Autoimmunity to deltaNp63alpha in chronic ulcerative stomatitis.

Area of Science:

• Immunology
• Dermatology
• Oral Medicine

Background:

• Chronic ulcerative stomatitis (CUS) is a mucocutaneous disorder presenting with persistent, painful oral ulcers.
• Diagnosis relies on detecting antinuclear antibodies (ANA) specific to deltaNp63alpha, a protein in stratified squamous epithelia basal cells.

Purpose of the Study:

• To comprehensively characterize the autoimmune response in patients diagnosed with CUS.
• Investigate antibody isotypes, immunodominant regions of deltaNp63alpha, and cross-reactivity with related proteins.

Main Methods:

• Utilized in vitro transcription/translation of PCR-amplified cDNAs to produce deltaNp63alpha protein antigens.
• Employed immunoblotting and immunoprecipitation assays using CUS patient serum.
• Analyzed antibody isotype, immunogenic domains, and cross-reactivity with p53, p73, and p63 proteins.

Main Results:

• Confirmed the presence of antibodies against deltaNp63alpha in CUS patients.
• Identified that 52% of CUS cases exhibit circulating IgA isotype antibodies.
• Determined the N-terminal and DNA-binding domains of deltaNp63alpha as the primary immunodominant regions.
• Observed limited antibody cross-reactivity with p53, p63, and p73 isoforms.

Conclusions:

• The autoimmune response in CUS is directed against the deltaNp63alpha protein.
• IgA antibodies and specific domains of deltaNp63alpha are significant in CUS pathogenesis.
• Limited cross-reactivity suggests deltaNp63alpha is a relatively specific target in CUS autoimmunity.