Generation of therapeutic antibody responses against IgE through vaccination

Abstract

IgE is the central mediator in atopic allergies such as hay fever, eczema, and asthma; therefore, it is a prime target in the development of allergen-independent preventive treatments. We describe an active immunization strategy that has the potential to reduce IgE to a clinically significant extent. The active vaccine component is a chimeric IgE molecule, Cepsilon2-Cepsilon3-Cepsilon4. The receptor-binding target domain, Cepsilon3, is derived from the recipient species, whereas the flanking domains, Cepsilon2 and Cepsilon4, are derived from an evolutionarily distant mammal. The flanking domains have dual functions, acting both as structural support for the Cepsilon3 domain and to break T cell tolerance by providing foreign T cell epitopes. The efficacy of the vaccine was studied in an ovalbumin-sensitized rat model. Vaccination resulted in antibody responses against IgE in all rats and in a substantial reduction in serum IgE levels in three out of four strains. The skin reactivity upon allergen challenge was significantly reduced in vaccinated animals. The vaccine appears to be safe to use as an antigen. No cross-linking activity was observed in sera of vaccinated animals, and the response to vaccination was reversible with time. Our results suggest that active immunization against IgE has the potential to become a therapeutic method for humans.

Mast Cell Chymase Degrades the Alarmins Heat Shock Protein 70, Biglycan, HMGB1, and Interleukin-33 (IL-33) and Limits Danger-induced Inflammation

“…The vector constructs encoding the HC were transfected into the human embryonic kidney cell line (HEK 293 EBNA) at ϳ80% confluency, using Lipofectamine (Invitrogen) as described previously (40). Selection of transfected cells was initiated by the addition of 1.5 g/ml puromycin to the cell culture medium (DMEM supplemented with 5% FCS, 50 g/ml gentamicin, and 5 g/ml heparin).…”

Mast cells limit extracellular levels of IL-13 via a serglycin proteoglycan-serine protease axis

“…The sequence was ordered from Genscript Corporation (Piscataway, NJ, USA) as a fragment inserted in the vector pUC 57, with EcoRI and XhoI sites in the 5 ′ and 3 ′ ends, respectively. This fragment was excised from the vector by cleavage with EcoRI and XhoI and inserted in the mammalian expression vector pCEP-Pu2 (Vernersson et al , 2002 ). Following transfection of this construct into HEK-293 EBNA cells and selection with puromycin (1.5 μ g/ml fi nal concentration), a producer cell line was obtained.…”

Vaccines targeting IgE in the treatment of asthma and allergy

“…IgE vaccines were reported by coupling or fusing a significantly large portion of rat IgE (whole Cε2 and/or Cε3) to a heterogonous carrier protein (either the glutathione-S-transferase protein 72 or opossum Cε2 and Cε4 64 ) forming a chimeric IgE molecule 72 or a fusion protein. 64 In the fusion protein, the target rat Cε3 was inserted between opossum Cε2 and opossum Cε4, forming a fusion protein "ORO." To enhance the immunogenecity, a variant of the IgE vaccine was constructed by vaccine would be an important contribution to the field and should be undertaken in future studies.…”

“…1). Based on providing effective T cell help, two broad experimental strategies have been used to design such vaccines: (1) to modify the intact self-protein by inserting a foreign peptide containing Th epitopes 59 or (2) to chemically couple or fuse the intact self-protein, [60][61][62][63] or a considerable part thereof, 64 to an immunogenic carrier protein.…”

“…73 Administration of the IgE vaccine in ovalbumin-sensitized rats resulted in anti-rat IgE antibody responses and in a substantial reduction of serum IgE that corresponds to a 92% reduction. 64 Although these vaccines induced strong anti-self-IgE responses, the polyclonal antibodies to IgE induced by the vaccine act against all epitopes in the target Cε2 and/or Cε3, which may cross-react with other immunoglobulins containing the same epitopes.…”