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Mapping the Binding Site of a Cross-Reactive Plasmodium falciparum PfEMP1 Monoclonal Antibody Inhibitory of ICAM-1 Binding.

Lennartz F, Bengtsson A, Olsen RW, Joergensen L, Brown A, Remy L, Man P, Forest E, Barfod LK, Adams Y, Higgins MK, Jensen AT - J. Immunol. (2015)

Bottom Line: When mapped onto a homology model of DBLβ3_D4, these cluster to a defined, surface-exposed region on the convex surface of DBLβ3_D4.Mutagenesis confirmed that the site most strongly protected is necessary for 24E9 binding, which is consistent with a low-resolution structure of the DBLβ3_D4::24E9 Fab complex derived from small-angle x-ray scattering.The convex surface of DBLβ3_D4 has previously been shown to contain the ICAM-1 binding site of DBLβ domains, suggesting that the mAb acts by occluding the ICAM-1 binding surface.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom;

No MeSH data available.


Related in: MedlinePlus

DC4-expressing P. falciparum IE are recognized by 24E9 mAb and Fab. PFD1235w DBLβ3_D4 mouse anti-sera and 24E9 mAb were tested by flow cytometry on 3D7 DC4+, BM57 DC4+, and 3D7 DC4− parasite lines. 24E9 Fab was tested only on DC4+ 3D7. IE with antisera, 24E9 mAb, or 24E9 Fab are shown in gray, whereas IE without Abs (negative controls) are shown in black.
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fig01: DC4-expressing P. falciparum IE are recognized by 24E9 mAb and Fab. PFD1235w DBLβ3_D4 mouse anti-sera and 24E9 mAb were tested by flow cytometry on 3D7 DC4+, BM57 DC4+, and 3D7 DC4− parasite lines. 24E9 Fab was tested only on DC4+ 3D7. IE with antisera, 24E9 mAb, or 24E9 Fab are shown in gray, whereas IE without Abs (negative controls) are shown in black.

Mentions: We have previously observed that 3D7 PFD1235w DBLβ3_D4 elicits adhesion-inhibitory Abs that are cross-reactive to DC4-containing PfEMP1 from genetically distant parasite isolates (12). To study the specific epitopes targeted by such protective Abs in more detail, we first raised a monoclonal mouse Ab against 3D7 PFD1235w DBLβ3_D4. This mAb, named 24E9, is of IgG1 isotype with κ L chains (data not shown). We tested the reactivity of 24E9 against native PfEMP1 on the surface of IE by flow cytometry. Both 24E9 mAb and Fab fragments generated from this Ab bound to erythrocytes infected with 3D7 parasites expressing DC4-containing PfEMP1 (Fig. 1). In contrast, 24E9 mAb did not recognize DC4− 3D7 IE.


Mapping the Binding Site of a Cross-Reactive Plasmodium falciparum PfEMP1 Monoclonal Antibody Inhibitory of ICAM-1 Binding.

Lennartz F, Bengtsson A, Olsen RW, Joergensen L, Brown A, Remy L, Man P, Forest E, Barfod LK, Adams Y, Higgins MK, Jensen AT - J. Immunol. (2015)

DC4-expressing P. falciparum IE are recognized by 24E9 mAb and Fab. PFD1235w DBLβ3_D4 mouse anti-sera and 24E9 mAb were tested by flow cytometry on 3D7 DC4+, BM57 DC4+, and 3D7 DC4− parasite lines. 24E9 Fab was tested only on DC4+ 3D7. IE with antisera, 24E9 mAb, or 24E9 Fab are shown in gray, whereas IE without Abs (negative controls) are shown in black.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4574524&req=5

fig01: DC4-expressing P. falciparum IE are recognized by 24E9 mAb and Fab. PFD1235w DBLβ3_D4 mouse anti-sera and 24E9 mAb were tested by flow cytometry on 3D7 DC4+, BM57 DC4+, and 3D7 DC4− parasite lines. 24E9 Fab was tested only on DC4+ 3D7. IE with antisera, 24E9 mAb, or 24E9 Fab are shown in gray, whereas IE without Abs (negative controls) are shown in black.
Mentions: We have previously observed that 3D7 PFD1235w DBLβ3_D4 elicits adhesion-inhibitory Abs that are cross-reactive to DC4-containing PfEMP1 from genetically distant parasite isolates (12). To study the specific epitopes targeted by such protective Abs in more detail, we first raised a monoclonal mouse Ab against 3D7 PFD1235w DBLβ3_D4. This mAb, named 24E9, is of IgG1 isotype with κ L chains (data not shown). We tested the reactivity of 24E9 against native PfEMP1 on the surface of IE by flow cytometry. Both 24E9 mAb and Fab fragments generated from this Ab bound to erythrocytes infected with 3D7 parasites expressing DC4-containing PfEMP1 (Fig. 1). In contrast, 24E9 mAb did not recognize DC4− 3D7 IE.

Bottom Line: When mapped onto a homology model of DBLβ3_D4, these cluster to a defined, surface-exposed region on the convex surface of DBLβ3_D4.Mutagenesis confirmed that the site most strongly protected is necessary for 24E9 binding, which is consistent with a low-resolution structure of the DBLβ3_D4::24E9 Fab complex derived from small-angle x-ray scattering.The convex surface of DBLβ3_D4 has previously been shown to contain the ICAM-1 binding site of DBLβ domains, suggesting that the mAb acts by occluding the ICAM-1 binding surface.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom;

No MeSH data available.


Related in: MedlinePlus