Identification of outcome-correlated cytokine clusters in chronic lymphocytic leukemia. Blood. 2011;118:5201-5210. [PMID: 21911837 DOI: 10.1182/blood-2011-03-342436]

Role of the tumor microenvironment in CLL pathogenesis

Chronic lymphocytic leukemia (CLL) cells extensively interact with and depend on their surrounding tumor microenvironment (TME). The TME encompasses a heterogeneous array of cell types, soluble signals, and extracellular vesicles, which contribute significantly to CLL pathogenesis. CLL cells and the TME cooperatively generate a chronic inflammatory milieu, which reciprocally reprograms the TME and activates a signaling network within CLL cells, promoting their survival and proliferation. Additionally, the inflammatory milieu exerts chemotactic effects, attracting CLL cells and other immune cells to the lymphoid tissues. The intricate CLL-TME interactions also facilitate immune evasion and compromise leukemic cell surveillance. We also review recent advances that have shed light on additional aspects that are substantially influenced by the CLL-TME interplay.

Translation of Data from Animal Models of Cancer to Immunotherapy of Breast Cancer and Chronic Lymphocytic Leukemia

The field of clinical oncology has been revolutionized over the past decade with the introduction of many new immunotherapies the existence of which have depended to a large extent on experimentation with both in vitro analysis and the use of various animal models, including gene-modified mice. The discussion below will review my own laboratory's studies, along with those of others in the field, on cancer immunotherapy. Our own studies have predominantly dwelt on two models of malignancy, namely a solid tumor model (breast cancer) and lymphoma. The data from our own laboratory, and that of other scientists, highlights the novel information so obtained, and the evidence that application of such information has already had an impact on immunotherapy of human oncologic diseases.

Linking tumor immune infiltrate and systemic immune mediators to treatment response and prognosis in advanced cervical cancer

Cervical cancer (CC) poses a significant burden on individuals in developing regions, exhibiting heterogeneous responses to standard chemoradiation therapy, and contributing to substantial mortality rates. Unraveling host immune dynamics holds promise for innovative therapies and discovery of clinically relevant biomarkers. We studied prospectively locally advanced CC patients pre-treatment, stratifying them as responders (R) or non-responders (NR). R patients had increased tumor-infiltrating lymphocytes (TILs), while NR patients showed elevated PD-1 scores, CD8+ and PD-L2+ TILs, and PD-L1 immune reactivity. NR patients exhibited higher systemic soluble mediators correlating with TIL immune markers. R patients demonstrated functional polarization of CD4 T cells (Th1, Th2, Th17, and Treg), while CD8+ T cells and CD68+ macrophages predominated in the NR group. Receiver operating characteristic analysis identified potential CC response predictors, including PD-L1-immunoreactive (IR) area, PD-L2, CD8, FGF-basic, IL-7, IL-8, IL-12p40, IL-15, and TNF-alpha. Dysfunctional TILs and imbalanced immune mediators contribute to therapeutic insufficiency, shedding light on local and systemic immune interplay. Our study informs immunological signatures for treatment prediction and CC prognosis.

Unraveling the Bone Tissue Microenvironment in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is the most frequent leukemia in Western countries. Although characterized by the progressive expansion and accumulation of leukemic B cells in peripheral blood, CLL cells develop in protective niches mainly located within lymph nodes and bone marrow. Multiple interactions between CLL and microenvironmental cells may favor the expansion of a B cell clone, further driving immune cells toward an immunosuppressive phenotype. Here, we summarize the current understanding of bone tissue alterations in CLL patients, further addressing and suggesting how the multiple interactions between CLL cells and osteoblasts/osteoclasts can be involved in these processes. Recent findings proposing the disruption of the endosteal niche by the expansion of a leukemic B cell clone appear to be a novel field of research to be deeply investigated and potentially relevant to provide new therapeutic approaches.

Identification of novel clusters of co-expressing cytokines in a diagnostic cytokine multiplex test

Introduction

Cytokines are mediators of the immune system that are essential for the maintenance, development and resolution of immune responses. Beneficial immune responses depend on complex, interdependent networks of signaling and regulatory events in which individual cytokines influence the production and release of others. Since disruptions in these signaling networks are associated with a wide spectrum of diseases, cytokines have gained considerable interest as diagnostic, prognostic and precision therapy-relevant biomarkers. However, currently individual cytokines testing has limited value because the wider immune response context is often overlooked. The aim of this study was to identify specific cytokine signaling patterns associated with different diseases.

Methods

Unbiased clustering analyses were performed on a clinical cytokine multiplex test using a cohort of human plasma specimens drawn from individuals with known or suspected diseases for which cytokine profiling was considered clinically indicated by the attending physician.

Results and discussion

Seven clusters of co-expressing cytokines were identified, representing common patterns of immune activation. Common expression profiles of the cytokine clusters and preliminary associations of these profiles with specific diseases or disease categories were also identified. These findings increase our understanding of the immune environments underlying the clinical presentations of patients of inflammatory, autoimmune and neoplastic diseases, which could then improve diagnoses and the identification of evidence-based treatment targets.

Rituximab induced cytokine release with high serum IP-10 (CXCL10) concentrations is associated with infusion reactions

Monoclonal antibody induced infusion reactions (IRs) can be serious and even fatal. We used clinical data and blood samples from 37 treatment naïve patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) initiating therapy for progressive disease with a single 50 mg dose of intravenous (IV) rituximab at 25 mg/h. Twenty-four (65 %) patients had IRs at a median of 78 min (range 35-128) and rituximab dose of 32 mg (range 15-50). IR risk did not correlate with patient or CLL characteristics, CLL counts or CD20 levels, or serum rituximab or complement concentrations. Thirty-five (95 %) patients had cytokine release response with a ≥ 4-fold increase in serum concentration of ≥ 1 inflammatory cytokine. IRs were associated with significantly higher post-infusion serum concentrations of gamma interferon induced cytokines IP-10, IL-6 and IL-8. IP-10 concentrations increased ≥ 4-fold in all patients with an IR and were above the upper limit of detection (40,000 pg/ml) in 17 (71 %). In contrast, to only three (23 %) patients without an IR had an ≥ 4-fold increase in serum concentrations of IP-10 (highest 22,013 pg/ml). Our data suggest that cytokine release could be initiated by activation of effector cells responsible for clearance of circulating CLL cells with IRs occurring in those with higher levels of gamma interferon induced cytokines. These novel insights could inform future research to better understand and manage IRs and understand the role of cytokines in the control of cytotoxic immune responses to mAb.

Elevated expression of interleukin 16 in chronic lymphocytic leukemia is associated with disease burden and abnormal immune microenvironment

Interleukin-16 (IL-16) is a novel biomarker that has been implicated in many cancers as well as inflammatory diseases. In this study, we examined plasma levels of 30 cytokines and chemokines in chronic lymphocytic leukemia (CLL) and monoclonal B cell lymphocytosis (MBL) patients, and examined their association with disease stage, CLL biomarkers and T cell subsets. Interleukin 16 (IL-16) was identified as a relatively uncharacterized cytokine significantly elevated in CLL patients compared to healthy controls and MBL patients. Plasma levels of IL-16 were significantly elevated by Rai stage 0, increased by Rai stage 3-4, correlated strongly with lymphocyte count and were decreased after Ibrutinib treatment. CLL cells expressed IL-16 mRNA and spontaneously secreted IL-16 in vitro. CLL cells express IL-16 mRNA at significantly higher levels in lymphoid tissues than blood, and we observed that IL-16 release was increased in co-cultures of CLL and autologous CD4 + T cells. Elevated plasma IL-16 levels were associated with abnormalities in the immune microenvironment including multiple inflammatory cytokines and chemokines and expansion of type 1 follicular helper T cells. Taken together, our results identify IL-16 as a novel biomarker in CLL with potential functional roles in cellular interactions between CLL cells and T cells.

