The structural basis for complement receptor type 2 (CR2, CD21)-mediated alternative pathway activation of complement: studies with CR2 deletion mutants and vaccinia virus complement-control protein-CR2 chimeras

Autor: Ariella M. Rosengard, Anna Ansaba Johnson, Joseph M. Ahearn, Karsten Skjødt, Robert Graham Quinton Leslie
Rok vydání: 1999
Předmět:
Zdroj: European Journal of Immunology. 29:3837-3844
ISSN: 1521-4141
0014-2980
Popis: Summary of COS transfections with wtCR2 cDNA and its deletion mutantsGene No. of experiments Deleted SCR Mean % transfection (range) Relative receptorexpression, % ± SDwtCR2 23 – 5.4 (1.2–10.0) 100 a, b) EK 14 10 + 11 1.8 (0.5– 5.8) 27.9 ± 26.9 b) NN 16 mid 5–8 4.7 (1.0–12.3) 70.4 ± 21.6 b) XB 17 3–6 3.1 (1.0– 6.7) 31.1 ± 13.2 c) NOP 17 mid 5–mid 14 5.4 (1.8– 9.7) 75.6 ± 38.9 b) PP 17 3–mid 14 3.9 (0.9–10.0) 34.8 ± 14.7 c) a) Mean wtCR2 expression per transfected COS cell = 5.0 ± 2.2 × 10 5 CR2/cell.b) Quantitation was performed with FITC-conjugated HB135 mAb.c) Quantitation was performed with FITC-conjugated OKB7 mAb. Figure 5. Relative activities of COS cells transfected withCR2deletionmutants.TherelativeiC3bindingandAPactivation are shown in (a) and (b), respectively. The verticalbars denote the 90% confidence interval for the means.not differ significantly from that of wtCR2 (relative activi-ties of 82.6 ± 35.3 and 88,9 ± 44.5% for NN and NOP,respectively), whilst EK displayed significant, thoughreduced, activity (53.1 ± 29.8%; see Fig. 5a). In terms ofAP activation, EK funktioned with an efficiency (83.4 ±44.7%) comparable to wtCR2 whilst, NN and NOP weresignificantly less effective (61.7 ± 51.2 and 49.4 ±26.4%, respectively, Fig. 5b). By contrast, the mutantsXB and PP, though similar in size to NN and NOP, respec-tively, were entirely inactive in the AP assay (Fig. 5b),while XB was also shown to be incapable of binding iC3(Fig. 5a). Furthermore, when the PP transfectant wastested in a single-staining assay (
Databáze: OpenAIRE
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