title: Cross-protective immunity against leptospirosis elicited by a live, attenuated lipopolysaccharide mutant.
abstract: BACKGROUND
  Leptospira species cause leptospirosis, a zoonotic disease found worldwide. Current vaccines against leptospirosis provide protection only against closely related serovars.
  
  
  METHODS
  We evaluated an attenuated transposon mutant of Leptospira interrogans serovar Manilae (M1352, defective in lipopolysaccharide biosynthesis) as a live vaccine against leptospirosis. Hamsters received a single dose of vaccine and were challenged with the homologous serovar (Manilae) and a serologically unrelated heterologous serovar (Pomona). Comparisons were made with killed vaccines. Potential cross-protective antigens against leptospirosis were investigated.
  
  
  RESULTS
  Live M1352 vaccine induced superior protection in hamsters against homologous challenge. The live vaccine also stimulated cross-protection against heterologous challenge, with 100% survival (live M1352) versus 40% survival (killed vaccine). Hamsters receiving either vaccine responded to the dominant membrane proteins LipL32 and LipL41. Hamsters receiving the live vaccine additionally recognized LA3961/OmpL36 (unknown function), Loa22 (OmpA family protein, recognized virulence factor), LA2372 (general secretory protein G), and LA1939 (hypothetical protein). Manilae LigA was recognized by M1352 vaccinates, whereas LipL36 was detected in Pomona.
  
  
  CONCLUSIONS
  This study demonstrated that a live, attenuated vaccine can stimulate cross-protective immunity to L. interrogans and has identified antigens that potentially confer cross-protection against leptospirosis.
authors.affiliation: Faculty of Medicine, Melioidosis Research Center, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Amporn
authors.initials: A
authors.lastname: Srikram
authors.forename: Kunkun
authors.initials: K
authors.lastname: Zhang
authors.forename: Thanatchaporn
authors.initials: T
authors.lastname: Bartpho
authors.forename: Miranda
authors.initials: M
authors.lastname: Lo
authors.forename: David E
authors.initials: DE
authors.lastname: Hoke
authors.forename: Rasana W
authors.initials: RW
authors.lastname: Sermswan
authors.forename: Ben
authors.initials: B
authors.lastname: Adler
authors.forename: Gerald L
authors.initials: GL
authors.lastname: Murray
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology*; D006224:Cricetinae; D003429:Cross Reactions; D016207:Cytokines / Q000096:biosynthesis / Q000097:blood / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D015870:Gene Expression; D007921:Leptospira interrogans / Q000235:genetics / Q000276:immunology*; D007922:Leptospirosis / Q000517:prevention & control*; D008647:Mesocricetus; D009154:Mutation; D014613:Vaccines, Attenuated / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D016207:Cytokines; D014613:Vaccines, Attenuated