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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

GP schematic and GP2-wing epitope analysis.(A) Schematic of purified GP ectodomains used in this study. Dashed lines represent deleted regions. SS, signal sequence; MLD, mucin-like domain; IFL, internal fusion loop; TM, transmembrane domain. A red triangle indicates the furin cleavage site, numbered in red. The GP2-wing region, which is unique to MARV, is colored orange. B) MARV sequence alignment of pepscan defined epitopes for anti-GP2 wing mAbs. This region has four residues unique to strain Ravn; notably, 465E is 465K in other strains. (C) ELISA binding of GP2-wing mAbs to wild type (wt) and E465K Ravn GPΔmuc at 2 and 0.2μg/ml.
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ppat.1005016.g002: GP schematic and GP2-wing epitope analysis.(A) Schematic of purified GP ectodomains used in this study. Dashed lines represent deleted regions. SS, signal sequence; MLD, mucin-like domain; IFL, internal fusion loop; TM, transmembrane domain. A red triangle indicates the furin cleavage site, numbered in red. The GP2-wing region, which is unique to MARV, is colored orange. B) MARV sequence alignment of pepscan defined epitopes for anti-GP2 wing mAbs. This region has four residues unique to strain Ravn; notably, 465E is 465K in other strains. (C) ELISA binding of GP2-wing mAbs to wild type (wt) and E465K Ravn GPΔmuc at 2 and 0.2μg/ml.

Mentions: To characterize the binding of mAbs, we performed enzyme-linked immunosorbent assays (ELISAs) with recombinant GPs from four MARV strains, and determined EC50 values for binding with different forms of MARV Ravn GP: GP, GPΔmuc, GPcl (Fig 2A). All ten mAbs exhibit medium binding (EC50 between 20ng/ml and 200ng/ml, colored dark yellow) to high binding (EC50 <20ng/ml, colored orange) against Ravn GP and GPΔmuc (Fig 1B), but only seven of the mAbs cross-react with GP from other MARV strains (Fig 1C). All mAbs bind the protease-cleaved Ravn GP core, termed GPcl, as well as GPΔmuc, with the exception of 9A11. Antibody 9A11 exhibits an 8-fold decrease in binding to GPcl as compared to GPΔmuc (Fig 1B). Additionally, to evaluate whether the mAbs have the capacity to bind cell-surface GP, ELISAs were performed with virus-like particles (VLPs) bearing full-length wild-type MARV Ravn GP. Eight mAbs bind as well (or nearly as well) to VLPs as purified recombinant Ravn GP. In contrast, 2A12 exhibits nearly 10-fold weaker binding to VLPs than to GP ectodomain, and 54G3 binding to VLPs is lost at the highest concentration tested (Fig 1B).


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)

GP schematic and GP2-wing epitope analysis.(A) Schematic of purified GP ectodomains used in this study. Dashed lines represent deleted regions. SS, signal sequence; MLD, mucin-like domain; IFL, internal fusion loop; TM, transmembrane domain. A red triangle indicates the furin cleavage site, numbered in red. The GP2-wing region, which is unique to MARV, is colored orange. B) MARV sequence alignment of pepscan defined epitopes for anti-GP2 wing mAbs. This region has four residues unique to strain Ravn; notably, 465E is 465K in other strains. (C) ELISA binding of GP2-wing mAbs to wild type (wt) and E465K Ravn GPΔmuc at 2 and 0.2μg/ml.
© Copyright Policy
Related In: Results  -  Collection

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

ppat.1005016.g002: GP schematic and GP2-wing epitope analysis.(A) Schematic of purified GP ectodomains used in this study. Dashed lines represent deleted regions. SS, signal sequence; MLD, mucin-like domain; IFL, internal fusion loop; TM, transmembrane domain. A red triangle indicates the furin cleavage site, numbered in red. The GP2-wing region, which is unique to MARV, is colored orange. B) MARV sequence alignment of pepscan defined epitopes for anti-GP2 wing mAbs. This region has four residues unique to strain Ravn; notably, 465E is 465K in other strains. (C) ELISA binding of GP2-wing mAbs to wild type (wt) and E465K Ravn GPΔmuc at 2 and 0.2μg/ml.
Mentions: To characterize the binding of mAbs, we performed enzyme-linked immunosorbent assays (ELISAs) with recombinant GPs from four MARV strains, and determined EC50 values for binding with different forms of MARV Ravn GP: GP, GPΔmuc, GPcl (Fig 2A). All ten mAbs exhibit medium binding (EC50 between 20ng/ml and 200ng/ml, colored dark yellow) to high binding (EC50 <20ng/ml, colored orange) against Ravn GP and GPΔmuc (Fig 1B), but only seven of the mAbs cross-react with GP from other MARV strains (Fig 1C). All mAbs bind the protease-cleaved Ravn GP core, termed GPcl, as well as GPΔmuc, with the exception of 9A11. Antibody 9A11 exhibits an 8-fold decrease in binding to GPcl as compared to GPΔmuc (Fig 1B). Additionally, to evaluate whether the mAbs have the capacity to bind cell-surface GP, ELISAs were performed with virus-like particles (VLPs) bearing full-length wild-type MARV Ravn GP. Eight mAbs bind as well (or nearly as well) to VLPs as purified recombinant Ravn GP. In contrast, 2A12 exhibits nearly 10-fold weaker binding to VLPs than to GP ectodomain, and 54G3 binding to VLPs is lost at the highest concentration tested (Fig 1B).

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