Immune checkpoint therapy, where CD8 tumor infiltrating T lymphocytes (TIL) are reactivated, is a promising anti‐cancer treatment approach, yet with low response rates. The extracellular matrix, in particular tenascin‐C, may generate barriers for TIL. To investigate this possibility, we used a MMTV‐NeuNT and syngeneic mammary gland grafting model derived thereof with engineered tenascin‐C levels and observed accumulation of CD8 TIL in tenascin‐C‐rich stroma. Inhibition studies revealed that tenascin‐C induced CXCL12 through TLR4. By binding CXCL12, tenascin‐C retained CD8 TIL in the stroma. Blockade of CXCR4, the receptor of CXCL12, enhanced macrophage and CD8 TIL infiltration and reduced tumor growth and subsequent metastasis. Retention of CD8 TIL by tenascin‐C/CXCL12 was also observed in human breast cancer by tissue staining. Moreover, whereas high CD8 TIL numbers correlated with longer metastasis‐free survival, this was not the case when also tenascin‐C and CXCL12 levels were high. Altogether, these results may be useful for improving tumor immunity as diagnostic tool and to formulate a future “TIL‐matrix‐release‐and‐reactivate” strategy.

The roles of the extracellular matrix molecule tenascin-C (TNC) in health and disease have been extensively reviewed since its discovery over 40 years ago. Here, we will describe recent insights into the roles of TNC in tumorigenesis, angiogenesis, immunity and metastasis. In addition to high levels of expression in tumors, and during chronic inflammation, and bacterial and viral infection, TNC is also expressed in lymphoid organs. This supports potential roles for TNC in immunity control. Advances using murine models with engineered TNC levels were instrumental in the discovery of important functions of TNC as a danger-associated molecular pattern (DAMP) molecule in tissue repair and revealed multiple TNC actions in tumor progression. TNC acts through distinct mechanisms on many different cell types with immune cells coming into focus as important targets of TNC in cancer. We will describe how this knowledge could be exploited for cancer disease management, in particular for immune (checkpoint) therapies.

Tumor-targeted therapies have often been inefficient due to the lack of concomitant control over the tumor microenvironment. Using an immunocompetent autologous breast cancer model, we investigated a MAtrix REgulating MOtif (MAREMO)-mimicking peptide, which inhibits the protumorigenic extracellular matrix (ECM) molecule tenascin-C that activates several cancer hallmarks. In cultured cells, targeting the MAREMO blocks tenascin-C signaling involved in cell adhesion and immune-suppression by inhibiting tenascin-C interactions with fibronectin, TGFβ, CXCL12, and others, thereby blocking downstream events. Using RNASequencing and various genetic, molecular, in situ, and in vivo assays, we demonstrate that the MAREMO peptide similarly blocks multiple tenascin-C functions in vivo. This includes releasing tumor-infiltrating leukocytes, including CD8+ T cells, from the stroma. The MAREMO peptide also triggers interferon signaling, restoring antitumor immunity, contributing to tumor growth inhibition and reduced dissemination. The MAREMO peptide targets tumor cells directly by promoting growth suppression and inhibiting phenotypic plasticity, subsequently enhancing responsiveness to the endogenous death inducer tumor necrosis factor-related apoptosis-inducing ligand, as shown by a loss-of-function approach. Moreover, the MAREMO peptide largely subdues the tumor bed by depleting fibroblasts, repressing tenascin-C and other ECM molecules, and restoring the function of the few remaining blood vessels. In conclusion, targeting tenascin-C with a MAREMO peptide represents a powerful anticancer strategy with a broad inhibition of several cancer hallmarks.

Antimicrobials are common drugs used to treat and prevent infectious diseases in plants, animals, and humans. Since their discovery in the mid-20th century, their use has dramatically increased for the benefit of humanity, and also for animal care. However, antimicrobial resistance soon appeared, which, according to the WHO, will limit or impede their use at the horizon of 2050. Indeed, antimicrobial resistance (AMR), which is a natural phenomenon in bacteria increased dramatically over the last 3 decades mainly due to the overuse and misuse of antibiotics in humans, animals, and plants. Apart from affecting human health, drug-resistant diseases also adversely affect plant and animal health, reduce agricultural productivity, and threaten food security. AMR affects all countries, regardless of economic status, and imposes high costs on health systems and national economies. Therefore, antimicrobial resistance should be studied and analyzed under the One Health paradigm. In mind of the One Health paradigm, to reduce and overcome AMR, we must take at least 3 complementary and integrated actions: (i) monitoring the resistome; (ii) developing protective strategies against antibiotic resistance; (iii) taking curative actions by designing new and original treatments. Moreover, the three actions must be conducted simultaneously due to the continuous adaptation of bacteria.