A phase 1b study of ibrutinib in combination with obinutuzumab in patients with relapsed or refractory chronic lymphocytic leukemia

This study investigated ibrutinib plus obinutuzumab in relapsed/refractory CLL, evaluating tolerability of 3 sequencing regimens as well as overall safety and efficacy. Fifty-two patients were initially randomized 1:1:1 to receive either obinutuzumab 1 month before ibrutinib initiation, ibrutinib 1 month prior to obinutuzumab initiation, or to start both drugs concomitantly. Higher rates of infusion-related reactions were observed with the first sequence, and only the latter 2 cohorts were expanded. Grade 4 hematologic toxicity was uncommon, and notable all-grade non-hematologic toxicities included bruising (58%), hypertension (46%), arthralgia (38%), diarrhea (37%), transaminitis (35%), atrial fibrillation (21%), and serious infection (17%). Best overall response rate was 96% (including 40% CR and 56% PR). Best rates of undetectable minimal residual disease in peripheral blood and bone marrow were 27% and 19%, respectively. With a median follow-up of 41.5 months, four-year progression-free and overall survival rates are 74% and 93%, respectively. Correlative studies demonstrated that serum CCL4 and CXCL13 levels were associated with clinical response, and BH3 profiling revealed increased BCL-2 and BCL-xL dependence in CLL cells from patients on treatment. Overall, ibrutinib plus obinutuzumab was highly active, with a manageable safety profile, supporting further investigation of this type of approach in relapsed/refractory CLL.

Paradoxical activation of chronic lymphocytic leukemia cells by ruxolitinib in vitro and in vivo

Introduction

Chronic lymphocytic leukemia (CLL) is characterized by an aberrant cytokine network that can support tumor growth by triggering janus kinase (JAK)/STAT pathways. Targeting cytokine-signaling should then be a rational therapeutic strategy but the JAK inhibitor ruxolitinib failed to control and seemingly accelerated the disease in clinical trials.

Methods

The effect of ruxolitinib on primary human CLL cells was studied in vitro and in vivo.

Results

Ruxolitinib increased phosphorylation of IRAK4, an important toll-like receptor (TLR)- signaling intermediate, in circulating CLL cells in vitro. It also enhanced p38 and NFKB1 phosphorylation while lowering STAT3 phosphorylation in CLL cells activated with TLR-7/8 agonists and IL-2. Among the cytokines made by activated CLL cells, high levels of IL-10 contributed strongly to STAT3 phosphorylation and inhibited TLR7 activity. Ruxolitinib limited TLR-mediated IL10 transcription and markedly reduced IL-10 production in vitro. It also decreased blood levels of IL-10 while increasing TNFα along with phospho-p38 expression and gene sets associated with TLR-activation in CLL cells in vivo. The bruton's tyrosine kinase inhibitor ibrutinib decreased IL-10 production in vitro but, in contrast to ruxolitinib, blocked initial IL10 transcription induced by TLR-signaling in vitro, decreased TNFα production, and deactivates CLL cells in vivo.

Discussion

These findings suggest the possible benefits of inhibiting growth factors with JAK inhibitors in CLL are outweighed by negative effects on potential tumor suppressors such as IL-10 that allow unrestrained activation of NFκB by drivers such as TLRs. Specific inhibition of growth-promoting cytokines with blocking antibodies or infusing suppressive cytokines like IL-10 might be better strategies to manipulate cytokines in CLL.

Natural Killer Cells in Chronic Lymphocytic Leukemia: Functional Impairment and Therapeutic Potential

Immunotherapy approaches have advanced rapidly in recent years. While the greatest therapeutic advances so far have been achieved with T cell therapies such as immune checkpoint blockade and CAR-T, recent advances in NK cell therapy have highlighted the therapeutic potential of these cells. Chronic lymphocytic leukemia (CLL), the most prevalent form of leukemia in Western countries, is a very immunosuppressive disease but still shows significant potential as a target of immunotherapy, including NK-based therapies. In addition to their antileukemia potential, NK cells are important immune effectors in the response to infections, which represent a major clinical concern for CLL patients. Here, we review the interactions between NK cells and CLL, describing functional changes and mechanisms of CLL-induced NK suppression, interactions with current therapeutic options, and the potential for therapeutic benefit using NK cell therapies.

Inhibition of p38 MAPK or immunoproteasome overcomes resistance of chronic lymphocytic leukemia cells to Bcl-2 antagonist venetoclax

Chronic lymphocytic leukemia (CLL) is a hematological neoplasm of CD19-positive mature-appearing B lymphocytes. Despite the clinical success of targeted therapies in CLL, the development of resistance diminishes their therapeutic activity. This is also true for the Bcl-2 antagonist venetoclax. We investigated the molecular mechanisms that drive venetoclax resistance in CLL, with a clear focus to provide new strategies to successfully combat it. Activation of CLL cells with IFNγ, PMA/ionomycin, and sCD40L diminished the cytotoxicity of venetoclax. We demonstrated that the metabolic activity of cells treated with 1 nM venetoclax alone was 48% of untreated cells, and was higher for cells co-treated with IFNγ (110%), PMA/ionomycin (78%), and sCD40L (62%). As of molecular mechanism, we showed that PMA/ionomycin and sCD40L triggered translocation of NFκB in primary CLL cells, while IFNγ activated p38 MAPK, suppressed spontaneous and venetoclax-induced apoptosis and induced formation of the immunoproteasome. Inhibition of immunoproteasome with ONX-0914 suppressed activity of immunoproteasome and synergized with venetoclax against primary CLL cells. On the other hand, inhibition of p38 MAPK abolished cytoprotective effects of IFNγ. We demonstrated that venetoclax-resistant (MEC-1 VER) cells overexpressed p38 MAPK and p-Bcl-2 (Ser70), and underexpressed Mcl-1, Bax, and Bak. Inhibition of p38 MAPK or immunoproteasome triggered apoptosis in CLL cells and overcame the resistance to venetoclax of MEC-1 VER cells and venetoclax-insensitive primary CLL cells. In conclusion, the p38 MAPK pathway and immunoproteasome represent novel targets to combat venetoclax resistance in CLL.

Drug-microenvironment perturbations reveal resistance mechanisms and prognostic subgroups in CLL

The tumour microenvironment and genetic alterations collectively influence drug efficacy in cancer, but current evidence is limited and systematic analyses are lacking. Using chronic lymphocytic leukaemia (CLL) as a model disease, we investigated the influence of 17 microenvironmental stimuli on 12 drugs in 192 genetically characterised patient samples. Based on microenvironmental response, we identified four subgroups with distinct clinical outcomes beyond known prognostic markers. Response to multiple microenvironmental stimuli was amplified in trisomy 12 samples. Trisomy 12 was associated with a distinct epigenetic signature. Bromodomain inhibition reversed this epigenetic profile and could be used to target microenvironmental signalling in trisomy 12 CLL. We quantified the impact of microenvironmental stimuli on drug response and their dependence on genetic alterations, identifying interleukin 4 (IL4) and Toll-like receptor (TLR) stimulation as the strongest actuators of drug resistance. IL4 and TLR signalling activity was increased in CLL-infiltrated lymph nodes compared with healthy samples. High IL4 activity correlated with faster disease progression. The publicly available dataset can facilitate the investigation of cell-extrinsic mechanisms of drug resistance and disease progression.

