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A MECHANISM OF IMMUNITY TO LEPTOSPIROSIS
Author(s) -
Faine S,
Adler B,
Ruta G
Publication year - 1974
Publication title -
australian journal of experimental biology and medical science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0004-945X
DOI - 10.1038/icb.1974.28
Subject(s) - serotype , antiserum , virulence , leptospira , microbiology and biotechnology , leptospira interrogans , leptospirosis , immunization , biology , antibody , virology , immunity , antigen , adjuvant , titer , serology , immunology , immune system , biochemistry , gene
Summary A leptospisal serotype‐specific lipopolysaccharide antigen (LPS F4) coated on to erythrocytes (RBC) or emulsified in Freund's adjuvant elicited the production of serotype‐specific IgM haemagglutinating antibodies with a peak titre at 21‐24 days in rabbits, guinea‐pigs, mice and Australian hopping mice ( Notomys alexis) . The antibodies haemagglutinated specifically‐sensitized sheep erythrocytes (SRBC) and agglutinated whole leptospires of the homologous serotype. These activities were still detectable 60 days after immunization. Precipitation of homologous LPS‐F4 was observed in gels only with antisera taken between 20‐40 days after immunization. Rabbit antiserum to the LPS from Leptospira interrogans, serotype icterohaemorrhagiae. had a serotype‐specific leptospiricidal action in vitro, which can be inhibited by culture supernatant. In vivo the antiserum caused an increased rate of clearance of virulent leptospires from the bloodstream of mice. Young mice passively immunized with anti‐LPS F4 serum resisted subsequent challenge with virulent organisms and immunized animals showed a resistance to the development of the carrier state. Hopping mice immunized with LPS from serotype icterohaemorrhagiae either on RBC or in Freund's incomplete adjuvant were more resistant to lethal or carrier infection following challenge with leptospires of the same serotype than were unimmunized controls.