Exploring the potential of combining IL-2-activated NK cells with an anti-PDL1 monoclonal antibody to target multiple myeloma-associated macrophages

Avelumab induces greater Fc-Fc receptor-dependent natural killer cell activation and dendritic cell crosstalk compared to durvalumab

Several FDA-approved anti-PD-L1 (programmed cell death ligand-1) monoclonal antibodies (mAbs) are used to treat cancer. While these mAbs primarily target and intercept PD-L1:PD-1 inhibitory signaling in T-cells, the Fc-domains of these mAbs are distinct, and the unique cellular cascades triggered by differing Fc-domains of PD-L1 mAbs have not been directly investigated. In this study, we compared the innate immune effects of two widely used anti-PD-L1 IgG1 mAbs which bear distinct Fc-domains, avelumab (native-Fc) and durvalumab (mutated-Fc), using two-cell and three-cell co-culture systems containing Natural Killer cells (NK-cells), dendritic cells (DCs) and various tumor cell lines of multiple cancer origins. We show a robust enhancement in NK-cell effector function, DC maturation, reciprocal NK:DC crosstalk and DC editing that is unique to avelumab treatment using multiple functional immune assays. By transcriptomic analysis, we show for the first time pivotal differences in gene sets involved in NK-cell effector function, DC maturation, immunoregulatory interactions, and cytokine production between innate immune cells treated with avelumab versus durvalumab. Furthermore, we report several previously unknown Fc-receptor-associated biological pathways uniquely triggered by avelumab. Our findings elucidate novel mechanisms of Fc-dependent actions of PD-L1 mAbs which may inform their use in future clinical trials.

Interactions of NK Cells and Macrophages: From Infections to Cancer Therapeutics

The interaction between immune cells brings a consequence either on their role and functioning or the functioning of the other immune cells, modulating the whole mechanistic pathway. The interaction between natural killer (NK) cells and macrophages is one such interaction which is relatively less explored amongst diseased conditions. Their significance comes from their innate nature and secretion of large proportions of cytokines and chemokines which results in influencing adaptive immune responses. Their interplay can lead to several functional outcomes such as NK cell activation/inhibition, increased cytotoxicity and IFNγ release by NK cells, inhibition of macrophage function, etc. This paper delves into the interaction amongst NK cells and macrophages via different receptor-ligands and cytokines, particularly emphasising microbial infections and tumours. The review has the potential to uncover new insights and approaches that could lead to the development of innovative therapeutic tools and targets.

Curcumin Nanoparticles-related Non-invasive Tumor Therapy, and Cardiotoxicity Relieve

Non-invasive antitumor therapy can treat tumor patients who cannot tolerate surgery or are unsuitable. However, tumor resistance to non-invasive antitumor therapy and cardiotoxicity caused by treatment seriously affect the quality of life and prognosis of patients. As a kind of polyphenol extracted from herbs, curcumin has many pharmacological effects, such as anti-inflammation, antioxidation, antitumor, etc. Curcumin plays the antitumor effect by directly promoting tumor cell death and reducing tumor cells' invasive ability. Curcumin exerts the therapeutic effect mainly by inhibiting the nuclear factor-κB (NF-κB) signal pathway, inhibiting the production of cyclooxygenase-2 (COX-2), promoting the expression of caspase-9, and directly inducing reactive oxygen species (ROS) production in tumor cells. Curcumin nanoparticles can solve curcumin's shortcomings, such as poor water solubility and high metabolic rate, and can be effectively used in antitumor therapy. Curcumin nanoparticles can improve the prognosis and quality of life of tumor patients by using as adjuvants to enhance the sensitivity of tumors to non-invasive therapy and reduce the side effects, especially cardiotoxicity. In this paper, we collect and analyze the literature of relevant databases. It is pointed out that future research on curcumin tends to alleviate the adverse reactions caused by treatment, which is of more significance to tumor patients.

Natural killer cell memory: challenges and opportunities for cancer immunotherapy

Substantial advancements have been made in recent years in comprehending immune memory, which enhances the secondary response through prior infections. The ability of vertebrate T and B lymphocytes to exhibit classic recall responses has long been regarded as a distinguishing characteristic. However, natural killer (NK) cells have been found to acquire immunological memory in a manner akin to T and B cells. The fundamental principles derived from the investigation of NK cell memory offer novel insights into innate immunity and have the potential to pave the way for innovative strategies to enhance therapeutic interventions against multiple diseases including cancer. Here, we reviewed the fundamental characteristics, memory development and regulatory mechanism of NK cell memory. Moreover, we will conduct a comprehensive evaluation of the accomplishments, obstacles, and future direction pertaining to the utilization of NK cell memory in the field of cancer immunotherapy.

