Engracia Filho Jair Rodini, Araújo Chiara Domingues, Pinto Gabriela Nishihara, Mendes Yann Henrique, Bechara Gervasio Henrique
School of Life Sciences, Pontifical Catholic University of Parana - PUCPR, Rua Imaculada Conceição, 1155, Prado Velho, Curitiba, Paraná, CEP 80215-901, Brazil.
Exp Appl Acarol. 2017 Jun;72(2):171-178. doi: 10.1007/s10493-017-0143-9. Epub 2017 Jun 8.
Ticks and tick-borne diseases are of global importance and can cause serious economic losses to cattle-raising businesses. However, only few attempts have been made to describe the relationships between various cellular immune components and tick counts of, and therefore resistance to, Rhipicephalus microplus. The present study evaluated the late inflammatory cellular response and dermal dendritic cells at the attachment site in naturally presensitized bovines, artificially infested by R. microplus ticks. Twenty-two crossbred (Holstein × Gir) male experimental cattle were artificially infested with approximately 10,000 larvae of R. microplus. Parasitic infestation was determined by counting the engorged female ticks (4.5-8.0 mm in diameter) at the 21st day after artificial infestation. Biopsies (6 mm) were taken prior to the infestation and along with the tick count from the right pinna of each animal, and examined with histological techniques and immunohistochemistry using S100 protein. Inflammatory cell counts were conducted in the sections stained with the May-Grünwald Giemsa technique, and immunostained dermal dendritic cells were evaluated and classified in scores ranging from 0 to 4. An average of 39.2 ticks per animal was found. Eosinophils (47.8%) constituted the major portion of the cellular infiltrate, followed by mononuclear cells (28.3%), neutrophils (14.4%), and basophils (0% to approximately 2%). The dendritic cell count shows a considerable population in the dermis, with pre- and post-infestation mean scores of 1.54 and 1.89, respectively; these scores were not significantly different. Our results pointed out the importance of the cellular response in the cattle resistance to ticks.
蜱虫及蜱传疾病具有全球重要性，会给养牛业造成严重经济损失。然而，针对各种细胞免疫成分与微小扇头蜱蜱虫数量（以及对其的抗性）之间关系的描述却很少。本研究评估了自然致敏的牛在被微小扇头蜱人工感染后，蜱虫附着部位的晚期炎症细胞反应和真皮树突状细胞。22头杂交（荷斯坦×吉尔）雄性实验牛被人工感染了约10,000只微小扇头蜱幼虫。在人工感染后第21天，通过计数饱血雌蜱（直径4.5 - 8.0毫米）来确定寄生虫感染情况。在感染前以及与每只动物右耳廓蜱虫计数同时进行活检（6毫米），并使用S100蛋白通过组织学技术和免疫组织化学进行检查。在经May - Grünwald Giemsa技术染色的切片中进行炎症细胞计数，并对免疫染色的真皮树突状细胞进行评估并分类，分数范围为0至4。每只动物平均发现39.2只蜱虫。嗜酸性粒细胞（47.8%）构成细胞浸润的主要部分，其次是单核细胞（28.3%）、中性粒细胞（14.4%）和嗜碱性粒细胞（0%至约2%）。树突状细胞计数显示真皮中有相当数量的细胞，感染前和感染后的平均分数分别为1.54和1.89；这些分数没有显著差异。我们的结果指出了细胞反应在牛对蜱虫抗性中的重要性。
