Extended Data Fig. 3 |. In vivo Siglec-7/9 trogocytosis dampens T cell effector functions.

a, Experimental workflow of investigation of in vivo trogocytosis. b, Analysis of Siglec-7/-9 trogocytosis by adoptively transferred P14 CD8⁺ T cells (Thy1.1) in the tumor dLNs, spleens and blood of SigE^KO and Sig7/9⁺ mice bearing B16-GP33/B16-GMCSF (9:1) tumors. c, Analysis of Siglec-7/-9 on endogenous CD8⁺ T cells. Data are mean ± s.d. Two-tailed unpaired Student’s t-test (b,c). d, Quantitative PCR analysis of Siglec-7 and -9 transcripts in isolated splenic CD11b⁺ and T cells from SigE^KO and Sig7/9⁺ mice. SIGLEC expressions were normalized based on GAPDH expression. e,f, Analysis of in vivo stability of Siglec-7/-9 on CFSE⁺CD8⁺ T cells (prepared from Sig7/9⁺ splenic cells) in the spleen and iLN tissues after adoptive transfer into SigE^KO recipient mice. CFSE, carboxyfluoroscein succinimidyl ester; iLN, inguinal lymph node. g,h, In vivo assessment of Siglec-7/-9 acquisition by SigE^KO T cells in spleen after adoptive transfer into Sig7/9⁺ recipient mice. i, Paired analysis of effector cytokine (IFNγ, TNFα, GZMB and IL2) production from Siglec-7/9⁻ and Siglec-7/9⁺ tumor dLN-infiltrating P14 CD8⁺ T cells, respectively. Paired Student’s t-test (i). j, Retroviral transduction of P14 T cells with individual Siglec-7 and -9, and both, respectively, characterized by staining with anti-Siglec-7 (6–434) and anti-Siglec-9 (K8).