Novel Ricin Subunit Antigens With Enhanced Capacity to Elicit Toxin-Neutralizing Antibody Responses in Mice.


Abstract

RiVax is a candidate ricin toxin subunit vaccine antigen that has proven to be safe in human phase I clinical trials. In this study, we introduced double and triple cavity-filling point mutations into the RiVax antigen with the expectation that stability-enhancing modifications would have a beneficial effect on overall immunogenicity of the recombinant proteins. We demonstrate that 2 RiVax triple mutant derivatives, RB (V81L/C171L/V204I) and RC (V81I/C171L/V204I), when adsorbed to aluminum salts adjuvant and tested in a mouse prime-boost-boost regimen were 5- to 10-fold more effective than RiVax at eliciting toxin-neutralizing serum IgG antibody titers. Increased toxin neutralizing antibody values and seroconversion rates were evident at different antigen dosages and within 7 days after the first booster. Quantitative stability/flexibility relationships analysis revealed that the RB and RC mutations affect rigidification of regions spanning residues 98-103, which constitutes a known immunodominant neutralizing B-cell epitope. A more detailed understanding of the immunogenic nature of RB and RC may provide insight into the fundamental relationship between local protein stability and antibody reactivity.

Submission Details

ID: bxLcoWc64

Submitter: Shu-Ching Ou

Submission Date: Dec. 19, 2018, 10:31 a.m.

