3.7 Infiltration of ILC2s and neutrophils at the site of attachment of ticks
Infiltrations of macrophages and basophils had been detected at the site of attachment of ticks (6,14). However, ILC2s are abundant in skin and are responsible to provide innate immunity against parasitic infections (15,16). Therefore, we planned to detect responsiveness of ILC2s at the tick bitten areas. For this, we collected skin samples from the sites tick attachment or non-infested wt or RAGE-/-mice and subjected to immune-histochemical analysis using anti-CD44. Our study revealed massive infiltration of CD44+ cells at the tick bitten lesion. Infiltration of the cells increased in the subsequent infestations and the highest infiltrations were detected during the tertiary infestations. However, accumulation of CD44+ cells was minimum during the feeding process of ticks on RAGE-/- mice, indicating the important role of RAGE on the trafficking of ILC2s at the attachment sites (Figure 4). Furthermore, infiltrations of neutrophils were detected by immune-histochemistry using anti-MPO. Very few anti-MPO-positive cells were found both in wt and RAGE-/- mice skin (Figure 5), indicating that neutrophils has no significant roles in the tick-inflicted injuries in skin.