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Protective mAbs and Cross-Reactive mAbs Raised by Immunization with Engineered Marburg Virus GPs.

Fusco ML, Hashiguchi T, Cassan R, Biggins JE, Murin CD, Warfield KL, Li S, Holtsberg FW, Shulenin S, Vu H, Olinger GG, Kim do H, Whaley KJ, Zeitlin L, Ward AB, Nykiforuk C, Aman MJ, Berry JD, Berry J, Saphire EO - PLoS Pathog. (2015)

Bottom Line: Antibodies against the filovirus surface glycoprotein (GP) have been shown to provide life-saving therapy in nonhuman primates, but such antibodies are generally virus-specific.Surprisingly, two of the mAbs raised against MARV GP also cross-react with the mucin-deleted GP cores of all tested ebolaviruses (Ebola, Sudan, Bundibugyo, Reston), but these epitopes are masked differently by the mucin-like domains themselves.The most efficacious mAbs in this panel were found to recognize a novel "wing" feature on the GP2 subunit that is unique to Marburg and does not exist in Ebola.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America.

ABSTRACT
The filoviruses, which include the marburg- and ebolaviruses, have caused multiple outbreaks among humans this decade. Antibodies against the filovirus surface glycoprotein (GP) have been shown to provide life-saving therapy in nonhuman primates, but such antibodies are generally virus-specific. Many monoclonal antibodies (mAbs) have been described against Ebola virus. In contrast, relatively few have been described against Marburg virus. Here we present ten mAbs elicited by immunization of mice using recombinant mucin-deleted GPs from different Marburg virus (MARV) strains. Surprisingly, two of the mAbs raised against MARV GP also cross-react with the mucin-deleted GP cores of all tested ebolaviruses (Ebola, Sudan, Bundibugyo, Reston), but these epitopes are masked differently by the mucin-like domains themselves. The most efficacious mAbs in this panel were found to recognize a novel "wing" feature on the GP2 subunit that is unique to Marburg and does not exist in Ebola. Two of these anti-wing antibodies confer 90 and 100% protection, respectively, one hour post-exposure in mice challenged with MARV.

No MeSH data available.


Related in: MedlinePlus

Negative stain EM and modeling of Fabs bound to MARV GP.Representative 2D class averages of MARV Ravn GP:Fab complexes (A) GPΔmuc + 9A11 (B) GPΔmuc + 30G5 (C) GP + 30G5. (D) The crystal structure of MARV GPcl is shown with the unresolved GP2-wing region (436–510) depicted by a dashed orange line. The footprints of 9A11 and 30G5 Fabs are unknown; possible binding areas are highlighted by gray dotted ovals. For simplification, Fab binding regions are highlighted on only one monomer of the trimer in each view.
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ppat.1005016.g006: Negative stain EM and modeling of Fabs bound to MARV GP.Representative 2D class averages of MARV Ravn GP:Fab complexes (A) GPΔmuc + 9A11 (B) GPΔmuc + 30G5 (C) GP + 30G5. (D) The crystal structure of MARV GPcl is shown with the unresolved GP2-wing region (436–510) depicted by a dashed orange line. The footprints of 9A11 and 30G5 Fabs are unknown; possible binding areas are highlighted by gray dotted ovals. For simplification, Fab binding regions are highlighted on only one monomer of the trimer in each view.

Mentions: Single particle electron microscopy of the most protective anti-GP1 (9A11) and anti-GP2 (30G5) antibodies was performed in complex with purified antigen. Negative stain 2D class averages of 9A11 Fabs in complex with MARV Ravn GPΔmuc show one, two, or three Fabs bound to the dense trimeric GP core (Fig 6A). In contrast, 2D class averages of the anti-GP2 wing mAb 30G5 in complex with MARV Ravn GPΔmuc show a single Fab bound to GP, at a distance further away from the high density GP trimer (Fig 6B). Deuterium exchange mass spectrometry (DXMS) studies suggest this GP wing region is unstructured and likely flexible (S2 Fig). To ensure that the wing epitope is not artificially positioned in GPΔmuc as compared to the biologically relevant mucin-containing GP, we also performed EM with 30G5 Fab in complex with the complete ectodomain of MARV Ravn GP. Images obtained were similar to those with GPΔmuc, with only one Fab binding per trimer (Fig 6C). Likely footprints of Fabs 9A11 and 30G5 are drawn onto the MARV Ravn GPcl crystal structure (Fig 6D).


