Table 1.
Effect of mycobacterial infection on human leucocyte antigen (HLA) expression by U937 cells
| Percentage (± SD) of cells expressing surface antigen | MFI (± SD) of cells expressing surface antigen | ||||
|---|---|---|---|---|---|
| HLA | Treatment | Isotypic Ab* | Specific Ab | Isotypic Ab | Specific Ab |
| HLA class II | Uninfected | 2·0 (± 1·0) | 3·2 (± 2·6) | 34·4 (± 20·9) | 30·3 (± 18·1) |
| BCG infected | 2·1 (± 0·6) | 2·5 (± 1·3) | 27·5 (± 11·2) | 29·7 (± 15·9) | |
| M. tb infected | 2·0 (± 0·7) | 2·2 (± 1·2) | 35·0 (± 10·7) | 32·8 (± 9·4) | |
| HLA class I | Uninfected | 2·1 (± 1·9) | 96·6 (± 2·6) | 12·6 (± 13·4) | 27·0 (± 12·1) |
| BCG infected | 2·5 (± 1·7) | 96·7 (± 2·1) | 18·2 (± 19·5) | 28·2 (± 8·9) | |
| M. tb infected | 2·3 (± 0·4) | 94·3 (± 1·3) | 23·8 (± 3·5) | 59·5 (± 9·7)† | |
These results are presented as the mean percentage (± SD) or mean fluorescence intensity (MFI) (± SD) of phorbol 12-myristate 13-acetate (PMA)-differentiated U937 cells expressing cell surface HLA class I or class II.
*
Isotypic controls were used in all cases to set cursors to allow 2% false positives. Ab, antibody.
†
HLA class I expression was significantly up-regulated (P < 0·05) following infection with Mycobacterium tuberculosis (M. tb) H37Rv but not with bacillus Calmette–Guérin (BCG).