A killed Leishmania vaccine with sand fly saliva extract and saponin adjuvant displays immunogenicity in dogs

Vaccine. 2008 Jan 30;26(5):623-38. doi: 10.1016/j.vaccine.2007.11.057. Epub 2007 Dec 17.

Abstract

A vaccine against canine visceral leishmaniasis (CVL), comprising Leishmania braziliensis promastigote protein, sand fly gland extract (SGE) and saponin adjuvant, was evaluated in dog model, in order to analyse the immunogenicity of the candidate vaccine. The vaccine candidate elicited strong antigenicity in dogs in respect of specific SGE and Leishmania humoral immune response. The major saliva proteins recognized by serum from immunized dogs exhibited molecular weights of 35 and 45 kDa, and were related to the resistance pattern against Leishmania infection. Immunophenotypic analysis revealed increased circulating CD21+ B-cells and CD5+ T-cells, reflected by higher counts of CD4+ and CD8+ T-cells. The observed interaction between potential antigen-presenting cells (evaluated as CD14+ monocytes) and lymphocyte activation status indicated a relationship between innate and adaptive immune responses. The higher frequency in L. chagasi antigen-specific CD8+ T-lymphocytes, and their positive association with intense cell proliferation, in addition to the progressively higher production of serum nitric oxide levels, showed a profile compatible with anti-CVL vaccine potential. Further studies on immunological response after challenge with L. chagasi may provide important information that will lead to a better understanding on vaccine trial and efficacy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / administration & dosage
  • Animals
  • Antibodies, Protozoan / blood
  • B-Lymphocytes / immunology
  • CD5 Antigens
  • Cross Reactions
  • Dog Diseases / blood
  • Dog Diseases / immunology*
  • Dogs
  • Female
  • Injections, Subcutaneous
  • Leishmania braziliensis / immunology*
  • Leishmaniasis Vaccines / administration & dosage
  • Leishmaniasis Vaccines / immunology*
  • Leishmaniasis, Visceral / blood
  • Leishmaniasis, Visceral / immunology*
  • Lymphocyte Count
  • Male
  • Molecular Weight
  • Nitric Oxide / blood
  • Proteins / chemistry
  • Proteins / immunology
  • Psychodidae
  • Receptors, Complement 3d
  • Saliva / chemistry
  • Salivary Glands / chemistry*
  • Saponins / administration & dosage
  • Saponins / immunology*
  • T-Lymphocytes / immunology
  • Tissue Extracts / immunology*

Substances

  • Adjuvants, Immunologic
  • Antibodies, Protozoan
  • CD5 Antigens
  • Leishmaniasis Vaccines
  • Proteins
  • Receptors, Complement 3d
  • Saponins
  • Tissue Extracts
  • Nitric Oxide