Epigenetic targets to enhance antitumor immune response through the induction of tertiary lymphoid structures.

Tertiary lymphoid structures (TLS) are ectopic lymphoid aggregates found in sites of chronic inflammation such as tumors and autoimmune diseases. The discovery that TLS formation at tumor sites correlated with good patient prognosis has triggered extensive research into various techniques to induce their formation at the tumor microenvironment (TME). One strategy is the exogenous induction of specific cytokines and chemokine expression in murine models. However, applying such systemic chemokine expression can result in significant toxicity and damage to healthy tissues. Also, the TLS formed from exogenous chemokine induction is heterogeneous and different from the ones associated with favorable prognosis. Therefore, there is a need to optimize additional approaches like immune cell engineering with lentiviral transduction to improve the TLS formation in vivo. Similarly, the genetic and epigenetic regulation of the different phases of TLS neogenesis are still unknown. Understanding these molecular regulations could help identify novel targets to induce tissue-specific TLS in the TME. This review offers a unique insight into the molecular checkpoints of the different stages and mechanisms involved in TLS formation. This review also highlights potential epigenetic targets to induce TLS neogenesis. The review further explores epigenetic therapies (epi-therapy) and ongoing clinical trials using epi-therapy in cancers. In addition, it builds upon the current knowledge of tools to generate TLS and TLS phenotyping biomarkers with predictive and prognostic clinical potential.

Early appearance of TNF-alpha and other cytokines in bronchus associated lymphoid tissues (BALT) from growing Wistar rats. what is the role of TNF-alpha?

Several different cytokines trigger the development of determined cell subsets in BALT of growing Wistar rats. Early appearance (4 days post partum) of gammadeltaT cells in BALT has been shown, as well as its role in up-regulating TNF-alpha production. In the present report, we studied in the BALT: (1) the profile of the cytokines, TNF-alpha, INF-alpha and IL-10 and (2) in TCR gammadelta+ cells, the existence of a colocalization with TNF-alpha as well as with INF-gamma. All the cytokines studied were observed at an early stage of BALT development by immunohistochemistry and in bronchoalveolar cells (BAL cells) by flow cytometry and western blot. (1) The principal cytokine found at 4 days of age in BALT cells was TNF-alpha that increases along BALT development. The same behavior was found for cells containing IL-10 and INF-gamma. (2) TCR gammadelta+ cells colocalize mainly with TNF-alpha as it has been shown by immunohistochemistry in BALT and by flow cytometry when we studied BAL. The early appearance of TNF-alpha concomitant with TCR gammadelta+ cell suggests an important role for this cytokine along BALT development. Moreover, mutual regulation between them exists taking part in the immune surveillance and repair of damaged epithelia.