Activated CLL cells regulate IL17F producing Th17 cells in miR155 dependent and outcome specific manners

Chronic lymphocytic leukemia (CLL) results from expansion of a CD5+ B-cell clone that requires interactions with other cell types, including T cells. Moreover, CLL patients have elevated circulating IL17A+ and IL17F+ CD4+ T cells (Th17s), with higher IL17A+Th17s correlating with better outcomes. We report that CLL Th17s express more miR155, a Th17 differentiation regulator, than control Th17s, despite naïve CD4+ T cell (TN) basal miR155 levels being similar in both. We also found that CLL cells directly regulate miR155 levels in TN, thereby affecting Th17 differentiation by documenting that: co-culturing TN with resting (Brest) or activated (Bact) CLL cells alters the magnitude and direction of T-cell miR155 levels; CLL Bact promote IL17A+ and IL17F+ T cell generation by a miR155-dependent mechanism, confirmed by miR155 inhibition; co-cultures of TN with CLL Bact lead to a linear correlation between the degree and direction of T-cell miR155 expression changes and IL17F production, but not IL17A; Bact-mediated changes in TN miR155 expression correlate with outcome, irrespective of IGHV mutation status, a strong prognostic indicator. Together, the results identify a previously unrecognized CLL Bact-dependent mechanism, upregulation of TN miR155 expression and subsequent enhancement of IL17F+ Th17 generation, that favors better clinical courses.

Identifying Potential Biomarkers of Prognostic Value in Colorectal Cancer via Tumor Microenvironment Data Mining

Colorectal cancer (CRC) is a common cancer that has increased rapidly worldwide in the past decades with a relatively high mortality rate. An increasing body of evidence has highlighted the importance of infiltrating immune and stromal cells in CRC. In this study, based on gene expression data of CRC patients in TCGA database we evaluated immune and stromal scores in tumor microenvironment using ESTIMATE method. Results showed there was potential correlation between these scores and the prognosis, and that patients with higher immune score and lower stromal score had longer survival time. We found that immune score was correlated with clinical characteristics including tumor location, tumor stage, and survival time. Specifically, the right-sided colon cancer had markedly elevated immune score, compared to left-sided colon cancer and rectal cancer. These results might be useful for understanding tumor microenvironment in colorectal cancer. Through the differential analysis we got a list of genes significantly associated with immune and stromal scores. Gene Set Enrichment and protein-protein interaction network analysis were used to further illustrate these differentially expressed genes. Finally, 15 hub genes were identified, and three (CXCL9, CXCL10 and SELL) of them were validated with favorable outcomes in CRC patients. Our result suggested that these tumor microenvironment related genes might be potential biomarkers for the prognosis of CRC.

MODIFICATION OF THE TUMOR/INDUCED BYSTANDER EFFECT BY IRRADIATION UNDER COCULTIVATION OF LYMPHOCYTES FROM PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA AND LYMPHOCYTES FROM HEALTHY DONORS

OBJECTIVE

Study the tumor-induced bystander effect of blood cells from chronic lymphocytic leukemia (CLL)patients on non-transformed bystander cells (peripheral blood lymphocytes (PBL) of conditionally healthy individ-uals) and the possibility of its modification after the impact of ionizing radiation.

MATERIALS AND METHODS

We carried out cocultivation and separate cultivation of blood samples from conditionallyhealthy volunteers and patients with CLL according to our technique. Using the Comet assay, the relative level ofDNA damage was evaluated.

RESULTS

A statistically significant increase (р < 0.001) in the level of DNA damage in PBL culture of conditionallyhealthy individuals after co-cultivation with malignant cells of CLL patients was observed. After irradiation, a drop in the level of cells with a high degree of DNA damage was noted, which was connected with an increase in the frequency of cells that were delayed in division at the S stage of the cell cycle. An increase in apoptotic activity in cultures of bystander cells was observed in all variants of the experiment (р < 0.001).

CONCLUSION

The influence of irradiated blood cells of patients with CLL results in an enhancement of the tumor-induced bystander effect manifestation in the PBL of conditionally healthy individuals.

Janus kinases restrain chronic lymphocytic leukemia cells in patients on ibrutinib: Results of a phase II trial

Preclinical observations that killing of chronic lymphocytic leukemia (CLL) cells was dexamethasone (DEX) were enhanced by concomitant inhibition of Bruton's tyrosine kinase and janus kinases (JAKs) motivated a phase II trial to determine if clinical responses to ibrutinib could be deepened by DEX and the JAK inhibitor ruxolitinib. Patients on ibrutinib at 420 mg daily for 2 months or with abnormal serum β2M levels after 6 months or with persistent lymphadenopathy or splenomegaly after 12 months were randomized to receive DEX 40 mg on days 1-4 of a 4-week cycle for six cycles alone (three patients) or with ruxolitinib 15 mg BID on days 1-21 of each cycle (five patients). Ruxolitinib dosing was based on a previous phase I trial. Steroid withdrawal symptoms and significantly decreased serum IgG levels occurred in all patients regardless of their exposure to ruxolitinib. A fatal invasive fungal infection was seen in a patient taking DEX without ruxolitinib. Complete responses anticipated with addition of ruxolitinib were not seen. Gene expression studies suggested ruxolitinib had turned off interferon signaling in CLL cells and turned on genes associated with the activation of NFκB by TNF-α. Ruxolitinib increased blood levels of TNF-α by cycle 3 and decreased the inhibitory cytokine IL-10. These results suggest ruxolitinib releases activating signals for CLL cells that persist in patients on ibrutinib. This inhibitory JAK signaling may contribute to the therapeutic activity of ibrutinib. Thus JAK inhibitors provide no added value with ibrutinib for disease control and should be used with caution in CLL patients. Combining glucocorticoids with ibrutinib may increase the risk of serious infects.

Impact of Immune Parameters and Immune Dysfunctions on the Prognosis of Patients with Chronic Lymphocytic Leukemia

Simple Summary

In chronic lymphocytic leukemia (CLL), immune alterations—affecting both the innate and adaptive immunity—are very common. As a clinical consequence, patients with CLL frequently present with autoimmune phenomena, increased risk of infections and second malignancies. The aim of this review article is to present available data on CLL-associated alterations of immune parameters that correlate with known prognostic markers and with clinical outcome. Also, data on the impact of immune-related clinical manifestations on the prognosis of patients with CLL will be discussed.

Abstract

Chronic lymphocytic leukemia (CLL) is characterized by a wide spectrum of immune alterations, affecting both the innate and adaptive immunity. These immune dysfunctions strongly impact the immune surveillance, facilitate tumor progression and eventually affect the disease course. Quantitative and functional alterations involving conventional T cells, γδ T cells, regulatory T cells, NK and NKT cells, and myeloid cells, together with hypogammaglobulinemia, aberrations in the complement pathways and altered cytokine signature have been reported in patients with CLL. Some of these immune parameters have been shown to associate with other CLL-related characteristics with a known prognostic relevance or to correlate with disease prognosis. Also, in CLL, the complex immune response dysfunctions eventually translate in clinical manifestations, including autoimmune phenomena, increased risk of infections and second malignancies. These clinical issues are overall the most common complications that affect the course and management of CLL, and they also may impact overall disease prognosis.

