Characterization of Leptospiral Outer Membrane Lipoprotein LipL36: Downregulation Associated with Late-Log-Phase Growth and Mammalian Infection
| Autor: | David A. Haake, Jay D. Pruetz, Ellen S. Shang, Carole A. Bolin, Mary K. Mazel, Carleen Martinich, Theresa A. Summers, Adam M. McCoy |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Male
Signal peptide Octoxynol Molecular Sequence Data Immunology Down-Regulation Molecular cloning Microbiology Mice Cricetinae Gene expression Animals Leptospirosis Amino Acid Sequence Peptide sequence Leptospira Base Sequence Mesocricetus biology biology.organism_classification Antibodies Bacterial Molecular biology Anti-Bacterial Agents Infectious Diseases Leptospira kirschneri Solubility Membrane protein Molecular and Cellular Pathogenesis Female Parasitology Peptides Bacterial outer membrane Bacterial Outer Membrane Proteins |
| Zdroj: | Infection and Immunity. 66:1579-1587 |
| ISSN: | 1098-5522 0019-9567 |
| DOI: | 10.1128/iai.66.4.1579-1587.1998 |
| Popis: | We report the cloning of the gene encoding a 36-kDa leptospiral outer membrane lipoprotein, designated LipL36. We obtained the N-terminal amino acid sequence of a staphylococcal V8 proteolytic-digest fragment in order to design an oligonucleotide probe. A Lambda-Zap II library containing Eco RI fragments of Leptospira kirschneri DNA was screened, and a 2.3-kb DNA fragment which contained the entire structural lipL36 gene was identified. Several lines of evidence indicate that LipL36 is lipid modified in a manner similar to that of LipL41, a leptospiral outer membrane lipoprotein we described in a previous study (E. S. Shang, T. A. Summers, and D. A. Haake, Infect. Immun. 64:2322–2330, 1996). The deduced amino acid sequence of LipL36 would constitute a 364-amino-acid polypeptide with a 20-amino-acid signal peptide, followed by an L-X-Y-C lipoprotein signal peptidase cleavage site. LipL36 is solubilized by Triton X-114 extraction of L. kirschneri ; phase separation results in partitioning of LipL36 exclusively into the hydrophobic, detergent phase. LipL36 is intrinsically labeled during incubation of L. kirschneri in media containing [ 3 H]palmitate. Processing of LipL36 is inhibited by globomycin, a selective inhibitor of lipoprotein signal peptidase. After processing, LipL36 is exported to the outer membrane along with LipL41 and lipopolysaccharide. Unlike LipL41, there appears to be differential expression of LipL36. In early-log-phase cultures, LipL36 is one of the most abundant L. kirschneri proteins. However, LipL36 levels drop considerably beginning in mid-log phase. LipL36 expression in vivo was evaluated by examining the humoral immune response to leptospiral antigens in the hamster model of leptospirosis. Hamsters surviving challenge with culture-adapted virulent L. kirschneri generate a strong antibody response to LipL36. In contrast, sera from hamsters surviving challenge with host-adapted L. kirschneri do not recognize LipL36. These findings suggest that LipL36 expression is downregulated during mammalian infection, providing a marker for studying the mechanisms by which pathogenic Leptospira species adapt to the host environment. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|