Table 3.
Expression of TLRs on resting and activated T cells in comparison with macrophages and B cells
| Cell population | Molecules per cell | |||
| TLR-1 | TLR-2 | TLR-4 | TLR-6 | |
| Spleen Thy1.2+ (ex vivo) | 611 | 46 | n.d. | n.d. |
| Spleen Thy1.2+ + PMA/ionomycin | 40 | 24 | 6 | n.d. |
| Spleen CD4+ T cells | 1874 | 30 | 7 | 47 |
| Spleen CD8+ T cells | 602 | 31 | 0 | 39 |
| CTLs | 248 | 219 | 43 | 56 |
| CTLs + PMA/ionomycin | 19 | 335 | 53 | 19 |
| CTLs (TLR-2-/-) | 0 | -a | 28 | 6 |
| Spleen (TLR-2-/-, ex vivo, unselected) | 101 | -a | 78 | 18 |
| Bone marrow macrophages (cultured) | -b | 6375 | 7056 | 113 |
| Spleen mature B cells | -b | 25 | 25 | 13 |
| Spleen marginal-zone B cells | -b | 49 | 33 | 11 |
aNot determined; sterile fusion transcripts of the mutated Toll-like receptor (TLR)-2 gene can be found with the indicated primer pairs; however, no protein product is detectable (CJ Kirschning, unpublished observations). bNot determined. Purified T cells (Thy1.2+, CD4+ or CD8+) or B cells (mature, marginal zone) from B6 mice, whole splenocytes from TLR-2-/- mice or purified cytotoxic T lymphocytes (CTLs) from C57BL/6 and TLR-2-/- anti-BALB/c mixed lymphocyte culture (purified by cell sorting for CD8-positive cells) were stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin for 24 h or frozen directly in TriReagent for RNA isolation and real-time polymerase chain reaction, as described in Materials and methods. As a control, cultured bone marrow-derived macrophages were used. Experiments, except for the measurement of mRNA in CTL lines and spleen cells that were stimulated with PMA and ionomycin, were repeated twice and gave similar results, both in the sense of inter-experimental and intra-experimental reproducibilities. n.d., not detectable.