The tprK Gene Is Heterogeneous among Treponema pallidum Strains and Has Multiple Alleles
AUTOR(ES)
Centurion-Lara, Arturo
FONTE
American Society for Microbiology
RESUMO
We have previously shown that the TprK antigen of T. pallidum, Nichols strain, is predominantly expressed in treponemes obtained 10 days after infection and that the hydrophilic domain of TprK is a target of opsonic antibodies and confers significant protection against homologous challenge. The T. pallidum genome sequence reported the presence of a single copy of the tprK gene in the Nichols strain. In the present study we demonstrate size heterogeneity in the central portions of the TprK hydrophilic domains of 14 treponemal isolates. Sequence analysis of the central domains and the complete open reading frames (ORFs) of the tprK genes confirms this heterogeneity. Further, multiple tprK sequences were found in the Nichols-defined tprK locus in three isolates (Sea 81-4, Bal 7, and Bal 73-1). In contrast, only a single tprK sequence could be identified in this locus in the Nichols strain. Alignment of the DNA and deduced amino acid sequences of the whole tprK ORFs shows the presence of seven discrete variable domains flanked by highly conserved regions. We hypothesize that these heterogeneous regions may be involved in antigenic heterogeneity and, in particular, evasion of the immune response. The presence of different tprK alleles in the tprK locus strongly suggests the existence of genetically different subpopulations within treponemal isolates.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=97211Documentos Relacionados
- The Sequence-Variable, Single-Copy tprK Gene of Treponema pallidum Nichols Strain UNC and Street Strain 14 Encodes Heterogeneous TprK Proteins
- Sequence Diversity of Treponema pallidum subsp. pallidum tprK in Human Syphilis Lesions and Rabbit-Propagated Isolates
- Multiple Alleles of Treponema pallidum Repeat Gene D in Treponema pallidum Isolates
- Sequence Conservation of Glycerophosphodiester Phosphodiesterase among Treponema pallidum Strains
- Conservation of the 15-kilodalton lipoprotein among Treponema pallidum subspecies and strains and other pathogenic treponemes: genetic and antigenic analyses.
