Immunohistochemical Characterization of Porcine Teschovirus Antigen Distribution and Histological Lesions in Chronic Infected Pigs

以免疫組織化學鑑定豬鐵士古病毒在慢性感染豬之抗原分佈及組織病變

邱淑君(Shu-Chun Chiu) ； 林意堅(Yi-Chien Lin) ； 黃天祥(Tien-Shine Huang) ； 邱國詔(Kuo-Chao Chiu) ； 胡書佳(Shu-Chia Hu) ； 黃金城(Chin-Cheng Huang) ； 龐飛(Victor F. Pang) ； 王汎熒(Fun-In Wang)

《臺灣獸醫學雜誌》 39卷1期 (2013/03) Pp. 8-18

摘要

在最近的過去，臺灣歷經兩波豬鐵士古病疫情，第一波在公元2000年，次一波在公元2004年，迄今該病毒幾乎存在所有豬群並且為慢性感染，持續排毒。目前全世界豬群幾乎無一倖免被感染。本研究目的在鑑定我國分離株PTV-1 AHRI在SPF豬接種後15及50日在慢性感染情況下，其致病性及抗原分佈位置。所有接種豬均呈現發燒、疲乏、厭食、咳嗽及下痢，但僅七頭中之一頭發展出右後肢麻痺的臨床神經症狀。病理上可見非化膿性脊髓炎及神經節炎，但未伴隨明顯的神經症狀。PTV-1抗原出現於一頭有神經症狀豬的血管內皮細胞、浸潤炎症細胞淋巴球及星狀細胞。在其他無神經症狀但有神經節炎的病變部位PTV-1抗原訊號反而比較微弱。有趣的是，在脾臟PTV-1抗原出現於白髓的marginal zone macrophage及紅髓的T淋巴球。在扁桃腺及淋巴結，PTV-1抗原出現在T淋巴球區比B淋巴球區明顯，也出現在扁桃腺上皮。在腸道，PTV-1抗原都在固有層內的T淋巴球。在有間質性肺炎的病變區，PTV-1抗原出現在炎症T淋巴球。總結PTV-1似較親和各臟器的T淋巴球及炎症浸潤的T淋巴球。其出現於marginal zone macrophage可能與長期的病毒血症有關。

關鍵字

豬鐵士古病毒 ； 免疫組織化學 ； 慢性感染 ； 地方性

並列摘要

In the recent past, Taiwan has had two waves of PTV-1 epidemics, one in 2000 and a second in 2004. Nowadays most swine herds are contaminated by PTVs and most infected pigs are in a subclinical or chronic infection status with continual viral shedding. The aim of this study was to investigate in which organs the PTV-1 localized and what lesions did it induced in an endemic or chronic infection status mimicking the situation in the field. Seronegative specific-pathogen-free (SPF) pigs were inoculated intranasally, and tissue specimens were collected on the 15th and 50th days postinfection (DPI). Fever, lassitude, anorexia, cough, and diarrhea were noted in all experimental pigs, and clinically only 1/7 infected pigs developed right hind leg paralysis. Non-suppurative myelitis and ganglionitis were noted without apparent neural signs. By immunohistochemistry, in the nervous system PTV-1 antigen signals were noted within endothelial cells, cuffed lymphocytes, and astrocytes of a pig with neural signs, but with weaker signals noted within ganglion cells of well-developed ganglionitis site in a pig without neural signs. Interestingly, in the spleen PTV-1 antigen was noted abundantly within marginal zone macrophages of the white pulp and T lymphocytes of the red pulp. In the tonsil, signals were presented more apparent within T lymphocytes and macrophages of the interfollicular area than those in the tonsillar epithelium and follicular center. In the intestines, signals were present within T lymphocytes of the lamina propia. In the lung signals were presented within inflammatory T lymphocytes of the interstitial pneumonia. This study indicates that, besides the commonly known fecal-oral route of infection, intranasal infection is able to establish infection. The significance of these findings regarding the perpetuation of viremia and recirculation of the virus within a herd, pathogenesis, and difficulties imposed on laboratory diagnosis are discussed.

並列關鍵字

teschovirus ； lymphocyte ； microphage ； marginal zone ； spleen ； intestine ； tonsil ； lymph node