Fig. 4: SULT2B1b expression promotes intratumor differentiation of monocyte-DCs migrating to draining lymph nodes.

A Schematic for assessing intratumor monocyte-DC differentiation. CD45.2⁺Ccr2^-/- mice bearing LLC-Mock and LLC-SULT2B1b tumors were administered with CD45.1⁺ bone-marrow purified monocytes (Ly6C⁺). Twenty-four hours later tumors were collected and analyzed by flow cytometry. B Percentage of CD45.1⁺ cells infiltrating LLC-Mock and LLC-SULT2B1b tumors 24 and 72 hours after the adoptive transfer of pure CD45.1⁺Ly6C⁺ monocytes. Mean and s.d. of 5 (24 h) and 7 (72 h) mice/group. No difference was observed between the two groups. ns, not significant. C-D Numbers of mono-DCs (C) and Ly6C^lowCD11c⁺MHC-II⁺ cells (D) infiltrating LLC-Mock and LLC-SULT2B1b tumors 24 and 72 hours after the adoptive transfer of pure CD45.1⁺Ly6C⁺ monocytes. Mean and s.d. of 5 (24 h) and 6-7 (72 h) mice/group. ns, not significant; *P < 0.05; **P < 0.01 (Student’s t-test). E Schematic for assessing tumor-engulfed monocyte-DCs in the draining lymph nodes. CD45.2⁺Ccr2^-/- mice bearing LLC-SULT2B1b tumors expressing mCherry were administered with CD45.1⁺ bone-marrow purified monocytes (Ly6C⁺). Forty-eight hours later draining lymph nodes were collected and analyzed by flow cytometry. As control, draining lymph nodes were collected from not adoptively transferred tumor-bearing mice. F Representative confocal microscopy imaging of LLC-SULT2B1b tumors expressing mCherry⁺, CD45.1⁺, CD11c⁺ cells in the draining lymph nodes. Red, mCherry⁺; Blue, DAPI, Green, CD45.1; Gray, CD11c (bars = 25 µm). G Representative flow cytometry image of CD45.1⁺ and CD45.2⁺ cells in the draining lymph nodes of tumor-bearing mice. (H) Quantification of CD45.1⁺ cells in the draining lymph nodes of tumor-bearing mice with or without adoptive transfer of CD45.1⁺ monocytes. Mean and s.d. of 3 (no AT) and 6 (AT) mice/group. ***P < 0.001 (Student’s t-test). I-K Quantification of CD45.1⁺Ly6C⁺ or CD45.2⁺Ly6C⁺ cells (I), Ly6C⁺CD11c⁺MHC^-II⁺ cells (J) and CD11c⁺MHC^-II⁺mCherry⁺ cells (K) in the draining lymph nodes of tumor-bearing mice adoptively transferred with bone marrow-derived CD45.1⁺ monocytes. The CD11c⁺MHC-II⁺mCherry⁺ cells are tumor^-engulfed mono-DCs migrated to draining lymph nodes. Mean and s.d. of 6 mice/group. ***P < 0.001; ****P < 0.0001 (Student’s t-test).