Absence of Acquired Resistance to Nymphal Ixodes ricinus Ticks in BALB/c Mice Developing Cutaneous Reactions

Abstract

BALB/c mice underwent 3 successive infestations with 15 Ixodes ricinus nymphs. No resistance was acquired as assessed by evaluating tick attachment, duration of blood meal, weights of engorged nymphs, and molting success. However, the hosts developed cutaneous immediate- and delayed-type hypersensitivity reactions when reinfested. Histological examination of tick attachment sites showed that inflammatory cells consisting of neutrophils, eosinophils, and mononuclear cells (lymphocytes and monocytes) infiltrated the skin more intensively during reinfestations. The number of intact mast cells did not vary between successive infestations, whereas the number of degranulated mast cells increased in the early stages of reinfestations. Basophils, which represent 12% of total infiltrating cells, were only observed and quantified in the skin of reinfested mice using transmission electron microscopy (TEM). Degranulating eosinophils were also observed by use of TEM.

Protective immunity against Ixodes ricinus induced by a salivary serpin

“…with values previously published [30]. However, an obvious shift of peaks of both future males and females to lower weights was observed in nymphs fed on immunized rabbits when compared to the normal values obtained on control rabbits (Fig.…”

“…4). As maleto-be nymphs are known to feed less, the lower weight peak corresponded to future males whereas the higher one corresponded to future females [30]. Furthermore, recorded weight values of nymphs fed on control rabbits were in accordance Results are expressed as average (±S.D.)…”

“…Rabbit and mice infestations were considered as complementary models. Indeed, rabbits are known to develop an immune resistance after repeated cycles of tick bites, whereas parameters of the blood meal do not change on mice after successive infestations [30]. Even if comparisons of the two animal models could be done only with nymphs infestations, it appears that the two species behave differently while reacting against infestations.…”

Triggering and modulation of the host-parasite interplay byEchinococcus multilocularis: a review

“…A primary early source of IL-4 is needed to drive the priming of naïve CD4+ T cells into differentiated Th2 type cells (Abbas et al 1996 ;O'Garra, 1998). It has been shown earlier in several models of ecto-or endo-parasitic infections that IL-4 might be produced early by different cell types, including DCs and other cells such as keratinocytes, Tcd, mast cells and basophils (Mbow et al 1994 ;Falcone et al 1996). Aumü ller et al (2004) used extracts from metacestodes of E. multilocularis to induce basophil degranulation, as well as the secretion of histamine, IL-4 and IL-13, in a dosedependent manner.…”

Vector Competence of Ixodes scapularis and Ixodes ricinus (Acari: Ixodidae) for Three Genospecies of Borrelia burgdorferi

“…Although I. scapularis nymphs were placed directly on mice, /. ricinus nymphs were placed in a feeding capsule attached to the mouse as previously described (Mbow et al 1994). Capsules were required for /.…”