Abstract 1315: High IFNγ and perforin and low GM-CSF and sCD40L production correlate with CD8 TIL growth in breast cancer
Authors: Torisu-Itakura Hitoe , Quan Yueqin , Sim Myung Shin , DiNome Maggie L. , Sieling Peter A. , Lee Delphine J. , Faries Mark B. 
Published: August 2015

Introduction: Adoptive cell therapy (ACT) with expanded autologous tumor-infiltrating lymphocytes (TIL) shows promise in melanoma but has not been developed for breast cancer (BC) because BC-TIL have not demonstrated consistent antitumor potency. This study examined the characteristics and potency of BC-TIL generated by using TIL culture techniques established for our ACT protocol in melanoma.

Methods: Clinically annotated fresh specimens of tumor tissue were collected during surgical treatment of 8 patients with breast cancer and 26 patients with melanoma. TIL for each specimen were grown from 3-24 tumor fragments, depending on tumor size. After several weeks of cell growth, the expression of CD3, CD4 and CD8 on TIL was measured by flow cytometry. Then TIL were co-cultured with autologous tumor cells, and IFNγ expression level was measured by ELISA as an indicator of antitumor potency. Luminex assay was used to measure the expression of 18 immune mediators (GM-CSF, IFNγ, IL-1α, IL-1Rα, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-17a, IP-10, sCD40L, MCP-1, TNFβ, sCD137, granzyme-B, and perforin) in the BC-TIL culture supernatant. Mixed effect model with random intercept was used for univariable and multivariable analysis to determine which immune mediators were associated with high CD8 cell percentage in TIL cultures.

Results: TIL were successfully grown from 62 of 64 (97%) BC fragments and from 487 of 622 (78%) melanoma fragments (p = 0.004). TIL reached a sufficient number for co-culture in 16±3 days for BC-TIL and in 25±9 days for melanoma-TIL (p&lt;0.0001). In the successful TIL cultures, 6 of 62 (9.6%) BC-TIL and 290 of 487 (60.0%) melanoma-TIL showed antitumor potency: 47.0% BC-TIL and 70.7% melanoma-TIL contained more CD8 cells than CD4 cells. The total number of expanded BC-TIL was inversely associated with MCP-1 expression (p&lt;0.0001) and AJCC stage (p&lt;0.0007). In univariable analysis, low expression of IL-10 and sCD40L, and high expression of perforin were associated with increased CD8 cell percentage in TIL cultures (P&lt;0.001, P&lt;0.03, and P&lt;0.0001, respectively). In multivariable analysis, low GM-CSF and sCD40L, and high IFNγ and perforin were associated with high CD8 cell percentage in TIL cultures (P&lt;0.002, P&lt;0.008, P = 0.02, and P&lt;0.001, respectively).

Conclusions:

Antitumor potency of BC-TIL was less frequently but BC fragments can grow TIL faster than melanoma fragments. The CD4:CD8 cell ratio was higher in BC-TIL than in melanoma-TIL. Blocking antibodies against IL-10, GM-CSF and sCD40L should be investigated to improve CD8 expansion from BC-TIL. In addition, because BC-TIL contained more CD4, it might be possible to promote tumor regression via mediation of a BC antigen by CD4 cells.

Citation Format: Hitoe Torisu-Itakura, Yueqin Quan, Myung Shin Sim, Maggie L. DiNome, Peter A. Sieling, Delphine J. Lee, Mark B. Faries. High IFNγ and perforin and low GM-CSF and sCD40L production correlate with CD8 TIL growth in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1315. doi:10.1158/1538-7445.AM2015-1315