immunology of infectious and parasitic diseases - XXXVII Congress ...

EVALUATION OF THE PROTECTIVE ABILITY OF LEISHMANIA INFANTUM
HISTONESIN THE INFECTION BY LEISHMANIA CHAGASI INFECTION IN
HAMSTERS
LAÍS PEREIRA 1 ; MELISSA ABBEHUSEN 1 ; JUREMA CUNHA 1 ; ALDINA
BARRAL 1 ; MANOEL BARRAL-NETTO 1 ; MANOEL SOTO 2 ; CLÁUDIA
BRODSKYN 1 .
1:FIOCruz - Centro de Pesquisas Gonçalo Moniz – LIMI 2:Universidade
Autónoma de Madrid,Centro de Biología Molecular Severo Ochoa,
Departamento de Biología Molecular
Introduction: Histones proteins are highly conserved antigens produced by
Leishmania, which are capable to induce a strong immune response. In
previous studies, genetic immunization with four histones, protected BALB/c
mice after challenge with L. braziliensis, controlling inflammation at the site of
infection and parasite spreading. We evaluated the immunoprotectiveability of
hamsters immunization using DNA or/and recombinant histones proteins
employing homologous and heterologous strategy against infection by L.
chagasi.
Methodology and Results: Two to 4 months male hamsters (15 per group)
were immunized with pcDNA3, pcDNA3LiH2A-H3, pcDNA3LiH2B-H4+ and /or
HIS( pQE-LiH2A; pQE-LiH2B, pQE-LiH3 e pQE-LiH4) plus CpG, three times, at
fifteen days of interval. After last immunization, sera and draining lymph node
were collected for serologic tests and quantification of cytokine, respectively.
Animals were challenged by intradermal route with 10 5 L. chagasi promastigotes
plus 1/2 pair of Lutzomya longipalpis salivary gland. Two, 5 and 7 months after
challenge, draining lymph node, spleen and liver were obtained to evaluate
parasite load during infection by limiting dilution. Only animals that received
heterologous strategy of vaccination showed significantly IgG antibodies anti-
His (p