Inhibitory receptor superfamily down-regulate natural killer cell apoptosis induced by specific soluble HLA class I alleles
| . | Nil . | Specific sHLA-I . | Specific sHLA-I + specific anti-IRS mAb . | Irrelevant sHLA-I + specific anti-IRS mAb . |
|---|---|---|---|---|
| Bulk NK-3 KIR2D+(CD158b+/GL183+) | 2 | 35 | 70 | 37 |
| Clone MZ25.4 KIR2D+(CD158b+/GL183+) | 3 | 25 | 40 | 28 |
| Bulk NK-4 (CD94+KIR2D−) | 5 | 37 | 60 | 40 |
| Clone RB50.3 (CD94+ KIR2D−) | 2 | 40 | 65 | 37 |
| . | Nil . | Specific sHLA-I . | Specific sHLA-I + specific anti-IRS mAb . | Irrelevant sHLA-I + specific anti-IRS mAb . |
|---|---|---|---|---|
| Bulk NK-3 KIR2D+(CD158b+/GL183+) | 2 | 35 | 70 | 37 |
| Clone MZ25.4 KIR2D+(CD158b+/GL183+) | 3 | 25 | 40 | 28 |
| Bulk NK-4 (CD94+KIR2D−) | 5 | 37 | 60 | 40 |
| Clone RB50.3 (CD94+ KIR2D−) | 2 | 40 | 65 | 37 |
A total of 5 × 104 cells (from natural killer [NK]-3 KIR2D+ bulk population 95% CD8+, or clone MZ25.4 KIR2D+ CD8bright, or NK-4 bulk population 90% CD8+CD94+ KIR2D−, or clone RB50.3 CD94+KIR2D−CD8bright) were cultured for 48 hours in medium alone (nil) or with 4 μg/mL specific soluble HLA class I (sHLA-I; HLA-Cw3 for KIR2D+[CD158b+/GL183+] or HLA-G1 for CD94+KIR2D− NK cells) or irrelevant sHLA-I (sHLA-A2 allele), either in the absence or after pretreatment with anti-inhibitory receptor superfamily (IRS) monoclonal antibody (mAb; GL183 for KIR2D+ or anti-CD94 for CD94+KIR2D− NK cells). Apoptosis was evaluated by staining with fluorescein isothiocyanate–annexin V. Samples were run on a FACSort (Becton Dickinson), and results are expressed as the percentage of annexin V+ PI− cells.