ABSTRACT
Objective To investigate human plasma glycoproteomie changes related to human immunodeficiency virus (HIV) infection,and to identify glycoproteins with potential anti-HIV activity or anti-HIV drug targets. Methods Plasma proteins with lower abundance were enriched through affinity purification to remove albumin and IgG in clinical samples (HIV-positive patient, n= 10, and healthy controls, n= 20). Proteins were separated by two-dimensional electrophoresis (2-DE) and stained by Pro-Q emerald glycoprotein stain kits. The 2-DE image was analyzed by ImageMaster software to find differential glycoproteins. Furthermore, the depleted HIV-positive and healthy control plasma proteins were digested by PNGase F. Glycoproteins were deglycoliszed, separated by 2-DE and analyzed by ImageMaster software. Differential glycoproteins were identified by liquid chromatography combined with high capacity ion trap mass spectrometry (HCT). Results The pretreatment of HIV-positive plasma prior to 2-DE could efficiently remove the high aboundant albumin and IgG in plasma and improve the detection of proteins with low-abundance. High revolution 2-DE gel images of glycoproteins from HIV positive and healthy control plasma samples were obtained. Glycoproteins were successfully deglycolized through PNGase F treatment. Thirteen differential glycoproteins were identified by liquid chromatography combined with mass spectrometry. These proteins included alphalantitrypsin precursor and serine/threonine-protein kinase N1. Conclusions Potential HIV infection related proteins,such as alphal-antitrypsin precursor are successfully identified. Our study may offer some help to understand the molecular mechanism of HIV infection and select new drug targets for preventing HIV infection.
ABSTRACT
The immunohistochemical expression of transforming growth factor-beta(TGF-beta), epidermal growth factor(EGF) and alpha-1-antitrypsin(AAT) was studied in 47cases of endoscopic biopsy matearials of gastric carcinoma to determine me correlation to the expression of alpha fetoprotein(AFP). And immunoreactivity of the antigens was correlated to me degree of tumor infiltrating lymphocytes and histologic differentiation of the tumors. And the results were analyzed to elucidate pathological AFP-producing gastric cancer. The results were summarized as follows. AFP immunoreactivity was demonstrated in 30 cases(63.8%) of the tumors, TGF-beta in 26 cases(55.3%), EGF in l4 cases(29.8%) and AAT in l0 cases(21.3%). The incidence of expression of the antigens was significantly higher in the cases of elevated serum AFP(>2ng/ml) than that of the cases with normal serum AFP(p<0.05). There was no relation between the expression of antigens and histological differentiation of gastric cancer. The expression of AFP and TGF-beta revealed good correlation(k=0.72). The relation between expression of TGF-beta and AAT and the degree of tumor infiltrating lymphocytes disclosed negative correlation(p<0.05). These results suggest that TGF-beta and AAT prodution contribute to the worse prognosis of AFP-producting gastric cancer. Possible immunosuppressive action of TGF-beta and AAT in the cancer tissue is discussed.