Historically, interleukin-2 (IL-2) was first described as an immunostimulatory factor that supports the expansion of activated effector T cells. A layer of sophistication arose when regulatory CD4+ T ...lymphocytes (Tregs) were shown to require IL-2 for their development, homeostasis, and immunosuppressive functions. Fundamental distinctions in the nature and spatiotemporal expression patterns of IL-2 receptor subunits on naive/memory/effector T cells versus Tregs are now being exploited to manipulate the immunomodulatory effects of IL-2 for therapeutic purposes. Although high-dose IL-2 administration has yielded discrete clinical responses, low-dose IL-2 as well as innovative strategies based on IL-2 derivatives, including "muteins," immunocomplexes, and immunocytokines, are being explored to therapeutically enhance or inhibit the immune response.
Humanized Mice for the Study of Immuno-Oncology De La Rochere, Philippe; Guil-Luna, Silvia; Decaudin, Didier ...
Trends in immunology,
September 2018, 2018-09-00, 20180901, Letnik:
39, Številka:
9
Journal Article
Recenzirano
Immunotherapy is revolutionizing cancer treatment; however, complete responses are achieved in only a small fraction of patients and tumor types. Thus, there is an urgent need for predictive ...preclinical models to drive rational immunotherapeutic drug development, treatment combinations, and to minimize failures in clinical trials. Humanized mouse models (HIS) have been developed to study and modulate the interactions between immune components and tumors of human origin. In this review, we discuss recent advances in the ‘humanization’ of mouse models to improve the quality of human immune cell reconstitution. We also highlight new insights into the basic mechanisms, and provide a preclinical evaluation of onco-immunotherapies, as well as the limitations thereof, which constitute drivers for the improvement of the models to increase their translational power.
Cancer immunotherapy has given impressive clinical responses but only in a minority of patients and only in certain cancer indications. Thus, predictive preclinical models are needed to drive rational immunotherapeutic drug development and minimize failures in clinical trials.
HIS, comprising immunodeficient host mice and human immune and tumor cells, recapitulate the interactions between immune components and tumors of human origin.
Limitations of HIS models include the development of xenograft-versus-host disease and incomplete reconstitution of certain human immune subpopulations.
HIS models have allowed the evaluation of onco-immunotherapies, including cellular and antibody-based immunotherapies.
Understanding the caveats of HIS mice and the increasing genetic optimizations are leading to improved models with heightened translational power.
Tumor-draining lymph node (TDLN) invasion by metastatic cells in breast cancer correlates with poor prognosis and is associated with local immunosuppression, which can be partly mediated by ...regulatory T cells (Tregs). Here, we study Tregs from matched tumor-invaded and non-invaded TDLNs, and breast tumors. We observe that Treg frequencies increase with nodal invasion, and that Tregs express higher levels of co-inhibitory/stimulatory receptors than effector cells. Also, while Tregs show conserved suppressive function in TDLN and tumor, conventional T cells (Tconvs) in TDLNs proliferate and produce Th1-inflammatory cytokines, but are dysfunctional in the tumor. We describe a common transcriptomic signature shared by Tregs from tumors and nodes, including CD80, which is significantly associated with poor patient survival. TCR RNA-sequencing analysis indicates trafficking between TDLNs and tumors and ongoing Tconv/Treg conversion. Overall, TDLN Tregs are functional and express a distinct pattern of druggable co-receptors, highlighting their potential as targets for cancer immunotherapy.
The ability of CD8
T lymphocytes to eliminate tumors is limited by their ability to engender an immunosuppressive microenvironment. Here we describe a subset of tumor-infiltrating CD8
T cells marked ...by high expression of the immunosuppressive ATP ecto-nucleotidase CD39. The frequency of CD39
CD8
T cells increased with tumor growth but was absent in lymphoid organs. Tumor-infiltrating CD8
T cells with high CD39 expression exhibited features of exhaustion, such as reduced production of TNF and IL2 and expression of coinhibitory receptors. Exhausted CD39
CD8
T cells from mice hydrolyzed extracellular ATP, confirming that CD39 is enzymatically active. Furthermore, exhausted CD39
CD8
T cells inhibited IFNγ production by responder CD8
T cells. In specimens from breast cancer and melanoma patients, CD39
CD8
T cells were present within tumors and invaded or metastatic lymph nodes, but were barely detectable within noninvaded lymph nodes and absent in peripheral blood. These cells exhibited an exhausted phenotype with impaired production of IFNγ, TNF, IL2, and high expression of coinhibitory receptors. Although T-cell receptor engagement was sufficient to induce CD39 on human CD8
T cells, exposure to IL6 and IL27 promoted CD39 expression on stimulated CD8
T cells from human or murine sources. Our findings show how the tumor microenvironment drives the acquisition of CD39 as an immune regulatory molecule on CD8
T cells, with implications for defining a biomarker of T-cell dysfunction and a target for immunotherapeutic intervention.
The tumor microenvironment elicits a subset of functionally exhausted CD8
T cells by creating conditions that induce cell surface expression of CD39, an immunosuppressive molecule that can be therapeutically targeted to restore effector T-cell function.
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Personalized cancer vaccines targeting patient-specific neoantigens are a promising cancer treatment modality; however, neoantigen physicochemical variability can present challenges to manufacturing ...personalized cancer vaccines in an optimal format for inducing anticancer T cells. Here, we developed a vaccine platform (SNP-7/8a) based on charge-modified peptide-TLR-7/8a conjugates that are chemically programmed to self-assemble into nanoparticles of uniform size (~20 nm) irrespective of the peptide antigen composition. This approach provided precise loading of diverse peptide neoantigens linked to TLR-7/8a (adjuvant) in nanoparticles, which increased uptake by and activation of antigen-presenting cells that promote T-cell immunity. Vaccination of mice with SNP-7/8a using predicted neoantigens (n = 179) from three tumor models induced CD8 T cells against ~50% of neoantigens with high predicted MHC-I binding affinity and led to enhanced tumor clearance. SNP-7/8a delivering in silico-designed mock neoantigens also induced CD8 T cells in nonhuman primates. Altogether, SNP-7/8a is a generalizable approach for codelivering peptide antigens and adjuvants in nanoparticles for inducing anticancer T-cell immunity.
