The Antibody Society

the official website of the antibody society

An international non-profit supporting antibody-related research and development.

You are here: Home / Archives for antibody engineering

James S. Huston – In Memoriam

by

Post written by: Richard Begent, Ph.D., Emeritus Professor of Oncology, University College London

James S. Huston Jr, Ph.D., antibody engineer and founding President of The Antibody Society, died in Boston on March 25, 2020.

Jim Huston was a distinguished biophysicist and a pioneering antibody engineer; his creation of the single chain Fv (scFv) antibody was a seminal advance. These genetically encoded molecules could express the vast diversity of antibody repertoires, and could be used for specific target binding by themselves, incorporated into multifunctional molecules, attached to cell surfaces or applied in any number of formats relevant to biomedicine.

Antibodies with their multiple functions, including the capacity for specific binding to a range of targets, became practical pharmaceuticals with the advent of monoclonal antibodies as described by Köhler and Milstein in 1975. Genetic manipulation humanized the constant regions, making repeated administration feasible with widespread benefits for human health.

It was evident that the smallest target recognition moiety of antibodies, the variable region (Fv), if produced separately could be linked to many agents, conferring exquisite binding specificity. Since the VH and VL domains are separate in the native form of the Fv, they needed to be joined in a way that retained stability, the binding performance of the two components together, and appropriate flexibility.

Jim proposed doing this with one genetic construct that encoded a single-chain Fv (scFv) in which the VH and VL were joined by a flexible linker. The design issues were complex, but, consummate biophysicist that he was, he translated the requirements into a successful design for the linker. Working with colleagues at Creative Biomolecules, Massachusetts General Hospital and Harvard Medical School, an sFv reactive with digoxin was successfully produced and tested. The report (Huston et al 1988) of this work has been cited more than 2,300 times.

scFvs are readily expressed on the surface of filamentous bacteriophage and have often been the basis for naïve human antibody libraries with potential for rapid selection of desired binders from diverse libraries of many millions. This technology can be used for antibody discovery and humanization, and it has been the foundation of many successful commercial ventures. Jim’s own work included the demonstration of scFv fusion proteins and the first scFv intrabody therapy for the neurodegenerative condition, Huntington’s disease, an approach that is now being investigated in Parkinson’s disease.

The scFv format itself forms the targeting basis of T-cell recruiting agents, bispecific T-cell engagers (BiTEs), and chimeric antigen receptors (CARs), the antigen binding moiety of CAR-T cells. A number of products based on these formats are already licensed for clinical use, while several others are in development. This is an important beginning, but the potential for further applications is great because of the diversity of antibody repertoires and the robust nature of the sFv format.

Jim graduated in Chemistry from the University of Michigan and was awarded his Ph.D. for work on the Fd fragment of IgG and its domains, supervised by Professor Charles Tanford at Duke University. After postdoctoral research at Stanford and Harvard Medical Schools, he joined Creative Biomolecules in Boston in 1983 where he undertook the original work on scFvs. There followed numerous publications and patents relating to engineered antibodies and their applications.

Jim was one of the first people to see the long-term potential of antibody engineering and recognize how broad the applications could be. His lectures on this topic gave a unique experience in that one sometimes seemed to be discovering the meaning of his data simultaneously with him. Those who had the privilege of working with him benefited greatly not only from his generosity, enthusiasm, intellectual rigor and encouragement, but also from his ability to advise wisely or find the appropriate expert. He took the mission of advancing antibody engineering to an international level by serving as the scientific adviser to the Antibody Engineering & Therapeutics meetings for nearly 30 years. Over time, he brought the antibody engineering and therapeutics community together at meetings in San Diego and elsewhere. His insistence that scientific quality and education were the principal criteria for the program resulted in progressive growth and helped to cement a culture encompassing academia and industry. Building on this, he co-founded The Antibody Society in 2007 and was the Founding President and Chairman, remaining a Board Member until his death. He shared the gratification of many that, after a long gestation, antibody engineering is proving so beneficial to human health, with the promise of much more to come.

Jim’s many friends around the world will remember his love of life based on a deep Episcopalian faith, his pride and joy in his family, and the fortitude with which he bore illness over recent years.

The Antibody Society will honor Jim Huston and his many contributions to the field of antibody engineering at our next annual meeting.

