LIVIVO - Search results -

Search results

Result 1 - 9 of total 9

Search options

Article ; Online: A new flow cytometry assay to measure antibody-dependent cellular cytotoxicity against SARS-CoV-2 Spike-expressing cells

Guillaume Beaudoin-Bussières / Jonathan Richard / Jérémie Prévost / Guillaume Goyette / Andrés Finzi

STAR Protocols, Vol 2, Iss 4, Pp 100851- (2021)

2021

Abstract: Summary: Antibodies can engage specific receptors at the surface of effector cells and mediate several functions beyond viral neutralization. Increasing evidence suggests that Fc-mediated effector functions, such as antibody-dependent cellular ... ...

Abstract	Summary: Antibodies can engage specific receptors at the surface of effector cells and mediate several functions beyond viral neutralization. Increasing evidence suggests that Fc-mediated effector functions, such as antibody-dependent cellular cytotoxicity (ADCC), have an important role in protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. We engineered a cell line stably expressing a GFP-tagged SARS-CoV-2 spike to measure ADCC. This protocol provides an optimized way of measuring ADCC activity mediated by anti-SARS-CoV-2 Spike monoclonal antibodies or plasma from previously infected or vaccinated individuals.For complete details on the use and execution of this protocol, please refer to Anand et al. (2021b).
Keywords	Immunology ; Microbiology ; Science (General) ; Q1-390
Language	English
Publishing date	2021-12-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Effects of gp120 Inner Domain (ID2) Immunogen Doses on Elicitation of Anti-HIV-1 Functional Fc-Effector Response to C1/C2 (Cluster A) Epitopes in Mice

Rebekah Sherburn / William D. Tolbert / Suneetha Gottumukkala / Guillaume Beaudoin-Bussières / Andrés Finzi / Marzena Pazgier

Microorganisms, Vol 8, Iss 1490, p

2020 Volume 1490

Abstract: Fc-mediated effector functions of antibodies, including antibody-dependent cytotoxicity (ADCC), have been shown to contribute to vaccine-induced protection from HIV-1 infection, especially those directed against non-neutralizing, CD4 inducible (CD4i) ... ...

Abstract	Fc-mediated effector functions of antibodies, including antibody-dependent cytotoxicity (ADCC), have been shown to contribute to vaccine-induced protection from HIV-1 infection, especially those directed against non-neutralizing, CD4 inducible (CD4i) epitopes within the gp120 constant 1 and 2 regions (C1/C2 or Cluster A epitopes). However, recent passive immunization studies have not been able to definitively confirm roles for these antibodies in HIV-1 prevention mostly due to the complications of cross-species Fc–FcR interactions and suboptimal dosing strategies. Here, we use our stabilized gp120 Inner domain (ID2) immunogen that displays the Cluster A epitopes within a minimal structural unit of HIV-1 Env to investigate an immunization protocol that induces a fine-tuned antibody repertoire capable of an effective Fc-effector response. This includes the generation of isotypes and the enhanced antibody specificity known to be vital for maximal Fc-effector activities, while minimizing the induction of isotypes know to be detrimental for these functions. Although our studies were done in in BALB/c mice we conclude that when optimally titrated for the species of interest, ID2 with GLA-SE adjuvant will elicit high titers of antibodies targeting the Cluster A region with potent Fc-mediated effector functions, making it a valuable immunogen candidate for testing an exclusive role of non-neutralizing antibody response in HIV-1 protection in vaccine settings.
Keywords	HIV-1 ; ADCC ; inner domain (ID2) immunogen ; non-neutralizing antibody response ; dosing ; fc-mediated effector functions ; Biology (General) ; QH301-705.5
Subject code	570
Language	English
Publishing date	2020-09-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Elicitation of Cluster A and Co-Receptor Binding Site Antibodies are Required to Eliminate HIV-1 Infected Cells

Guillaume Beaudoin-Bussières / Jérémie Prévost / Gabrielle Gendron-Lepage / Bruno Melillo / Junhua Chen / Amos B. Smith III / Marzena Pazgier / Andrés Finzi

Microorganisms, Vol 8, Iss 710, p

2020 Volume 710

Abstract: HIV-1-infected individuals raise a polyclonal antibody response targeting multiple envelope glycoprotein (Env) epitopes. Interestingly, two classes of non-neutralizing CD4-induced (CD4i) antibodies, present in the majority of HIV-1-infected individuals ... ...