Version: 1

Publication Details
Wahome N;Sully E;Singer C;Thomas JC;Hu L;Joshi SB;Volkin DB;Fang J;Karanicolas J;Jacobs DJ;Mantis NJ;Middaugh CR,J Pharm Sci (2016) Novel Ricin Subunit Antigens With Enhanced Capacity to Elicit Toxin-Neutralizing Antibody Responses in Mice. PMID:26987947
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
3PX8 2011-06-22 1.29 RTA in complex with 7-carboxy-pterin
2VC4 2007-10-16 1.39 Ricin A-Chain (Recombinant) E177D Mutant
1UQ5 2004-01-02 1.4 RICIN A-CHAIN (RECOMBINANT) N122A MUTANT
4Z9K 2016-07-20 1.5 Ricin A chain bound to camelid nanobody (VHH2)(F5)
5DDZ 2016-09-07 1.5 Crystal structure of the RTA-c10-P2 complex
1J1M 2004-02-03 1.5 Ricin A-Chain (Recombinant) at 100K
4HUO 2012-12-26 1.52 Structure of Ricin A chain bound with N-(N-(pterin-7-yl)carbonylglycyl)-L-phenylalanine
4MX5 2014-01-15 1.52 Structure of ricin A chain bound with benzyl-(2-(2-amino-4-oxo-3,4-dihydropteridine-7-carboxamido)ethyl)carbamate
4HV3 2012-12-26 1.54 Structure of Ricin A chain bound with N-(N-(pterin-7-yl)carbonyl-L-serinyl)-L-tryptophan
5GU4 2016-11-02 1.55 rRNA N-glycosylase RTA
4MX1 2014-01-15 1.59 Structure of ricin A chain bound with 2-amino-4-oxo-N-(2-(3-phenylureido)ethyl)-3,4-dihydropteridine-7-carboxamide
2VC3 2007-10-16 1.6 Ricin A-Chain (Recombinant) E177D Mutant with a bound acetate
4LGR 2014-06-11 1.65 Ricin A chain bound to camelid nanobody (VHH3)
5J57 2016-12-07 1.7 V5E1-RTA complex
4HUP 2012-12-26 1.7 Structure of ricin A chain bound with N-(N-(pterin-7-yl)carbonylglycyl)-L-phenylalanyl)-L-phenylalanine
4LHJ 2014-06-11 1.8 Ricin A chain bound to camelid nanobody (VHH5)
2PJO 2007-11-20 1.8 Ricin a-chain (recombinant) complex with n-methylurea
5J56 2016-12-07 1.8 RTA-V1C7
1IFT 1998-01-14 1.8 RICIN A-CHAIN (RECOMBINANT)
4ESI 2012-10-31 1.87 Structure of ricin A chain bound with N-((1H-1,2,3-triazol-4-yl)methyl-2-amino-4-oxo-3,4-dihydropteridine-7-carboxamide
4HV7 2012-12-26 1.87 Structure of ricin A chain bound with N-(N-(pterin-7-yl)carbonylglycyl)glycine
3PX9 2011-06-22 1.89 RTA in complex with N-(furanylmethyl)-7-carbamoyl-pterin
1UQ4 2004-01-02 1.9 RICIN A-CHAIN (RECOMBINANT) R213D MUTANT
2P8N 2007-11-20 1.94 Ricin a-chain (recombinant) complex with adenine
3HIO 2009-12-08 2.0 Crystal structure of Ricin A-chain in complex with the cyclic tetranucleotide inhibitor, a transition state analogue
1IFS 1998-01-14 2.0 RICIN A-CHAIN (RECOMBINANT) COMPLEX WITH ADENOSINE (ADENOSINE BECOMES ADENINE IN THE COMPLEX)
5E1H 2016-08-03 2.03 Ricin toxin in complex with neutralizing single chain monoclonal antibodies (VHHs)
3MK9 2010-11-10 2.08 Stabilized Ricin Immunogen 1-33/44-198
2R3D 2007-11-20 2.09 Ricin A-chain (recombinant) complex with Acetamide
3SRP 2011-08-03 2.14 Structure of Rivax: A Human Ricin Vaccine
3BJG 2008-12-16 2.14 Structure of Rivax: A Human Ricin Vaccine
1OBS 1997-06-16 2.2 STRUCTURE OF RICIN A CHAIN MUTANT
4Q2V 2015-04-15 2.2 Crystal Structure of Ricin A chain complexed with Baicalin inhibitor
4IMV 2013-02-13 2.25 Ricin A-chain variant 1-33/44-198 with engineered disulfide bond, R48C/T77C/D75N
3LC9 2010-11-10 2.28 Ricin A-chain variant 1-33/44-198 with engineered disulfide bond
1BR6 1998-09-02 2.3 RICIN A CHAIN (RECOMBINANT) COMPLEX WITH PTEROIC ACID
1RTC 1993-10-31 2.3 THE STRUCTURE OF RECOMBINANT RICIN A CHAIN AT 2.3 ANGSTROMS
4LHQ 2014-06-11 2.3 Ricin A chain bound to camelid nanobody (VHH8)
2R2X 2007-11-20 2.4 Ricin A-chain (recombinant) complex with Urea
4LGP 2014-06-11 2.4 Ricin A chain bound to camelid nanobody (VHH1)
1IFU 1998-01-14 2.4 RICIN A-CHAIN (RECOMBINANT) COMPLEX WITH FORMYCIN
5U4L 2017-12-13 2.5 RTA-V1C7_G29R-high-salt
3EJ5 2009-04-07 2.5 complex of Ricin A chain and pyrimidine-based inhibitor
5U4M 2017-12-13 2.5 RTA-V1C7-G29R-no_salt
1BR5 1998-09-02 2.5 RICIN A CHAIN (RECOMBINANT) COMPLEX WITH NEOPTERIN
2AAI 1994-01-31 2.5 Crystallographic refinement of ricin to 2.5 Angstroms
6CWG 2019-01-16 2.6 Ricin catalytic subunit bound go A9 VHH antibody
1IL4 2002-01-16 2.6 STRUCTURE OF RICIN A CHAIN BOUND WITH INHIBITOR 9-DEAZAGUANINE
1RZO 2004-12-28 2.63 Agglutinin from Ricinus communis with galactoaza
4LGS 2014-06-11 2.7 Ricin A chain bound to camelid nanobody (VHH4)
5SV3 2016-10-19 2.73 RTA1-33/44-198 (RVEC) bound to Single Domain Antibody A3C8
4KUC 2013-07-17 2.79 Crystal structure of ricin-A chain in complex with the antibody 6C2
1OBT 1997-06-16 2.8 STRUCTURE OF RICIN A CHAIN MUTANT, COMPLEX WITH AMP
1IL5 2002-01-16 2.8 STRUCTURE OF RICIN A CHAIN BOUND WITH INHIBITOR 2,5-DIAMINO-4,6-DIHYDROXYPYRIMIDINE (DDP)
1IL3 2002-01-16 2.8 STRUCTURE OF RICIN A CHAIN BOUND WITH INHIBITOR 7-DEAZAGUANINE
3RTI 2011-08-31 2.8 Crystal structure of ricin bound with formycin monophosphate
3RTJ 2011-08-31 3.0 Crystal structure of ricin bound with dinucleotide ApG
5BOZ 2016-12-07 3.1 Ricin A chain bound to camelid nanobody (VHH9)(E1)
1IL9 2002-01-16 3.1 STRUCTURE OF RICIN A CHAIN BOUND WITH INHIBITOR 8-METHYL-9-OXOGUANINE

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
92.9 Ricin P06750 AGGL_RICCO
99.3 Ricin P02879 RICI_RICCO