Study on the Epidemiological Characteristics of Angiostrongylus Cantonesis and Protective Effects of Monoclonal Antibody 12D5 Against Angiostrongyliasis
|Course||Biochemistry and Molecular Biology|
|Keywords||A. cantonensis epidemic focus investigation monoclonal antibody eosinophil|
Angiostrongyliasis is a disease in humans and animals, distributing widely in Southeast Asia and the Pacific areas, by ingesting the infective third-stage larvae (L3) of A. cantonensis that are found in raw or insufficiently cooked molluscs or crustaceans. Many kind of snails, including Pomacea canaliculata, Camacna cicatricose, Cipangopaludina chinensis, Achatina fulica and Babylomia formosae, are the intermediate hosts for A. cantonensis. When rats, definitive host of A. cantonensis, ingest infected intermediate hosts, L3 worms will move to their brains, arrive to the lung of rats lastly, and develop into adults. Thus, A. cantonensis is also called the rat lungworm. If human are infected by A. cantonensis, the third-stage larvae 3 worm (L3) can cause the eosinophils increasing cerebrospinal meningitis, if in humans central nervous system, also cause headache, dizziness, fever, neck firmness ,facial nerve paralysis, dementia and death, if in cerebrospinal fluid (CSF). Since the angiostrongyliasis occurred on a large scale in Peking in 2006, the related departments of all local governments enhanced the work about detection and prevention on angiostrongyliasis. Therefore, it is an important research area to research the epidemic focus of A. cantonensis and the prevention and cure of angiostrongyliasis. This study researched the epidemic focus of A. cantonensis in Shenzhen city and the inhibiting effect of the monoclonal antibody (mAb) 12D5 on eosinophils in brains of BABL/c mice. The results of our study are summarized as follows:In Shenzhen, the weather is warm and rainy. There is lots of humus in soil and frutex. It offers a favourable living environment for P. canaliculata and A. fulica, which are the intermediate hosts for A. cantonensis. And, they become the main amphibious and shellfish animals in Shenzhen city and largely distribute in vegetable fields, pools, wildernesses and parks, which hold water always. The results of epidemic focus of A. cantonensis are that infected intermediate hosts distribute in the southwest of Shenzhen city, where the frutex grows thick and there are in damp, humus content high zone. And, the infectiosity of A. cantonensis L3 in A. fulica whose weight are≥55g is significantly higher than that are<55g. The results about final host of A. cantonensis are that infection rate of Rattus norvegicus is largest, and the infection rate of female is larger than that of male. Eosinophils are a kind of leucocyte and act as an important work in resisting parasitic infection and THⅠhypersensitivity. The accumulation and activation of eosinophils in brain is an important hallmark of A. cantonensis infection in both humans and mice. We researched the inhibitory effects of the 12D5 mAb on eosinophils in brains and the survival ratio of BABL/c mice infected with A. cantonensis. According to the survival situation of each group mice, 12D5 mAb significantly extended the mouse life and also remitted symptoms of angiostrongyliasis including piloerection, asitia and fewer moving. Our results suggest that 12D5 mAb may have an important work in the cure and delaying of angiostrongyliasis. We also researched the mRNA expression levels of Eotaxin, IL-4 and IL-5 in the spleen. The results are the 12D5 mAb can reduce the expression of IL-5 and inhibits the survival of eosinophils. Although the expression of Eotaxin is increased, the reduction of IL-5 expression stops eosinophils to accumulate in brain and reduces the occurrence of eosinophilic meningitis or eased the symptoms of eoxinophilic meningitis.