2.2 Development of a recombinant vaccine against canine leishmaniasis. From differential gene expression to the field

London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom - Institute of Tropical Medicine (ITM), Antwerp, Belgium - Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain   - CZ Veterinaria S.A., O Porriño, Spain

Area of research: Prevention
Research programme: Basic Science

L.infantum amastigotes inside dog bone marrow macrophages

Objectives:

1) Determination of strength and length of protective immune response in dogs induced by plasmids containing protective genes, 2) Detection of the level of protection induced in field dogs, (clinical protection and Th1 protective immune response) 3) Determination of parameters for scaling up of the vaccine production (GMP) and determination of safety

Expected results:

(1) Obtention of an intranasal vaccine effective against canine leishmaniasis (L. infantum)

(2) Determination of parameters of a protective response (interleukins corresponding to Th1 pathway)

(3) To obtain the parameters for industrial production of the plasmid as well as safety of the vaccine.

Summary:

Background: A protective DNA vaccine containing a L. infantum protective gene (LACK) and using the intranasal via has been developed against experimental L. infantum infection (10 specimens/dog). The protective immune response inducing Th1 has been determined and is being assessed. Length and strength of the immune protective response has to be determined in a field experiment. Safety of the vaccine has also to be assessed.

Methodology: The type and level of the immune response is measured by detecting by RTPCR of the levels of TNF alfa, IFN gamma, IL-10, IL-2  and  iNOs at the lymph node and bone marrow as well as IgGs production between the protected and  non protected dogs. Clinical signs and IFI positive for L.infantum infection will also be measured. Presence and distribution of the DNA plasmid in different organs will be tracked in dogs for safety experiment. Scaling up of plasmid production under GMP will be carried out at CZ Veterinaria (Porriño, Spain).