Abstract	HIV-1-infected individuals raise a polyclonal antibody response targeting multiple envelope glycoprotein (Env) epitopes. Interestingly, two classes of non-neutralizing CD4-induced (CD4i) antibodies, present in the majority of HIV-1-infected individuals have been described to mediate antibody-dependent cellular cytotoxicity (ADCC) in the presence of small CD4 mimetic compounds (CD4mc). These antibodies recognize the coreceptor binding site (CoRBS) and the constant region one and two (C1C2 or inner domain cluster A) of the gp120. In combination with CD4mc they have been shown to stabilize an antibody-vulnerable Env conformation, known as State 2A. Here we evaluated the importance of these two families of Abs in ADCC responses by immunizing guinea pigs with gp120 immunogens that have been modified to elicit or not these types of antibodies. Underlying the importance of anti-CoRBS and anti-cluster A Abs in stabilizing State 2A, ADCC responses were only observed in the presence of these two types of CD4i antibodies. Altogether, our results suggest that these two families of CD4i antibodies must be taken into account when considering future strategies relying on the use of CD4mc to eliminate HIV-1-infected cells in vivo.
Keywords	HIV-1 ; ADCC ; cluster A ; coreceptor binding site ; guinea pigs ; small CD4 mimetics ; Biology (General) ; QH301-705.5
Subject code	570
Language	English
Publishing date	2020-05-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Interaction of Human ACE2 to Membrane-Bound SARS-CoV-1 and SARS-CoV-2 S Glycoproteins

Sai Priya Anand / Yaozong Chen / Jérémie Prévost / Romain Gasser / Guillaume Beaudoin-Bussières / Cameron F. Abrams / Marzena Pazgier / Andrés Finzi

Viruses, Vol 12, Iss 1104, p

2020 Volume 1104

Abstract: Severe acute respiratory syndrome virus 2 (SARS-CoV-2) is responsible for the current global coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The viral entry of SARS-CoV-2 depends on ... ...

Abstract	Severe acute respiratory syndrome virus 2 (SARS-CoV-2) is responsible for the current global coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The viral entry of SARS-CoV-2 depends on an interaction between the receptor-binding domain of its trimeric spike glycoprotein and the human angiotensin-converting enzyme 2 (ACE2) receptor. A better understanding of the spike/ACE2 interaction is still required to design anti-SARS-CoV-2 therapeutics. Here, we investigated the degree of cooperativity of ACE2 within both the SARS-CoV-2 and the closely related SARS-CoV-1 membrane-bound S glycoproteins. We show that there exist differential inter-protomer conformational transitions between both spike trimers. Interestingly, the SARS-CoV-2 spike exhibits a positive cooperativity for monomeric soluble ACE2 binding when compared to the SARS-CoV-1 spike, which might have more structural restraints. Our findings can be of importance in the development of therapeutics that block the spike/ACE2 interaction.
Keywords	Coronavirus ; SARS-CoV-1 ; SARS-CoV-2 ; spike glycoproteins ; human ACE2 receptor ; ACE2-Fc ; Microbiology ; QR1-502 ; covid19
Subject code	612
Language	English
Publishing date	2020-09-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Incorporating the Cluster A and V1V2 Targets into a Minimal Structural Unit of the HIV-1 Envelope to Elicit a Cross-Clade Response with Potent Fc-Effector Functions

Rebekah Sherburn / William D. Tolbert / Suneetha Gottumukkala / Andrew P. Hederman / Guillaume Beaudoin-Bussières / Sherry Stanfield-Oakley / Marina Tuyishime / Guido Ferrari / Andrés Finzi / Margaret E. Ackerman / Marzena Pazgier

Vaccines, Vol 9, Iss 975, p

2021 Volume 975

Abstract: The generation of a potent vaccine for the prevention and/or control of HIV-1 has been unsuccessful to date, despite decades of research. Existing evidence from both infected individuals and clinical trials support a role for non-neutralizing or weakly ... ...

