Periodic Reporting for period 3 - ARTimmune (Programmable ARTificial immune systems to fight cancer)
Periodo di rendicontazione: 2022-11-01 al 2024-04-30
Immunotherapy has entered centre stage as a novel treatment modality for cancer. Notwithstanding this major step forward, toxicity and immunosuppression remain major obstacles, and illustrate the pressing need for more powerful immunotherapies against cancer.
To overcome these roadblocks, in ARTimmune, we will follow a radically different approach by developing locally administered immunotherapies. Taking advantage of the architecture of a lymph node (LN).
The overall objective is to design fully synthetic immune niches to locally instruct immune cell function, and that will as powerhouses to generate bursts of cytotoxic T cells for local tumour destruction as well as at distant sites, but without toxic side effects related to systemically administered immunotherapies.
Single cell omics of interacting antigen presenting cells and T cells, will provide unique insight in communication within immune cell clusters and provide a blueprint for the intelligent design of synthetic immune niches.
Chemical tools will be used to build branched polymeric structures decorated with immunomodulators to mimic a lymph node architecture. These will be injected, mixed with sponge-like scaffolds to provide porosity needed for immune cell infiltration. Programming of immune cell function will be accomplished by combining a variety of immunomodulators to fine-tune T cell activation and expansion of T cells without exhaustion.
The innovative character of ARTimmune: 1) novel fundamental immunological insight in complex communication within immune cell clusters, 2) a revolutionary new approach in immunotherapy, by the development of 3) injectable- and 4) programmable- synthetic immune niches by state-of-the-art chemical technology.
When successful, it will revolutionize cancer immunotherapy, moving from maximal tolerable dose systemic treatment with significant toxicity to local low dose treatment, yet resulting in systemic immunity.
To overcome these roadblocks, in ARTimmune, we will follow a radically different approach by developing locally administered immunotherapies. Taking advantage of the architecture of a lymph node (LN).
The overall objective is to design fully synthetic immune niches to locally instruct immune cell function, and that will as powerhouses to generate bursts of cytotoxic T cells for local tumour destruction as well as at distant sites, but without toxic side effects related to systemically administered immunotherapies.
Single cell omics of interacting antigen presenting cells and T cells, will provide unique insight in communication within immune cell clusters and provide a blueprint for the intelligent design of synthetic immune niches.
Chemical tools will be used to build branched polymeric structures decorated with immunomodulators to mimic a lymph node architecture. These will be injected, mixed with sponge-like scaffolds to provide porosity needed for immune cell infiltration. Programming of immune cell function will be accomplished by combining a variety of immunomodulators to fine-tune T cell activation and expansion of T cells without exhaustion.
The innovative character of ARTimmune: 1) novel fundamental immunological insight in complex communication within immune cell clusters, 2) a revolutionary new approach in immunotherapy, by the development of 3) injectable- and 4) programmable- synthetic immune niches by state-of-the-art chemical technology.
When successful, it will revolutionize cancer immunotherapy, moving from maximal tolerable dose systemic treatment with significant toxicity to local low dose treatment, yet resulting in systemic immunity.
The overall objective of ARTimmune is to design innovative synthetic immune niches, that facilitate cellular interactions, as also take place in a natural lymph nodes to induce an effective anti-tumour response. It consists of 4 workpackages:
Summary of work performed and main results (November 2019-May 2022).
WP1. Natural immune cell clusters as a blueprint to engineer synthetic immune niches.
We developed a hanging drop technique to study interactions in immune cell clusters composed of dendritic cells and T cells. This prevents interactions of the cells with artificial surfaces. We studied interactions of both human and mouse CD8 T cells expressing antigen specific T cell receptors. Immune cell clusters were formed with different types of antigen presenting dendritic cells. Initial analyses revealed that antigen specific T cell responses result in a totally different transcriptome compared to T cells exposed to DC not loaded with antigen.
WP2. Design of Flexible Immune Response Modulators
A variety of bioactive materials developed to expand T cells for adoptive transfer into cancer patients are currently evaluated in the clinic. In most cases, T cell activating biomolecules are attached to rigid surfaces or matrices and form a static interface between materials and the signaling receptors on the T cells. We hypothesized that a T cell activating polymer brush interface might better mimic the cell surface of a natural antigen-presenting cell, facilitating receptor movement and concomitant advantageous mechanical forces to provide enhanced T cell activating capacities. This would rather mimic immune cell clusters, as discussed above and would also facilitate interaction of multiple T cells with such an immunobrush acting as an artificial antigen presenting cell. As a proof of concept, we synthesized semiflexible polyisocyanopeptide (PIC) polymer-based immunobrushes equipped with T cell activating antibodies placed on magnetic microbeads. We demonstrated enhanced efficiency of ex vivo expansion of activated primary human T cells even at very low numbers of stimulating antibodies compared to rigid beads.
WP3. Design of an injectable 3D semi-rigid Immune Response Matrix.
