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Immunogenicity of the Plasmodium falciparum PfEMP1-VarO Adhesin: Induction of Surface-Reactive and Rosette-Disrupting Antibodies to VarO Infected Erythrocytes.

Guillotte M, Juillerat A, Igonet S, Hessel A, Petres S, Crublet E, Le Scanf C, Lewit-Bentley A, Bentley GA, Vigan-Womas I, Mercereau-Puijalon O - PLoS ONE (2015)

Bottom Line: High levels of rosette-disrupting and rosette-preventing antibodies are induced by DBL1 and the Head domain.Reduced-alkylated or denatured proteins fail to induce surface-reacting and rosette-disrupting antibodies, indicating that surface epitopes are conformational.These results highlight the high immunogenicity of the individual domains in outbred animals and provide a strong basis for a rational vaccination strategy targeting rosetting.

View Article: PubMed Central - PubMed

Affiliation: Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, Paris, France; Centre National de la Recherche Scientifique, Unité de recherche associée 2581, Paris, France.

ABSTRACT
Adhesion of Plasmodium falciparum-infected red blood cells (iRBC) to human erythrocytes (i.e. rosetting) is associated with severe malaria. Rosetting results from interactions between a subset of variant PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1) adhesins and specific erythrocyte receptors. Interfering with such interactions is considered a promising intervention against severe malaria. To evaluate the feasibility of a vaccine strategy targetting rosetting, we have used here the Palo Alto 89F5 VarO rosetting model. PfEMP1-VarO consists of five Duffy-Binding Like domains (DBL1-5) and one Cysteine-rich Interdomain Region (CIDR1). The binding domain has been mapped to DBL1 and the ABO blood group was identified as the erythrocyte receptor. Here, we study the immunogenicity of all six recombinant PfEMP1-VarO domains and the DBL1- CIDR1 Head domain in BALB/c and outbred OF1 mice. Five readouts of antibody responses are explored: ELISA titres on the recombinant antigen, VarO-iRBC immunoblot reactivity, VarO-iRBC surface-reactivity, capacity to disrupt VarO rosettes and the capacity to prevent VarO rosette formation. For three domains, we explore influence of the expression system on antigenicity and immunogenicity. We show that correctly folded PfEMP1 domains elicit high antibody titres and induce a homogeneous response in outbred and BALB/c mice after three injections. High levels of rosette-disrupting and rosette-preventing antibodies are induced by DBL1 and the Head domain. Reduced-alkylated or denatured proteins fail to induce surface-reacting and rosette-disrupting antibodies, indicating that surface epitopes are conformational. We also report limited cross-reactivity between some PfEMP1 VarO domains. These results highlight the high immunogenicity of the individual domains in outbred animals and provide a strong basis for a rational vaccination strategy targeting rosetting.

No MeSH data available.


Related in: MedlinePlus

Surface reactivity and functionality of antibodies elicited by PfEMP1-Var0 derived recombinant constructs.Surface immunofluorescence of the monovariant Palo Alto 89F5 VarO parasites with sera raised to the recombinant domains and analysed by FACS. (A) Representative profiles of BALB/c and OF1 mice immunised with bDBL2. (B) Representative profiles of animals immunised with different DBL1 constructs as indicated. (C) Representative profiles of mice immunised with CIDR constructs as indicated. (D) Comparative profiles of pools of sera from mice immunised with PfEMP1-VarO derived domains as indicated. (E) Disruption capacity of Palo Alto VarO rosettes (see Materials and Methods for details). Left panel: sera from animals (at a 1/20 dilution) immunised with PfEMP1-VarO derived domains as indicated were tested for their capacity to disrupt rosettes; right panel: titration curves of the rosette-disrupting capacity of mouse sera raised to eDBL1 or bDBL1 as indicated.
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pone.0134292.g005: Surface reactivity and functionality of antibodies elicited by PfEMP1-Var0 derived recombinant constructs.Surface immunofluorescence of the monovariant Palo Alto 89F5 VarO parasites with sera raised to the recombinant domains and analysed by FACS. (A) Representative profiles of BALB/c and OF1 mice immunised with bDBL2. (B) Representative profiles of animals immunised with different DBL1 constructs as indicated. (C) Representative profiles of mice immunised with CIDR constructs as indicated. (D) Comparative profiles of pools of sera from mice immunised with PfEMP1-VarO derived domains as indicated. (E) Disruption capacity of Palo Alto VarO rosettes (see Materials and Methods for details). Left panel: sera from animals (at a 1/20 dilution) immunised with PfEMP1-VarO derived domains as indicated were tested for their capacity to disrupt rosettes; right panel: titration curves of the rosette-disrupting capacity of mouse sera raised to eDBL1 or bDBL1 as indicated.

Mentions: All animals produced surface-reacting antibodies (examples are shown Fig 5A and 5B). Overall, 13/15 outbred animals immunised with bDBL1 had potent rosette-inhibiting and—disrupting antibodies (Fig 5E shows one example; see also S1 Fig). Rosette disruption was marginal with the anti bDBL2 sera (idem Fig 5E; Table 2).


