Forced expression of IL-7R promotes CD8 T cell cytotoxicity to self antigen

Dexamethasone potentiates chimeric antigen receptor T cell persistence and function by enhancing IL-7Rα expression

Dexamethasone (dex) is a glucocorticoid that is a mainstay for the treatment of inflammatory pathologies, including immunotherapy-associated toxicities, yet the specific impact of dex on the activity of CAR T cells is not fully understood. We assessed whether dex treatment given ex vivo or as an adjuvant in vivo with CAR T cells impacted the phenotype or function of CAR T cells. We demonstrated that CAR T cell expansion and function were not inhibited by dex. We confirmed this observation using multiple CAR constructs and tumor models, suggesting that this is a general phenomenon. Moreover, we determined that dex upregulated interleukin-7 receptor α on CAR T cells and increased the expression of genes involved in activation, migration, and persistence when supplemented ex vivo. Direct delivery of dex and IL-7 into tumor-bearing mice resulted in increased persistence of adoptively transferred CAR T cells and complete tumor regression. Overall, our studies provide insight into the use of dex to enhance CAR T cell therapy and represent potential novel strategies for augmenting CAR T cell function during production as well as following infusion into patients.

Low transcriptomic of PTPRCv1 and CD3E is an independent predictor of mortality in HIV and tuberculosis co-infected patient

A comprehensive assessment of immunological profiles during HIV-TB co-infection is essential to predict mortality, and facilitate the development of effective diagnostic assays, therapeutic agents, and vaccines. Expression levels of 105 immune-related genes were measured at enrolment and 6th month follow-up from 9 deceased HIV and TB coinfected patients who died between 3 and 7th months follow-up and at enrolment, 6th and 18th month from 18 survived matched controls groups for 2 years. Focused gene expression profiling was assessed from peripheral whole blood using a dual-color Reverse-Transcription Multiplex Ligation-dependent Probe Amplification assay. Eleven of the 105 selected genes were differentially expressed between deceased individuals and survivor-matched controls at baseline. At baseline, IL4δ2 was significantly more highly expressed in the deceased group than survivor matched controls, whereas CD3E, IL7R, PTPRCv1, CCL4, GNLY, BCL2, CCL5, NOD1, TLR3, and NLRP13 had significantly lower expression levels in the deceased group compared to survivor matched controls. At baseline, a non-parametric receiver operator characteristic curve was conducted to determine the prediction of mortality of single genes identified CCL5, PTPRCv1, CD3E, and IL7R with Area under the Curve of 0.86, 0.86, 0.86, and 0.85 respectively. The expression of these genes in the survived control was increased at the end of TB treatment from that at baseline, while decreased in the deceased group. The expression of PTPRCv1, CD3E, CCL5, and IL7R host genes in peripheral blood of patients with TB-HIV coinfected can potentially be used as a predictor of mortality in the Ethiopian setting. Anti-TB treatment might be less likely to restore gene expression in the level expression of the deceased group. Therefore, other new therapeutics that can restore these genes (PTPRCv1, CD3E, IL7R, and CCL5) in the deceased groups at baseline might be needed to save lives.

Prosurvival IL-7-Stimulated Weak Strength of mTORC1-S6K Controls T Cell Memory via Transcriptional FOXO1-TCF1-Id3 and Metabolic AMPKα1-ULK1-ATG7 Pathways

CD8⁺ memory T (T_M) cells play a critical role in immune defense against infection. Two common γ-chain family cytokines, IL-2 and IL-7, although triggering the same mTORC1-S6K pathway, distinctly induce effector T (T_E) cells and T_M cells, respectively, but the underlying mechanism(s) remains elusive. In this study, we generated IL-7R-/and AMPKα1-knockout (KO)/OTI mice. By using genetic and pharmaceutical tools, we demonstrate that IL-7 deficiency represses expression of FOXO1, TCF1, p-AMPKα1 (T₁₇₂), and p-ULK1 (S₅₅₅) and abolishes T cell memory differentiation in IL-7R KO T cells after Listeria monocytogenesis rLmOVA infection. IL-2- and IL-7-stimulated strong and weak S6K (IL-2/S6K^strong and IL-7/S6K^weak) signals control short-lived IL-7R^-CD62L^-KLRG1⁺ T_E and long-term IL-7R⁺CD62L⁺KLRG1^- T_M cell formations, respectively. To assess underlying molecular pathway(s), we performed flow cytometry, Western blotting, confocal microscopy, and Seahorse assay analyses by using the IL-7/S6K^weak-stimulated T_M (IL-7/T_M) and the control IL-2/S6K^strong-stimulated T_E (IL-2/T_E) cells. We determine that the IL-7/S6K^weak signal activates transcriptional FOXO1, TCF1, and Id3 and metabolic p-AMPKα1, p-ULK1, and ATG7 molecules in IL-7/T_M cells. IL-7/T_M cells upregulate IL-7R and CD62L, promote mitochondria biogenesis and fatty acid oxidation metabolism, and show long-term cell survival and functional recall responses. Interestingly, AMPKα1 deficiency abolishes the AMPKα1 but maintains the FOXO1 pathway and induces a metabolic switch from fatty acid oxidation to glycolysis in AMPKα1 KO IL-7/T_M cells, leading to loss of cell survival and recall responses. Taken together, our data demonstrate that IL-7-stimulated weak strength of mTORC1-S6K signaling controls T cell memory via activation of transcriptional FOXO1-TCF1-Id3 and metabolic AMPKα1-ULK1-ATG7 pathways. This (to our knowledge) novel finding provides a new mechanism for a distinct IL-2/IL-7 stimulation model in T cell memory and greatly impacts vaccine development.

