Interaction of tick saliva with the host immune mechanisms and its
significance for pathogen transmission
N.
Fuchsberger 1 , P.Kocáková 1 ,
V.Hajnická 2 , M. Slovák 3 , M. Labuda 3 & P.A. Nuttall 4
1 Inst. Virology, Slovak Acad. Sci., 842 45 Bratislava,
Slovakia; 2 Institute of Preventive and Clinical Medicine, Limbova
14, 83301 Bratislava, Slovakia; 3 Institute of Zoology, Slovak
Academy of Sciences, Dubravska 9, 84306 Bratislava, Slovakia; 4
CEH Institute of Virology and Environmental Microbiology, Oxford,
OX1 3SR United Kingdom
Ticks are of
great medical and veterinary importance not only as
haematophagous ectoparasites infesting humans and domestic
animals, but also as vectors of a wide variety of pathogenic
organisms. Ixodid ticks are obligate blood-feeders in all
their life stages. In contrast to other haematophagous
parasites, the contact between an ixodid tick and its host
lasts for days or even weeks. During the prolonged feeding
period, the salivary glands increases in protein content.
Feeding provokes host haemostatic, inflammatory and immune
responses. Therefore, ticks counterattack with
anti-haemostatic, anti-inflammatory and immunomodulatory
substances. We demonstrate the differences in protein patterns
of different tick species (Ixodes ricinus, Haemaphysalis
inermis, Dermacentor reticulatus, Rhipicephalus appendiculatus,
Amblyomma variegatum), differences in patterns at different
stages of feeding, differences between sexes and collaboration
of both sexes during feeding. The salivary glands are also the
primary means for transmission of tick-borne pathogens. Such
pathogens exploit the immunomodulatory activities of tick
saliva. This phenomenon is known as Saliva activated
transmission (SAT). We demonstrate the promotion of virus
growth by tick SGE in an animal-free system. We demonstrate
the interaction of tick SGE with host immune mechanisms namely
with the interferon system, with natural killer cells, and
with chemotaxis. We demonstrate the interaction of tick saliva
with the host cytokine network at the levels of both
production and action.
Copyright:
The copyrights of this original work belong to the authors
(see right-most box in title table). This abstract appeared
in Session 13 – INSECT PHISIOLOGY, NEUROSCIENCES, IMMUNITY
AND CELL BIOLOGY Symposium and Poster Session, ABSTRACT BOOK
II – XXI-International Congress of Entomology, Brazil,
August 20-26, 2000.
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