Immunogenicity of the Plasmodium falciparum PfEMP1-VarO Adhesin: Induction of Surface-Reactive and Rosette-Disrupting Antibodies to VarO Infected Erythrocytes.

Guillotte M, Juillerat A, Igonet S, Hessel A, Petres S, Crublet E, Le Scanf C, Lewit-Bentley A, Bentley GA, Vigan-Womas I, Mercereau-Puijalon O - PLoS ONE (2015)

Surface reactivity and functionality of antibodies elicited by PfEMP1-Var0 derived recombinant constructs.Surface immunofluorescence of the monovariant Palo Alto 89F5 VarO parasites with sera raised to the recombinant domains and analysed by FACS. (A) Representative profiles of BALB/c and OF1 mice immunised with bDBL2. (B) Representative profiles of animals immunised with different DBL1 constructs as indicated. (C) Representative profiles of mice immunised with CIDR constructs as indicated. (D) Comparative profiles of pools of sera from mice immunised with PfEMP1-VarO derived domains as indicated. (E) Disruption capacity of Palo Alto VarO rosettes (see Materials and Methods for details). Left panel: sera from animals (at a 1/20 dilution) immunised with PfEMP1-VarO derived domains as indicated were tested for their capacity to disrupt rosettes; right panel: titration curves of the rosette-disrupting capacity of mouse sera raised to eDBL1 or bDBL1 as indicated.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519321&req=5

pone.0134292.g005: Surface reactivity and functionality of antibodies elicited by PfEMP1-Var0 derived recombinant constructs.Surface immunofluorescence of the monovariant Palo Alto 89F5 VarO parasites with sera raised to the recombinant domains and analysed by FACS. (A) Representative profiles of BALB/c and OF1 mice immunised with bDBL2. (B) Representative profiles of animals immunised with different DBL1 constructs as indicated. (C) Representative profiles of mice immunised with CIDR constructs as indicated. (D) Comparative profiles of pools of sera from mice immunised with PfEMP1-VarO derived domains as indicated. (E) Disruption capacity of Palo Alto VarO rosettes (see Materials and Methods for details). Left panel: sera from animals (at a 1/20 dilution) immunised with PfEMP1-VarO derived domains as indicated were tested for their capacity to disrupt rosettes; right panel: titration curves of the rosette-disrupting capacity of mouse sera raised to eDBL1 or bDBL1 as indicated.
Mentions: All animals produced surface-reacting antibodies (examples are shown Fig 5A and 5B). Overall, 13/15 outbred animals immunised with bDBL1 had potent rosette-inhibiting and—disrupting antibodies (Fig 5E shows one example; see also S1 Fig). Rosette disruption was marginal with the anti bDBL2 sera (idem Fig 5E; Table 2).

Bottom Line: High levels of rosette-disrupting and rosette-preventing antibodies are induced by DBL1 and the Head domain.Reduced-alkylated or denatured proteins fail to induce surface-reacting and rosette-disrupting antibodies, indicating that surface epitopes are conformational.These results highlight the high immunogenicity of the individual domains in outbred animals and provide a strong basis for a rational vaccination strategy targeting rosetting.

View Article: PubMed Central - PubMed

Affiliation: Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, Paris, France; Centre National de la Recherche Scientifique, Unité de recherche associée 2581, Paris, France.

ABSTRACT
Adhesion of Plasmodium falciparum-infected red blood cells (iRBC) to human erythrocytes (i.e. rosetting) is associated with severe malaria. Rosetting results from interactions between a subset of variant PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1) adhesins and specific erythrocyte receptors. Interfering with such interactions is considered a promising intervention against severe malaria. To evaluate the feasibility of a vaccine strategy targetting rosetting, we have used here the Palo Alto 89F5 VarO rosetting model. PfEMP1-VarO consists of five Duffy-Binding Like domains (DBL1-5) and one Cysteine-rich Interdomain Region (CIDR1). The binding domain has been mapped to DBL1 and the ABO blood group was identified as the erythrocyte receptor. Here, we study the immunogenicity of all six recombinant PfEMP1-VarO domains and the DBL1- CIDR1 Head domain in BALB/c and outbred OF1 mice. Five readouts of antibody responses are explored: ELISA titres on the recombinant antigen, VarO-iRBC immunoblot reactivity, VarO-iRBC surface-reactivity, capacity to disrupt VarO rosettes and the capacity to prevent VarO rosette formation. For three domains, we explore influence of the expression system on antigenicity and immunogenicity. We show that correctly folded PfEMP1 domains elicit high antibody titres and induce a homogeneous response in outbred and BALB/c mice after three injections. High levels of rosette-disrupting and rosette-preventing antibodies are induced by DBL1 and the Head domain. Reduced-alkylated or denatured proteins fail to induce surface-reacting and rosette-disrupting antibodies, indicating that surface epitopes are conformational. We also report limited cross-reactivity between some PfEMP1 VarO domains. These results highlight the high immunogenicity of the individual domains in outbred animals and provide a strong basis for a rational vaccination strategy targeting rosetting.

No MeSH data available.


Related in: MedlinePlus