Effect of ibrutinib on CCR7 expression and functionality in chronic lymphocytic leukemia and its implication for the activity of CAP-100, a novel therapeutic anti-CCR7 antibody

CAP-100 is a novel therapeutic antibody directed against the ligand binding site of human CCR7. This chemokine receptor is overexpressed in chronic lymphocytic leukemia (CLL) and orchestrates the homing of CLL cells into the lymph node. Previous studies, on a very limited number of samples, hypothesized that the Bruton's tyrosine kinase inhibitor (BTKi) ibrutinib might induce loss of surface CCR7 levels in CLL cells. CAP-100 will be evaluated in clinical trials as a therapy for relapse/refractory CLL patients, who have received at least two systemic therapies (NCT04704323). As nowadays many relapse/refractory CLL patients will have received ibrutinib as a prior therapy, we aimed to investigate in a large cohort of CLL patients the impact of this BTKi on CCR7 expression and functionality as well as on the therapeutic activity of CAP-100. Our data confirm that ibrutinib moderately down-regulates the very high expression of CCR7 in CLL cells but has no apparent effect on CCR7-induced chemotaxis. Moreover, CLL cells are perfectly targetable by CAP-100 which led to a complete inhibition of CCR7-mediated migration and induced strong target cell killing through antibody-dependent cell-mediated cytotoxicity, irrespective of previous or contemporary ibrutinib administration. Together, these results validate the therapeutic utility of CAP-100 as a next-line single-agent therapy for CLL patients who failed to ibrutinib and confirm that CAP-100 and ibrutinib have complementary non-overlapping mechanisms of action, potentially allowing for combination therapy.

Rapid improvement in symptoms and physical function following ibrutinib initiation in chronic lymphocytic leukemia and the associated changes in plasma cytokines

A prospective pilot study was carried out on 34 CLL patients treated with ibrutinib, evaluating the effects on symptoms and physical function with changes in plasma exosomes (EXs), β2-microglobulin (β2M) and 26 plasma cytokines. The revised Edmonton Symptom Assessment Scale (ESAS-R) demonstrated moderate fatigue, shortness of breath and a sense of unwellness before treatment, which significantly improved within 2 weeks of starting ibrutinib. These changes were associated with a rapid improvement in sit-to-stand and 4 m walking speeds. The plasma levels of CCL11, IL-7, -8 and -10 dropped initially while the levels of TNF-α/-β, CCL3, CCL4, CCL17, and IL-16 continued to decline for 12 months. Despite the initial lymphocytosis, plasma β2M levels fell but no consistent change in plasma EXs occurred. Thus, ibrutinib can produce a rapid and sustained improvement in symptoms and physical function in CLL, associated with a decline in multiple plasma cytokines.

Targeting CD38 is lethal to Breg-like chronic lymphocytic leukemia cells and Tregs, but restores CD8+ T-cell responses

Patients with chronic lymphocytic leukemia (CLL) are characterized by monoclonal expansion of CD5+CD23+CD27+CD19+κ/λ+ B lymphocytes and are clinically noted to have profound immune suppression. In these patients, it has been recently shown that a subset of B cells possesses regulatory functions and secretes high levels of interleukin 10 (IL-10). Our investigation identified that CLL cells with a CD19+CD24+CD38hi immunophenotype (B regulatory cell [Breg]-like CLL cells) produce high amounts of IL-10 and transforming growth factor β (TGF-β) and are capable of transforming naive T helper cells into CD4+CD25+FoxP3+ T regulatory cells (Tregs) in an IL-10/TGF-β-dependent manner. A strong correlation between the percentage of CD38+ CLL cells and Tregs was observed. CD38hi Tregs comprised more than 50% of Tregs in peripheral blood mononuclear cells (PBMCs) in patients with CLL. Anti-CD38 targeting agents resulted in lethality of both Breg-like CLL and Treg cells via apoptosis. Ex vivo, use of anti-CD38 monoclonal antibody (mAb) therapy was associated with a reduction in IL-10 and CLL patient-derived Tregs, but an increase in interferon-γ and proliferation of cytotoxic CD8+ T cells with an activated phenotype, which showed an improved ability to lyse patient-autologous CLL cells. Finally, effects of anti-CD38 mAb therapy were validated in a CLL-patient-derived xenograft model in vivo, which showed decreased percentage of Bregs, Tregs, and PD1+CD38hiCD8+ T cells, but increased Th17 and CD8+ T cells (vs vehicle). Altogether, our results demonstrate that targeting CD38 in CLL can modulate the tumor microenvironment; skewing T-cell populations from an immunosuppressive to immune-reactive milieu, thus promoting immune reconstitution for enhanced anti-CLL response.

Myeloid-derived suppressor cell subtypes differentially influence T-cell function, T-helper subset differentiation, and clinical course in CLL

Cancer pathogenesis involves the interplay of tumor- and microenvironment-derived stimuli. Here we focused on the influence of an immunomodulatory cell type, myeloid-derived suppressor cells (MDSCs), and their lineage-related subtypes on autologous T lymphocytes. Although MDSCs as a group correlated with an immunosuppressive Th repertoire and worse clinical course, MDSC subtypes (polymorphonuclear, PMN-MDSC, and monocytic, M-MDSCs) were often functionally discordant. In vivo, PMN-MDSCs existed in higher numbers, correlated with different Th-subsets, and more strongly associated with poor clinical course than M-MDSCs. In vitro, PMN-MDSCs were more efficient at blocking T-cell growth and promoted Th17 differentiation. Conversely, in vitro M-MDSCs varied in their ability to suppress T-cell proliferation, due to the action of TNFα, and promoted a more immunostimulatory Th compartment. Ibrutinib therapy impacted MDSCs differentially as well, since after initiating therapy, PMN-MDSC numbers progressively declined, whereas M-MDSC numbers were unaffected, leading to a set of less immunosuppressive Th cells. Consistent with this, clinical improvement based on decreasing CLL-cell numbers correlated with the decrease in PMN-MDSCs. Collectively, the data support a balance between PMN-MDSC and M-MDSC numbers and function influencing CLL disease course.

Expanded antigen-experienced CD160+CD8+effector T cells exhibit impaired effector functions in chronic lymphocytic leukemia

Background

T cell exhaustion compromises antitumor immunity, and a sustained elevation of co-inhibitory receptors is a hallmark of T cell exhaustion in solid tumors. Similarly, upregulation of co-inhibitory receptors has been reported in T cells in hematological cancers such as chronic lymphocytic leukemia (CLL). However, the role of CD160, a glycosylphosphatidylinositol-anchored protein, as one of these co-inhibitory receptors has been contradictory in T cell function. Therefore, we decided to elucidate how CD160 expression and/or co-expression with other co-inhibitory receptors influence T cell effector functions in patients with CLL.

Methods

We studied 56 patients with CLL and 25 age-matched and sex-matched healthy controls in this study. The expression of different co-inhibitory receptors was analyzed in T cells obtained from the peripheral blood or the bone marrow. Also, we quantified the properties of extracellular vesicles (EVs) in the plasma of patients with CLL versus healthy controls. Finally, we measured 29 different cytokines, chemokines or other biomarkers in the plasma specimens of patients with CLL and healthy controls.

