great amount of characteristics, partly those used by these researchers and additional characteristics that we consider to be important for the distinction mentioned before. A new method based on evolutionary algorithms will be used to realise a selection of the most relevant characteristics and to obtain a classifier that will be capable of distinguishing the different types of this pathology.

scholarly journals Selection of neutralizing antibody escape mutants with type A influenza virus HA-specific polyclonal antisera: possible significance for antigenic drift

1997 ◽  
Vol 118 (2) ◽  
pp. 149-154 ◽  
Author(s):  
S. M. CLEVELAND ◽  
H. P. TAYLOR ◽  
N. J. DIMMOCK
Keyword(s):  
Haemagglutination Inhibition ◽  
Antigenic Site ◽  
Neutralizing Antibody ◽  
Type A ◽  
Antigenic Drift ◽  
Progeny Virus ◽  
Escape Mutant ◽  
Virus Growth ◽  
Escape Mutants ◽  
Selection Of

Ten antisera were produced in rabbits by two or three intravenous injections of inactivated whole influenza type A virions. All contained haemagglutination-inhibition (HI) antibody directed predominantly to an epitope in antigenic site B and, in addition, various amounts of antibodies to an epitope in site A and in site D. The ability of untreated antisera to select neutralization escape mutants was investigated by incubating virus possessing the homologous haemagglutinin with antiserum adjusted to contain anti-B epitope HI titres of 100, 1000 and 10000 HIU/ml. Virus-antiserum mixtures were inoculated into embryonated hen's eggs, and progeny virus examined without further selection. Forty percent of the antisera at a titre of 1000 HIU/ml selected neutralizing antibody escape mutants as defined by their lack of reactivity to Mab HC10 (site B), and unchanged reactivity to other Mabs to site A and site D epitopes. All escape mutant-selecting antisera had a ratio of anti-site B (HC10)-epitope antibody[ratio ]other antibodies of [ges ]2·0[ratio ]1. The antiserum with the highest ratio (7·4[ratio ]1) selected escape mutants in all eggs tested in four different experiments. No antiserum used at a titre of 10000 HIU/ml allowed multiplication of any virus. All antisera used at a titre of 100 HIU/ml permitted virus growth, but this was wild-type (wt) virus. We conclude that a predominant epitope-specific antibody response, a titre of [ges ]1000 HIU/ml, and a low absolute titre of other antibodies ([les ]500 HIU/ml) are three requirements for the selection of escape mutants. None of the antisera in this study could have selected escape mutants without an appropriate dilution factor, so the occurrence of an escape mutant-selecting antiserum in nature is likely to be a rare event.

scholarly journals Activities of Mutant Prevention Concentration-Targeted Moxifloxacin and Levofloxacin against Streptococcus pneumoniae in an In Vitro Pharmacodynamic Model

2003 ◽  
Vol 47 (8) ◽  
pp. 2606-2614 ◽  
Author(s):  
George P. Allen ◽  
Glenn W. Kaatz ◽  
Michael J. Rybak
Keyword(s):  
Streptococcus Pneumoniae ◽  
Pharmacodynamic Model ◽  
The Other ◽  
Time Curve ◽  
Development Of Resistance ◽  
Concentration Time ◽  
Mutant Prevention Concentration ◽  
Resistant Mutants ◽  
Selection Of

ABSTRACT The differential effects of moxifloxacin and levofloxacin on the development of resistance in four Streptococcus pneumoniae isolates were examined by using an in vitro pharmacodynamic model. Therapeutic regimens (moxifloxacin: peak, 4.5 μg/ml; half-life [t 1/2], 12 h; and levofloxacin: peak, 6 μg/ml; t 1/2, 6 h) were tested against two fluoroquinolone-susceptible isolates (strains 79 and ATCC 49619) and KD2138 and KD2139 (parC and gyrA mutants, respectively, of ATCC 49619). Mutant prevention concentration (MPC)-targeted regimens with modified pharmacokinetics of each drug were simulated to match the area under the concentration-time curve (AUC) above the MPC for the two fluoroquinolones. Moxifloxacin MICs and MPCs (MIC/MPC) for isolates 79, ATCC 49619, KD2138, and KD2139, respectively, were 0.125 and 0.5, 0.125 and 0.5, 0.25 and 8, and 0.25 and 4 μg/ml. Levofloxacin MICs and MPCs for the same isolates were 1 and 4, 0.5 and 2, 1 and 64, and 0.5 and 32 μg/ml, respectively. Therapeutic levofloxacin concentrations led to isolation of mutants of ATCC 49619 (S79Y in ParC), KD2138 (S81Y in GyrA), and KD2139 (S79Y in ParC). Therapeutic moxifloxacin concentrations against the gyrA mutant KD2139 resulted in outgrowth of a mutant with a ParC substitution (S79Y) but caused no emergence of mutants of the other three isolates. MPC-targeted moxifloxacin (lower-than-normal peak = 0.75 to 1.5 μg/ml, administered at levofloxacin's t 1/2) caused growth of a GyrA variant (S81Y) of KD2138 and a ParC variant (S79Y) of KD2139, while no mutants of ATCC 49619 were recovered. MPC-targeted levofloxacin (higher-than-normal peak = 14.5 to 29.5 μg/ml, administered at moxifloxacin's t 1/2) against KD2138 and KD2139 did not prevent the development of the mutations observed in therapeutic regimens, but resistance in the fluoroquinolone-susceptible ATCC 49619 was no longer noted. Normalization of the respective AUC/MPC ratios of moxifloxacin and levofloxacin did not eliminate differences in resistance selectivity of the two agents in all cases. We conclude that the reduced recovery of resistant mutants of S. pneumoniae following moxifloxacin exposure compared to levofloxacin may be due to intrinsic differences between the drugs. Increasing the concentration and exposure (t 1/2) to exceed the MPC may prevent mutations from occurring in fluoroquinolone-susceptible strains. However, this strategy did not prevent the selection of secondary mutants in strains with preexisting mutations. Further study of the MPC concept to evaluate these relationships is warranted.

scholarly journals Evaluation of the Antigenic Relationships among Canine Parvovirus Type 2 Variants

2007 ◽  
Vol 15 (3) ◽  
pp. 534-539 ◽  
Author(s):  
Alessandra Cavalli ◽  
Vito Martella ◽  
Costantina Desario ◽  
Michele Camero ◽  
Anna Lucia Bellacicco ◽  
...  
Keyword(s):  
Vaccine Efficacy ◽  
Hemagglutination Inhibition ◽  
Canine Parvovirus ◽  
Immune Pressure ◽  
Homologous Virus ◽  
Canine Population ◽  
Antigenic Relationships ◽  
Canine Parvovirus Type 2 ◽  
Selection Of

ABSTRACT The antigenic relationships among the original canine parvovirus type 2 (CPV-2) and the variants CPV-2a, -2b, and -2c were evaluated. Cross-antigenic evaluation revealed clear differences among the CPV variants, which were more appreciable by serum neutralization (SN) than by hemagglutination inhibition. Antigenic differences were found mostly between the original CPV-2 and the variants, but they were also observed among the variants CPV-2a, -2b, and -2c. The variant CPV-2c exhibited a unique antigenic pattern, since it was poorly recognized by the sera of animals immunized with CPV-2, CPV-2a, and CPV-2b. However, animals immunized with CPV-2c exhibited higher SN titers to CPV-2b than to the homologous virus CPV-2c. The observed antigenic differences might drive selection of CPV strains by generating differential immune pressure in the canine population, which raises concerns about vaccine efficacy.

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