Publications by authors named "Fabrizio Biuso"

4 Publications

  • Page 1 of 1

Serologically-Based Evaluation of Cross-Protection Antibody Responses among Different A(H1N1) Influenza Strains.

Vaccines (Basel) 2020 Nov 5;8(4). Epub 2020 Nov 5.

Department of Molecular and Developmental Medicine, University of Siena, 53100 Siena, Italy.

After the influenza H1N1 pandemic of 2009, the seasonal A/Brisbane/59/2007 strain was replaced by the A/California/07/2009 strain for the influenza virus vaccine composition. After several seasons with no indications on the occurrence of antigenic drift, A/Michigan/45/2015 was chosen as the H1N1 vaccine strain for the 2017/2018 season. Since the immune response to influenza is shaped by the history of exposure to antigenically similar strains, the potential cross-protection between seasonal human influenza vaccine strains and the emerging pandemic strains was investigated. Human serum samples were tested by hemagglutination inhibition and single radial hemolysis assays against A/Brisbane/59/2007, A/California/07/2009, and A/Michigan/45/2015 strains. Strong cross-reactions between A/California/07/2009 and A/Michigan/45/2015 strains were observed in 2009/2010, most likely induced by the start of the 2009 pandemic, and the subsequent post-pandemic seasons from 2010/2011 onward when A/California/07/2009 became the predominant strain. In the 2014/2015 season, population immunity against A/California/07/2009 and A/Michigan/45/2015 strains increased again, associated with strong cross-reactions. Whereas hemagglutination inhibition assay has a higher sensitivity for detection of new seasonal drift, the single radial hemolysis assay is an excellent tool for determining the presence of pre-existing immunity, allowing a potential prediction on the booster potential of influenza vaccines against newly emerging drifted strains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/vaccines8040656DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7712556PMC
November 2020

Influenza D Virus: Serological Evidence in the Italian Population from 2005 to 2017.

Viruses 2019 12 27;12(1). Epub 2019 Dec 27.

Department of Molecular and Developmental Medicine, University of Siena, Via Aldo Moro, 53100 Siena, Italy.

Influenza D virus is a novel influenza virus, which was first isolated from an ailing swine in 2011 and later detected in cattle, suggesting that these animals may be a primary natural reservoir. To date, few studies have been performed on human samples and there is no conclusive evidence on the ability of the virus to infect humans. The aim of this serological study was to assess the prevalence of antibodies against influenza D virus in human serum samples collected in Italy from 2005 to 2017. Serum samples were analysed by haemagglutination inhibition and virus neutralization assays. The results showed that the prevalence of antibodies against the virus increased in the human population in Italy from 2005 to 2017, with a trend characterized by a sharp increase in some years, followed by a decline in subsequent years. The virus showed the ability to infect and elicit an immune response in humans. However, prevalence peaks in humans appear to follow epidemics in animals and not to persist in the human population.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/v12010030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019439PMC
December 2019

Use of lentiviral pseudotypes as an alternative to reassortant or Triton X-100-treated wild-type Influenza viruses in the neuraminidase inhibition enzyme-linked lectin assay.

Influenza Other Respir Viruses 2019 09;13(5):504-516

VisMederi s.r.l., Strada del Petriccio e Belriguardo, Siena, Italy.

Background: Formulation of neuraminidase (NA) within influenza vaccines is gaining importance in light of recent human studies. The enzyme-linked lectin assay (ELLA) is considered a reliable assay to evaluate human anti-NA antibodies.

Objectives: To overcome interference by hemagglutinin (HA)-specific antibodies and detect neuraminidase inhibitory (NI) antibodies only, two different sources of antigen have been studied in ELLA: reassortant viruses with a mismatched avian origin-HA or Triton X-100 (Tx)-treated wild-type viruses. Pseudotypes or pseudovirus (PV), characterized by a lentivirus core bearing human influenza NA and avian influenza HA, were investigated as an alternative source of antigen and compared to HA-mismatched and Tx-treated viruses, since represent a safer product to be handled.

Methods: Two independent panels of sera were analyzed by ELLA to evaluate the anti-NA response against N1 (A/California/07/2009 (H1N1pdm)) and N2 (A/Hong Kong/4801/2014 (H3N2)). The NA inhibition (NI) antibody titers measured as either the 50% end point or 50% inhibitory concentration (IC ) were compared for every source of antigen.

Results: The ELLA assay performed well with all three sources of antigen. NI titers measured using each antigen type correlated well when reported either as end point titers or as the IC .

Conclusions: This study suggests that HA-mismatched whole virus, Triton-treated wild-type virus or PV can be used to measure NI antibody titers of human sera, but further comparability/validation assays should be performed to assess statistical differences. The data support the use of PV as an attractive alternative source of antigen and justify further investigation to improve stability of this antigen source.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/irv.12669DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6692537PMC
September 2019

H1N1 viral proteome peptide microarray predicts individuals at risk for H1N1 infection and segregates infection versus Pandemrix(®) vaccination.

Immunology 2015 Jul 15;145(3):357-66. Epub 2015 Apr 15.

Therapeutic Immunology Unit, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.

A high content peptide microarray containing the entire influenza A virus [A/California/08/2009(H1N1)] proteome and haemagglutinin proteins from 12 other influenza A subtypes, including the haemagglutinin from the [A/South Carolina/1/1918(H1N1)] strain, was used to gauge serum IgG epitope signatures before and after Pandemrix(®) vaccination or H1N1 infection in a Swedish cohort during the pandemic influenza season 2009. A very narrow pattern of pandemic flu-specific IgG epitope recognition was observed in the serum from individuals who later contracted H1N1 infection. Moreover, the pandemic influenza infection generated IgG reactivity to two adjacent epitopes of the neuraminidase protein. The differential serum IgG recognition was focused on haemagglutinin 1 (H1) and restricted to classical antigenic sites (Cb) in both the vaccinated controls and individuals with flu infections. We further identified a novel epitope VEPGDKITFEATGNL on the Ca antigenic site (251-265) of the pandemic flu haemagglutinin, which was exclusively recognized in serum from individuals with previous vaccinations and never in serum from individuals with H1N1 infection (confirmed by RNA PCR analysis from nasal swabs). This epitope was mapped to the receptor-binding domain of the influenza haemagglutinin and could serve as a correlate of immune protection in the context of pandemic flu. The study shows that unbiased epitope mapping using peptide microarray technology leads to the identification of biologically and clinically relevant target structures. Most significantly an H1N1 infection induced a different footprint of IgG epitope recognition patterns compared with the pandemic H1N1 vaccine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/imm.12448DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4479535PMC
July 2015