Figure 8.

Infiltrating lymphocytes are recruited into the tumor after LTX-315 treatment. (A) Schedule of experiment to study cell infiltration and modification of cell composition in tumors after LTX-315 treatment. Rats were s.c. inoculated with 2·10⁵ rTMSCs in one flank day ÷2 and 2·10⁴ rTMSCs in the opposite flank on day 0. Rats (n = 8) with pre-established tumors were given i.t. injections of 1 mg LTX-315 daily for 3 subsequent days. Tumor-bearing rats in the control group (n = 6) received saline injections in parallel. Single-cell suspensions were prepared from fresh tumor tissue at different time points during the week after LTX-315 treatment. (B) Representative dot plots of the morphological characteristics (SSC vs. FSC) exhibited by progressing tumors and LTX-315-treated tumors. Schematic illustration of gating: Tumor-infiltrating lymphocytes determined by forward and side scatter properties, stained with relevant antibodies for flow cytometric analysis to identify NK (NKR-P1A⁺CD3⁻) cell and T (CD3⁺NKR-P1A⁻) cell populations, including CD4⁺ and CD8⁺ T cell subsets. The percentage of Tregs was derived from the percentage of FoxP3⁺ cells within the total CD4⁺ T cell population. (C) Bar graphs showing the percentage of TIL subsets in primary treated lesion (light gray bars), secondary lesion (dark gray bars) of treated rats compared with lesions from the control group (black bars). Graphs show the mean ± SD. *P < 0.5, **P < 0.1 with Student's t test. (D) Representative images of primary and secondary tumors from treated rats vs. untreated controls stained for CD3 or CD8 (brown) and counterstained with DAPI (blue).