Variable expression of immunoreactive surface proteins of Propionibacterium acnes Lodes, Michael J. and Secrist, Heather and Benson, Darin R. and Jen, Shyian and Shanebeck, Kurt D. and Guderian, Jeffrey and Maisonneuve, Jean-François and Bhatia, Ajay and Persing, David and Patrick, Sheila and Skeiky, Yasir A. W.,, 152, 3667-3681 (2006), doi = https://doi.org/10.1099/mic.0.29219-0, publicationName = Microbiology Society, issn = 1350-0872, abstract= Despite accumulating data implicating Propionibacterium acnes in a variety of diseases, its precise role in infection remains to be determined. P. acnes antigen-specific CD4+ T cells are present in early inflamed acne lesions and may be involved in the inflammatory response; however, little is known about the specific antigens involved. In this study, B cell and T cell antigens from P. acnes expression libraries were cloned and evaluated and the four predominant proteins identified were investigated. Two of these antigens share some homology with an M-like protein of Streptococcus equi and have dermatan-sulphate-binding activity (PA-25957 and 5541). The remaining two antigens, PA-21693 and 4687, are similar to the product of the Corynebacterium diphtheriae htaA gene from the hmu ABC transport locus, although only one of these (PA-21693) is encoded within an hmu-like operon and conserved amongst a range of clinical isolates. All four proteins contain an LPXTG motif, although only PA-21693 contains a characteristic sortase-sorting signal. Variation in the expression of PA-4687, 25957 and 5541 is evident amongst clinical isolates and is generated both by frameshifts associated with the putative signal peptide and by variable numbers of repeat regions toward the carboxy-terminus, potentially generating heterogeneity of molecular mass and antigenic variation. In addition, in the case of PA-25957, a frameshift in a C-rich region at the extreme carboxy-terminus eliminates the LPXTG motif in some isolates. For the dermatan-sulphate-binding PA-25957, IgG1 antibody in serum from acne-positive donors was shown to be specific for the amino-terminal region of the protein, which also contains a CD4+ T cell epitope. In contrast, serum from acne-negative donors shows an IgG2 and IgG3 antibody subclass response to the carboxy-terminal region. These data have implications for the potential role of P. acnes in inflammatory acne and other diseases., language=, type=