Control of infestations by Ixodes ricinus tick larvae in rabbits vaccinated with aquaporin recombinant antigens.

BACKGROUND: Tick-borne diseases greatly impact human and animal health worldwide, and vaccines are an environmentally friendly alternative to acaricides for their control. Recent results have suggested that aquaporin (AQP) water channels have a key function during tick feeding and development, and constitute good candidate antigens for the control of tick infestations. METHODS: Here we describe the effect of vaccination with the Ixodes ricinus AQP1 (IrAQP) and a tick AQP conserved region (CoAQP) on I. ricinus tick larval mortality, feeding and molting. RESULTS: We demonstrated that vaccination with IrAQP and CoAQP had an efficacy of 32% and 80%, respectively on the control of I. ricinus larvae by considering the cumulative effect on reducing tick survival and molting. CONCLUSIONS: The effect of the AQP vaccines on larval survival and molting is essential to reduce tick infestations, and extended previous results on the effect of R. microplus AQP1 on the control of cattle tick infestations. These results supports that AQP, and particularly CoAQP, might be a candidate protective antigen for the control of different tick species.

AAV2-mediated transfer of the human aquaporin-1 cDNA restores fluid secretion from irradiated miniature pig parotid glands.

Previously (Shan et al, 2005), we reported that adenoviral vector-mediated transfer of the human aquaporin-1 (hAQP1) cDNA to minipig parotid glands following irradiation (IR) transiently restored salivary flow to near normal levels. This study evaluated a serotype 2, adeno-associated viral (AAV2) vector for extended correction of IR (single dose; 20 Gy)-induced, parotid salivary hypofunction in minipigs. At 16 weeks following the IR parotid salivary flow decreased by 85-90%. AAV2hAQP1 administration at week 17 transduced only duct cells and resulted in a dose-dependent increase in salivary flow to approximately 35% of pre-IR levels (to approximately 1 ml per 10 min) after 8 weeks (peak response). Administration of a control AAV2 vector or saline was without effect. Little change was observed in clinical chemistry and hematology values after AAV2hAQP1 delivery. Vector-treated animals generated high anti-AAV2 neutralizing antibody titers by week 4 (approximately 1:1600) and significant elevations in salivary (approximately 15%), but not serum, granulocyte macrophage colony-stimulating factor levels. Following vector administration, salivary [Na(+)] was dramatically increased, from approximately 10 to approximately 55 mM (at 4 weeks) and finally to 39 mM (8 weeks). The findings demonstrate that localized delivery of AAV2hAQP1 to IR-damaged parotid glands leads to increased fluid secretion from surviving duct cells, and may be useful in providing extended relief of salivary hypofunction in previously irradiated patients.