CD4 T-cell immune stimulation of HER2 + breast cancer cells alters response to trastuzumab in vitro

• Published in: Cancer cell international 2020-11, Vol.20 (1), p.544-544, Article 544
• Main Authors: Song, Patrick N, Mansur, Ameer, Dugger, Kari J, Davis, Tessa R, Howard, Grant, Yankeelov, Thomas E, Sorace, Anna G
• Format: Article
• Language: English
• Subjects: Breast cancer; Cancer therapies; CD4 antigen; CD4 + T-cell; Cell culture; Cell cycle; Cell growth; Cell viability; Co-culture; Cytokines; Cytotoxicity; Enzyme-linked immunosorbent assay; ErbB-2 protein; Experiments; Herceptin; Immunogenicity; Immunotherapy; Inflammation; Live-cell imaging; Lymphocytes; Lymphocytes T; Macrophages; Monoclonal antibodies; Natural killer cells; Primary Research; Targeted cancer therapy; TNF-α; Trastuzumab; Tumor necrosis factor-TNF; Tumor necrosis factor-α
• ISSN: 1475-2867; 1475-2867
• DOI: 10.1186/s12935-020-01625-w

The HER2 + tumor immune microenvironment is composed of macrophages, natural killer cells, and tumor infiltrating lymphocytes, which produce pro-inflammatory cytokines. Determining the effect of T-cells on HER2 + cancer cells during therapy could guide immunogenic therapies that trigger antibody-dependent cellular cytotoxicity. This study utilized longitudinal in vitro time-resolved microscopy to measure T-cell influence on trastuzumab in HER2 + breast cancer. Fluorescently-labeled breast cancer cells (BT474, SKBR3, MDA-MB-453, and MDA-MB-231) were co-cultured with CD4 + T-cells (Jurkat cell line) and longitudinally imaged to quantify cancer cell viability when treated with or without trastuzumab (10, 25, 50 and 100 μg/mL). The presence and timing of T-cell co-culturing was manipulated to determine immune stimulation of trastuzumab-treated HER2 + breast cancer. HER2 and TNF-α expression were evaluated with western blot and ELISA, respectively. Significance was calculated using a two-tailed parametric t-test. The viability of HER2 + cancer cells significantly decreased when exposed to 25 μg/mL trastuzumab and T-cells, compared to cancer cells exposed to trastuzumab without T-cells (p = 0.01). The presence of T-cells significantly increased TNF-α expression in trastuzumab-treated cancer cells (p = 0.02). Conversely, cancer cells treated with TNF-α and trastuzumab had a similar decrease in viability as trastuzumab-treated cancer cells co-cultured with T-cells (p = 0.32). The presence of T-cells significantly increases the efficacy of targeted therapies and suggests trastuzumab may trigger immune mediated cytotoxicity. Increased TNF-α receptor expression suggest cytokines may interact with trastuzumab to create a state of enhanced response to therapy in HER2 + breast cancer, which has potential to reducing tumor burden.