Results

We found that CD160 was the most upregulated co-inhibitory receptor in patients with CLL. Its expression was associated with an exhausted T cell phenotype. CD160⁺CD8⁺ T cells were highly antigen-experienced/effector T cells, while CD160⁺CD4⁺ T cells were more heterogeneous. In particular, we identified EVs as a source of CD160 in the plasma of patients with CLL that can be taken up by T cells. Moreover, we observed a dominantly proinflammatory cytokine profile in the plasma of patients with CLL. In particular, interleukin-16 (IL-16) was highly elevated and correlated with the advanced clinical stage (Rai). Furthermore, we observed that the incubation of T cells with IL-16 results in the upregulation of CD160.

Conclusions

Our study provides a novel insight into the influence of CD160 expression/co-expression with other co-inhibitory receptors in T cell effector functions in patients with CLL. Besides, IL-16-mediated upregulation of CD160 expression in T cells highlights the importance of IL-16/CD160 as potential immunotherapy targets in patients with CLL. Therefore, our findings propose a significant role for CD160 in T cell exhaustion in patients with CLL.

Of Lymph Nodes and CLL Cells: Deciphering the Role of CCR7 in the Pathogenesis of CLL and Understanding Its Potential as Therapeutic Target

The lymph node (LN) is an essential tissue for achieving effective immune responses but it is also critical in the pathogenesis of chronic lymphocytic leukemia (CLL). Within the multitude of signaling pathways aberrantly regulated in CLL the homeostatic axis composed by the chemokine receptor CCR7 and its ligands is the main driver for directing immune cells to home into the LN. In this literature review, we address the roles of CCR7 in the pathophysiology of CLL, and how this chemokine receptor is of critical importance to develop more rational and effective therapies for this malignancy.

Stem cell factor is implicated in microenvironmental interactions and cellular dynamics of chronic lymphocytic leukemia

The inflammatory cytokine stem cell factor (SCF, ligand of c-kit receptor) has been implicated as a pro-oncogenic driver and an adverse prognosticator in several human cancers. Increased SCF levels have recently been reported in a small series of patients with chronic lymphocytic leukemia (CLL), however its precise role in CLL pathophysiology remains elusive. In this study, CLL cells were found to express predominantly the membrane isoform of SCF, which is known to elicit a more robust activation of the c-kit receptor. SCF was significantly overexpressed in CLL cells compared to healthy tonsillar B cells and it correlated with adverse prognostic biomarkers, shorter time-to-first treatment and shorter overall survival. Activation of immune receptors and long-term cell-cell interactions with the mesenchymal stroma led to an elevation of SCF primarily in CLL cases with an adverse prognosis. Contrariwise, suppression of oxidative stress and the BTK inhibitor ibrutinib lowered SCF levels. Interestingly, SCF significantly correlated with mitochondrial dynamics and hypoxia-inducible factor-1a which have previously been linked with clinical aggressiveness in CLL. SCF was able to elicit direct biological effects in CLL cells, affecting redox homeostasis and cell proliferation. Overall, the aberrantly expressed SCF in CLL cells emerges as a key response regulator to microenvironmental stimuli while correlating with poor prognosis. On these grounds, specific targeting of this inflammatory molecule could serve as a novel therapeutic approach in CLL.

Chronic lymphocytic leukemia-like monoclonal B-cell lymphocytosis exhibits an increased inflammatory signature that is reduced in early-stage chronic lymphocytic leukemia

Several studies in chronic lymphocytic leukemia (CLL) patients have reported impaired immune cell functions, which contribute to tumor evasion and disease progression. However, studies on CLL-like monoclonal B-cell lymphocytosis (MBL) are scarce. In the study described here, we characterized the immune environment in 62 individuals with clinical MBL, 56 patients with early-stage CLL, and 31 healthy controls. Gene expression arrays and quantitative reverse transcription polymerase chain reaction were performed on RNA from CD4⁺ peripheral blood cells; serum cytokines were measured with immunoassays; and HLA-DR expression on circulating monocytes, as well as the percentages of Th1, cytotoxic, exhausted, and effector CD4⁺ T cells, were evaluated by flow cytometry. In addition, cell cultures of clonal B cells and CD14-enriched or -depleted cell fractions were performed. Strikingly, MBL and early-stage CLL differed in pro-inflammatory signatures. An increased inflammatory drive orchestrated mainly by monocytes was identified in MBL, which exhibited enhanced phagocytosis, pattern recognition receptors, interleukin-8 (IL8), HMGB1, and acute response signaling pathways and increased pro-inflammatory cytokines (in particular IL8, interferon γ [IFNγ], and tumor necrosis factor α). This inflammatory signature was diminished in early-stage CLL (reduced IL8 and IFNγ levels, IL8 signaling pathway, and monocytic HLA-DR expression compared with MBL), especially in those patients with mutations in IGHV genes. Additionally, CD4⁺ T cells of MBL and early-stage CLL exhibited a similar upregulation of Th1 and cytotoxic genes and expanded CXCR3⁺ and perforin⁺ CD4⁺ T cells, as well as PD1⁺ CD4⁺ T cells, compared with controls. Cell culture assays disclosed tumor-supporting effects of monocytes similarly observed in MBL and early-stage CLL. These novel findings reveal differences in the inflammatory environment between MBL and CLL, highlighting an active role for antigen stimulation in the very early stages of the disease, potentially related to malignant B-cell transformation.

Targeting cancer homing into the lymph node with a novel anti-CCR7 therapeutic antibody: the paradigm of CLL

Lymph node (LN) is a key tissue in the pathophysiology of mature blood cancers, especially for chronic lymphocytic leukemia (CLL). Within the multiple de-regulated pathways affecting CLL homeostasis, the CC-chemokine receptor 7 (CCR7) grants homing of CLL cells into the LN where protective environments foster tumor progression. To cover the lack of specific therapies targeting the CCR7-dependence of CLL to enter into the LN, and aiming to displace the disease from LN, we generated CAP-100, an antibody that specifically binds to hCCR7 and neutralizes its ligand-binding site and signaling. In various in vitro and in vivo preclinical models CAP-100 strongly inhibited CCR7-induced migration, extravasation, homing, and survival in CLL samples. Moreover, it triggered potent tumor cell killing, mediated by host immune mechanisms, and was effective in xenograft models of high-risk disease. Additionally, CAP-100 showed a favorable toxicity profile on relevant hematopoietic subsets. Our results validated CAP-100 as a novel therapeutic tool to prevent the access of CLL cells, and other neoplasia with nodal-dependence, into the LN niches, thus hitting a central hub in the pathogenesis of cancer. The first-in-human clinical trial (NCT04704323), which will evaluate this novel therapeutic approach in CLL patients, is pending.

Research hotspots and trends analysis of ankylosing spondylitis: a bibliometric and scientometric analysis from 2009 to 2018

Background

This study utilized bibliometric analysis to qualitatively and quantitatively analyze hotspots and predict trends in the field of ankylosing spondylitis (AS) research.

Methods

Articles about AS were obtained from the Web of Science Core Collection and PubMed database, and bibliometric analysis was carried out through CiteSpace and the Online Analysis Platform of Literature Metrology and Bibliographic Item Co-Occurrence Matrix Builder (BICOMB). Then, co-word biclustering analysis was conducted to obtain research hotspots and predict trends using gCLUTO software.