Abstract	The generation of a potent vaccine for the prevention and/or control of HIV-1 has been unsuccessful to date, despite decades of research. Existing evidence from both infected individuals and clinical trials support a role for non-neutralizing or weakly neutralizing antibodies with potent Fc-effector functions in the prevention and control of HIV-1 infection. Vaccination strategies that induce such antibodies have proven partially successful in preventing HIV-1 infection. This is largely thought to be due to the polyclonal response that is induced in a vaccine setting, as opposed to the infusion of a single therapeutic antibody, which is capable of diverse Fc-effector functions and targets multiple but highly conserved epitopes. Here, we build on the success of our inner domain antigen, ID2, which incorporates conformational CD4-inducible (CD4i) epitopes of constant region 1 and 2 (C1C2 or Cluster A), in the absence of neutralizing antibody epitopes, into a minimal structural unit of gp120. ID2 has been shown to induce Cluster A-specific antibodies in a BALB/c mouse model with Fc-effector functions against CD4i targets. In order to generate an immunogen that incorporates both epitope targets implicated in the protective Fc-effector functions of antibodies from the only partially successful human vaccine trial, RV144, we incorporated the V1V2 domain into our ID2 antigen generating ID2-V1V2, which we used to immunize in combination with ID2. Immunized BALB/c mice generated both Cluster A- and V1V2-specific antibodies, which synergized to significantly improve the Fc-mediated effector functions compared to mice immunized with ID2 alone. The sera were able to mediate both antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). We therefore conclude that ID2-V1V2 + ID2 represents a promising vaccine immunogen candidate for the induction of antibodies with optimal Fc-mediated effector functions against HIV-1.
Keywords	HIV-1 ; ID2 ; ID2-V1V2 ; ADCC ; ADCP ; Fc-effector functions ; Medicine ; R
Subject code	570
Language	English
Publishing date	2021-08-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Antibody Binding to SARS-CoV-2 S Glycoprotein Correlates with but Does Not Predict Neutralization

Shilei Ding / Annemarie Laumaea / Mehdi Benlarbi / Guillaume Beaudoin-Bussières / Romain Gasser / Halima Medjahed / Marie Pancera / Leonidas Stamatatos / Andrew T. McGuire / Renée Bazin / Andrés Finzi

Viruses, Vol 12, Iss 1214, p

2020 Volume 1214

Abstract: Convalescent plasma from SARS-CoV-2 infected individuals and monoclonal antibodies were shown to potently neutralize viral and pseudoviral particles carrying the S glycoprotein. However, a non-negligent proportion of plasma samples from infected ... ...

Abstract	Convalescent plasma from SARS-CoV-2 infected individuals and monoclonal antibodies were shown to potently neutralize viral and pseudoviral particles carrying the S glycoprotein. However, a non-negligent proportion of plasma samples from infected individuals, as well as S-specific monoclonal antibodies, were reported to be non-neutralizing despite efficient interaction with the S glycoprotein in different biochemical assays using soluble recombinant forms of S or when expressed at the cell surface. How neutralization relates to the binding of S glycoprotein in the context of viral particles remains to be established. Here, we developed a pseudovirus capture assay (VCA) to measure the capacity of plasma samples or antibodies immobilized on ELISA plates to bind to membrane-bound S glycoproteins from SARS-CoV-2 expressed at the surface of lentiviral particles. By performing VCA, ELISA, and neutralization assays, we observed a strong correlation between these parameters. However, while we found that plasma samples unable to capture viral particles did not neutralize, capture did not guarantee neutralization, indicating that the capacity of antibodies to bind to the S glycoprotein at the surface of pseudoviral particles is required but not sufficient to mediate neutralization. Altogether, our results highlight the importance of better understanding the inactivation of S by plasma and neutralizing antibodies.
Keywords	COVID-19 ; SARS-COV-2 ; convalescent plasma ; ELISA ; neutralization ; virus capture assay ; Microbiology ; QR1-502 ; covid19
Subject code	500 ; 570
Language	English
Publishing date	2020-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Humoral immune responses against SARS-CoV-2 Spike variants after mRNA vaccination in solid organ transplant recipients

iScience, Vol 25, Iss 9, Pp 104990- (2022)

2022

Abstract: Summary: Although SARS-CoV-2 mRNA vaccination has been shown to be safe and effective in the general population, immunocompromised solid organ transplant recipients (SOTRs) were reported to have impaired immune responses after one or two doses of vaccine. ...

Abstract	Summary: Although SARS-CoV-2 mRNA vaccination has been shown to be safe and effective in the general population, immunocompromised solid organ transplant recipients (SOTRs) were reported to have impaired immune responses after one or two doses of vaccine. In this study, we examined humoral responses induced after the second and the third dose of mRNA vaccine in different SOTR (kidney, liver, lung, and heart). Compared to a cohort of SARS-CoV-2 naïve immunocompetent health care workers (HCWs), the second dose induced weak humoral responses in SOTRs, except for the liver recipients. The third dose boosted these responses but they did not reach the same level as in HCW. Interestingly, although the neutralizing activity against Delta and Omicron variants remained very low after the third dose, Fc-mediated effector functions in SOTR reached similar levels as in the HCW cohort. Whether these responses will suffice to protect SOTR from severe outcome remains to be determined.
Keywords	Surgery ; Immunology ; Virology ; Science ; Q
Subject code	610
Language	English
Publishing date	2022-09-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Longitudinal analysis of humoral immunity against SARS-CoV-2 Spike in convalescent individuals up to 8 months post-symptom onset

