Department of Parasitology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh.
Department of Veterinary Immunology, Graduate School of Veterinary Sciences, Osaka Metropolitan University, Izumisano, Japan.
Parasite Immunol. 2024 Jun;46(6):e13039. doi: 10.1111/pim.13039.
Ticks are notorious blood-sucking ectoparasites that affect both humans and animals. They serve as a unique vector of various deadly diseases. Here, we have shown the roles of the receptor for advanced glycation end products (RAGE) during repeated infestations by the tick Haemaphysalis longicornis using RAGE mice. In primary infestation, a large blood pool developed, which was flooded with numerous RBCs, especially during the rapid feeding phase of the tick both in wild-type (wt) and RAGE mice. Very few inflammatory cells were detected around the zones of haemorrhage in the primary infestations. However, the number of inflammatory cells gradually increased in the subsequent tick infestations, and during the third infestations, the number of inflammatory cells reached to the highest level (350.3 ± 16.8 cells/focus). The site of attachment was totally occupied by the inflammatory cells in wt mice, whereas very few cells were detected at the ticks' biting sites in RAGE mice. RAGE was highly expressed during the third infestation in wt mice. In the third infestation, infiltration of CD44 lymphocytes, eosinophils and expression of S100A8 and S100B significantly increased at the biting sites of ticks in wt, but not in RAGE mice. In addition, peripheral eosinophil counts significantly increased in wt but not in RAGE mice. Taken together, our study revealed that RAGE-mediated inflammation and eosinophils played crucial roles in the tick-induced inflammatory reactions.
蜱虫是臭名昭著的吸血外寄生虫，会影响人类和动物。它们是各种致命疾病的独特传播媒介。在这里，我们使用 RAGE 小鼠研究了 RAGE（晚期糖基化终产物受体）在重复感染长角血蜱（Haemaphysalis longicornis）时的作用。在初次感染中，形成了一个大的血池，其中充满了大量 RBC，尤其是在野生型（wt）和 RAGE 小鼠的蜱虫快速进食阶段。在初次感染中，在出血区周围很少检测到炎症细胞。然而，在随后的蜱虫感染中，炎症细胞的数量逐渐增加，在第三次感染中，炎症细胞的数量达到最高水平（350.3±16.8 个/焦点）。在 wt 小鼠中，附着部位完全被炎症细胞占据，而在 RAGE 小鼠中，蜱虫叮咬部位仅检测到很少的细胞。在 wt 小鼠的第三次感染中，RAGE 高度表达。在第三次感染中，CD44 淋巴细胞、嗜酸性粒细胞的浸润以及 S100A8 和 S100B 的表达在 wt 但不在 RAGE 小鼠的蜱虫叮咬部位显著增加。此外，wt 小鼠的外周嗜酸性粒细胞计数显著增加，但 RAGE 小鼠没有。综上所述，我们的研究表明，RAGE 介导的炎症和嗜酸性粒细胞在蜱虫诱导的炎症反应中起关键作用。
