In the present study we compared the immunological reactions between @entity278 tick-infested susceptible ( @entity235 and @entity19 ) and tick-resistant hosts ( @entity840 ), elucidating some of the components of efficient protective responses against ticks. We found that T-cells from @entity840 infested with adult ticks proliferate vigorously in the presence of concanavalin A (ConA), whereas ConA-induced cell proliferation of tick-infested @entity19 and @entity235 was significantly decreased at 43.1 and 94.0%, respectively, compared to non-infested controls. Moreover, cells from @entity19 and @entity235 submitted to one or three successive @entity277 did not exhibit a T-cell proliferative response to tick antigens, whilst cells from thrice tick-infested @entity840 , when cultured with either a tick extract or tick saliva, displayed a significant increase in cell proliferation. Also, we evaluated the response of tick-infested @entity19 to a cutaneous @entity56 test induced by a tick extract. Tick-infested @entity19 developed a significant immediate reaction, whereby a 29.9% increase in the footpad thickness was observed. No @entity56 ( @entity56 ) reaction was detected. Finally, the differential cell count at the tick attachment site in repeatedly infested @entity19 exhibited a 6.6- and 4.1-fold increase in the percentage of @entity1712 and neutrophils, respectively, compared to non-infested animals, while a decrease of 77.0-40.9 in the percentage of mononuclear cells was observed. The results of the cutaneous @entity56 test and the cellular counts at the tick feeding site for @entity19 support the view that tick-infested @entity19 develop an immune response to @entity278 ticks very similar to @entity235 , the natural host of this species of tick, but very different from @entity840 (resistant host), which develop a @entity56 reaction in addition to a basophil and mononuclear cell infiltration at the tick-attachment site. In conclusion, saliva introduced during @entity277 reduces the ability of a susceptible animal host to respond to tick antigens that could stimulate a protective immune response. As a consequence, the animals present a lack of @entity56 response and disturbed cellular migration to tick feeding site, which can represent a deficient response against ticks.

Antigens from XXXX ticks elicit potent cell-mediated immune responses in resistant but not in susceptible animals.

@entity1712 :: ('MESH:D004802', 'Disease') :: ['eosinophils'] @entity235 :: ('9615', 'Species') :: ['dogs'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity840 :: ('10141', 'Species') :: ['guinea pigs'] @entity277 :: ('MESH:D013984', 'Disease') :: ['infestations', 'tick infestations'] @entity56 :: ('MESH:D004342', 'Disease') :: ['DTH', 'delayed-type hypersensitivity', 'hypersensitivity'] @entity278 :: ('34632', 'Species') :: ['Rhipicephalus sanguineus', 'R. sanguineus']
@entity278 :: (34632,Species) :: ['Rhipicephalus sanguineus']
