title: LBSapSal-vaccinated dogs exhibit increased circulating T-lymphocyte subsets (CD4⁺ and CD8⁺) as well as a reduction of parasitism after challenge with Leishmania infantum plus salivary gland of Lutzomyia longipalpis.
abstract: BACKGROUND
  The development of a protective vaccine against canine visceral leishmaniasis (CVL) is an alternative approach for interrupting the domestic cycle of Leishmania infantum. Given the importance of sand fly salivary proteins as potent immunogens obligatorily co-deposited during transmission of Leishmania parasites, their inclusion in an anti-Leishmania vaccine has been investigated in the last few decades. In this context, we previously immunized dogs with a vaccine composed of L. braziliensis antigens plus saponin as the adjuvant and sand fly salivary gland extract (LBSapSal vaccine). This vaccine elicited an increase in both anti-saliva and anti-Leishmania IgG isotypes, higher counts of specific circulating CD8⁺ T cells, and high NO production.
  
  
  METHODS
  We investigated the immunogenicity and protective effect of LBSapSal vaccination after intradermal challenge with 1 × 10⁷ late-log-phase L. infantum promastigotes in the presence of sand fly saliva of Lutzomyia longipalpis. The dogs were followed for up to 885 days after challenge.
  
  
  RESULTS
  The LBSapSal vaccine presents extensive antigenic diversity with persistent humoral and cellular immune responses, indicating resistance against CVL is triggered by high levels of total IgG and its subtypes (IgG1 and IgG2); expansion of circulating CD5⁺, CD4⁺, and CD8⁺ T lymphocytes and is Leishmania-specific; and reduction of splenic parasite load.
  
  
  CONCLUSIONS
  These results encourage further study of vaccine strategies addressing Leishmania antigens in combination with proteins present in the saliva of the vector.
authors: Rodrigo Dian de Oliveira
authors: RD
authors: Aguiar-Soares
authors: Bruno Mendes
authors: BM
authors: Roatt
authors: Henrique Gama
authors: HG
authors: Ker
authors: Nádia das Dores
authors: Nd
authors: Moreira
authors: Fernando Augusto Siqueira
authors: FA
authors: Mathias
authors: Jamille Mirelle de Oliveira
authors: JM
authors: Cardoso
authors: Nelder Figueiredo
authors: NF
authors: Gontijo
authors: Oscar
authors: O
authors: Bruna-Romero
authors: Andréa
authors: A
authors: Teixeira-Carvalho
authors: Olindo Assis
authors: OA
authors: Martins-Filho
authors: Rodrigo
authors: R
authors: Corrêa-Oliveira
authors: Rodolfo Cordeiro
authors: RC
authors: Giunchetti
authors: Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas/NUPEB, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brasil. alexreisufop@gmail.com.
authors: Alexandre Barbosa
authors: AB
authors: Reis
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes; D018414:CD8-Positive T-Lymphocytes; D004283:Dog Diseases / Q000469:parasitology / Q000517:prevention & control*; D004285:Dogs; D005260:Female; D018314:Leishmania infantum / Q000276:immunology*; D054332:Leishmaniasis Vaccines / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D008213:Lymphocyte Activation; D008297:Male; D011576:Psychodidae / Q000469:parasitology / Q000502:physiology*; D012469:Salivary Glands
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D054332:Leishmaniasis Vaccines