Fig. 5.

GSH inhibits terminal attack complex formation induced by both classic and alternation pathway. (A-D) Effect of GSH on the cellular deposition of C9. (A) Immunofluorescent staining of C9. MCs were either left untreated (control) or treated with 10 μg/ml Thy-1 for 1 h, followed by incubation with 10% GSH-treated or untreated human serum for an additional 30 min. The cellular deposition of C9 was detected by IF staining. Note the deposition of C9 in Thy-1 plus human serum-treated cells and its prevention by GSH. (B) Western blot analysis of C9 in the cell lysate. Cells were treated with 10 μg/ml Thy-1 plus 10% native or heat-treated serum for 1 h in the presence or absence of 5 mM GSH or NAC. The cellular lysates were analyzed by native electrophoretic separation and immunoblotted for C9. (C) Densitometric analysis of the band intensity in (B). Data shown are mean ±SE (n =3). ** P<0.01. (D) Western blot analysis of C9 in native and heat-treated human serum. Note that the detection of C9 was not affected by heat treatment. (E-G) Effect of GSH on the alternative complement activation pathway. The complement activity induced by activation of the alternative pathway in the positive control (E) or 4 normal human sera (F) in the presence or absence of 3 mM GSH was determined via detection of the C5b-9 formation. (G) The influence of different concentrations of GSH on complement activity of a normal adult serum. Data shown are mean ±SE (n =4), ** P<0.01.