Leishmania DNA load and cytokine expression levels in asymptomatic naturally infected dogs.
The factors responsible for the clinical progress of visceral leishmaniasis (VL) in dogs have not been yet established. The starting hypothesis was the possibility of associating the changing level of a specific type of cytokines with the evolution of the infection towards infection-manifested disease or resistant behaviour. For this purpose the authors have established a connection between Leishmania load, cytokine mRNA accumulation, and the progression of the disease in naturally infected asymptomatic dogs. We made use of real-time (RT) PCR system to detect the expression of cytokine mRNA levels during all the phases of the infection. In particular, we measured the amount of parasites in samples such as blood, lymph nodes and skin, and the expression levels of IFN-gamma, IL-2, IL-4, IL-10, IL-12 and IL-18 cytokines in the blood. We employed different targeted real-time PCR assay on 40 naturally infected dogs, initially asymptomatic; 20 of these progressed to overt disease, and the 20 remaining dogs remained asymptomatic throughout the period of study (2 years). Two other groups included: 20 naturally infected dogs with clinical signs of VL, and 20 healthy dogs living in a non-endemic area. All these animals were employed as positive and negative controls, respectively. The overall results obtained demonstrate that the simultaneous evaluation of parasites and cytokine levels represents a reliable tool for predicting disease development, and thus for choosing the best treatment for the asymptomatic form of the disease.
Manna
Laura
L
Dipartimento di Scienze Cliniche Veterinarie, Università di Napoli Federico II, Via F. Delpino, n. 1, 80137 Napoli, Italy.
Reale
Stefano
S
Viola
Elisabetta
E
Vitale
Fabrizio
F
Foglia Manzillo
Valentina
V
Pavone
Luigi Michele
LM
Michele
Pavone Luigi
PL
Caracappa
Santo
S
Gravino
Angelo Elio
AE
D000818:Animals; D016207:Cytokines / Q000097:blood*; D017931:DNA Primers / Q000737:chemistry; D016054:DNA, Protozoan / Q000032:analysis*; D004283:Dog Diseases / Q000469:parasitology / Q000503:physiopathology*; D004285:Dogs; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis; D007891:Leishmania / Q000235:genetics / Q000302:isolation & purification*; D018314:Leishmania infantum / Q000235:genetics / Q000302:isolation & purification; D007896:Leishmaniasis / Q000503:physiopathology / Q000662:veterinary*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D013997:Time Factors
D016207:Cytokines; D017931:DNA Primers; D016054:DNA, Protozoan; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases