scholarly journals From Structure to Sequence: Identification of polyclonal antibody families using cryoEM

2021 ◽  
Author(s):  
Aleksandar Antanasijevic ◽  
Charles A. Bowman ◽  
Robert N. Kirchdoerfer ◽  
Cristopher A. Cottrell ◽  
Gabriel Ozorowski ◽  
...  

One of the rate-limiting steps in analyzing immune responses to vaccines or infections is the isolation and characterization of monoclonal antibodies. Here, we present a hybrid structural and bioinformatic approach to directly assign the heavy and light chains, identify complementarity- determining regions and discover sequences from cryoEM density maps of serum-derived polyclonal antibodies bound to an antigen. When combined with next generation sequencing of immune repertoires we were able to specifically identify clonal family members, synthesize the monoclonal antibodies and confirm that they interact with the antigen in a manner equivalent to the corresponding polyclonal antibodies. This structure-based approach for identification of monoclonal antibodies from polyclonal sera opens new avenues for analysis of immune responses and iterative vaccine design.

2013 ◽  
Vol 47 (2) ◽  
pp. 128-137 ◽  
Author(s):  
Sendi Montanic ◽  
Michela Terdoslavich ◽  
Uros Rajcevic ◽  
Luigina De Leo ◽  
Serena Department of Medical Sciences, Uni ◽  
...  

Background. Bilitranslocase (TC 2.A.65.1.1) is a bilirubin-specific membrane transporter, found on absorptive (stomach and intestine) and excretory (kidney and liver) epithelia and in vascular endothelium. Polyclonal antibodies have been raised in rabbits in the past, using a synthetic peptide corresponding to AA65-77 of rat liver bilitranslocase, as an antigen. Affinity-purified antibodies from immune sera have been found to inhibit various membrane transport functions, including the bilirubin uptake into human hepatocytes and the uptake of some flavonoids into human vascular endothelial cells. It was described by means of immunohistochemistry using polyclonal antibodies that bilitranslocase expression is severely down-regulated in clear cell renal carcinoma. The aim of our work was development and characterization of high-affinity, specific mAbs against bilitranslocase, which can be used as a potential diagnostic tool in renal cell carcinoma as well as in a wide variety of biological assays on different human tissues. Materials and methods. Mice were immunized with a multi-antigen peptide corresponding to segment 65-75 of predicted primary structure of the bilitranslocase protein. By a sequence of cloning, immune- and functional tests, we aimed at obtaining a specific monoclonal antibody which recognizes a 37 kDa membrane protein, and influences the transport activity of bilitranslocase. Results. On the basis of previous results, specific IgM monoclonal antibodies were produced in BALB/c mice, in order to further improve and extend the immunological approach to the study of bilitranslocase in renal cancer cells as well as to develop its potential diagnostics use. Conclusions. In this article we show an immunological approach, based on newly developed monoclonal antibodies, to a detailed biochemical and functional characterization of a protein whose gene and protein structure is still unknown. We were able to demonstrate our novel mAb as a tumor marker candidate of renal cell carcinoma, which may prove useful in the diagnostic procedures.


2014 ◽  
Vol 21 (4) ◽  
pp. 587-593 ◽  
Author(s):  
Martha J. Brown ◽  
Hanna Seitz ◽  
Victoria Towne ◽  
Martin Müller ◽  
Adam C. Finnefrock

ABSTRACTHuman papillomavirus (HPV) is the etiological agent for all cervical cancers, a significant number of other anogenital cancers, and a growing number of head and neck cancers. Two licensed vaccines offer protection against the most prevalent oncogenic types, 16 and 18, responsible for approximately 70% of cervical cancer cases worldwide and one of these also offers protection against types 6 and 11, responsible for 90% of genital warts. The vaccines are comprised of recombinantly expressed major capsid proteins that self-assemble into virus-like particles (VLPs) and prevent infection by eliciting neutralizing antibodies. Adding the other frequently identified oncogenic types 31, 33, 45, 52, and 58 to a vaccine would increase the coverage against HPV-induced cancers to approximately 90%. We describe the generation and characterization of panels of monoclonal antibodies to these five additional oncogenic HPV types, and the selection of antibody pairs that were high affinity and type specific and recognized conformation-dependent neutralizing epitopes. Such characteristics make these antibodies useful tools for monitoring the production and potency of a prototype vaccine as well as monitoring vaccine-induced immune responses in the clinic.


1998 ◽  
Vol 160 (6 Part 2) ◽  
pp. 2396-2401 ◽  
Author(s):  
GERALD P. MURPHY ◽  
THOMAS G. GREENE ◽  
WILLIAM T. TINO ◽  
ALTON L. BOYNTON ◽  
ERIC H. HOLMES

Virology ◽  
1988 ◽  
Vol 164 (1) ◽  
pp. 275-279 ◽  
Author(s):  
Rhonda Lunt ◽  
Michael E. Vayda ◽  
Marjorie Young ◽  
S.J. Flint

1989 ◽  
Vol 67 (8) ◽  
pp. 411-421 ◽  
Author(s):  
Om P. Malhotra

Isolation and characterization of γ-carboxyglutamic acid (Gla) deficient prothrombins induced by Warfarin or dicoumarol are useful for studying the role of specific Gla residues in prothrombin. In addition to 7-Gla prothrombin, we have isolated two more atypical prothrombins from the barium citrate eluate, one containing 6.11, and the other, 7.85 Gla residues, presumably 6- and 8-Gla prothrombins. The actual Gla content of the 7-Gla isomer was 7.05. Each of the 6-, 7-, and 8-Gla variants showed a single component by agar or dodecyl sulfate Polyacrylamide gel electrophoresis. When agar gel electrophoresis was performed in calcium, each of the variants moved more rapidly than normal (10-Gla) prothrombin. In the presence of EDTA, the 8-Gla isomer exhibited the fastest mobility, equivalent to that of normal prothrombin, followed by 7-, and then 6-Gla variants. The physiological activities of the isomers were found to be 18 to 23% for 8-, 6 to 8% for 7-, and 2 to 3% of normal prothrombin for 6-Gla variant. Prothrombin fragment 1, derived from 8-Gla prothrombin, exhibited 23% of calcium-induced fluorescence quenching, compared with 40% for 10-Gla and 8% or less for 7- and 6-Gla fragments 1. Competition radioimmunoassay data show that calcium-dependent anti (normal) prothrombin polyclonal antibodies are not specific for 10-Gla prothrombin, since the 7- and 8-Gla isomers were able to displace radiolabeled (125I) normal prothrombin.Key words: prothrombin, blood clotting, dicoumarol, Warfarin, γ-carboxyglutamic acid, vitamin K deficiency.


1996 ◽  
Vol 178 (2) ◽  
pp. 187-198 ◽  
Author(s):  
Sei Morita ◽  
Shigeru Tsuchiya ◽  
Hiromi Fujie ◽  
Masayuki Itano ◽  
Yoshiyuki Ohashi ◽  
...  

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