Sai Priya Anand / Jérémie Prévost / Manon Nayrac / Guillaume Beaudoin-Bussières / Mehdi Benlarbi / Romain Gasser / Nathalie Brassard / Annemarie Laumaea / Shang Yu Gong / Catherine Bourassa / Elsa Brunet-Ratnasingham / Halima Medjahed / Gabrielle Gendron-Lepage / Guillaume Goyette / Laurie Gokool / Chantal Morrisseau / Philippe Bégin / Valérie Martel-Laferrière / Cécile Tremblay /

Jonathan Richard / Renée Bazin / Ralf Duerr / Daniel E. Kaufmann / Andrés Finzi

Cell Reports Medicine, Vol 2, Iss 6, Pp 100290- (2021)

2021

Abstract: Summary: With the recent approval of highly effective coronavirus disease 2019 (COVID-19) vaccines, functional and lasting immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently under investigation as antibody levels in ... ...

Abstract	Summary: With the recent approval of highly effective coronavirus disease 2019 (COVID-19) vaccines, functional and lasting immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently under investigation as antibody levels in plasma were shown to decline during convalescence. Since the absence of antibodies does not equate to absence of immune memory, we evaluate the presence of SARS-CoV-2-specific memory B cells in convalescent individuals. Here, we report a longitudinal assessment of humoral immune responses on 32 donors up to 8 months post-symptom onset. Our observations indicate that anti-Spike and anti-receptor binding domain (RBD) immunoglobulin M (IgM) in plasma decay rapidly, whereas the reduction of IgG is less prominent. Neutralizing activity also declines rapidly when compared to Fc-effector functions. Concomitantly, the frequencies of RBD-specific IgM+ B cells wane significantly when compared to RBD-specific IgG+ B cells, which remain stable. Our results add to the current understanding of immune memory following SARS-CoV-2 infection, which is critical for secondary infection prevention and vaccine efficacy.
Keywords	coronavirus ; COVID-19 ; SARS-CoV-2 ; Spike glycoproteins ; RBD ; antibodies ; Medicine (General) ; R5-920
Language	English
Publishing date	2021-06-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Cross-Sectional Evaluation of Humoral Responses against SARS-CoV-2 Spike

Jérémie Prévost / Romain Gasser / Guillaume Beaudoin-Bussières / Jonathan Richard / Ralf Duerr / Annemarie Laumaea / Sai Priya Anand / Guillaume Goyette / Mehdi Benlarbi / Shilei Ding / Halima Medjahed / Antoine Lewin / Josée Perreault / Tony Tremblay / Gabrielle Gendron-Lepage / Nicolas Gauthier / Marc Carrier / Diane Marcoux / Alain Piché /

Myriam Lavoie / Alexandre Benoit / Vilayvong Loungnarath / Gino Brochu / Elie Haddad / Hannah D. Stacey / Matthew S. Miller / Marc Desforges / Pierre J. Talbot / Graham T. Gould Maule / Marceline Côté / Christian Therrien / Bouchra Serhir / Renée Bazin / Michel Roger / Andrés Finzi

Cell Reports Medicine, Vol 1, Iss 7, Pp 100126- (2020)

2020

Abstract: Summary: SARS-CoV-2 is responsible for the coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The Spike glycoproteins of SARS-CoV-2 mediate viral entry and are the main targets for ... ...

Abstract	Summary: SARS-CoV-2 is responsible for the coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The Spike glycoproteins of SARS-CoV-2 mediate viral entry and are the main targets for neutralizing antibodies. Understanding the antibody response directed against SARS-CoV-2 is crucial for the development of vaccine, therapeutic, and public health interventions. Here, we perform a cross-sectional study on 106 SARS-CoV-2-infected individuals to evaluate humoral responses against SARS-CoV-2 Spike. Most infected individuals elicit anti-Spike antibodies within 2 weeks of the onset of symptoms. The levels of receptor binding domain (RBD)-specific immunoglobulin G (IgG) persist over time, and the levels of anti-RBD IgM decrease after symptom resolution. Although most individuals develop neutralizing antibodies within 2 weeks of infection, the level of neutralizing activity is significantly decreased over time. Our results highlight the importance of studying the persistence of neutralizing activity upon natural SARS-CoV-2 infection.
Keywords	coronavirus ; COVID-19 ; SARS-CoV-2 ; Spike glycoproteins ; RBD ; IgM ; Medicine (General) ; R5-920
Language	English
Publishing date	2020-10-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED