近日，微生物學(xué)系助理教授Kirsten Nielsen博士等研究人員發(fā)現(xiàn)巨細(xì)胞在感染過(guò)程中能保護(hù)真菌型隱球菌,，他們的發(fā)現(xiàn)可能有助于開發(fā)新的方法來(lái)對(duì)付隱球菌引起的感染,。
研究結(jié)果刊登在六月的Eukaryotic Cell雜志上。這項(xiàng)研究是由國(guó)家衛(wèi)生部和明尼蘇達(dá)大學(xué)醫(yī)學(xué)院資助,。
隱球菌是一種經(jīng)常存在灰塵和污垢中的一種真菌,，全世界每年有超過(guò)65萬(wàn)艾滋病患者因此種真菌而死亡。這也是化療患者和器官移植的病人潛在的致命的危險(xiǎn),。
Nielsen博士說(shuō)：雖然大多數(shù)健康人能抗隱球菌感染,，但真菌可導(dǎo)致那些薄弱的免疫系統(tǒng)抵抗性更弱，最終導(dǎo)致致命疾病,。
隱球菌吸入時(shí)可引起肺部感染,。這種感染可擴(kuò)散到大腦和腦膜炎，引發(fā)大腦和脊椎致命性炎癥,。
Nielsen和Okagaki發(fā)現(xiàn)巨細(xì)胞或隱球菌細(xì)胞是正常細(xì)胞體積的十到二十倍,，因?yàn)轶w積太大，人體的免疫系統(tǒng)無(wú)法摧毀這些細(xì)胞,。
研究人員發(fā)現(xiàn)泰坦細(xì)胞的存在可以保護(hù)所有在部位的隱球菌細(xì)胞,，即使是正常大小的隱球菌細(xì)胞。
Nielsen說(shuō)：這就告訴我們,，泰坦細(xì)胞是隱球菌在宿主與生物體之間相互作用以引起疾病的一個(gè)重要方面,。這些研究結(jié)果將幫助我們找到新的方法來(lái)治療隱球菌感染。（生物谷：Bioon.com）
Titan cells confer protection from phagocytosis in Cryptococcus neoformans infections
Laura H. Okagaki* and Kirsten Nielsen*
The human fungal pathogen Cryptococcus neoformans produces an enlarged “titan” cell morphology when exposed to the host pulmonary environment. Titan cells exhibit traits that promote survival in the host. Previous studies showed that titan cells are not phagocytosed and that increased titan cell production in the lungs results in reduced phagocytosis of cryptococcal cells by host immune cells. Here, the effect of titan cell production on host-pathogen interactions during early stages of pulmonary cryptococcosis was explored. The relationship between titan cell production and phagocytosis was found to be non-linear; moderate increases in titan cell production resulted in profound decreases in phagocytosis with significant differences occurring within the first 24 hours of the infection. Not only were titan cells themselves protected from phagocytosis, but titan cell formation also conferred protection from phagocytosis to normal size cryptococcal cells. Large particles introduced into the lungs were not phagocytosed, suggesting the large size of titan cells protects against phagocytosis. The presence of large particles was unable to protect smaller particles from phagocytosis, revealing that titan cell size alone is not sufficient to provide the observed cross-protection of normal size cryptococcal cells. These data suggest that titan cells play a critical role in establishment of the pulmonary infection by promoting the survival of the entire population of cryptococcal cells.
