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Mechanisms of Variable p44 Expression by Anaplasma phagocytophilum
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| Zeitschriftentitel: | Infection and Immunity |
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| Personen und Körperschaften: | , , , |
| In: | Infection and Immunity, 71, 2003, 10, S. 5650-5661 |
| Format: | E-Article |
| Sprache: | Englisch |
| veröffentlicht: |
American Society for Microbiology
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| Schlagwörter: |
| Zusammenfassung: | <jats:title>ABSTRACT</jats:title> <jats:p> The human intragranulocytic bacterium <jats:italic>Anaplasma phagocytophilum</jats:italic> promotes variation of P44s, which are surface-exposed proteins encoded by a <jats:italic>p44</jats:italic> multigene family. In the present study, the specific <jats:italic>p44</jats:italic> gene expression loci in four strains of <jats:italic>A. phagocytophilum</jats:italic> were identified and it was determined that each consisted of four tandem genes, <jats:italic>tr1</jats:italic> , <jats:italic>omp-1X</jats:italic> , <jats:italic>omp-1N</jats:italic> , and <jats:italic>p44</jats:italic> . A putative σ <jats:sup>70</jats:sup> -type promoter was found upstream of <jats:italic>tr1</jats:italic> . The <jats:italic>p44</jats:italic> genes include a central hypervariable region flanked by conserved regions. The hypervariable region sequence in the <jats:italic>p44</jats:italic> expression locus was duplicated and, regardless of the expression status, conserved at another locus in both low- and high-passage cell cultures of strain NY-37. No significant differences in the hypervariable region were found when we compared <jats:italic>p44</jats:italic> sequences, at the level of cDNA, within the expression locus and within other loci in the genomes of strains NY-37 and HZ. Similarly, in cDNA isolated from patients and from assorted cultures of strains NY-31, NY-36, and NY-37, hypervariable regions of 450 deduced amino acid sequences of various <jats:italic>p44</jats:italic> s within each strain were found to be identical, as were those of <jats:italic>p44</jats:italic> sequences in the genome of strain HZ. These data suggest that variations in <jats:italic>p44</jats:italic> sequences at the level of the <jats:italic>p44</jats:italic> expression locus occur through unidirectional conversion of the entire (nonsegmental) <jats:italic>p44</jats:italic> hypervariable region including flanking regions with a corresponding sequence copied from one of the conserved donor <jats:italic>p44</jats:italic> genomic loci. The data suggest that the P44 antigenic repertoire within the hypervariable region is restricted. </jats:p> |
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| Umfang: | 5650-5661 |
| ISSN: |
0019-9567
1098-5522 |
| DOI: | 10.1128/iai.71.10.5650-5661.2003 |