Trypanosoma brucei: Immunisation with plasmid DNA encoding invariant surface glycoprotein gene is able to induce partial protection in experimental African trypanosomiasis

Trypanosoma brucei is the etiological agent responsible for African trypanosomiasis, an infectious pathology which represents a serious problem of public health and economic losses in Sub-Saharan Africa. As one of the foremost neglected illnesses, few resources have been available for the development of vaccines or new drugs, in spite of the current therapeutical drugs showing little efficiency and high toxicity. Hence, it is obviously important to widen effective therapeutics and preventive strategies against African trypanosomiasis. In this work, we use the DNA vaccine model to evaluate immunisation effectiveness in mice challenged with Trypanosoma brucei brucei. We demonstrate that Balb/C mice immunised intramuscularly with a single dose of a DNA plasmid encoding a bloodstream-stage specific invariant surface glycoprotein (ISG) are partially protected from a lethal dose of T. b. brucei. Interestingly, the surviving animals show high levels of IgG2a anti-trypanosoma antibodies, suggesting that the Th1 response profile seems important for the induced mechanisms of immune protection.