Faculty Opinions recommendation of Facilitating T Cell Infiltration in Tumor Microenvironment Overcomes Resistance to PD-L1 Blockade.

Anti–programmed cell death 1 ligand 1 (PD-L1) therapy is extraordinarily effective in select patients with cancer. However, insufficient lymphocytic infiltration, weak T cell–induced inflammation, and immunosuppressive cell accumulation in the tumor microenvironment (TME) may greatly diminish the efficacy. Here, we report development of the FX@HP nanocomplex composed of fluorinated polymerized CXCR4 antagonism (FX) and paclitaxel-loaded human serum albumin (HP) for pulmonary delivery of anti–PD-L1 small interfering RNA (siPD-L1) to treat orthotopic lung tumors. FX@HP induced T cell infiltration, increased expression of calreticulin on tumor cells, and reduced the myeloid-derived suppressor cells/regulatory T cells in the TME, thereby acting synergistically with siPD-L1 for effective immunotherapy. Our work suggests that the CXCR4-inhibiting nanocomplex decreases tumor fibrosis, facilitates T cell infiltration and relieves immunosuppression to modulate the immune process to improve the objective response rate of anti–PD-L1 immunotherapy.

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Single cell transcriptomics reveals the effect of PD-L1/TGF-β blockade on the tumor microenvironment

10.1101/2020.11.13.382358 ◽

2020 ◽

Author(s):

Yoong Wearn Lim ◽

Garry L. Coles ◽

Savreet K. Sandhu ◽

David S. Johnson ◽

Adam S. Adler ◽

...

Keyword(s):

T Cell ◽

Tumor Microenvironment ◽

Single Cell ◽

Immune Cell ◽

Single Cells ◽

Cell Infiltration ◽

Cytotoxic Lymphocytes ◽

T Cell Infiltration ◽

Anti Tumor Activity

AbstractBackgroundThe anti-tumor activity of anti-PD-1/PD-L1 therapies correlates with T cell infiltration in tumors. Thus, a major goal in oncology is to find strategies that enhance T cell infiltration and efficacy of anti-PD-1/PD-L1 therapy. TGF-β has been shown to contribute to T cell exclusion and anti-TGF-β improves anti-PD-L1 efficacy in vivo. However, TGF-β inhibition has frequently been shown to induce toxicity in the clinic, and the clinical efficacy of combination PD-L1 and TGF-β blockade has not yet been proven. To identify strategies to overcome resistance to PD-L1 blockade, the transcriptional programs associated with PD-L1 and/or TGF-β blockade in the tumor microenvironment should be further elucidated.ResultsFor the first time, we used single-cell RNA sequencing to characterize the transcriptomic effects of PD-L1 and/or TGF-β blockade on nearly 30,000 single cells in the tumor and surrounding microenvironment. Combination treatment led to upregulation of immune response genes, including multiple chemokine genes such as CCL5, in CD45+ cells, and down-regulation of extracellular matrix genes in CD45-cells. Analysis of publicly available tumor transcriptome profiles showed that the chemokine CCL5 was strongly associated with immune cell infiltration in various human cancers. Further investigation with in vivo models showed that intratumorally administered CCL5 enhanced cytotoxic lymphocytes and the anti-tumor activity of anti-PD-L1.ConclusionsTaken together, our data could be leveraged translationally to improve anti-PD-L1 plus anti-TGF-β combination therapy, for example through companion biomarkers, and/or to identify novel targets that could be modulated to overcome resistance.

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Therapeutic Induction of Tertiary Lymphoid Structures in Cancer Through Stromal Remodeling

Frontiers in Immunology ◽

10.3389/fimmu.2021.674375 ◽

2021 ◽

Vol 12 ◽

Author(s):

Anna Johansson-Percival ◽

Ruth Ganss

Keyword(s):

