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

Abstract

Introduction 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. Methods 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. Results 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). Conclusions 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.

Quantifying the Effects of Combination Trastuzumab and Radiation Therapy in Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer

“…Previously collected data revealed that trastuzumab has the potential to reprogram the immunosuppressive components of the tumor microenvironment and could contribute to anti-tumor responses. The evaluation of immune cell characterization and impact on tumor regression in this treatment regimen is needed to further elucidate the mechanisms contributing to enhanced tumor regression in the combination treatment group [ 29 ]. Although no significant differences were shown in hypoxia and the vascular maturation index, previous studies using longitudinal imaging have revealed that trastuzumab can reduce hypoxia and increase vascular perfusion [ 17 , 30 ].…”

Dual anti-HER2/EGFR inhibition synergistically increases therapeutic effects and alters tumor oxygenation in HNSCC

“…For in vitro live cell imaging experiments, SCC1, FADU and OSC19 cell lines were transfected to express green fluorescent protein (GFP) for longitudinal tracking of cell viability. The plasmid and protocol used to induce stable nuclear transfection were previously described 27 . Briefly, cell lines were co-transfected with pCMV (CAT) T7-SB100 (Addgene plasmid #34879) and a GFP clone Sleeping Beauty compatible vector (Addgene plasmid #60525).…”

A Comprehensive Review of HER2 in Cancer Biology and Therapeutics

“…Addressing the immunosuppressive mechanisms associated with HER2 signaling can help overcome resistance to HER2-targeted therapies and immunotherapies. The rationale is that HER2-targeted therapies can enhance antigen presentation and T-cell activation, making tumors more susceptible to checkpoint blockade [72]. The interplay between HER2 signaling and immune regulation is complex and has significant implications for developing and optimizing cancer therapies.…”