Cyclophosphamide and Vinorelbine Activate Stem-Like CD8+ T Cells and Improve Anti-PD-1 Efficacy in Triple-Negative Breast Cancer

Abstract

Checkpoint inhibitors (CI) instigate anticancer immunity in many neoplastic diseases, albeit only in a fraction of patients. The clinical success of cyclophosphamide (C)-based haploidentical stem-cell transplants indicates that this drug may re-orchestrate the immune system. Using models of triple-negative breast cancer (TNBC) with different intratumoral immune contexture, we demonstrate that a combinatorial therapy of intermittent C, CI, and vinorelbine (V), activates antigen presenting cells (APC), and abrogates local and metastatic tumour growth by a T-cell-related effect. Single-cell transcriptome analysis of >50,000 intratumoral immune cells after therapy treatment showed a gene signature suggestive of a change resulting from exposure to a mitogen, ligand, or antigen for which it is specific, as well as APC-toT cell adhesion. This transcriptional program also increased intratumoral tcf1+ stem-like CD8+ T cells and altered the balance between terminally and progenitorexhausted T cells favoring the latter. Overall, our data support the clinical investigation of this therapy in TNBC. Statement of Significance A combinatorial therapy in mouse models of breast cancer increases checkpoint inhibition by activating antigen presenting cells, enhancing intratumoral tcf1+ stem-like CD8+ T-cells, and increasing progenitor exhausted CD8+ T-cells. of combinatorial therapies (2). The clinical success of cyclophosphamide (C)-based haploidentical stem cell transplants in hematological malignancies indicates that this drug has the potential to reorchestrate the immune system against cancer cells (3). Along a similar way, C is administered before CART cell infusion to improve their clinical efficacy (4). We have previously found that low-dose, daily C, in association with V was able to improve the Research.

A “two-hit” (chemo)therapy to improve checkpoint inhibition in cancer

“…Secondly, we found that intermitted, medium dosage cyclophosphamide (140 mg/Kg every 6 days, C140) can generate new CD3+CD4+ and CD3+CD8+T cell clones. In our models, a “two-hit” approach (V plus C140) significantly improved CI preclinical activity against local and disseminated neoplastic growth [ 5 - 6 ].…”

“…In both cases, antibody-mediated depletion of CD3+CD4+ or of CD3+CD8+ T cells abrogated the preclinical efficacy of the V plus C140 plus CI combinatorial therapy. These data suggest that anti-cancer activity was largely related to these immune T cells [ 6 ].…”

“…Single-cell transcriptome analysis of >50,000 intratumoural immune cells, after V plus C140 and CI combinatorial therapy, showed a gene signature suggestive of a change resulting from exposure to a mitogen, ligand, or an antigen for which it is specific, as well as APC-to-T-cell adhesion [ 6 ]. This transcriptional program also significantly increased the number of intratumoural Tcf1 + stem-like CD8+ T-cells [ 7 ] and altered the balance between terminally and progenitor exhausted T-cells, favoring the latter [ 6 ]. The proposed mechanism of V plus C140 and CI combinatorial therapy is showed in (Figure 1 )…”

Immunomodulating Therapies in Breast Cancer—From Prognosis to Clinical Practice

“…In addition, vinorelbine, cyclophosphamide, and 5-FU had significant preclinical effects on circulating and tumour-infiltrating immune cells and could be used to obtain synergy with anti-PD-L1 [ 60 ]. Furthermore, a combinatorial therapy in preclinical models of breast cancer increased checkpoint inhibition by activating antigen-presenting cells, enhancing intratumoral CD8+ T cells, and increasing progenitor exhausted CD8+ T cells [ 61 ]. Radiation therapy also has immunomodulatory effects that could contribute to increased efficacy of immunotherapies [ 62 ].…”

A single-cell transcriptomic landscape of innate and adaptive intratumoral immunity in triple negative breast cancer during chemo- and immunotherapies

“…As this work focuses on the computational analysis of scRNAseq data previously published, in vivo and in vitro experiments were performed as mentioned in 27 . Briefly the laboratory procedures included the injection of two TNBC cell lines (4T1 and EMT6) in the mammary fat pad as in 26 .…”