Table 2.
Increased secretion of antigen-specific antibodies in presence of lipopolysaccharide
| Experiment | Total IgG (μg/106cells) | Ratio ‘A’ (+LPS/−LPS) | Antigen-specific IgG (OD/106cells)1 | Ratio ‘B’ (+LPS/−LPS) | Overall increase (Ratio B/A) | |
|---|---|---|---|---|---|---|
| 1 | −LPS | 8·1 | 0·62 | 0·133 | 2·3 | 3·7 |
| +LPS | 5·0 | 0·306 | ||||
| 2 | −LPS | 9·2 | 0·84 | 0·032 | 1·7 | 2·0 |
| +LPS | 7·7 | 0·054 | ||||
| 3 | −LPS | 4·2 | 0·79 | 0·018 | 34·1 | 43·2 |
| +LPS | 3·3 | 0·613 | ||||
| 4 | −LPS | 5·3 | 0·32 | 0·012 | 9·3 | 29·1 |
| +LPS | 1·7 | 0·112 | ||||
| 5 | −LPS | 5·6 | 1·30 | 0·187 | 2·1 | 1·6 |
| +LPS | 7·3 | 0·390 | ||||
IgG, immunoglobulin G; LPS, lipopolysaccharide; OD, optical density.
Total IgG and tetanus toxin-specific (exp. 1, 2, 4 and 5) or hepatitis B surface antigen-specific (exp. 3) antibodies were measured by enzyme-linked immunosorbent assay, after 10 days of culture in the presence or absence of LPS. The experiments were performed using B cells from three different donors.
The OD at similar dilutions of culture supernatants were used as a measure of the amount of antigen-specific antibodies and normalized by dividing with the cell number at day 10. Ratio ‘A’: relative increase : decrease in total IgG secretion in presence of LPS. Ratio ‘B’: relative increase in antigen-specific IgG secretion in presence of LPS. Ratio B/A : increase in antigen-specific IgG secretion among total IgG.