Analysis of host cell binding specificity mediated by the Tp0136 adhesin of the syphilis agent Treponema pallidum subsp. pallidum
Fig 5
Both purified tissue fibronectin and laminin bind to Tp0136 alleles expressed on B314 strain.
Spirochetes on coverglasses were incubated with purified tissue fibronectin or laminin and binding was detected using anti-fibronectin (antiFn-FITC), 2nd row from top, and anti-laminin (DyLight 410) using YFP filter (antiLm-YFP) antibodies, bottom row. DAPI stained DNA in B314 transformants depict all spirochetes present in the respective microscopic fields. Top row shows all spirochetes in the field of view depicting fibronectin binding (2nd row) while 3rd row shows all transformed B314 in the field of view showing laminin binding (bottom row). Both allelic variants of Tp0136 showed similar efficiency in binding to fibronectin. Overall, binding of laminin to both Tp0136-expressing strains was observed with more pronounced binding to B314 expressing the SS14 Tp0136, compared to the strain expressing the Nichols variant. No laminin binding to B314(V) control was detected. Bars represent 16 μm.