Loosmore S M, Yang Y P, Coleman D C, Shortreed J M, England D M, Harkness R E, Chong P S, Klein M H
Connaught Centre for Biotechnology Research, Ontario, Canada.
Mol Microbiol. 1996 Feb;19(3):575-86. doi: 10.1046/j.1365-2958.1996.406943.x.
The genomic transferrin receptor genes (tbpA and tbpB) from two strains of Haemophilus influenzae type b (Hib) and two strains of non-typable H. influenzae (NTHi) have been cloned and sequenced. The deduced protein sequences of the H. influenzae tbpA genes were 95-100% conserved and those of the tbpB genes were 66-100% conserved. The tbpB gene from one strain of NTHi was found to encode a truncated Tbp2 protein. The tbpB genes from four additional NTHi strains were amplified by the polymerase chain reaction (PCR) utilizing primers derived from the conserved N-terminal sequences of Tbp1 and Tbp2 and were found to encode full-length proteins. Although several bacterial species express transferrin receptors, when the Tbp1 and Tbp2 sequences from different organisms were compared, there was only limited homology. Recombinant Tbp1 and Tbp2 proteins were expressed from Escherichia coli and antisera were raised to the purified proteins. There was significant antigenic conservation of both Tbp1 and Tbp2 amongst H. influenzae strains, as determined by Western blot analysis. In a passive model of bacteraemia, infant rats were protected from challenge with Hib after transfer of anti-rTbp2 antiserum, but not after anti-rTbp1 antiserum.
已对两株b型流感嗜血杆菌（Hib）和两株不可分型流感嗜血杆菌（NTHi）的基因组转铁蛋白受体基因（tbpA和tbpB）进行了克隆和测序。流感嗜血杆菌tbpA基因推导的蛋白质序列保守性为95% - 100%，tbpB基因的保守性为66% - 100%。发现一株NTHi的tbpB基因编码一种截短的Tbp2蛋白。利用源自Tbp1和Tbp2保守N端序列的引物，通过聚合酶链反应（PCR）扩增了另外四株NTHi菌株的tbpB基因，发现它们编码全长蛋白。尽管有几种细菌物种表达转铁蛋白受体，但比较不同生物体的Tbp1和Tbp2序列时，同源性有限。从大肠杆菌中表达了重组Tbp1和Tbp2蛋白，并针对纯化的蛋白制备了抗血清。通过蛋白质印迹分析确定，流感嗜血杆菌菌株中Tbp1和Tbp2均具有显著的抗原保守性。在菌血症的被动模型中，给幼鼠注射抗rTbp2抗血清后可保护其免受Hib攻击，但注射抗rTbp1抗血清后则不能。
