Differentially expressed genes between normal SPG-A1 cells and SPC-A1 cells infected by RSV were investigated using differential display. The novel z1g10 gene codes for a novel protein, ZLG10, which has previously been reported to be up-regulated in RSV-infected SPC-A1 cells. Its putative open reading frame was also identified. To better understand the structure, function, and possible role of ZLG10 as a potential candidate for diagnosis and vaccine studies, the intact region encoding ZLG10 was obtained by PCR and expressed in Escherichia coli as a GST-fusion protein. After purification, GST-ZLG10 fusion protein was used to immunize the adult rabbits following standard protocols. Consequently, we found that the produced antiserum of the novel fusion protein significantly suppressed the infection by RSV on SPC-A1 cells by using neutral red uptake assay and quantitative measurement. Together, our data demonstrate that ZLG10, a novel protein expressed and purified in this report, might be a potential effective therapeutic candidate for treating RSV infections. (c) 2005 Elsevier Inc. All rights reserved.