Phosphatidylserine and/or Sialic Acid Modified Liposomes Increase Uptake by Tumor-associated Macrophages and Enhance the Anti-tumor Effect

DOX liposomes have better therapeutic effects and lower toxic side effects. The targeting ability of liposomes is one of the key factors affecting the therapeutic effect of DOX liposomes. This study developed two types of targeted liposomes. Sialic acid (SA)-modified liposomes were designed to target the highly expressed Siglec-1 receptor on tumor-associated macrophages surface. Phosphatidylserine (PS)-modified liposomes were designed to promote phagocytosis by monocyte-derived macrophages through PS apoptotic signaling. In order to assess and compare the therapeutic potential of different targeted pathways in the context of anti-tumor treatment, we compared four phosphatidylserine membrane materials (DOPS, DSPS, DPPS and DMPS) and found that liposomes prepared using DOPS as material could significantly improve the uptake ability of RAW264.7 cells for DOX liposomes. On this basis, normal DOX liposomes (CL-DOX) and SA-modified DOX liposomes (SAL-DOX), PS-modified DOX liposomes (PS-CL-DOX), SA and PS co-modified DOX liposomes (PS-SAL-DOX) were prepared. The anti-tumor cells function of each liposome on S180 and RAW264.7 in vitro was investigated, and it was found that SA on the surface of liposomes can increase the inhibitory effect. In vivo efficacy results exhibited that SAL-DOX and PS-CL-DOX were superior to other groups in terms of ability to inhibit tumor growth and tumor inhibition index, among which SAL-DOX had the best anti-tumor effect. Moreover, SAL-DOX group mice had high expression of IFN-γ as well as IL-12 factors, which could significantly inhibit mice tumor growth, improve the immune microenvironment of the tumor site, and have excellent targeted delivery potential.

Tumor-associated macrophage subtypes on cancer immunity along with prognostic analysis and SPP1-mediated interactions between tumor cells and macrophages

Tumor-associated macrophages (TAM) subtypes have been shown to impact cancer prognosis and resistance to immunotherapy. However, there is still a lack of systematic investigation into their molecular characteristics and clinical relevance in different cancer types. Single-cell RNA sequencing data from three different tumor types were used to cluster and type macrophages. Functional analysis and communication of TAM subpopulations were performed by Gene Ontology-Biological Process and CellChat respectively. Differential expression of characteristic genes in subpopulations was calculated using zscore as well as edgeR and Wilcoxon rank sum tests, and subsequently gene enrichment analysis of characteristic genes and anti-PD-1 resistance was performed by the REACTOME database. We revealed the heterogeneity of TAM, and identified eleven subtypes and their impact on prognosis. These subtypes expressed different molecular functions respectively, such as being involved in T cell activation, apoptosis and differentiation, or regulating viral bioprocesses or responses to viruses. The SPP1 pathway was identified as a critical mediator of communication between TAM subpopulations, as well as between TAM and epithelial cells. Macrophages with high expression of SPP1 resulted in poorer survival. By in vitro study, we showed SPP1 mediated the interactions between TAM clusters and between TAM and tumor cells. SPP1 promoted the tumor-promoting ability of TAM, and increased PDL1 expression and stemness of tumor cells. Inhibition of SPP1 attenuated N-cadherin and β-catenin expression and the activation of AKT and STAT3 pathway in tumor cells. Additionally, we found that several subpopulations could decrease the sensitivity of anti-PD-1 therapy in melanoma. SPP1 signal was a critical pathway of communication between macrophage subtypes. Some specific macrophage subtypes were associated with immunotherapy resistance and prognosis in some cancer types.

Immune microenvironment dynamics of HER2 overexpressing breast cancer under dual anti-HER2 blockade

Introduction

The clinical prognosis of the HER2-overexpressing (HER2-OE) subtype of breast cancer (BC) is influenced by the immune infiltrate of the tumor. Specifically, monocytic cells, which are promoters of pro-tumoral immunosuppression, and NK cells, whose basal cytotoxic function may be enhanced with therapeutic antibodies. One of the standards of care for HER2+ BC patients includes the combination of the anti-HER2 antibodies trastuzumab and pertuzumab. This dual combination was a breakthrough against trastuzumab resistance; however, this regimen does not yield complete clinical benefit for a large fraction of patients. Further therapy refinement is still hampered by the lack of knowledge on the immune mechanism of action of this antibody-based dual HER2 blockade.

Methods

To explore how the dual antibody challenge influences the phenotype and function of immune cells infiltrating the HER2-OE BC microenvironment, we developed in vitro 3D heterotypic cell models of this subtype. The models comprised aggregates of HER2+ BC cell lines and human peripheral blood mononuclear cells. Cells were co-encapsulated in a chemically inert alginate hydrogel and maintained in agitation-based culture system for up to 7 days.

Results

The 3D models of the HER2-OE immune microenvironment retained original BC molecular features; the preservation of the NK cell compartment was achieved upon optimization of culture time and cytokine supplementation. Challenging the models with the standard-of-care combination of trastuzumab and pertuzumab resulted in enhanced immune cytotoxicity compared with trastuzumab alone. Features of the response to therapy within the immune tumor microenvironment were recapitulated, including induction of an immune effector state with NK cell activation, enhanced cell apoptosis and decline of immunosuppressive PD-L1+ immune cells.

Conclusions

This work presents a unique human 3D model for the study of immune effects of anti-HER2 biologicals, which can be used to test novel therapy regimens and improve anti-tumor immune function.