Antibody Engineering & Therapeutics, December 2019

by

Thank you for joining us at The Antibody Society’s annual Antibody Engineering & Therapeutics meeting held December 9-13, 2019 in San Diego. The meeting was a great opportunity for Society members to connect with industry and academic scientists and executives from around the world, and learn about advances in antibody discovery and development.

As always, The Antibody Society’s members designed the scientific program and acted as session Chairs. The meeting featured sessions on Antibody Libraries, Selection, Screening and Engineering; Bioinformatics and Computational Tools for Antibody Optimization and Engineering; Clinical Data and Lessons from Cancer Immunotherapy; Systems Immunology for Target Discovery; and Targeting Subcellular Trafficking Pathways to Generate Antibody Therapeutics.

AE&T Student/Postdoc Poster Competition

The Society sponsored a poster competition for students and postdocs, with winners receiving complimentary registration, support for travel expenses, and an opportunity to present at the conference. Congratulations to the winners:

Timothy Czajka, University of New York at Albany. Poster title: RIP-Off: An Intrabody-based Strategy to Neutralize Ricin and other Ribosome-Inactivating Protein (RIP) Toxins.

Kamal Joshi, PhD., Genentech. Poster title: Toward Deeper Understanding of Bispecific Antibodies

“Thank you again to the Antibody Society for this recognition and opportunity to speak here.  This is my third time attending the Antibody Engineering and Therapeutics conference and each time I’ve learned more than I could possibly remember and return to the lab with a huge surge of excitement and several new ideas that I’d like to apply to my own project.  I’m honored to be able to present my own research this year alongside so many fascinating talks and to be able to engage with many different experts in the field.  I would also like to thank my advisor, Nicholas Mantis, and Anne Messer for their help with my research and encouragement to attend and apply for this award.” Timothy Czajka

 

“It is an honor to receive this award. I would like to thank the judges for conferring this recognition on my work. I would also like to thank the Antibody Society, of course for funding my trip here but more importantly for organizing these fantastic meetings and providing a solid platform for the exchange of the latest information on antibody research and development benefiting all including early stage career scientists like me. It’s a real treat coming back to this meeting every time. Not only do I learn what is ongoing in the field, this meeting also provides me the opportunity to network with fellow scientists and facilitate connections. So again, thank you to the Antibody Society for this award. Thank you all.” Kamal Joshi, Ph.D.

 

Moments at Antibody Engineering & Therapeutics

 

We look forward to seeing you at AE&T in December 2020!

All Society members receive discounts on registration to Antibody Engineering & Therapeutics (US), as well as registration at many antibody-related meetings.

Most read from mAbs, Nov/Dec 2019

by

The Antibody Society is pleased to be affiliated with mAbs, a multi-disciplinary journal dedicated to advancing the art and science of antibody research and development. We hope you enjoy these summaries based on the abstracts of the most read papers published in a recent issue.

All the articles are open access; PDFs can be freely downloaded by following the links below.

Issue 11.8 (Nov/Dec 2019)

Insights into the IgG heavy chain engineering patent landscape as applied to IgG4 antibody development

In this new Perspective, Dumet et al., present the results from their study of the patent landscape of IgG4 Fc engineering, i.e., patents claiming modifications in the heavy chain. Thirty-seven relevant patent families were identified, comprising hundreds of IgG4 Fc variants focusing on removal of residual effector functions (since IgG4s bind to FcγRI and weakly to other FcγRs), half-life enhancement and IgG4 stability. Given the number of expired or soon to expire major patents in those 3 areas, companies developing blocking antibodies now have, or will in the near future, access to free tools to design silenced, half-life extended and stable IgG4 antibodies.

Antibody discovery and engineering by enhanced CRISPR-Cas9 integration of variable gene cassette libraries in mammalian cells

Parola et al. describe an antibody engineering and screening approach where complete variable light (VL) and heavy (VH) chain cassette libraries are stably integrated into the genome of hybridoma cells by enhanced Cas9-driven homology-directed repair (HDR), resulting in their surface display and secretion. By developing an improved HDR donor format that utilizes in situ linearization, they were able to achieve >15-fold improvement of genomic integration, resulting in a screening workflow that only requires a simple plasmid electroporation. This proved suitable for different applications in antibody discovery and engineering. By integrating and screening an immune library obtained from the variable gene repertoire of an immunized mouse, they isolated a diverse panel of >40 unique antigen-binding variants. They also successfully performed affinity maturation by directed evolution screening of an antibody library based on random mutagenesis, leading to the isolation of several clones with affinities in the picomolar range.

