Preclinical safety and tolerability of a repeatedly administered human leishmaniasis DNA vaccine

Riede, O; Seifert, K; Oswald, D; Endmann, A; Hock, C; Winkler, A; Salguero, F J; Schroff, M; Croft, S L; Juhls, C

Determination of efficacy and tolerability parameters. Mouse weights were recorded prior to the first dose of treatments administered and in weekly intervals thereafter. The injection site was monitored following administration of treatments and animals were observed daily by trained staff for the whole duration of the experiments. Mice were humanely killed by exsanguination under terminal anesthesia and blood collected by cardiac puncture. Livers and spleens were removed and their weight recorded. Tissue impression smears were prepared, fixed in 100% methanol and stained in 10% Giemsa. Parasite burden was determined microscopically and Leishman-Donovan Units calculated by the formula number of parasites per host cell nucleus × organ weight in mg, as described previously. 43 Serum was harvested from blood stored overnight at 4°C by centrifugation at 1500 g, 4°C for 15 min and stored at − 80°C. Biochemical analysis of standard serum parameters was carried out by LABOKLIN GmbH&Co.KG (Bad Kissingen, Germany). For histology, organs were fixed in 10% neutral buffered formalin, embedded in paraffin and routinely stained with hematoxylin and eosin. Histological data were evaluated in blinded fashion.