A recombinant Der p 1-specific allergen-toxin demonstrates superior killing of allergen-reactive IgG+ hybridomas in comparison to its recombinant allergen-drug conjugate

A K Daramola; O A Akinrinmade; E A Fajemisin; K Naran; N Mthembu; S Hadebe; F Brombacher; A M Huysamen; O E Fadeyi; R Hunter; S Barth

doi:10.1093/immadv/ltac023

A recombinant Der p 1-specific allergen-toxin demonstrates superior killing of allergen-reactive IgG⁺ hybridomas in comparison to its recombinant allergen-drug conjugate

Immunother Adv. 2022 Dec 6;3(1):ltac023. doi: 10.1093/immadv/ltac023. eCollection 2023.

Authors

A K Daramola^{1

2}, O A Akinrinmade^{1

2

3}, E A Fajemisin^{1

2}, K Naran^{1

2}, N Mthembu⁴, S Hadebe⁴, F Brombacher^{4

5

6}, A M Huysamen⁷, O E Fadeyi⁷, R Hunter⁷, S Barth^{1

2}

Affiliations

¹ South African Research Chair in Cancer Biotechnology, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
² Medical Biotechnology & Immunotherapy Research Unit, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
³ Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
⁴ Division of Immunology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
⁵ International Centre for Genetic Engineering and Biotechnology (ICGEB) and Institute of Infectious Diseases and Molecular Medicine (IDM), Division of Immunology, Faculty of Health Sciences, University of Cape Town, South Africa.
⁶ Wellcome Centre for Infectious Diseases Research in Africa (CIDRI-Africa), Institute of Infectious Diseases and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, South Africa.
⁷ Department of Chemistry, Faculty of Sciences, University of Cape Town, Cape Town, South Africa.

Abstract

Introduction: Current treatments for asthma help to alleviate clinical symptoms but do not cure the disease. In this study, we explored a novel therapeutic approach for the treatment of house dust mite allergen Der p 1induced asthma by aiming to eliminate specific population of B-cells involved in memory IgE response to Der p 1.

Materials and methods: To achieve this aim, we developed and evaluated two different proDer p 1-based fusion proteins; an allergen-toxin (proDer p 1-ETA) and an allergen-drug conjugate (ADC) (proDer p 1-SNAP-AURIF) against Der p 1 reactive hybridomas as an in vitro model for Der p 1 reactive human B-cells. The strategy involved the use of proDer p 1 allergen as a cell-specific ligand to selectively deliver the bacterial protein toxin Pseudomonas exotoxin A (ETA) or the synthetic small molecule toxin Auristatin F (AURIF) into the cytosol of Der p 1 reactive cells for highly efficient cell killing.

Results: As such, we demonstrated recombinant proDer p 1 fusion proteins were selectively bound by Der p 1 reactive hybridomas as well as primary IgG1⁺ B-cells from HDM-sensitized mice. The therapeutic potential of proDer p 1-ETA' and proDer p 1-SNAP-AURIF was confirmed by their selective cytotoxic activities on Der p 1 reactive hybridoma cells. The allergen-toxin demonstrated superior cytotoxic activity, with IC₅₀ values in the single digit nanomolar value, compared to the ADC.

Discussions: Altogether, the proof-of-concept experiments in this study provide a promising approach for the treatment of patients with house dust mite-driven allergic asthma.

Keywords: Allergen-toxin; Auristatin F and Pseudomonas exotoxin A; Der p 1; allergen-drug conjugate; house dust mite.