The potential immunogenicity of human insulin and insulin analogues evaluated in a transgenic mouse model

Abstract

Transgenic mice with tissue-specific expression of the human insulin gene in the beta cells of the pancreas do not produce insulin-specific antibodies when injected with human insulin. Tolerant transgenic mice injected with human or porcine insulin reflect the clinical situation. When injected with bovine insulin the transgenic mice produce antibodies. The potential immunogenicity of 12 recombinant human insulin analogues has been tested in this transgenic model. The analogues were designed either to prevent hexamer formation or to improve chemical stability or both. The analogues have amino acid substitutions or deletions at residue 8, 10 and 21 in the A-chain and residue 3, 9, 27 and 28 in the B-chain. The results show that substitution of single amino acids in the A-chain loop of human insulin for the corresponding amino acids in bovine insulin at residues A8 or A10 is sufficient to elicit an antibody response in responder mice. Only human insulin analogues with substitutions at residues 8 or 10 in the A-chain elicit antibody formation in the transgenic mice, whereas non-transgenic control groups respond to insulin and all analogues. Antibodies developed against the human insulin analogues are cross reactive with recombinant human insulin. Antibodies developed against an immunogenic analogue could therefore neutralize both the analogue and the native insulin and thereby aggravate the patient's condition. This transgenic mouse immunogenicity model should be useful as an in vivo model to map immunogenic areas of recombinant proteins.

Allergy reactions to insulin: effects of continuous subcutaneous insulin infusion and insulin analogues

“…Interestingly, in vitro data suggested that insulin aggregates rather than native monomers cause cutaneous allergy and that antigenicity of insulin preparations correlates with the relative concentration of aggregates [16]. Structural changes leading to insulin lispro and insulin aspart (monomeric insulins) were initially reported to result in decreased immunogenicity in in vivo studies [17,18]. However, recent studies with both insulin lispro [42,43] or insulin aspart [44] rather reported results supporting similar immunogenicity of the two analogues when compared to human regular insulin.…”

“…For instance, continued use of subcutaneous insulin-infusion pumps raises the important issue of stability of insulin within the delivery system as insulin aggregates may promote insulin hypersensitivity reactions [16]. Furthermore, insulin analogues, resulting from a modified sequence of amino acids of recombinant human insulin, may present new epitopes for recognition by the immune system and thus potentially alter the antigenicity and immunogenicity of insulin in diabetic patients [17][18][19]. However, as previously suggested [16], the development of physically stable insulin monomers (thus reducing the risk of insulin aggregates) may further decrease the clinical incidence of cutaneous insulin allergy as compared to human regular insulin and minimize the complications associated with insulininfusion therapy.…”

Immune Responses to Insulin Aspart and Biphasic Insulin Aspart in People With Type 1 and Type 2 Diabetes

“…Beef insulin differs from HI by three amino acids, whereas porcine insulin differs by one amino acid at position B30. IAsp differs from HI by one amino acid at position B28 and was as immunogenic as porcine insulin and less immunogenic than bovine insulin in a transgenic mouse model (16). When studying experiences with beef and pork insulin, it has to be kept in mind that the first such preparations contained insulin-like contaminants that could also be immunogenic.…”

Effect of cow's milk exposure and maternal type 1 diabetes on cellular and humoral immunization to dietary insulin in infants at genetic risk for type 1 diabetes. Finnish Trial to Reduce IDDM in the Genetically at Risk Study Group.

“…When BI was used for treatment of type 1 diabetes, it induced insulin-binding antibodies (27). Interspecies differences in insulin have also been reported to be important for antigenic recognition (28) and for tolerance induction (29,30). A one-amino acid difference in the B-chain of the insulin molecule was crucial for prevention of autoimmune diabetes in NOD mice (30).…”