Results

A total of 6,818 articles on AS from 2009 to 2018 were analyzed, showing an increasing publication trend (558 articles in 2009 to 851 articles in 2018). The Journal of Rheumatology was the leading journal in AS research, with an impact factor (IF) of 3.634 and H-index value of 49. In terms of region, the United States led the world in this field, and The University of Toronto was the leading institution for AS research. Van Der Heijde, D was the most prolific author in the field. Eight research hotspots in the field of AS were also identified.

Conclusions

Our analysis identified eight research hotspots, and predicted that surgical treatment and etiology will be the main AS research trends in the future. This study provides new directions and ideas for future research in AS.

Macrophage Polarization in Chronic Lymphocytic Leukemia: Nurse-Like Cells Are the Caretakers of Leukemic Cells

Macrophages are terminally differentiated innate immune cells. Through their activation, they can be polarized towards the pro-inflammatory M1 type or the wound healing-associated, anti-inflammatory M2 type macrophages. In the tumor microenvironment (TME), M2 is the dominant phenotype and these cells are referred to as tumor-associated macrophages (TAMs). TAMs secrete cytokines and chemokines, exerting an antiapoptotic, proliferative and pro-metastatic effect on the tumor cells. TAMs can be found in many cancers, including chronic lymphocytic leukemia (CLL), where they are called nurse-like cells (NLCs). Despite the generally indolent behavior of CLL, the proportion of treatment-refractory patients is significant. As with the majority of cancers, despite significant recent progress, CLL pathogenesis is poorly understood. The emerging role of the TME in nurturing the neoplastic process warrants the investigation of macrophages as a significant pathogenetic element of tumors. In this paper, we review the current knowledge on the role of stromal macrophages in CLL.

Evolution of Advanced Chronic Lymphoid Leukemia Unveiled by Single-Cell Transcriptomics: A Case Report

Genetic and transcriptional heterogeneity of Chronic lymphocytic leukaemia (CLL) limits prevention of disease progression. Longitudinal single-cell transcriptomics represents the state-of-the-art method to profile the disease heterogeneity at diagnosis and to inform about disease evolution. Here, we apply single-cell RNA-seq to a CLL case, sampled at diagnosis and relapse, that was treated with FCR (Fludarabine, Cyclophosphamide, Rituximab) and underwent a dramatic decrease in CD19 expression during disease progression. Computational analyses revealed a major switch in clones’ dominance during treatment. The clone that expanded at relapse showed 17p and 3p chromosomal deletions, and up-regulation of pathways related to motility, cytokine signaling and antigen presentation. Single-cell RNA-seq uniquely revealed that this clone was already present at low frequency at diagnosis, and it displays feature of plasma cell differentiation, consistent with a more aggressive phenotype. This study shows the benefit of single-cell profiling of CLL heterogeneity at diagnosis, to identify clones that might otherwise not be recognized and to determine the best treatment options.

Effect of Ibrutinib on the IFN Response of Chronic Lymphocytic Leukemia Cells

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has profound activity in chronic lymphocytic leukemia (CLL) but limited curative potential by itself. Residual signaling pathways that maintain survival of CLL cells might be targeted to improve ibrutinib's therapeutic activity, but the nature of these pathways is unclear. Ongoing activation of IFN receptors in patients on ibrutinib was suggested by the presence of type I and II IFN in blood together with the cycling behavior of IFN-stimulated gene (ISG) products when IFN signaling was blocked intermittently with the JAK inhibitor ruxolitinib. IFN signaling in CLL cells from human patients was not prevented by ibrutinib in vitro or in vivo, but ISG expression was significantly attenuated in vitro. ISGs such as CXCL10 that require concomitant activation of NF-κB were decreased when this pathway was inhibited by ibrutinib. Other ISGs, exemplified by LAG3, were decreased as a result of inhibited protein translation. Effects of IFN on survival remained intact as type I and II IFN-protected CLL cells from ibrutinib in vitro, which could be prevented by ruxolitinib and IFNR blocking Abs. These observations suggest that IFNs may help CLL cells persist and specific targeting of IFN signaling might deepen clinical responses of patients on ibrutinib.

B cell signalling pathways-New targets for precision medicine in chronic lymphocytic leukaemia

The B cell receptor (BCR) is a master regulator of B cells, controlling cellular processes such as proliferation, migration and survival. Cell signalling downstream of the BCR is aberrantly activated in the B cell malignancy chronic lymphocytic leukaemia (CLL), supporting the pathophysiology of the disease. This insight has led to development and approval of small molecule inhibitors that target components of the BCR pathway. These advances have greatly improved the management of CLL, but the disease remains incurable. This may partly be explained by the inter-patient heterogeneity of the disease, also when it comes to treatment responses. Precision medicine is therefore required to optimize treatment and move towards a cure. Here, we discuss how the introduction of BCR signalling inhibitors has facilitated the development of functional in vitro assays to guide clinical treatment decisions on use of the same therapeutic agents in individual patients. The cellular responses to these agents can be analysed in high-throughput assays such as dynamic BH3 profiling, phospho flow experiments and drug sensitivity screens to identify predictive biomarkers. This progress exemplifies the positive synergy between basal and translational research needed to optimize patient care.

Relevant Cytokines in the B Cell Lymphoma Micro-Environment

Cytokines are soluble protein factors with importance in intercellular communication and, as such, play pivotal roles in the pathogenesis of B cell malignancies. Evidence from in vitro cultures permitted us to choose example cytokines that bind to different biochemical receptor types. Activated malignant B cells or stromal fibroblasts and macrophages prominently secrete the chemokines CCL3 or CXCL12 and CXCL13, respectively. Apart from helper T cells, various cell types of the B cell lymphoma microenvironment are capable of producing the cytokines IL-4, IL-6, IL-10 and TNFα. Owing to its impact on the development of myeloid cells, CSF-1 is among important soluble factors in the B cell lymphoma microenvironment. Inhibitors of B cell receptor-associated kinases often act via the blockade of cytokine production, but also prevent cytokine effects, e.g., chemotaxis. Increments in blood levels in chronic lymphocytic leukemia patients compared to healthy donors and normalization upon treatment with ibrutinib can be explained by producing cell types and modulation of cytokine production observed in vitro.

Peripheral cytokine levels as predictive biomarkers of benefit from immune checkpoint inhibitors in cancer therapy

Currently, only a small subset of cancer patients can benefit from anti-PD-1/PD-L1 monotherapy, indicating that further predictive biomarkers are needed. In the retrospective study, plasma samples were collected before anti-PD-L1/PD-L1 treatment in two subsets of patients. A total of 59 immunological factors, including cytokines, chemokines, and soluble immune checkpoints, were measured by using a multiplex immunoassay kit. Moreover, multiplex immunohistochemistry (mIHC) was performed in a subgroup of patients. In the discovery cohort, multiplex immunoassay profiling data revealed that both soluble PD-L1 and C-C motif chemokine 5 (CCL5/RANTES) showed rising trends across the three subgroups PD, SD and CR/PR. Further investigation demonstrated the predictive and prognostic value of the pre-treatment levels of PD-L1, CCL5/RANTES, and their combinatorial signature the "2-cytokine signature". As expected, the signature-high patients displayed a remarkably increased disease control rate (DCR) and prolonged survival versus that of the lower subgroup. More importantly, the relevance between the three signatures and the efficiency of immunotherapy was confirmed in the pan-cancer validation cohort. Notably, the significant association between the "2-cytokine signature" and longer survival was validated. Further quantitative analyses of the tumor microenvironment composition suggested a link between the "2-cytokine signature" and NK cell infiltration. In conclusion, a combined peripheral signature comprising CCL5/RANTES and soluble PD-L1 appears to be an effective biomarker to predict benefit from anti-PD-1/PD-L1 monotherapy. Our study underscores that peripheral immunological features may play an essential role in guiding patient selection and are worthy of future prospective investigations.

