Alloreaction increases or restores CD40, CD54, and/or HLA molecule expression in acute myelogenous leukemia blasts, through secretion of inflammatory cytokines: dominant role for TNFβ, in concert with IFNγ

Inflammatory response mediates cross-talk with immune function and reveals clinical features in acute myeloid leukemia

Accumulated genetic mutations are an important cause for the development of acute myeloid leukemia (AML), but abnormal changes in the inflammatory microenvironment also have regulatory effects on AML. Exploring the relationship between inflammatory response and pathological features of AML has implications for clinical diagnosis, treatment and prognosis evaluation. We analyzed the expression variation landscape of inflammatory response-related genes (IRRGs) and calculated an inflammatory response score for each sample using the gene set variation analysis (GSVA) algorithm. The differences in clinical- and immune-related characteristics between high- and low-inflammatory response groups were further analyzed. We found that most IRRGs were highly expressed in AML samples, and patients with high inflammatory response had poor prognosis and were accompanied with highly activated chemokine-, cytokine- and adhesion molecule-related signaling pathways, higher infiltration ratios of monocytes, neutrophils and M2 macrophages, high activity of type I/II interferon (IFN) response, and higher expression of immune checkpoints. We also used the Genomics of Drug Sensitivity in Cancer (GDSC) database to predict the sensitivity of AML samples with different inflammatory responses to common drugs, and found that AML samples with low inflammatory response were more sensitive to cytarabine, doxorubicin and midostaurin. SubMap algorithm also demonstrated that high-inflammatory response patients are more suitable for anti-PD-1 immunotherapy. Finally, we constructed a prognostic risk score model to predict the overall survival (OS) of AML patients. Patients with higher risk score had significantly shorter OS, which was confirmed in two validation cohorts. The analysis of inflammatory response patterns can help us better understand the differences in tumor microenvironment (TME) of AML patients, and guide clinical medication and prognosis prediction.

Enhancing the pro-inflammatory anti-cancer T cell response via biomanufactured, secretome-based, immunotherapeutics

T lymphocytes play a critical role in the pro-inflammatory anti-cancer response; hence, significant pharmacologic efforts have been made to enhance the endogenous T cell response. Unfortunately, significant toxicity arises consequent to pan T cell activation. In contrast, the less robust T cell alloresponse has also demonstrated an anti-cancer effect, but poses an inherent risk of GvHD. To overcome the GvHD risk, an acellular pro-inflammatory agent (IA1) has been biomanufactured from the secretome of the allorecognition response. To assess IA1's immunomodulatory activity, T cell proliferation and differentiation were determined in vitro. The pro-inflammatory properties of the IA1 therapeutic were mediated by the miRNA-enriched fractions. Moreover, cross-species efficacy was observed consequent to the evolutionary conservation of miRNA. IA1 exerted no toxicity to resting PBMC but induced significant proliferation of resting CD3⁺ (CD4⁺ and CD8⁺) T cells and skewed the response towards a pro-inflammatory state (i.e., increased Teff:Treg ratio). Crucially, IA1-activated PBMC demonstrated a potent inhibition of cancer cell (HeLa and SH-4 melanoma) proliferation relative to the resting PBMC. The anti-proliferation effect of IA1-activated PBMC was noted within ˜12 h versus 4-5 days for resting cells. A second biomanufactured therapeutic (IA2; produced using HeLa cells) surprisingly demonstrated direct toxicity to cancer cells but was less effective than IA1 in inducing a cell-mediated response. This study demonstrates that miRNA-enriched therapeutics can be biomanufactured from the secretome and can induce a potent pro-inflammatory, anti-cancer, effect on resting lymphocytes.

The doubling potential of T lymphocytes allows clinical-grade production of a bank of genetically modified monoclonal T-cell populations

BACKGROUND AIMS

To produce an anti-leukemic effect after hematopoietic stem cell transplantation we have long considered the theoretical possibility of using banks of HLA-DP specific T-cell clones transduced with a suicide gene. For that application as for any others, a clonal strategy is constrained by the population doubling (PD) potential of T cells, which has been rarely explored or exploited.

METHODS

We used clinical-grade conditions and two donors who were homozygous and identical for all HLA-alleles except HLA-DP. After mixed lymphocyte culture and transduction, we obtained 14 HLA-DP-specific T-cell clones transduced with the HSV-TK suicide gene. Clones were then selected on the basis of their specificity and functional characteristics and evaluated for their doubling potential.

RESULTS

After these steps of selection the clone NAT-DP4^(TK), specific for HLA-DPB1*04:01/04:02, which produced high levels of interferon-γ (IFNγ), tumor necrosis factor (TNF), interleukin-2 (IL-2) and granulocyte-macrophage colony-stimulating factor (GM-CSF), was fully sequenced. It has two copies of the HSV-TK suicide transgene whose localizations were determined. Four billion NAT-DP4^(TK) cells were frozen after 50 PDs. Thawed NAT-DP4^(TK) cells retain the potential to undergo 50 additional PDs, a potential very far beyond that required to produce a biological effect. This PD potential was confirmed on 6/16 additional different T-cell clones. This type of well-defined clone can also support a second genetic modification with CAR constructs.

CONCLUSION

The possibility of choosing rare donors and exploiting the natural proliferative potential of T lymphocytes may dramatically reduce the clinical and immunologic complexity of adoptive transfer protocols that rely on the use of third-party T-cell populations.

