Research in this laboratory focuses on Treponema pallidum, the etiologic agent of syphilis. Our goal is to define the function and cellular localization of the Tpr proteins, a newly identified multi-membered antigen family. Specifically, we will determine whether Tpr antigens are playing an important role in immune evasion by mechanisms such as antigenic and phase variation. We have shown the presence of different tprK alleles in treponemal subpopulations within T. pallidum isolates and identified a gene conversion-like mechanism for generation of tprK diversity during active infection. We are attempting to elucidate the role of the different recombination pathways (Rec A, Rec F pathway) as well as from site specific recombinases in the generation of tprK heterogeneity. 

This laboratory is also studying the different elements involved in regulation of expression of the tpr genes (operons, promoters, termination sites, sigma factors), and, in collaboration with Drs. Sheila Lukehart and Wesley Van Voorhis, we are studying the transcription patterns and the genetic diversity of the tpr genes in different T. pallidum strains.

Centurion-Lara A, Eileen SS, Barrett LK, Castro C, Lukehart SA, Van Voorhis WC. Multiple alleles of Treponema pallidum repeat gene D in Treponema pallidum isolates. J Bacteriol 182:2332-5, 2001.

Centurion-Lara A, Godornes C, Castro C, Van Voorhis WC, Lukehart SA. The tprK gene is heterogeneous among Treponema pallidum strains and has multiple alleles. Infect Immun 68:824-31, 2000.

Centurion-Lara A, Castro C, Barrett L, Cameron C, Mostowfi M, Van Voorhis WC, Lukehart SA. Treponema pallidum major sheath protein homologue TprK is a target of opsonic antibody and the protective immune response. J Exp Med 189:647-56, 1999.

Centurion-Lara A, Castro C, Castillo R, Shaffer JM, Van Voorhis WC, Lukehart SA. The flanking region sequences of the 15-kDa lipoprotein gene differentiate pathogenic treponemes. J Infect Dis 177:1036-40, 1998.