RACK1 promotes cancer progression by increasing the M2/M1 macrophage ratio via the NF-κB pathway in oral squamous cell carcinoma

Receptor for activated C kinase 1 (RACK1) has been shown to promote oral squamous cell carcinoma (OSCC) progression, and RACK1 expression levels have been negatively correlated with prognosis in patients with OSCC. Here, we investigated the impact of RACK1 OSCC expression on the recruitment and differentiation of tumor-associated macrophages. High RACK1 expression in OSCC cells correlated with increased M2 macrophage infiltration in tumor samples from a clinical cohort study. Moreover, the combination of RACK1 expression and the M2/M1 ratio could successfully predict prognosis in OSCC. OSCC cells with high RACK1 expression inhibited the migration of THP-1 cells, promoted M2-like macrophage polarization in vitro, and increased the proportion of M2-like macrophages in a xenograft mouse model. Moreover, both M1- and M2-like macrophage polarization-associated proteins were induced in macrophages cocultured with RACK1-silenced cell supernatant. A mechanistic study revealed that the expression and secretion of C-C motif chemokine 2 (CCL2), C-C motif chemokine 5 (CCL5), interleukin-6 (IL-6), and interleukin-1 (IL-1) are closely related to RACK1 expression. In addition, blocking nuclear factor-kappa B (NF-κB) could promote M2-like macrophage polarization. These results indicate that RACK1 and the M2/M1 ratio are predictors of a poor prognosis in OSCC. RACK1 promotes M2-like polarization by regulating NF-κB and could be used as a potential therapeutic target for antitumor immunity.

Clinico-Biological Implications of Modified Levels of Cytokines in Chronic Lymphocytic Leukemia: A Possible Therapeutic Role

B-cell chronic lymphocytic leukemia (B-CLL) is the main cause of mortality among hematologic diseases in Western nations. B-CLL is correlated with an intense alteration of the immune system. The altered functions of innate immune elements and adaptive immune factors are interconnected in B-CLL and are decisive for its onset, evolution, and therapeutic response. Modifications in the cytokine balance could support the growth of the leukemic clone via a modulation of cellular proliferation and apoptosis, as some cytokines have been reported to be able to affect the life of B-CLL cells in vivo. In this review, we will examine the role played by cytokines in the cellular dynamics of B-CLL patients, interpret the contradictions sometimes present in the literature regarding their action, and evaluate the possibility of manipulating their production in order to intervene in the natural history of the disease.

Immunoregulatory effects of Lurbinectedin in chronic lymphocytic leukemia

Despite significant therapeutic improvements chronic lymphocytic leukemia (CLL) remains an incurable disease and there is a persistent pursuit of new treatment alternatives. Lurbinectedin, a selective inhibitor of active transcription of protein-coding genes, is currently in phase II/III clinical trials for solid tumors such as small-cell lung cancer (SCLC). In this study, we aimed to evaluate the activity of Lurbinectedin on circulating mononuclear cells from CLL patients and to determine whether Lurbinectedin could affect the cross-talk between B-CLL cells and the tumor microenvironment. We found that Lurbinectedin induced a dose- and time-dependent death in all cell types evaluated, with B cells, monocytes and monocytic myeloid derived suppressor cells (Mo-MDSC) being the most susceptible populations. At sub-apoptotic doses, Lurbinectedin decreased the expression of CCR7 in B-CLL cells and impaired their migration towards CCL19 and CCL21. Furthermore, low concentrations of Lurbinectedin stimulated the synthesis of pro-IL1β in monocytes and nurse-like cells, without inducing the inflammasome activation. Altogether, these results indicate that Lurbinectedin might have antitumor activity in CLL due to its direct action on leukemic cells in combination with its effects on the tumor microenvironment. Our findings encourage further investigation of Lurbinectedin as a potential therapy for CLL.

TBET-expressing Th1 CD4+ T cells accumulate in chronic lymphocytic leukaemia without affecting disease progression in Eµ-TCL1 mice

Chronic lymphocytic leukaemia (CLL) is associated with alterations in T cell number, subset distribution and function. Among these changes, an increase in CD4⁺ T cells was reported. CD4⁺ T cells are a heterogeneous population and distinct subsets have been described to exert pro- and anti-tumour functions. In CLL, controversial reports describing the dominance of IFNγ-expressing Th1 T cells or of IL-4-producing Th2 T cells exist. Our study shows that blood of CLL patients is enriched in Th1 T cells producing high amounts of IFNγ. Moreover, we observed that their frequency remains relatively stable in CLL patients over a time course of five years. Furthermore, we provide evidence for an accumulation of Th1 T cells in the Eµ-TCL1 mouse model of CLL. As TBET (encoded by Tbx21) is a crucial transcription factor for Th1 polarization, we generated Tbx21^-/- bone marrow chimaeric mice which showed a lower number of IFNγ-producing Th1 T cells, and used them for adoptive transfer of Eµ-TCL1 leukaemia. Disease development in these mice was, however, comparable to that in wild-type controls, excluding a major role for TBET-expressing Th1 cells in Eµ-TCL1 leukaemia. Collectively, our data highlight that Th1 T cells accumulate in CLL but reducing their number has no impact on disease development.

Cirmtuzumab blocks Wnt5a/ROR1 stimulation of NF-κB to repress autocrine STAT3 activation in chronic lymphocytic leukemia

Coculture of nurse-like cells (NLCs) with chronic lymphocytic leukemia (CLL) cells induced leukemia cell phosphorylation of STAT3 (pSTAT3), which could be blocked by anti-Wnt5a antibodies or the anti-ROR1 monoclonal antibody, cirmtuzumab. Time-course studies revealed Wnt5a could induce activation of NF-κB within 30 minutes, but required more than 3 hours to induce pSTAT3. Culture of isolated CLL cells for 24 hours revealed Wnt5a-induced expression of interleukin 6 (IL-6), IL-8, CCL2, CCL3, CCL4, and CXCL1, which in turn could induce pSTAT3 in unstimulated CLL cells within 30 minutes. We found that Wnt5a could induce CLL cell expression of NF-κB target genes, including IL-6, and that this effect could be blocked by cirmtuzumab or drugs that inhibit NF-κB. Examination of CLL cells and plasma collected from patients treated with cirmtuzumab revealed reduced levels of phosphorylated p65 and diminished expression of NF-κB and STAT3 target genes in CLL cells, as well as lower plasma levels of IL-6, in the samples after therapy. Collectively, these studies indicate that Wnt5a/ROR1-dependent signaling contributes to CLL cell activation of NF-κB, which in turn causes autocrine IL-6-induced activation of pSTAT3. As such, this study demonstrates that cirmtuzumab can inhibit leukemia cell activation of both NF-κB and STAT3 in patients with CLL.

