title: Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation.
abstract: BACKGROUND
  Leishmania (Viannia) shawi parasite was first characterized in 1989. Recently the protective effects of soluble leishmanial antigen (SLA) from L. (V.) shawi promastigotes were demonstrated using BALB/c mice, the susceptibility model for this parasite. In order to identify protective fractions, SLA was fractionated by reverse phase HPLC and five antigenic fractions were obtained.
  
  
  METHODS
  F1 fraction was purified from L. (V.) shawi parasite extract by reverse phase HPLC. BALB/c mice were immunized once a week for two consecutive weeks by subcutaneous routes in the rump, using 25 μg of F1. After 1 and 16 weeks of last immunization, groups were challenged in the footpad with L. (V.) shawi promastigotes. After 2 months, those same mice were sacrificed and parasite burden, cellular and humoral immune responses were evaluated.
  
  
  RESULTS
  The F1 fraction induced a high degree of protection associated with an increase in IFN-γ, a decrease in IL-4, increased cell proliferation and activation of CD8+T lymphocytes. Long-term protection was acquired in F1-immunized mice, associated with increased CD4+ central memory T lymphocytes and activation of both CD4+ and CD8+ T cells. In addition, F1-immunized groups showed an increase in IgG2a levels.
  
  
  CONCLUSIONS
  The inductor capability of antigens to generate memory lymphocytes that can proliferate and secrete beneficial cytokines upon infection could be an important factor in the development of vaccine candidates against American Tegumentary Leishmaniasis.
authors.affiliation: Depto, de Patologia da Faculdade de Medicina da Universidade de São Paulo, Laboratório de Patologia de Moléstias Infecciosas (LIM-50), São Paulo, Brazil. felipepassero@yahoo.com.br
authors.forename: Luiz Felipe D
authors.initials: LF
authors.lastname: Passero
authors.forename: Ana Kely
authors.initials: AK
authors.lastname: Carvalho
authors.forename: Maria Lac
authors.initials: ML
authors.lastname: Bordon
authors.forename: Alexis
authors.initials: A
authors.lastname: Bonfim-Melo
authors.forename: Karina
authors.initials: K
authors.lastname: Carvalho
authors.forename: Esper G
authors.initials: EG
authors.lastname: Kallás
authors.forename: Bianca Ba
authors.initials: BB
authors.lastname: Santos
authors.forename: Marcos H
authors.initials: MH
authors.lastname: Toyama
authors.forename: Adriana
authors.initials: A
authors.lastname: Paes-Leme
authors.forename: Carlos Ep
authors.initials: CE
authors.lastname: Corbett
authors.forename: Márcia D
authors.initials: MD
authors.lastname: Laurenti
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology* / Q000302:isolation & purification; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D007891:Leishmania / Q000276:immunology*; D007896:Leishmaniasis / Q000276:immunology / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D015800:Protozoan Proteins / Q000276:immunology* / Q000302:isolation & purification; D018417:Th1 Cells / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D015847:Interleukin-4; D007371:Interferon-gamma