One of the major beyond the stage of the art approaches of this ERC grant is that we aim to design 3D scaffolds to create immune niches at any anatomic site of the body. For this we exploit porous hydrogels which are semi-rigid. We explored two types of hydrogels, 1) hydrogels loaded with nanoparticles to creates a fully synthetic immunostimulatory niche that stimulates DCs and evokes strong antigen-specific T cell responses, or 2) hydrogels equipped with immunostimulating molecules to activate and expand T cells. We demonstrated that both types of hydrogels can be injected through an injection needle after which they reshape to their original size.We observed that these synthetic immune stimulatory immune niches induced strong murine and human T cell activation resulting in multifunctional T cells with limited T cell exhaustion. The modular biomaterial-based scaffolds we engineered can be easily adapted to attach a variety of biomolecules and may therefore be a valuable tool in the development of new local biomaterial-based cancer immunotherapies
WP4 In vivo validation of synthetic immune niches.
Finally, initial steps towards the in vivo application of these synthetic immune niches have been made. We injected cryogel scaffolds to see if they survived and remained stable in vivo, which was the case. When preloading the cryogels with T cells we noticed that a significant proportion of human and murine T cell were retained within the scaffolds after injection. These findings are promising and will be extended in the second part of the grant period.
Summary of work performed and main results (November 2019-May 2022).
WP1. Natural immune cell clusters as a blueprint to engineer synthetic immune niches.
We developed a hanging drop technique to study interactions in immune cell clusters composed of dendritic cells and T cells. This prevents interactions of the cells with artificial surfaces. We studied interactions of both human and mouse CD8 T cells expressing antigen specific T cell receptors. Immune cell clusters were formed with different types of antigen presenting dendritic cells. Initial analyses revealed that antigen specific T cell responses result in a totally different transcriptome compared to T cells exposed to DC not loaded with antigen.
WP2. Design of Flexible Immune Response Modulators
A variety of bioactive materials developed to expand T cells for adoptive transfer into cancer patients are currently evaluated in the clinic. In most cases, T cell activating biomolecules are attached to rigid surfaces or matrices and form a static interface between materials and the signaling receptors on the T cells. We hypothesized that a T cell activating polymer brush interface might better mimic the cell surface of a natural antigen-presenting cell, facilitating receptor movement and concomitant advantageous mechanical forces to provide enhanced T cell activating capacities. This would rather mimic immune cell clusters, as discussed above and would also facilitate interaction of multiple T cells with such an immunobrush acting as an artificial antigen presenting cell. As a proof of concept, we synthesized semiflexible polyisocyanopeptide (PIC) polymer-based immunobrushes equipped with T cell activating antibodies placed on magnetic microbeads. We demonstrated enhanced efficiency of ex vivo expansion of activated primary human T cells even at very low numbers of stimulating antibodies compared to rigid beads.
WP3. Design of an injectable 3D semi-rigid Immune Response Matrix.
One of the major beyond the stage of the art approaches of this ERC grant is that we aim to design 3D scaffolds to create immune niches at any anatomic site of the body. For this we exploit porous hydrogels which are semi-rigid. We explored two types of hydrogels, 1) hydrogels loaded with nanoparticles to creates a fully synthetic immunostimulatory niche that stimulates DCs and evokes strong antigen-specific T cell responses, or 2) hydrogels equipped with immunostimulating molecules to activate and expand T cells. We demonstrated that both types of hydrogels can be injected through an injection needle after which they reshape to their original size.We observed that these synthetic immune stimulatory immune niches induced strong murine and human T cell activation resulting in multifunctional T cells with limited T cell exhaustion. The modular biomaterial-based scaffolds we engineered can be easily adapted to attach a variety of biomolecules and may therefore be a valuable tool in the development of new local biomaterial-based cancer immunotherapies
WP4 In vivo validation of synthetic immune niches.
Finally, initial steps towards the in vivo application of these synthetic immune niches have been made. We injected cryogel scaffolds to see if they survived and remained stable in vivo, which was the case. When preloading the cryogels with T cells we noticed that a significant proportion of human and murine T cell were retained within the scaffolds after injection. These findings are promising and will be extended in the second part of the grant period.
Immunobrushes
So far most artificial antigen presenting cells consist of solid surfaces. With the design of immunobrushes, we showed already that a much better T cell activation is obtained. Apparently, immunobrusches better mimic natural antigen presenting cells to form an immunological synapse. In the second part of the project we will extend this work and make a direct comparison of immunobrushes with natural dendritic cells as antigen presenting cell.
Injectable synthetic immune niches.
We engineered 3D macroporous cryogels to mimic a natural lymph node architecture. Our initial promising results clearly show that these synthetic immune niches can be modified such to activate antigen presenting cells or directly activate T cells. Moreover, we believe that in particular the injectability of these cryogels is certainly beyond the state of the art. In the second part of the project we will explore this in vivo.
So far most artificial antigen presenting cells consist of solid surfaces. With the design of immunobrushes, we showed already that a much better T cell activation is obtained. Apparently, immunobrusches better mimic natural antigen presenting cells to form an immunological synapse. In the second part of the project we will extend this work and make a direct comparison of immunobrushes with natural dendritic cells as antigen presenting cell.
Injectable synthetic immune niches.
We engineered 3D macroporous cryogels to mimic a natural lymph node architecture. Our initial promising results clearly show that these synthetic immune niches can be modified such to activate antigen presenting cells or directly activate T cells. Moreover, we believe that in particular the injectability of these cryogels is certainly beyond the state of the art. In the second part of the project we will explore this in vivo.