Ratzlaff R E, Wikel S K
Department of Microbiology, University of South Dakota School of Medicine, Vermillion 57069.
J Med Entomol. 1990 Nov;27(6):1002-7. doi: 10.1093/jmedent/27.6.1002.
Mice with restricted grooming capabilities were infested with the solenophagous louse, Polyplax serrata (Burmeister). Louse burdens on Cox/Swiss and C3H/HeSN mice increased for approximately 1 mo, reaching burden/host weight ratios of 1.14 and 1.26 mg/g, respectively, followed by a steady decline. Fifty days after initial ectoparasite contact, both strains were resistant to lice. Resistance was anamnestic, lasting several months with second infestation weights reduced by 98 and 78% on Cox/Swiss and C3H/HeSN, respectively. Furthermore, mice were systemically resistant because infestations on naive body sites of resistant hosts were reduced by 59%. Host resistance was associated with the development of antilouse immune responses. After the first week of a primary infestation, the draining lymph nodes contained cells that proliferated in vitro to louse antigens. Skin responses to louse antigens were also detected: (1) delayed, (2) immediate and delayed, and (3) no significant reactivity on days 19, 34, and 54, respectively. The presence of systemic antilouse responses provided an immunologic basis for immunization against lice. Intradermal injections of soluble louse components reduced primary infestation weights by 62%. Immunized mice had immediate and delayed skin responses containing an inflammatory infiltrate 1 wk following immunization. This study, using the natural host of P. serrata, demonstrates an inducible, anamnestic immune component in louse resistance.
具有有限梳理能力的小鼠感染了吸血虱——锯啮虱（Polyplax serrata，布迈斯特）。Cox/Swiss和C3H/HeSN小鼠身上的虱负荷在大约1个月内增加，分别达到每克宿主重量1.14毫克和1.26毫克的虱负荷/宿主重量比，随后稳步下降。初次接触体外寄生虫50天后，这两个品系的小鼠对虱子都产生了抗性。这种抗性是记忆性的，持续数月，再次感染时，Cox/Swiss和C3H/HeSN小鼠身上的虱子重量分别减少了98%和78%。此外，小鼠具有全身性抗性，因为抗性宿主未感染虱子的身体部位的感染率降低了59%。宿主抗性与抗虱免疫反应的发展有关。初次感染第一周后，引流淋巴结中含有在体外对虱抗原增殖的细胞。还检测到皮肤对虱抗原的反应：（1）迟发型，（2）速发型和迟发型，以及（3）在第19、34和54天分别无明显反应。全身性抗虱反应的存在为虱子免疫提供了免疫学基础。皮内注射可溶性虱成分可使初次感染时的虱子重量减少62%。免疫小鼠在免疫后1周出现含有炎性浸润的速发型和迟发型皮肤反应。本研究使用锯啮虱的天然宿主，证明了虱子抗性中存在可诱导的记忆性免疫成分。