Protective mAbs and Cross-Reactive mAbs Raised by Immunization with Engineered Marburg Virus GPs.

Fusco ML, Hashiguchi T, Cassan R, Biggins JE, Murin CD, Warfield KL, Li S, Holtsberg FW, Shulenin S, Vu H, Olinger GG, Kim do H, Whaley KJ, Zeitlin L, Ward AB, Nykiforuk C, Aman MJ, Berry JD, Berry J, Saphire EO - PLoS Pathog. (2015)

Negative stain EM and modeling of Fabs bound to MARV GP.Representative 2D class averages of MARV Ravn GP:Fab complexes (A) GPΔmuc + 9A11 (B) GPΔmuc + 30G5 (C) GP + 30G5. (D) The crystal structure of MARV GPcl is shown with the unresolved GP2-wing region (436–510) depicted by a dashed orange line. The footprints of 9A11 and 30G5 Fabs are unknown; possible binding areas are highlighted by gray dotted ovals. For simplification, Fab binding regions are highlighted on only one monomer of the trimer in each view.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4482612&req=5

ppat.1005016.g006: Negative stain EM and modeling of Fabs bound to MARV GP.Representative 2D class averages of MARV Ravn GP:Fab complexes (A) GPΔmuc + 9A11 (B) GPΔmuc + 30G5 (C) GP + 30G5. (D) The crystal structure of MARV GPcl is shown with the unresolved GP2-wing region (436–510) depicted by a dashed orange line. The footprints of 9A11 and 30G5 Fabs are unknown; possible binding areas are highlighted by gray dotted ovals. For simplification, Fab binding regions are highlighted on only one monomer of the trimer in each view.
Mentions: Single particle electron microscopy of the most protective anti-GP1 (9A11) and anti-GP2 (30G5) antibodies was performed in complex with purified antigen. Negative stain 2D class averages of 9A11 Fabs in complex with MARV Ravn GPΔmuc show one, two, or three Fabs bound to the dense trimeric GP core (Fig 6A). In contrast, 2D class averages of the anti-GP2 wing mAb 30G5 in complex with MARV Ravn GPΔmuc show a single Fab bound to GP, at a distance further away from the high density GP trimer (Fig 6B). Deuterium exchange mass spectrometry (DXMS) studies suggest this GP wing region is unstructured and likely flexible (S2 Fig). To ensure that the wing epitope is not artificially positioned in GPΔmuc as compared to the biologically relevant mucin-containing GP, we also performed EM with 30G5 Fab in complex with the complete ectodomain of MARV Ravn GP. Images obtained were similar to those with GPΔmuc, with only one Fab binding per trimer (Fig 6C). Likely footprints of Fabs 9A11 and 30G5 are drawn onto the MARV Ravn GPcl crystal structure (Fig 6D).

Bottom Line: Antibodies against the filovirus surface glycoprotein (GP) have been shown to provide life-saving therapy in nonhuman primates, but such antibodies are generally virus-specific.Surprisingly, two of the mAbs raised against MARV GP also cross-react with the mucin-deleted GP cores of all tested ebolaviruses (Ebola, Sudan, Bundibugyo, Reston), but these epitopes are masked differently by the mucin-like domains themselves.The most efficacious mAbs in this panel were found to recognize a novel "wing" feature on the GP2 subunit that is unique to Marburg and does not exist in Ebola.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America.

ABSTRACT
The filoviruses, which include the marburg- and ebolaviruses, have caused multiple outbreaks among humans this decade. Antibodies against the filovirus surface glycoprotein (GP) have been shown to provide life-saving therapy in nonhuman primates, but such antibodies are generally virus-specific. Many monoclonal antibodies (mAbs) have been described against Ebola virus. In contrast, relatively few have been described against Marburg virus. Here we present ten mAbs elicited by immunization of mice using recombinant mucin-deleted GPs from different Marburg virus (MARV) strains. Surprisingly, two of the mAbs raised against MARV GP also cross-react with the mucin-deleted GP cores of all tested ebolaviruses (Ebola, Sudan, Bundibugyo, Reston), but these epitopes are masked differently by the mucin-like domains themselves. The most efficacious mAbs in this panel were found to recognize a novel "wing" feature on the GP2 subunit that is unique to Marburg and does not exist in Ebola. Two of these anti-wing antibodies confer 90 and 100% protection, respectively, one hour post-exposure in mice challenged with MARV.

No MeSH data available.


Related in: MedlinePlus