T Cell ◽

Tumor Microenvironment ◽

Cancer Immunotherapy ◽

Tumor Rejection ◽

Cell Infiltration ◽

Cytotoxic T Cell ◽

T Cell Infiltration ◽

Anti Cancer ◽

Tertiary Lymphoid Structures ◽

Lymphoid Structures

Improving the effectiveness of anti-cancer immunotherapy remains a major clinical challenge. Cytotoxic T cell infiltration is crucial for immune-mediated tumor rejection, however, the suppressive tumor microenvironment impedes their recruitment, activation, maturation and function. Nevertheless, solid tumors can harbor specialized lymph node vasculature and immune cell clusters that are organized into tertiary lymphoid structures (TLS). These TLS support naïve T cell infiltration and intratumoral priming. In many human cancers, their presence is a positive prognostic factor, and importantly, predictive for responsiveness to immune checkpoint blockade. Thus, therapeutic induction of TLS is an attractive concept to boost anti-cancer immunotherapy. However, our understanding of how cancer-associated TLS could be initiated is rudimentary. Exciting new reagents which induce TLS in preclinical cancer models provide mechanistic insights into the exquisite stromal orchestration of TLS formation, a process often associated with a more functional or “normalized” tumor vasculature and fueled by LIGHT/LTα/LTβ, TNFα and CC/CXC chemokine signaling. These emerging insights provide innovative opportunities to induce and shape TLS in the tumor microenvironment to improve immunotherapies.

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SOD3 induces a HIF-2α-dependent program in endothelial cells that provides a selective signal for tumor infiltration by T cells

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2019-000432 ◽

2020 ◽

Vol 8 (1) ◽

pp. e000432 ◽

Cited By ~ 4

Author(s):

Lorena Carmona-Rodríguez ◽

Diego Martínez-Rey ◽

Maria Jesús Fernández-Aceñero ◽

Alicia González-Martín ◽

Mateo Paz-Cabezas ◽

...

Keyword(s):

T Cells ◽

Endothelial Cells ◽

T Cell ◽

Tumor Microenvironment ◽

T Lymphocytes ◽

Adhesion Molecule ◽

Cell Infiltration ◽

Tumor Infiltration ◽

T Cell Infiltration

BackgroundTumor-infiltrating lymphocytes (TILs), mainly CD8+ cytotoxic T lymphocytes (CTL), are linked to immune-mediated control of human cancers and response to immunotherapy. Tumors have nonetheless developed specific mechanisms that selectively restrict T cell entry into the tumor microenvironment. The extracellular superoxide dismutase (SOD3) is an anti-oxidant enzyme usually downregulated in tumors. We hypothesize that upregulation of SOD3 in the tumor microenvironment might be a mechanism to boost T cell infiltration by normalizing the tumor-associated endothelium.ResultsHere we show that SOD3 overexpression in endothelial cells increased in vitro transmigration of naïve and activated CD4+ and CD8+ T cells, but not of myeloid cells. Perivascular expression of SOD3 also specifically increased CD4+ and CD8+ effector T cell infiltration into tumors and improved the effectiveness of adoptively transferred tumor-specific CD8+ T cells. SOD3-induced enhanced transmigration in vitro and tumor infiltration in vivo were not associated to upregulation of T cell chemokines such as CXCL9 or CXCL10, nor to changes in the levels of endothelial adhesion receptors such as intercellular adhesion molecule-1 (ICAM-1) or vascular cell adhesion molecule-1 (VCAM-1). Instead, SOD3 enhanced T cell infiltration via HIF-2α-dependent induction of specific WNT ligands in endothelial cells; this led to WNT signaling pathway activation in the endothelium, FOXM1 stabilization, and transcriptional induction of laminin-α4 (LAMA4), an endothelial basement membrane component permissive for T cell infiltration. In patients with stage II colorectal cancer, SOD3 was associated with increased CD8+ TIL density and disease-free survival. SOD3 expression was also linked to a T cell–inflamed gene signature using the COAD cohort from The Cancer Genome Atlas program.ConclusionOur findings suggest that SOD3-induced upregulation of LAMA4 in endothelial cells boosts selective tumor infiltration by T lymphocytes, thus transforming immunologically “cold” into “hot” tumors. High SOD3 levels are associated with human colon cancer infiltration by CD8+ T cells, with potential consequences for the clinical outcome of these patients. Our results also uncover a cell type–specific, distinct activity of the WNT pathway for the regulation of T cell infiltration into tumors.

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