Differential requirements for myeloid leukemia IFN-γ conditioning determine graft-versus-leukemia resistance and sensitivity

The graft-versus-leukemia (GVL) effect in allogeneic hematopoietic stem cell transplantation (alloSCT) is potent against chronic phase chronic myelogenous leukemia (CP-CML), but blast crisis CML (BC-CML) and acute myeloid leukemias (AML) are GVL resistant. To understand GVL resistance, we studied GVL against mouse models of CP-CML, BC-CML, and AML generated by the transduction of mouse BM with fusion cDNAs derived from human leukemias. Prior work has shown that CD4+ T cell-mediated GVL against CP-CML and BC-CML required intact leukemia MHCII; however, stem cells from both leukemias were MHCII negative. Here, we show that CP-CML, BC-CML, and AML stem cells upregulate MHCII in alloSCT recipients. Using gene-deficient leukemias, we determined that BC-CML and AML MHC upregulation required IFN-γ stimulation, whereas CP-CML MHC upregulation was independent of both the IFN-γ receptor (IFN-γR) and the IFN-α/β receptor IFNAR1. Importantly, IFN-γR-deficient BC-CML and AML were completely resistant to CD4- and CD8-mediated GVL, whereas IFN-γR/IFNAR1 double-deficient CP-CML was fully GVL sensitive. Mouse AML and BC-CML stem cells were MHCI+ without IFN-γ stimulation, suggesting that IFN-γ sensitizes these leukemias to T cell killing by mechanisms other than MHC upregulation. Our studies identify the requirement of IFN-γ stimulation as a mechanism for BC-CML and AML GVL resistance, whereas independence from IFN-γ renders CP-CML more GVL sensitive, even with a lower-level alloimmune response.

Challenges and future perspectives of T cell immunotherapy in cancer

Since the formulation of the tumour immunosurveillance theory, considerable focus has been on enhancing the effectiveness of host antitumour immunity, particularly with respect to T cells. A cancer evades or alters the host immune response by various ways to ensure its development and survival. These include modifications of the immune cell metabolism and T cell signalling. An inhibitory cytokine milieu in the tumour microenvironment also leads to immune suppression and tumour progression within a host. This review traces the development in the field and attempts to summarize the hurdles that the approach of adoptive T cell immunotherapy against cancer faces, and discusses the conditions that must be improved to allow effective eradication of cancer.

Harnessing the power of alloreactivity without triggering graft-versus-host disease: how non-engrafting alloreactive cellular therapy might change the landscape of acute myeloid leukemia treatment

Human leukocyte antigen-mismatched leukocyte infusions outside of the context of transplantation are a promising strategy for acute myeloid leukemia. Recent studies using such non-engrafting alloreactive cellular therapy (NEACT) revealed that survival of elderly patients increased from 10% to 39% when NEACT was given following chemotherapy, and that durable complete remissions were achieved in about a third of patients with relapsed or chemorefractory disease. We review the clinical reports of different NEACT approaches to date and describe how although T-cell and NK alloreactivity could generate immediate anti-leukemic effects, long-term disease control may be achieved by stimulating recipient-derived T-cell responses against tumor-associated antigens. Other variables likely impacting NEACT such as the release of pro-inflammatory cytokines from donor-host bidirectional alloreactivity and the choice of chemotherapeutics as well as future avenues for improving NEACT, such as optimizing the cell dose and potential synergies with adjuvant pharmacologic immune checkpoint blockade, are discussed.

Induction of tolerogenic lung CD4+ T cells by local treatment with a pSTAT-3 and pSTAT-5 inhibitor ameliorated experimental allergic asthma

Signal transducer and activator of transcription (STAT)-3 inhibitors play an important role in regulating immune responses. Galiellalactone (GL) is a fungal secondary metabolite known to interfere with the binding of phosphorylated signal transducer and activator of transcription (pSTAT)-3 as well of pSTAT-6 dimers to their target DNA in vitro. Intra nasal delivery of 50 μg GL into the lung of naive Balb/c mice induced FoxP3 expression locally and IL-10 production and IL-12p40 in RNA expression in the airways in vivo. In a murine model of allergic asthma, GL significantly suppressed the cardinal features of asthma, such as airway hyperresponsiveness, eosinophilia and mucus production, after sensitization and subsequent challenge with ovalbumin (OVA). These changes resulted in induction of IL-12p70 and IL-10 production by lung CD11c(+) dendritic cells (DCs) accompanied by an increase of IL-3 receptor α chain and indoleamine-2,3-dioxygenase expression in these cells. Furthermore, GL inhibited IL-4 production in T-bet-deficient CD4(+) T cells and down-regulated the suppressor of cytokine signaling-3 (SOCS-3), also in the absence of STAT-3 in T cells, in the lung in a murine model of asthma. In addition, we found reduced amounts of pSTAT-5 in the lung of GL-treated mice that correlated with decreased release of IL-2 by lung OVA-specific CD4(+) T cells after treatment with GL in vitro also in the absence of T-bet. Thus, GL treatment in vivo and in vitro emerges as a novel therapeutic approach for allergic asthma by modulating lung DC phenotype and function resulting in a protective response via CD4(+)FoxP3(+) regulatory T cells locally.