Mechanism for IL-15-Driven B Cell Chronic Lymphocytic Leukemia Cycling: Roles for AKT and STAT5 in Modulating Cyclin D2 and DNA Damage Response Proteins

Clonal expansion of B cell chronic lymphocytic leukemia (B-CLL) occurs within lymphoid tissue pseudofollicles. IL-15, a stromal cell-associated cytokine found within spleens and lymph nodes of B-CLL patients, significantly boosts in vitro cycling of blood-derived B-CLL cells following CpG DNA priming. Both IL-15 and CpG DNA are elevated in microbe-draining lymphatic tissues, and unraveling the basis for IL-15-driven B-CLL growth could illuminate new therapeutic targets. Using CpG DNA-primed human B-CLL clones and approaches involving both immunofluorescent staining and pharmacologic inhibitors, we show that both PI3K/AKT and JAK/STAT5 pathways are activated and functionally important for IL-15→CD122/ɣc signaling in ODN-primed cells expressing activated pSTAT3. Furthermore, STAT5 activity must be sustained for continued cycling of CFSE-labeled B-CLL cells. Quantitative RT-PCR experiments with inhibitors of PI3K and STAT5 show that both contribute to IL-15-driven upregulation of mRNA for cyclin D2 and suppression of mRNA for DNA damage response mediators ATM, 53BP1, and MDC1. Furthermore, protein levels of these DNA damage response molecules are reduced by IL-15, as indicated by Western blotting and immunofluorescent staining. Bioinformatics analysis of ENCODE chromatin immunoprecipitation sequencing data from cell lines provides insight into possible mechanisms for STAT5-mediated repression. Finally, pharmacologic inhibitors of JAKs and STAT5 significantly curtailed B-CLL cycling when added either early or late in a growth response. We discuss how the IL-15-induced changes in gene expression lead to rapid cycling and possibly enhanced mutagenesis. STAT5 inhibitors might be an effective modality for blocking B-CLL growth in patients.

Cerdulatinib Pharmacodynamics and Relationships to Tumor Response Following Oral Dosing in Patients with Relapsed/Refractory B-cell Malignancies

PURPOSE

Preclinical studies suggest SYK and JAK contribute to tumor-intrinsic and microenvironment-derived survival signals. The pharmacodynamics of cerdulatinib, a dual SYK/JAK inhibitor, and associations with tumor response were investigated.

PATIENTS AND METHODS

In a phase I dose-escalation study in adults with relapsed/refractory B-cell malignancies, cerdulatinib was administered orally to sequential dose-escalation cohorts using once-daily or twice-daily schedules. The study enrolled 8 patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), 13 with follicular lymphoma, 16 with diffuse large B-cell lymphoma (DLBCL), and 6 with mantle cell lymphoma. Correlation of tumor response with pharmacodynamic markers was determined in patients with meaningful clinical responses.

RESULTS

Following cerdulatinib administration, complete SYK and JAK pathway inhibition was achieved in whole blood of patients at tolerated exposures. Target inhibition correlated with serum cerdulatinib concentration, and IC₅₀ values against B-cell antigen receptor (BCR), IL2, IL4, and IL6 signaling pathways were 0.27 to 1.11 μmol/L, depending on the phosphorylation event. Significant correlations were observed between SYK and JAK pathway inhibition and tumor response. Serum inflammation markers were reduced by cerdulatinib, and several significantly correlated with tumor response. Diminished expression of CD69 and CD86 (B-cell activation markers), CD5 (negative regulator of BCR signaling), and enhanced expression of CXCR4 were observed in 2 patients with CLL, consistent with BCR and IL4 suppression and loss of proliferative capacity.

CONCLUSIONS

Cerdulatinib potently and selectively inhibited SYK/JAK signaling at tolerated exposures in patients with relapsed/refractory B-cell malignancies. The extent of target inhibition in whole-blood assays and suppression of inflammation correlated with tumor response. (ClinicalTrials.gov ID:NCT01994382).

The phase 3 DUO trial: duvelisib vs ofatumumab in relapsed and refractory CLL/SLL

Duvelisib (also known as IPI-145) is an oral, dual inhibitor of phosphatidylinositol 3-kinase δ and γ (PI3K-δ,γ) being developed for treatment of hematologic malignancies. PI3K-δ,γ signaling can promote B-cell proliferation and survival in clonal B-cell malignancies, such as chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). In a phase 1 study, duvelisib showed clinically meaningful activity and acceptable safety in CLL/SLL patients. We report here the results of DUO, a global phase 3 randomized study of duvelisib vs ofatumumab monotherapy for patients with relapsed or refractory (RR) CLL/SLL. Patients were randomized 1:1 to oral duvelisib 25 mg twice daily (n = 160) or ofatumumab IV (n = 159). The study met the primary study end point by significantly improving progression-free survival per independent review committee assessment compared with ofatumumab for all patients (median, 13.3 months vs 9.9 months; hazard ratio [HR] = 0.52; P < .0001), including those with high-risk chromosome 17p13.1 deletions [del(17p)] and/or TP53 mutations (HR = 0.40; P = .0002). The overall response rate was significantly higher with duvelisib (74% vs 45%; P < .0001) regardless of del(17p) status. The most common adverse events were diarrhea, neutropenia, pyrexia, nausea, anemia, and cough on the duvelisib arm, and neutropenia and infusion reactions on the ofatumumab arm. The DUO trial data support duvelisib as a potentially effective treatment option for patients with RR CLL/SLL. This trial was registered at www.clinicaltrials.gov as #NCT02004522.

A Comprehensive Safety Trial of Chimeric Antibody 14.18 With GM-CSF, IL-2, and Isotretinoin in High-Risk Neuroblastoma Patients Following Myeloablative Therapy: Children's Oncology Group Study ANBL0931

Purpose

A phase 3 randomized study (COG ANBL0032) demonstrated significantly improved outcome by adding immunotherapy with ch14.18 antibody to isotretinoin as post-consolidation therapy for high-risk neuroblastoma (NB). This study, ANBL0931, was designed to collect FDA-required safety/toxicity data to support FDA registration of ch14.18.

Experimental design

Newly diagnosed high-risk NB patients who achieved at least a partial response to induction therapy and received myeloablative consolidation with stem cell rescue were enrolled to receive six courses of isotretinoin with five concomitant cycles of ch14.18 combined with GM-CSF or IL2. Ch14.18 infusion time was 10–20 h per dose. Blood was collected for cytokine analysis and its association with toxicities and outcome.

Results

Of 105 patients enrolled, five patients developed protocol-defined unacceptable toxicities. The most common grade ≥ 3 non-hematologic toxicities of immunotherapy for cycles 1–5, respectively, were neuropathic pain (41, 28, 22, 31, 24%), hypotension (10, 17, 4, 14, 8%), allergic reactions (ARs) (3, 10, 5, 7, 2%), capillary leak syndrome (1, 4, 0, 2, 0%), and fever (21, 59, 6, 32, 5%). The 3-year event-free survival and overall survival were 67.6 ± 4.8% and 79.1 ± 4.2%, respectively. AR during course 1 was associated with elevated serum levels of IL-1Ra and IFNγ, while severe hypotension during this course was associated with low IL5 and nitrate. Higher pretreatment CXCL9 level was associated with poorer event-free survival (EFS).

Conclusion

This study has confirmed the significant, but manageable treatment-related toxicities of this immunotherapy and identified possible cytokine biomarkers associated with select toxicities and outcome. EFS and OS appear similar to that previously reported on ANBL0032.