TIM3 Expression in Anaplastic-Thyroid-Cancer-Infiltrating Macrophages: An Emerging Immunotherapeutic Target

PALACIOS, LUZ MARIA; PEYRET, VICTORIA; VIANO, ESTEFANIA; GEYSELS ROMINA; CHOCOBAR, YAIR; VOLPINI, XIMENA; PELLIZAS, CLAUDIA GABRIELA; NICOLA, JUAN PABLO; MOTRAN, CLAUDIA CRISTINA; RODRIGUEZ GALAN, CECILIA; FOZZATTI, LAURA

Biology

MDPI

Año: 2022

2079-7737

naplastic thyroid cancer (ATC) is a clinically aggressive form of undifferentiated thyroid cancer with limited treatment options. Immunotherapy for patients with ATC remains challenging. Tumor-associated macrophages (TAMs) constitute over 50% of ATC-infiltrating cells, and their presence is associated with a poor prognosis. Consequently, the development of new therapies targeting immune checkpoints in TAMs is considered a promising therapeutic approach for ATC. We have previously shown that soluble factors secreted by ATC cells induced pro-tumor M2-like polarization of human monocytes by upregulating the levels of the inhibitory receptor TIM3. Here, we extended our observations on ATC-cell-induced xenograft tumors. We observed a large number of immune cells infiltrating the ATC xenograft tumors. Significantly, 24–28% of CD45+ immune cells were macrophages (CD11b+ F4/80+). We further showed that 40% of macrophages were polarized toward a M2-like phenotype, as assessed by CD206 expressi