Immune reactivity to type VII collagen: implications for gene therapy of recessive dystrophic epidermolysis bullosa

Abstract

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe genodermatosis caused by loss-of-function mutations in COL7A1 encoding type VII collagen, the component of anchoring fibrils. As exogenous type VII collagen may elicit a deleterious immune response in RDEB patients during upcoming clinical trials of gene therapies or protein replacement therapies, we developed enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunosorbent spot (ELISPOT) assays to analyze B-and T-cell responses, to the full-length type VII collagen. The ELISA was highly sensitive and specific when tested against sera from 41 patients with epidermolysis bullosa acquisita (EBA), and the IFN-g ELI-SPOT detected a cellular response that correlated with ongoing EBA manifestations. Both tests were next applied to assess the risk of an immune response to type VII collagen in seven RDEB patients with a range of type VII collagen expression profiles. Immune responses against type VII collagen were dependent on the expression of type VII collagen protein, and consequently on the nature and position of the respective COL7A1 mutations. These immunologic tests will be helpful for the selection of RDEB patients for future clinical trials aiming at restoring type VII collagen expression, and in monitoring their immune response to type VII collagen after treatment.

Prevalence of collagen VII-specific autoantibodies in patients with autoimmune and inflammatory diseases

“…Several immunoassays have been developed so far for the detection of autoantibodies against collagen VII (Table 2) [22,25-27]. To further improve the detection of collagen VII-specific autoantibodies, in the present study we have generated a chimeric antigen substrate containing virtually all autoepitopes, which have been reported in previous epitope mapping studies in patients.…”

“…For detection of collagen VII-specific IgG autoantibodies by ELISA, immunoassays using recombinant forms of the NC1 domain or the full-length molecule have been developed [22,25-27]. Based on B cell epitope in silico prediction and wetlab mapping studies, a recombinant form of collagen VII containing both the NC1 and NC2 domains as well as the hinge region would allow a most sensitive detection of anti-collagen VII antibodies in patients.…”

Black Patients of African Descent and HLA-DRB1*15:03 Frequency Overrepresented in Epidermolysis Bullosa Acquisita

“…Direct IF and indirect IF on rat and/or monkey esophagus and salt-split skin, as well as antinuclear antibodies, were routinely processed, and direct immunoelectron microscopy and ELISA for type VII collagen were performed as previously described (Prost et al, 1987;Pendaries et al, 2010).…”

De Novo Anti-Type VII Collagen Antibodies in Patients with Recessive Dystrophic Epidermolysis Bullosa

“…A previous smaller study found that 1 of 7 RDEB patients exhibited anti-C7 antibodies by ELISA (Pendaries et al, 2010). In accordance with our data herein, a recent study of 17 RDEB patients showed that 15 of 17 of the patients exhibited anti-C7 antibodies (Tampolini et al, 2013).…”