TY - JOUR
T1 - Expression, Immunogenicity and Variation of Iron-Regulated Surface Protein A from Bovine Isolates of Staphylococcus aureus
AU - Misra, Neha
AU - Wines, Tyler F.
AU - Knopp, Colton L.
AU - McGuire, Mark A.
AU - Tinker, Juliette K.
PY - 2017/5/1
Y1 - 2017/5/1
N2 - Staphylococcus aureus iron-regulated surface protein A (IsdA) is a fibrinogen and fibronectin adhesin that also contributes to iron sequestration and resistance to innate immunity. IsdA is conserved in human isolates and has been investigated as a human vaccine candidate. Here we report the expression of isd A, the efficacy of anti-IsdA responses and the existence of IsdA sequence variants from bovine Staphylococcus. Clinical staphylococci were obtained from US dairy farms and assayed by PCR for the presence and expression of isd A. isd A-positive species from bovines included S. aureus , S. haemolyticus and S. chromogenes . Immunoassays on bovine milk and serum confirmed the induction and opsonophagocytic activity of anti-IsdA humoral responses. The variable region of isd A was sequenced and protein alignments predicted the presence of two main variants consistent with those from human S. aureus . Mouse antibodies against one IsdA variant reduced staphylococcal binding to fibronectin in vitro in an isotype-dependent manner. Purified IsdA variants bound distinctly to fibronectin and fibrinogen. Our findings demonstrate that variability within the C-terminus of this adhesin affects immune reactivity and binding specificity, but are consistent with the significance of IsdA in bovine disease and relevant for vaccine development.
AB - Staphylococcus aureus iron-regulated surface protein A (IsdA) is a fibrinogen and fibronectin adhesin that also contributes to iron sequestration and resistance to innate immunity. IsdA is conserved in human isolates and has been investigated as a human vaccine candidate. Here we report the expression of isd A, the efficacy of anti-IsdA responses and the existence of IsdA sequence variants from bovine Staphylococcus. Clinical staphylococci were obtained from US dairy farms and assayed by PCR for the presence and expression of isd A. isd A-positive species from bovines included S. aureus , S. haemolyticus and S. chromogenes . Immunoassays on bovine milk and serum confirmed the induction and opsonophagocytic activity of anti-IsdA humoral responses. The variable region of isd A was sequenced and protein alignments predicted the presence of two main variants consistent with those from human S. aureus . Mouse antibodies against one IsdA variant reduced staphylococcal binding to fibronectin in vitro in an isotype-dependent manner. Purified IsdA variants bound distinctly to fibronectin and fibrinogen. Our findings demonstrate that variability within the C-terminus of this adhesin affects immune reactivity and binding specificity, but are consistent with the significance of IsdA in bovine disease and relevant for vaccine development.
KW - bovine
KW - iron-regulated surface protein
KW - staphylococcus aureus
UR - https://scholarworks.boisestate.edu/bio_facpubs/512
UR - https://doi.org/10.1093/femsle/fnx082
U2 - 10.1093/femsle/fnx082
DO - 10.1093/femsle/fnx082
M3 - Article
C2 - 28430959
JO - History Faculty Publications and Presentations
JF - History Faculty Publications and Presentations
ER -