Acid phosphatases in the haemolymph of the desert locust, Schistocerca gregaria, infected with the entomopathogenic fungus Metarhizium anisopliae.
Acid phosphatases in the haemolymph of the desert locust, Schistocerca gregaria, infected with the entomopathogenic fungus Metarhizium anisopliae.
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DOI：
10.1016/s0022-1910(00)00045-7
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发表时间：
2000-09
影响因子：
2.2
通讯作者：
Y. Xia;P. Dean;A. J. Judge;J. Gillespie;J. Clarkson;A. Charnley
中科院分区：
文献类型：
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作者：
Y. Xia;P. Dean;A. J. Judge;J. Gillespie;J. Clarkson;A. Charnley
比较了伤害、免疫系统化学刺激和真菌感染对荒漠蝗虫血淋巴酸性磷酸酶（AcP）活性的影响。未经处理的对照蝗虫的AcP构成水平。作为一种溶酶体酶，AcP可能在自噬和细胞翻转以及防御中发挥作用。注射生理盐水和β-1,3-葡聚糖引起血细胞和血浆AcP显著升高。接种昆虫病原真菌m.s appliae var acridum后第3天，血淋巴中AcP活性也有所增加。与此同时，总血细胞计数下降，血浆细胞和凝血细胞AcP染色呈阳性的比例显著减少。因此，从先验的角度来看，受感染昆虫体内额外的AcP似乎不太可能来自宿主。从不同处理的血淋巴中鉴定出AcP异构体，表明该酶的真菌起源。对照接种（仅油）昆虫的AcP pI为4.3，注射层粘连蛋白进一步刺激AcP pI。在层压素处理中出现了7.3-7.5左右的其他异构体。然而，在感染了金龟子分枝杆菌的昆虫中，4.3亚型似乎被抑制了。与注射层流蛋白的昆虫相比，纹带强度更接近于对照组。后来在感染中出现了两个新的同工异构体。这些酶的pi与真菌在体外产生的一些acp相对应。根据真菌分泌的酸性磷酸酶对病原体的可能益处，讨论了这些结果。
A comparison has been made between the effects of wounding, chemical stimulation of the immune system and fungal infection on acid phosphatase (AcP) activity in the haemolymph of the desert locust, Schistocerca gregaria. Untreated control locusts had constitutive levels of AcP. As a lysosomal enzyme, AcP may have a role in autophagy and cell turn over as well as defence. Injection of saline and β-1,3-glucan caused significant increases in haemocyte and plasma AcP. AcP activity also increased in the haemolymph on the 3rd day after inoculation with the entomopathogenic fungus M. anisopliae var acridum. This coincided with a decline in the total haemocyte count and a marked reduction in the proportion of plasmatocytes and coagulocytes that stained positive for AcP. Therefore a priori it seemed unlikely that the extra AcP in infected insects came from the host. A fungal origin for the enzyme was suggested by the identification of AcP isoforms from haemolymph of different treatments. Control inoculated (oil only) insects had an AcP at a pI of 4.3 that was stimulated further by the injection of laminarin. Additional isoforms appeared at around 7.3–7.5 in the laminarin treatment. However, the 4.3 isoform appeared to be suppressed in the insects infected with M. anisopliae var acridum. The band intensity was more like that of the control than the laminarin-injected insects. Two new isoforms appeared later on in infection. These enzymes had pIs that corresponded to some of the AcPs produced in vitro by the fungus. The results are discussed in the light of the possible benefits of secreted fungal acid phosphatases to the pathogen.