DuoMab: a novel CrossMab-based IgG-derived antibody format for enhanced antibody-dependent cell-mediated cytotoxicity

In this new Report,  Sustmann et al. present a generic approach to generate two novel IgG-derived antibody formats that are based on a modification of the CrossMab technology. MoAbs harbor two heavy chains (HCs) resulting in one binding entity and one Fc, whereas DuoMabs are composed of four HCs harboring two binding entities and two Fc regions linked at a disulfide-bridged hinge. The latter bivalent format is characterized by avidity-enhanced target cell binding while simultaneously increasing the ‘Fc-load’ on the surface. DuoMabs were shown to be producible in high yield and purity and bind to surface cells with affinities comparable to IgGs. The increased Fc load directed at the surface of target cells by DuoMabs modulates their ADCC competency toward target cells, making them attractive for applications that require or are modulated by FcR interactions.

Single-step Protein A and Protein G avidity purification methods to support bispecific antibody discovery and development

Heavy chain (Hc) heterodimers represent a majority of bispecific antibodies (bsAbs) under clinical development. Although recent technologies achieve high levels of Hc heterodimerization (HD), traces of homodimer contaminants are often present, and as a consequence robust purification techniques for generating highly pure heterodimers in a single step are needed. Ollier et al. describe two different purification methods that exploit differences in Protein A (PA) or Protein G (PG) avidity between homo- and heterodimers. Differential elution between species was enabled by removing PA or PG binding in one of the Hcs of the bsAb. The PA method allowed the avidity purification of heterodimers based on the VH3 subclass, which naturally binds PA and interferes with separation, by using a combination of IgG3 Fc and a single amino acid change in VH3, N82aS. The PG method relied on a combination of three mutations that completely disrupts PG binding, M428G/N434A in IgG1 Fc and K213V in IgG1 CH1. Both methods achieved a high level of heterodimer purity as single-step techniques without Hc HD (93–98%). Since PA and PG have overlapping binding sites with the neonatal Fc receptor (FcRn), they investigated the effects of the engineering both in vitro and in vivo. Mild to moderate differences in FcRn binding and Fc thermal stability were observed, but these did not significantly change the serum half-lives of engineered control antibodies and heterodimers. The methods are conceptually compatible with various Hc HD platforms such as BEAT® (Bispecific Engagement by Antibodies based on the T cell receptor), in which the PA method has already been successfully implemented.

Student/Post-doc Poster Competition Winners Announced!

by

Congratulations to our winners!

To recognize the research activities of promising student and postdoctoral attendees of Antibody Engineering & Therapeutics, The Antibody Society sponsors a competition for our student/postdoc members who submit posters for display at the meeting. Our judges select the best work based on originality, relevance and perceived impact on the field of antibody R&D.

This year, our judges selected one student and one postdoc winners who receive: 1) a complimentary registration to attend the conference and pre-conference sessions; 2) an opportunity to give a short oral presentation of their work in one of the conference sessions; and 3) support for travel expenses.

The winners of the contest are:

Timothy Czajka, University of New York at Albany (graduate student winner)
Poster title: RIP-Off: An Intrabody-based Strategy to Neutralize Ricin and other Ribosome-Inactivating Protein (RIP) Toxins

Kamal Joshi, Genentech (Postdoctoral research fellow winner)
Poster title: Toward Deeper Understanding of Bispecific Antibodies

Antibody Engineering & Therapeutics, the annual meeting of The Antibody Society, managed by KNect365, will be held December 10-13, 2019 in San Diego, CA.

Society members receive a 15% discount on the registration fee. Contact us at membership@antibodysociety.org for the code.

Like this post but not a member? Please join!

Most read from mAbs, October 2019

by

The Antibody Society is pleased to be affiliated with mAbs, a multi-disciplinary journal dedicated to advancing the art and science of antibody research and development. We hope you enjoy these summaries based on the abstracts of the most read papers published in a recent issue.

All the articles are open access; PDFs can be freely downloaded by following the links below.

