An Intelligent DNA Nanoreactor for Easy-to-Read In Vivo Tumor Imaging and Precise Therapy

Nanomaterial-based in vivo tumor imaging and therapy have attracted extensive attention; however, they suffer from the unintelligent "always ON" or single-parameter responsive signal output, substantial off-target effects, and high cost. Therefore, achieving in vivo easy-to-read tumor imaging and precise therapy in a multi-parameter responsive and intelligent manner remains challenging. Herein, an intelligent DNA nanoreactor (iDNR) was constructed following the "AND" Boolean logic algorithm to address these issues. iDNR-mediated in situ deposition of photothermal substance polydopamine (PDA) can only be satisfied in tumor tissues with abundant membrane protein biomarkers "AND" hydrogen peroxide (H2 O2 ). Therefore, intelligent temperature-based in vivo easy-to-read tumor imaging is realized without expensive instrumentation, and its diagnostic performance matches with that of flow cytometry, and photoacoustic imaging. Moreover, precise photothermal therapy (PTT) of tumors could be achieved via intelligent heating of tumor tissues. The precise PTT of primary tumors in combination with immune checkpoint blockade (ICB) therapy suppresses the growth of distant tumors and inhibits tumor recurrence. Therefore, highly programmable iDNR is a powerful tool for intelligent biomedical applications.

CLDN18.2 BiTE Engages Effector and Regulatory T Cells for Antitumor Immune Response in Preclinical Models of Pancreatic Cancer

BACKGROUND & AIMS

BiTE (bispecific T-cell engager) immune therapy has demonstrated clinical activity in multiple tumor indications, but its influence in the tumor microenvironment remains unclear. CLDN18.2 is overexpressed in solid tumors including gastric cancer (GC) and pancreatic ductal adenocarcinoma (PDAC), both of which are characterized by the presence of immunosuppressive cells, including regulatory T cells (Tregs) and few effector T cells (Teffs).

METHODS

We evaluated the activity of AMG 910, a CLDN18.2-targeted half-life extended (HLE) BiTE molecule, in GC and PDAC preclinical models and cocultured Tregs and Teffs in the presence of CLDN18.2-HLE-BiTE.

RESULTS

AMG 910 induced potent, specific cytotoxicity in GC and PDAC cell lines. In GSU and SNU-620 GC xenograft models, AMG 910 engaged human CD3+ T cells with tumor cells, resulting in significant antitumor activity. AMG 910 monotherapy, in combination with a programmed death-1 (PD-1) inhibitor, suppressed tumor growth and enhanced survival in an orthotopic Panc4.14 PDAC model. Moreover, Treg infusion enhanced the antitumor efficacy of AMG 910 in the Panc4.14 model. In syngeneic KPC models of PDAC, treatment with a mouse surrogate CLDN18.2-HLE-BiTE (muCLDN18.2-HLE-BiTE) or the combination with an anti-PD-1 antibody significantly inhibited tumor growth. Tregs isolated from mice bearing KPC tumors that were treated with muCLDN18.2-HLE-BiTE showed decreased T cell suppressive activity and enhanced Teff cytotoxic activity, associated with increased production of type I cytokines and expression of Teff gene signatures.

CONCLUSIONS

Our data suggest that BiTE molecule treatment converts Treg function from immunosuppressive to immune enhancing, leading to antitumor activity in immunologically "cold" tumors.

CD28/PD1 co-expression: dual impact on CD8+ T cells in peripheral blood and tumor tissue, and its significance in NSCLC patients' survival and ICB response

BACKGROUND

Immune checkpoint blockade (ICB) has significantly prolonged survival of non-small cell lung cancer (NSCLC) patients, although most patients develop mechanisms of resistance. Recently single-cell RNA-sequencing (scRNA-Seq) revealed a huge T-cell phenotypic and (dys)functional state variability. Accordingly, T-cell exhaustion is recognized as a functional adaptation, with a dynamic progression from a long-lived "pre-exhausted stem-like progenitor" to a "terminally exhausted" state. In this scenario it is crucial to understand the complex interplay between co-stimulatory and inhibitory molecules in CD8+ T-cell functionality.

METHODS

To gain a baseline landscape of the composition, functional states, and transcriptomic signatures predictive of prognosis, we analyzed CD8+ T-cell subsets characterized by the presence/absence of PD1 and CD28 from periphery, adjacent non-tumor tissue and tumor site of a cohort of treatment-naïve NSCLC patients, by integrated multiparametric flow cytometry, targeted multi-omic scRNA-seq analyses, and computational pipelines.

RESULTS

Despite the increased PD1 levels, an improved PD1+CD28+ T-cell polyfunctionality was observed with the transition from periphery to tumor site, associated with lack of TIGIT, TIM-3 and LAG-3, but not with Ag-experienced-marker CD11a. Differently from CD28+ T cells, the increased PD1 levels in the tumor were associated with reduced functionality in PD1+CD28- T cells. CD11ahigh, although expressed only in a small fraction of this subset, still sustained its functionality. Absence of TIGIT, TIM-3 and CTLA-4, alone or combined, was beneficial to CD28- T cells. Notably, we observed distinct TRM phenotypes in the different districts, with CD28+ T cells more capable of producing TGFβ in the periphery, potentially contributing to elevated CD103 levels. In contrast CD28- TRM mainly produced CXCL13 within the tumor. ScRNA-seq revealed 5 different clusters for each of the two subsets, with distinctive transcriptional profiles in the three districts. By interrogating the TCGA dataset of patients with lung adenocarcinoma (LUAD) and metastatic NSCLC treated with atezolizumab, we found signatures of heterogeneous TRM and "pre-exhausted" long-lived effector memory CD8+ T cells associated with improved response to ICB only in the presence of CD28.