Predicting single-cell gene expression profiles of imaging flow cytometry data with machine learning

High-content imaging and single-cell genomics are two of the most prominent high-throughput technologies for studying cellular properties and functions at scale. Recent studies have demonstrated that information in large imaging datasets can be used to estimate gene mutations and to predict the cell-cycle state and the cellular decision making directly from cellular morphology. Thus, high-throughput imaging methodologies, such as imaging flow cytometry can potentially aim beyond simple sorting of cell-populations. We introduce IFC-seq, a machine learning methodology for predicting the expression profile of every cell in an imaging flow cytometry experiment. Since it is to-date unfeasible to observe single-cell gene expression and morphology in flow, we integrate uncoupled imaging data with an independent transcriptomics dataset by leveraging common surface markers. We demonstrate that IFC-seq successfully models gene expression of a moderate number of key gene-markers for two independent imaging flow cytometry datasets: (i) human blood mononuclear cells and (ii) mouse myeloid progenitor cells. In the case of mouse myeloid progenitor cells IFC-seq can predict gene expression directly from brightfield images in a label-free manner, using a convolutional neural network. The proposed method promises to add gene expression information to existing and new imaging flow cytometry datasets, at no additional cost.

miRNA-5119 regulates immune checkpoints in dendritic cells to enhance breast cancer immunotherapy

Dendritic cell (DC) based immunotherapy is a promising approach to clinical cancer treatment. miRNAs are a class of small non-coding RNA molecules that bind to RNAs to mediate multiple events which are important in diverse biological processes. miRNA mimics and antagomirs may be potent agents to enhance DC-based immunotherapy against cancers. miRNA array analysis was used to identify a representative miR-5119 potentially regulating PD-L1 in DCs. We evaluated levels of ligands of immune cell inhibitory receptors (IRs) and miR-5119 in DCs from immunocompetent mouse breast tumor-bearing mice, and examined the molecular targets of miR-5119. We report that miRNA-5119 was downregulated in spleen DCs from mouse breast cancer-bearing mice. In silico analysis and qPCR data showed that miRNA-5119 targeted mRNAs encoding multiple negative immune regulatory molecules, including ligands of IRs such as PD-L1 and IDO2. DCs engineered to express a miR-5119 mimic downregulated PD-L1 and prevented T cell exhaustion in mice with breast cancer homografts. Moreover, miR-5119 mimic-engineered DCs effectively restored function to exhausted CD8⁺ T cells in vitro and in vivo, resulting in robust anti-tumor cell immune response, upregulated cytokine production, reduced T cell apoptosis, and exhaustion. Treatment of 4T1 breast tumor-bearing mice with miR-5119 mimic-engineered DC vaccine reduced T cell exhaustion and suppressed mouse breast tumor homograft growth. This study provides evidence supporting a novel therapeutic approach using miRNA-5119 mimic-engineered DC vaccines to regulate inhibitory receptors and enhance anti-tumor immune response in a mouse model of breast cancer. miRNA/DC-based immunotherapy has potential for advancement to the clinic as a new strategy for DC-based anti-breast cancer immunotherapy.

Immunomodulatory activity of humanized anti-IL-7R monoclonal antibody RN168 in subjects with type 1 diabetes

BACKGROUND

The cytokine IL-7 is critical for T cell development and function. We performed a Phase Ib study in patients with type 1 diabetes (T1D) to evaluate how blockade of IL-7 would affect immune cells and relevant clinical responses.

METHODS

Thirty-seven subjects with T1D received s.c. RN168, a monoclonal antibody that blocks the IL -7 receptor α (IL7Rα) in a dose-escalating study.

RESULTS

Between 90% and 100% IL-7R occupancy and near-complete inhibition of pSTAT5 was observed at doses of RN168 1 mg/kg every other week (Q2wk) and greater. There was a significant decline in CD4+ and CD8+ effector and central memory T cells and CD4+ naive cells, but there were fewer effects on CD8+ naive T cells. The ratios of Tregs to CD4+ or CD8+ effector and central memory T cells versus baseline were increased. RNA sequencing analysis showed downmodulation of genes associated with activation, survival, and differentiation of T cells. Expression of the antiapoptotic protein Bcl-2 was reduced. The majority of treatment-emergent adverse events (TEAEs) were mild and not treatment related. Four subjects became anti-EBV IgG+ after RN168, and 2 had symptoms of active infection. The immunologic response to tetanus toxoid was preserved at doses of 1 and 3 mg/kg Q2wk but reduced at higher doses.

CONCLUSIONS

This trial shows that, at dosages of 1-3 mg/kg, RN168 selectively inhibits the survival and activity of memory T cells while preserving naive T cells and Tregs. These immunologic effects may serve to eliminate pathologic T cells in autoimmune diseases.

TRIAL REGISTRATION

NCT02038764.

FUNDING

Pfizer Inc.