Chimeric epitope vaccine against Leptospira interrogans infection and induced specific immunity in guinea pigs.
BACKGROUND
Leptospirosis is an important reemerging zoonosis, with more than half a million cases reported annually, and is caused by pathogenic Leptospira species. Development of a universal vaccine is one of the major strategic goals to overcome the disease burden of leptospirosis. In this study, a chimeric multi-epitope protein-based vaccine was designed and tested for its potency to induce a specific immune response and provide protection against L. interrogans infection.


RESULTS
The protein, containing four repeats of six T- and B-cell combined epitopes from the leptospiral outer membrane proteins, OmpL1, LipL32 and LipL21, was expressed and purified. Western blot analysis showed that the recombinant protein (named r4R) mainly expressed in a soluble pattern, and reacted with antibodies raised in rabbit against heat-killed Leptospira and in guinea pigs against the r4R vaccine. Microscopic agglutination tests showed that r4R antisera was immunological cross-reactive with a range of Chinese standard reference strains of Leptospira belonging to different serogroups. In guinea pigs, the r4R vaccine induced a Th1-biased immune response, as reflected by the IgG2a/IgG1 ratio and cytokine production of stimulated splenocytes derived from immunized animals. Finally, r4R-immunized guinea pigs showed increased survival of lethal Leptospira challenges compared with PBS-immunized animals and tissue damage and leptospiral colonization of the kidney were reduced.


CONCLUSIONS
The multi-epitope chimeric r4R protein is a promising antigen for the development of a universal cross-reactive vaccine against leptospirosis.
["Lin|Xu'ai|X|", 'Xiao|Guohui|G|', 'Luo|Dongjiao|D|', 'Kong|Liangliang|L|', 'Chen|Xu|X|', 'Sun|Dexter|D|', 'Yan|Jie|J|']
D000372:Agglutination Tests D000818:Animals D000907:Antibodies, Bacterial D000942:Antigens, Bacterial D001402:B-Lymphocytes D001425:Bacterial Outer Membrane Proteins D001428:Bacterial Vaccines D015153:Blotting, Western D056738:Cross Protection D003429:Cross Reactions D016207:Cytokines D004195:Disease Models, Animal D018985:Epitopes, B-Lymphocyte D018984:Epitopes, T-Lymphocyte D006168:Guinea Pigs D007074:Immunoglobulin G D007921:Leptospira interrogans D007922:Leptospirosis D008074:Lipoproteins D011817:Rabbits D011993:Recombinant Fusion Proteins D013601:T-Lymphocytes
Vaccine Leptospira Multi-epitope Outer membrane protein Cross protection