Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - ENLIGHTEN (INTEGRATION AND PROPAGATION OF IMMUNOLOGICAL SIGNALS DURING CANCER AND INFECTION)

Teaser

The immune system uses both short- and long-range communication mechanisms to mount the coordinated and sophisticated cellular responses required to control microbial infections or fight tumors. Yet, our understanding of how immunological signals are integrated and propagated...

Summary

The immune system uses both short- and long-range communication mechanisms to mount the coordinated and sophisticated cellular responses required to control microbial infections or fight tumors. Yet, our understanding of how immunological signals are integrated and propagated by individual cells in complex tissue microenvironments remains largely limited.

ENLIGHTEN is a research program dedicated to establish new mechanisms by which the immune system fight tumors or infections, based on the direct manipulation of immunological signals in vivo. In relevant mouse models of human disease, we will combine intravital imaging, fluorescent sensors and optogenetic actuators to control single cell functions in real-time. We wish to understand how T cells sense and interpret cell-contacts in lymphoid organs and in developing tumors at steady state or during immunotherapy. In addition, we aim to establish how cytokine and chemokine gradients form and are interpreted in tissues during infection or cancer.


Our specific aims are:

Aim I. To design a pipeline for the generation of immune cells expressing actuators and reporters. We will establish a new strategy based on hematopoietic progenitor cell lines to generate immune cells expressing reporters and optogenetic actuators.

Aim II. To dissect how T cells interpret cellular interactions: from priming to tumor surveillance. We will identify how sequences of TCR signals regulate motility and differentiation. In the context of tumors, we will establish how the killing ability of intratumoral T cells is regulated by the pattern of TCR stimulation and by the presence of checkpoint inhibitors.

Aim III. To establish basic principles of cytokine and chemokine gradients and fields in vivo. We will identify how chemokine and cytokine gradients are formed in vivo and how their shape and size orchestrate the immune reaction to an infectious agent or to a tumor.

By determining the functional contribution of single immune cells in vivo, we aim to identify new paradigms for information transfer in the immune system during cancer or infection and to establish the combination of optogenetics and intravital imaging as a powerful strategy for decoding immune reactions in the context of disease pathogenesis.

Work performed

Using functional in vivo imaging, our laboratory studies mechanisms of immune communication during disease pathogenesis. Our work in the last years has contributed to i) identify how cellular interactions regulate T cell priming in lymph nodes, ii) dissect mechanisms regulating immune responses to intracellular pathogens and iii) uncover new mechanisms of tumor immunosurveillance and mode of action of tumor immunotherapies

Our main achievements are

• The identification of a cellular mechanism contributing to the termination of T cell priming

• The discovery of a quorum-sensing mechanism that terminate inflammatory responses

• The description of anatomical and functional heterogeneity in CAR T cell activity in vivo

• The characterization of the impact of anti-tumor responses on tumor genetic heterogeneity

Final results

From the perspective of fundamental research, the project will not only consolidate our knowledge on adaptive immunity but also establish new paradigms for information transfer in the immune system. From the perspective of technological development, this project will generate new tools for the control of immune cell functions and create a bank of hematopoietic progenitor cell lines dedicated to imaging experiments. In 2002, we pioneered (with two other groups) the use of two-photon microscopy for the study of immune responses. Since then, this approach has been used by many immunologists, providing tremendous insight into immune cell dynamics during infection, cancer and autoimmunity. Our ambition is now to define or redefine the key communication rules that coordinate these immune responses with the expectation that these findings will profoundly modify our perception of these cellular reactions at a mechanistic level. These fundamental advances should also serve to establish the combination of optogenetics and intravital imaging as a new standard approach for dissecting the complexity of immune reactions in the context of disease pathogenesis.

Website & more info

More info: https://research.pasteur.fr/en/team/dynamics-of-immune-responses/.