LaHood NA*, Min J*, Keswani T, Richardson CM, Amoako K, Zhou J, Marini-Rapoport O, Bernard H, Hazebrouck S, Shreffler WG, Love JC, Pomes A, Pedersen LC, Mueller GA, Patil SU. Immunotherapy-induced neutralizing antibodies disrupt allergen binding and sustain allergen tolerance in peanut allergy. J Clin Invest. 2023 Jan 17;133(2):e164501. doi: 10.1172/JCI164501. PMID: 36647835; PMCID: PMC9843057.
While immunotherapy has been used for over a hundred years in the field of allergy, the mechanism of long-lived tolerance after therapy has been elusive. Here, we described for the first time, neutralizing antibodies that underlie long-lived tolerance after peanut oral immunotherapy. These antibodies bind to the dominant allergen Ara h 2 in a unique location, which gives them their functional capacity to prevent many different pathogenic antibodies from being able to bind to the allergen, thereby preventing allergic activation. This paper contains the first crystal structure of the dominant allergen Ara h 2 as well as the first crystal structure of human-derived monoclonal antibodies that bind to the allergen. Even more importantly, the comprehensive epitope mapping presented in this paper has spurred further industry efforts to develop new therapeutic approaches. This paper is also the basis of a filed patent on therapeutic use of Ara h 2 antibodies, which is the first in the field to be filed.
Keswani T, LaHood NA, Marini-Rapoport O, Karmakar B, Andrieux L, Reese B, Sneed SL, Pedersen LC, Mueller GA, Patil SU. Neutralizing IgG4 antibodies are a biomarker of sustained efficacy after peanut oral immunotherapy. J Allergy Clin Immunol. 2024 Jun;153(6):1611-1620.e7. doi: 10.1016/j.jaci.2024.02.017
Using the epitope mapping from the previous work, this paper studied the combinatorial efficacy of blocking IgG antibodies. The combination of the previously identified two neutralizing antibodies results in maximal blocking of pathogenic IgE to the allergen. Furthermore, of all the IgG subclasses, only IgG4 neutralizing antibodies increase in individuals with sustained responses after immunotherapy. Finally, neutralizing IgG4 antibodies can completely block allergic reactions in a murine model of passive cutaneous anaphylaxis using human serum. This paper established that circulating neutralizing IgG4 antibodies structurally and functionally underlie sustained tolerance after immunotherapy, not only broadening the impact of the previous paper but also providing a novel biomarker of tolerance.
Min J*, Keswani T*, LaHood NA, Lytle IR, Marini-Rapoport O, Andrieux L, Sneed SL, Edwards LL, Petrovich RM, Perera L, Pomés A, Pedersen LC, Patil SU, Mueller GA. Design of an Ara h 2 hypoallergen from conformational epitopes. Clin Exp Allergy. 2024 Jan;54(1):46-55. doi: 10.1111/cea.14433. Epub 2024 Jan 2. PMID: 38168500; PMCID: PMC10843581.
In collaboration with structural biologists Drs. Mueller and Pedersen at NIEHS, comprehensive epitope mapping of human monoclonal antibodies from the Patil lab was performed, leading to the development of a hypoallergen with only 6 point mutations. These were then tested using well-characterized peanut-allergic sera by the Patil Laboratory to show significant abrogation of IgE binding, demonstrating the critical contribution of only 6 amino acids to the allergenicity of Ara h 2. The human relevance, both antibodies, serum, binding assays were all done in the Patil Lab. The shared first authorship reflects this contribution as Dr. Keswani is a post-doctoral fellow in the lab. This work led to a shared MGH-NIEHS patent on Ara h 2 mutants and their use in diagnostics and therapeutics.
Marini-Rapoport O, Fernández-Quintero ML, Keswani T, Zong G, Shim J, Pedersen LC, Mueller GA, Patil SU. Defining the cross-reactivity between peanut allergens Ara h 2 and Ara h 6 using monoclonal antibodies. Clin Exp Immunol. 2024 Mar 12;216(1):25-35. doi: 10.1093/cei/uxae005. PMID: 38346116; PMCID: PMC10929694.
In peanut, the allergen Ara h 2 is more dominant than Ara h 6 but the reason has not been known. Here, Ara h 6 is found to only have 3 of the 8 epitopes that Ara h 2 contains. Furthermore, the dynamics with Ara h 6 result in a less favorable binding kinetics to Ara h 6 than Ara h 2. This is the first paper to epitope-map Ara h 6, and the use of human monoclonal antibodies helped establish a way to dissect allergenic cross-reactivity. This cross-reactivity is a core principle of allergenicity, and those with more cross-reactive antibodies tend to have poorer outcomes.
Marini-Rapoport O, Andreiux L, Keswani T, Zong G, Duchen D, Yaari G, Min J, Lytle I, Rosenberg AF, Fucile C, Kobie JJ, Pipenbrink MS, Sun T, Martin VM, Yuan Q, Shreffler WG, Seppo AE, Jarvinen KM, Loeffler JR, Ward AB, Kleinstein SH, Pedersen LC, Fernandez-Quintero M, Mueller GA, Patil, SU. Germline-encoded recognition of peanut underlies convergent antibodies in human. Science Translational Medicine
Convergent, or public, antibodies to peanut were first discovered in 2015, by the Patil lab.
Humans develop antibodies to dietary antigens upon ingestion. Here, monoclonal antibodies were used to investigate convergent antibodies to peanut allergen Ara h 2. These have high affinity for Ara h 2 even before somatic hypermutation. These antibodies bind to Ara h 2 with homologous energetics, showing they are structurally convergent. This structural convergence occurs even in these antibodies when all mutations are removed, supporting that these binding interactions are encoded by common antibody genes. Using infant sera, this convergent antibody was found to occur early in life after peanut introduction. These data suggest that humans are inherently pre-programmed by their germline antibody repertoire to be poised to respond to peanut. This work is the first to suggest that allergenicity is due to human germline antibody recognition of antigens in a stereotyped fashion, providing a new paradigm for understanding how allergy can develop.