 

 

Issue 11.7 (Oct 2019)

Glycoform-resolved FcɣRIIIa affinity chromatography–mass spectrometry

Lippold et al. describe a method to determination the impact of individual antibody glycoforms on FcɣRIIIa affinity, and consequently antibody-dependent cell-mediated cytotoxicity (ADCC) without performing high purity glycoengineering. They hyphenated FcɣRIIIa affinity chromatography to mass spectrometry, which allowed direct affinity comparison of glycoforms of intact monoclonal antibodies. The approach enabled reproduction and refinement of known glycosylation effects, and insights on afucosylation pairing as well as on low-abundant, unstudied glycoforms. Their method greatly improves the understanding of individual glycoform structure–function relationships, and it is highly relevant for assessing Fc-glycosylation critical quality attributes related to ADCC.

Looking for therapeutic antibodies in next-generation sequencing repositories

It is now possible to query the great diversity of natural antibody repertoires using next-generation sequencing (NGS) using methods capable of producing millions of sequences in a single experiment. In this new article, Krawczyk et al. compare clinical-stage therapeutic antibodies to the ~1b sequences from 60 independent sequencing studies in the Observed Antibody Space database, which includes antibody sequences from NGS analysis of immunoglobulin gene repertoires. Of 242 post-Phase 1 antibodies, they found 16 with sequence identity matches of 95% or better for both heavy and light chains. There were also 54 perfect matches to therapeutic CDR-H3 regions in the NGS outputs, suggesting a nontrivial amount of convergence between naturally observed sequences and those developed artificially. The authors discuss the potential implications for both the legal protection of commercial antibodies and the discovery of antibody therapeutics.

Elucidating heavy/light chain pairing preferences to facilitate the assembly of bispecific IgG in single cells

Joshi et al. report that a high yield (>65%) of bispecific IgG1 (BsIgG1) without Fab engineering can be a surprisingly common occurrence, i.e., observed for 33 of the 99 different antibody pairs evaluated. Installing charge mutations at both CH1/CL interfaces was sufficient for near quantitative yield (>90%) of BsIgG1 for most (9 of 11) antibody pairs tested with this inherent cognate chain pairing preference. Mechanistically, they demonstrate that a strong cognate pairing preference in one Fab arm can be sufficient for high BsIgG1 yield. These observed chain pairing preferences are apparently driven by variable domain sequences and can result from a few specific residues in the complementarity-determining region (CDR) L3 and H3. Transfer of these CDR residues into other antibodies increased BsIgG1 yield in most cases. Mutational analysis revealed that the disulfide bond between heavy and light chains did not affect the yield of BsIgG1. This study provides some mechanistic understanding of factors contributing to antibody heavy/light chain pairing preference and subsequently contributes to the efficient production of BsIgG in single host cells.

Antibody Fc engineering for enhanced neonatal Fc receptor binding and prolonged circulation half-life

The neonatal Fc receptor (FcRn) promotes antibody recycling through rescue from normal lysosomal degradation. The binding interaction is pH-dependent with high affinity at low pH, but not under physiological pH conditions. In this new article, Mackness et al. describe how they combined rational design and saturation mutagenesis to generate novel antibody variants with prolonged half-life and acceptable development profiles. First, a panel of saturation point mutations was created at 11 key FcRn-interacting sites on the Fc region of an antibody. Multiple variants with slower FcRn dissociation kinetics than the wildtype (WT) antibody at pH 6.0 were successfully identified. The mutations were further combined and characterized for pH-dependent FcRn binding properties, thermal stability and the FcγRIIIa and rheumatoid factor binding. The most promising variants, YD (M252Y/T256D), DQ (T256D/T307Q) and DW (T256D/T307W), exhibited significantly improved binding to FcRn at pH 6.0 and retained similar binding properties as WT at pH 7.4. The pharmacokinetics in human FcRn transgenic mice and cynomolgus monkeys demonstrated that these properties translated to significantly prolonged plasma elimination half-life compared to the WT control. The novel variants exhibited thermal stability and binding to FcγRIIIa in the range comparable to clinically validated YTE and LS variants, and showed no enhanced binding to rheumatoid factor compared to the WT control. These engineered Fc mutants are promising new variants that are widely applicable to therapeutic antibodies, to extend their circulation half-life with obvious benefits of increased efficacy, and reduced dose and administration frequency.

Like this post but not a member? Please join!