Intestinal and free-living protozoa, such as Giardia lamblia, express a dense coat of variant-specific surface proteins (VSPs) on trophozoites that protects the parasite inside the host's intestine. ...Here we show that VSPs not only are resistant to proteolytic digestion and extreme pH and temperatures but also stimulate host innate immune responses in a TLR-4 dependent manner. We show that these properties can be exploited to both protect and adjuvant vaccine antigens for oral administration. Chimeric Virus-like Particles (VLPs) decorated with VSPs and expressing model surface antigens, such as influenza virus hemagglutinin (HA) and neuraminidase (NA), are protected from degradation and activate antigen presenting cells in vitro. Orally administered VSP-pseudotyped VLPs, but not plain VLPs, generate robust immune responses that protect mice from influenza infection and HA-expressing tumors. This versatile vaccine platform has the attributes to meet the ultimate challenge of generating safe, stable and efficient oral vaccines.
Changes in the oral microbiome, particularly Fusobacterium nucleatum, are associated with oral squamous cell carcinoma (OSCC). F. nucleatum has been reported to modulate local immunity in cancers. We ...aimed to assess the association between intratumoral F. nucleatum and clinico-pathological features, relapse, and overall survival (OS) in two independent cohorts of patients with OSCC, and to explore the interplay with immune-related genes. We retrospectively analyzed tissue samples from a first cohort of 122 patients with head and neck squamous cell carcinoma, including 61 OSCC (cohort #1), and a second cohort of 90 additional OSCC (cohort #2). We then performed a sensitivity analysis on the merged cohort of OSCC patients (N = 151). F. nucleatum 16S rRNA gene sequences were quantified using real-time quantitative PCR. The presence of gram-negative bacteria and macrophages was confirmed by LPS and CD163 immunostainings, respectively. F. nucleatum positivity was associated with older age, less alcohol and combined alcohol plus tobacco consumption, and less frequent lymph node invasion. There was a trend for a lower recurrence rate in F. nucleatum-positive cases, with less metastatic relapses compared to F. nucleatum-negative tumors, and significantly longer OS, relapse-free and metastasis-free survival. F. nucleatum status was independently associated with OS in multivariate analysis. Immune-related gene and immunohistochemistry analyses showed that gram-negative bacteria load inversely correlated with M2 macrophages. F. nucleatum-associated OSCC has a specific immune microenvironment, is more frequent in older, non-drinking patients, and associated with a favorable prognosis.
Tumor necrosis factor α (TNF) is a potent pro-inflammatory cytokine that has deleterious effect in some autoimmune diseases, which led to the use of anti-TNF drugs in some of these diseases. However, ...some rare patients treated with these drugs paradoxically develop an aggravation of their disease or new onset autoimmunity, revealing an immunosuppressive facet of TNF. A possible mechanism of this observation is the direct and positive effect of TNF on regulatory T cells (Tregs) through its binding to the TNF receptor type 2 (TNFR2). Indeed, TNF is able to increase expansion, stability, and possibly function of Tregs
TNFR2. In this review, we discuss the role of TNF in graft-versus-host disease as an example of the ambivalence of this cytokine in the pathophysiology of an immunopathology, highlighting the therapeutic potential of triggering TNFR2 to boost Treg expansion. We also describe new targets in immunotherapy of cancer, emphasizing on the putative suppressive effect of TNF in antitumor immunity and of the interest of blocking TNFR2 to regulate the Treg compartment.
The dynamics of CD4
+ effector T cells (Teff cells) and CD4
+Foxp3
+ regulatory T cells (Treg cells) during diabetes progression in nonobese diabetic mice was investigated to determine whether an ...imbalance of Treg cells and Teff cells contributes to the development of type 1 diabetes. Our results demonstrated a progressive decrease in the Treg cell:Teff cell ratio in inflamed islets but not in pancreatic lymph nodes. Intra-islet Treg cells expressed reduced amounts of CD25 and Bcl-2, suggesting that their decline was due to increased apoptosis. Additionally, administration of low-dose interleukin-2 (IL-2) promoted Treg cell survival and protected mice from developing diabetes. Together, these results suggest intra-islet Treg cell dysfunction secondary to defective IL-2 production is a root cause of the progressive breakdown of self-tolerance and the development of diabetes in nonobese diabetic mice.
CD4
T cell antitumor responses have mostly been studied in transplanted tumors expressing secreted model antigens (Ags), while most mutated proteins in human cancers are not secreted. The fate of ...Ag-specific CD4
T cells recognizing a cytoplasmic Ag in mice bearing autochthonous tumors is still unclear. Here we show, using a genetically engineered lung adenocarcinoma mouse model, that naive tumor-specific CD4
T cells are activated and proliferate in the tumor-draining lymph node (TdLN) but do not differentiate into effectors or accumulate in tumors. Instead, these CD4
T cells are driven toward anergy or peripherally-induced Treg (pTreg) differentiation, from the early stage of tumor development. This bias toward immune suppression is restricted to the TdLN, and is maintained by Tregs enriched in the tumor Ag-specific cell population. Thus, tumors may enforce a dominant inhibition of the anti-tumor CD4 response in the TdLN by recapitulating peripheral self-tolerance mechanisms.
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