PH of Y or 125I-labeled Y was quantitated microscopically and radioactively. An average of 4.05 ± 0.3 Y/PMN (170,000 cpm) was ingested in the presence of normal human serum (NS) diluted 1:20; whereas only 1.45 ± 0.3 Y/PMN (70,000 cpm) were ingested in the absence of NS. OP was unaffected by heating NS at 50°C for 30 sec or after adsorption of NS with Y. OP was reduced by 48% in the presence of 0.005 M EDTA or EGTA, by 60% after heating of NS at 56°C for 30 min, and by 42% after treatment of NS with 1 M KCNS (KCNS-ser). A 45% reduction of OP was also seen in C5-deficient (5DS) (Miller and Nilsson) as well as in C7-deficient (7DS) human serum (Boyer, to be published). OP was fully restored in the following recombinations: (5DS + C5), (7D5 + C7), (5DS + 7DS), (KCNS-ser + C3 + C5); but not in the following recombinations: (5DS + C7), (7DS + C5), (KCNS-ser + C3), (KCNs-ser + C5). The humoral requirements for OP of Y therefore appear to include: C3, C5, and C7. The activation mechanism for OP of Y appears to be distinct from the classical and the C3A pathways. In contrast to Y, trypsin-treated Y (TY) sensitized with rabbit anti-TY antibody was fully opsonized with 5DS as well as after treatment with C1 through C3. (Supported by grants from the Hartford Foundation Inc., United States Public Health Service Grants AM13515 and HL15061.)
No takes yet. Share an insight, caveat, or question.
Nilsson et al. (1973) studied this question.