An Antivector Vaccine Protects against a Lethal Vector-Borne Pathogen

PLoS Pathogens

Martina Ličková¹  Mária Kazimírová²  Milan Labuda²  Adama R Trimnell³  Gillian M Davies³  Olga Lissina³  Rosie S Hails³  Patricia A Nuttall³ 

[1] Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia;Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia;Natural Environment Research Council Centre for Ecology and Hydrology, Oxford, United Kingdom

关键词: Mouse models;    Ticks;    Vaccines;    Nymphs;    Immune response;    T cells;    Cements;    Ricinus;   

DOI  :  10.1371/journal.ppat.0020027

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Vaccines that target blood-feeding disease vectors, such as mosquitoes and ticks, have the potential to protect against the many diseases caused by vector-borne pathogens. We tested the ability of an anti-tick vaccine derived from a tick cement protein (64TRP) of Rhipicephalus appendiculatus to protect mice against tick-borne encephalitis virus (TBEV) transmitted by infected Ixodes ricinus ticks. The vaccine has a “dual action” in immunized animals: when infested with ticks, the inflammatory and immune responses first disrupt the skin feeding site, resulting in impaired blood feeding, and then specific anti-64TRP antibodies cross-react with midgut antigenic epitopes, causing rupture of the tick midgut and death of engorged ticks. Three parameters were measured: “transmission,” number of uninfected nymphal ticks that became infected when cofeeding with an infected adult female tick; “support,” number of mice supporting virus transmission from the infected tick to cofeeding uninfected nymphs; and “survival,” number of mice that survived infection by tick bite and subsequent challenge by intraperitoneal inoculation of a lethal dose of TBEV. We show that one dose of the 64TRP vaccine protects mice against lethal challenge by infected ticks; control animals developed a fatal viral encephalitis. The protective effect of the 64TRP vaccine was comparable to that of a single dose of a commercial TBEV vaccine, while the transmission-blocking effect of 64TRP was better than that of the antiviral vaccine in reducing the number of animals supporting virus transmission. By contrast, the commercial antitick vaccine (TickGARD) that targets only the tick's midgut showed transmission-blocking activity but was not protective. The 64TRP vaccine demonstrates the potential to control vector-borne disease by interfering with pathogen transmission, apparently by mediating a local cutaneous inflammatory immune response at the tick-feeding site.

【 授权许可】

CC BY