CONCLUSIONS

Our findings identify signatures able to stratify survival of LUAD patients and predict ICB response in advanced NSCLC. CD28 is advocated as a key determinant in the signatures identified, in both periphery and tumor site, thus likely providing feasible biomarkers of ICB response.

PD-1 and PD-L1 inhibitors foster the progression of adult T-cell Leukemia/Lymphoma

Immunotherapy through immune checkpoints blockade and its subsequent clinical application has revolutionized the treatment of a spectrum of solid tumors. Blockade of Programmed cell death protein-1 and its ligand has shown promising results in clinical studies. The clinical trials that enrolled patients with different hematopoietic malignancies including non-Hodgkin lymphoma, Hodgkin lymphoma, and acute myeloid leukemia (AML) showed that anti-PD-1 agents could have potential therapeutic effects in the patients. Adult T-cell leukemia/lymphoma (ATLL) is a non-Hodgkin T-cell Lymphoma that is developed in a minority of HTLV-1-infected individuals after a long latency period. The inhibition of PD-1 as a treatment option is currently being investigated in ATLL patients. In this review, we present a summary of the biology of the PD-1/PD-L1 pathway, the evidence in the literature to support anti-PD-1/PDL-1 application in the treatment of different lymphoid, myeloid, and virus-related hematological malignancies, and controversies related to PD-1/PD-L1 blocking in the management of ATLL patients.

Targeting CXCL12-CXCR4 Signaling Enhances Immune Checkpoint Blockade Therapy Against Triple Negative Breast Cancer

Insufficient T cell infiltration in triple-negative breast cancer (TNBC) has limited its response rate to immune checkpoint blockade (ICB) therapies and motivated the development of immunostimulatory approaches to enhance the ICB therapy. CXCR4 is a chemokine receptor highly upregulated both on cell surface and cytoplasm in tumor tissues. Activating CXCR4 has been associated with increased immunosuppression in the tumor microenvironment. Here, we developed a CXCR4-targeted liposomal formulation (Liposomal-AMD3100) to enhance therapeutic efficacy of AMD3100, a CXCR4 antagonist. Particularly, AMD3100 is not only encapsulated into the liposome but coated on the surface of the formulation to serve as a targeting moiety and a dual blocker capable of inhibiting CXCR4 activation extracellularly and intracellularly. The Liposomal-AMD3100 remodeled both immune and stromal microenvironment more efficiently compared with free AMD3100, indicating better pharmacodynamic profile of AMD3100 achieved by liposomal formulation. The combination of anti-PD-L1 with Liposomal-AMD3100 formulation exhibited an increased antitumor effect and prolonged survival time compared with monotherapies in a murine TNBC model (4T1). This work proves that immune activation via liposomal delivery of CXCR4 inhibitors has a great potential to expand ICB therapies to originally ICB-insensitive cancer types.

A Tumor-Specific Super-Enhancer Drives Immune Evasion by Guiding Synchronous Expression of PD-L1 and PD-L2

PD-L1 and PD-L2 are important targets for immune checkpoint blockade, but how tumor cells achieve their expression remains to be addressed. Here, we find that PD-L1 and PD-L2 are co-expressed in cancer cell lines and tissues across different cancer types. In breast cancer, MDA-MB-231 and SUM-159 cells show high expression of both PD-L1 and PD-L2. The expression of both PD-L1 and PD-L2 is greatly reduced upon treatment of inhibitors of super-enhancers. Bioinformatic analysis identifies a potential super-enhancer (PD-L1L2-SE) that is located between the CD274 and CD273 genes. Genetic deletion of PD-L1L2-SE profoundly reduces the expression of PD-L1 and PD-L2. PD-L1L2-SE-deficient cancer cells fail to generate immune evasion and are sensitive to T cell-mediated killing. Notably, epigenetic activation of such a region (PD-L1L2-SE) is correlated with PD-L1 and PD-L2. Taken together, we identify a super-enhancer (PD-L1L2-SE) that is responsible for the overexpression of PD-L1 and PD-L2 as well as immune evasion in cancer.

Immunologic Milieu of Mature T-Cell and NK-Cell Lymphomas-Implications for Therapy

PURPOSE OF THE REVIEW

T-cells and natural killer (NK) cells share the same ontogeny, and lymphomas derived from them are clinically diverse, occurring in nodal and extranodal sites. In addition to inherent properties of these lymphomas, their microenvironment also impacts on pathogenesis and response to therapy. An understanding of the milieu of T-cell and NK cell lymphomas has important implications on treatment.

RECENT FINDINGS

Components of the microenvironment include tumour-associated macrophages (TAM), non-neoplastic T-cells and B-cells, eosinophils, dendritic cells, endothelial cells and blood vessels. TAM typically undergoes M2 polarization, promoting angiogenesis and inhibiting anti-tumour cellular immunity. In lymphomas of follicular helper T-cell derivation, increased B-cell proliferation occurs, which may in turn enhance neoplastic T-cell growth. The expression of immune checkpoint ligands on TAM, dendritic cells or lymphoma cells induces an immunosuppressive environment conducive to neoplastic proliferation. Strategies against this complex cellular and immunologic microenvironment have shown promises. These include the use of signal transduction inhibitors, monoclonal antibodies against chemokines or non-neoplastic microenvironmental cells, immunomodulatory drugs and immune checkpoint blockade. As T-cell and NK cell lymphomas are highly heterogeneous, clinical trials to demonstrate efficacy of a given therapeutic approach requires careful design aiming at enriching patient populations who will best respond. Targeting of the immunologic milieu in T-cell and NK-cell lymphomas offers exciting challenges and opportunities.