Dynamic metabolic change of cancer cells induced by natural killer cells at single-cell level studied by label-free mass cytometry

Natural killer cell（NK cell）is an important immune cell which attracts increasing attention in cancer immunotherapy. Due to the heterogeneity of cells, individual cancer cell shows different resistance to NK cytotoxicity,...

Romidepsin in Conditioning and Maintenance Mitigates Relapse Risk and Enhances NK-Cell Cytotoxicity in Patients Receiving Allogeneic Stem Cell Transplant for Aggressive T-Cell Malignancies: Results of a Phase I/II Clinical Trial

Background: Allo-SCT is the only curative option for patients with high risk and relapsed/refractory T-cell malignancies. Even among allo-SCT recipients, survival is less than 50% and relapse rates are 55-60%. We developed a clinical trial to decrease relapse after allo-SCT for these patients using romidepsin (rom), a histone deacetylase inhibitor approved for the treatment of relapsed T-cell lymphomas. Based on pre-clinical data demonstrating enhanced and synergistic cell killing with the addition of rom to busulfan (Bu) and fludarabine (Flu) in malignant T-cells, we created a novel transplant regimen (BuFluRom). We hypothesized this regimen, coupled with maintenance rom (m-rom), would enhance malignant T-cell killing, eradicate MRD at transplant, decrease relapse, and stimulate the GVL effect by stimulating NK-cells. Here we present results of this clinical trial, with correlative data evaluating NK-cytotoxicity. This is the first trial designed specifically to treat T-cell malignancies with allo-SCT. (NCT02512497) Methods: This is a phase I/II clinical trial. Eligible patients had: a diagnosis of T-cell leukemia (including T-acute lymphoblastic leukemia) or T-cell lymphoma (cutaneous or peripheral) in at least a partial remission requiring an allo-SCT, <70 years of age, with a matched sibling/unrelated donor. The primary objective was to determine the recommended phase 2 dose (RP2D) of rom from 3 dose levels (1, 2, 3 mg/m2) when combined with BuFlu (AUC 20000 or 16000, Figure). Patients received standard tacrolimus/methotrexate GVHD prophylaxis with ATG for MUDs. Once RP2D was determined, an expansion cohort of up to 30 patients (total) was included. M-rom was initiated between day +28 and +100 for 1 year (2 years max). The effect of rom on NK-cell cytotoxicity was assessed on samples taken pre-transplant, and 1, 3, 6, 12 months post allo-SCT. NK cytotoxicity was assessed by isolating mononuclear cells from patient samples and targeting them against K562 and T-cell lymphoma targets using the calcein-AM assay. Fine-Gray models were used to estimate PFS, OS, and cumulative incidence, and compare survival curves across groups. Results: 21 patients have been enrolled (Table). One DLT was observed (VOD), at dose level 2, and the RP2D of rom in conditioning was determined to be 2 mg/m2. With a median follow-up time of 10.1 months, the median OS has not been reached (3.3-NR months), with a 1 and 3-year OS probability of 62.8% & 55.8%. The median PFS is 28.2 months (3.8-28.1), with 1 and 3 year PFS of 57% & 30.4%. Cumulative incidence (CI) of NRM at day 100 and 1 year were 14.8% and 20%. CI of grade II-IV aGHVD and extensive cGVHD were 47.6% and 18.5%. The CI of relapse (CIR) was 22.8% at 1 year (95% CI 6.6-44.9%). There was no difference between PFS among patients with MRD versus those without MRD prior to transplant (p=0.96), and no difference in 1-year CIR (p=0.9). PFS and CIR at 1 year was substantially better in the lymphoma than leukemia patients (85.7% vs 44%, p=0.049), and (0% vs 32.1%, p=0.05). No patients with PTCL relapsed, and 3/5 patients with T-PLL are alive, disease free. 13/21 (62%) of patients received m-rom with a median number of 10 cycles (range 1-41). (Table) 7 patients experienced grade 3/4 adverse events (AE), though no patients discontinued m-rom due to toxicity. NK-cytotoxicity was higher at each time point in patients who received m-rom compared to those who did not, though there were insufficient patients to reach statistical significance. When NK-cytotoxicity was assessed between the two groups after starting maintenance, NK-cytotoxicity in the m-rom group was significantly higher than in those without m-rom (p=0.05) (Figure). Conclusions: BuFluRom with m-rom is effective at decreasing relapse in patients with T-cell malignancies, with 1-year CI relapse below expected relapse rates for this set of diseases. Toxicities were similar to standard BuFlu alone and the RP2D of rom in conditioning was established at 2 m g/m2. Intriguingly, BuFluRom mitigated the poor outcomes of patients with MRD prior to transplant. Further, early data suggests m-rom enhances NK-cell cytotoxicity post allo-SCT, potentially augmenting the GVL effect and accounting for decreased relapse rates. Long-term follow-up is needed to evaluate these results, but these results suggest the BuFluRom regimen with m-rom could become a new option for patients receiving allo-SCT for T-cell malignancies to mitigate relapse. Figure 1 Figure 1. Disclosures Hosing: Nkarta Therapeutics: Membership on an entity's Board of Directors or advisory committees. Popat: Bayer: Research Funding; Abbvie: Research Funding; Novartis: Research Funding; Incyte: Research Funding. Vasu: Boehringer Ingelheim: Other: Travel support; Seattle Genetics: Other: travel support; Kiadis, Inc.: Research Funding; Omeros, Inc.: Membership on an entity's Board of Directors or advisory committees. de Lima: Miltenyi Biotec: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. William: Dova Pharmaceuticals: Research Funding; Incyte: Research Funding; Kyowa Kirin: Consultancy; Merck: Research Funding; Guidepoint Global: Consultancy. Lee: Kiadis Pharma: Divested equity in a private or publicly-traded company in the past 24 months, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Courier Therapeutics: Current holder of individual stocks in a privately-held company. Brammer: Kymera Therapeutics: Consultancy; Celgene: Research Funding; Seattle Genetics: Speakers Bureau.

Cordycepin Sensitizes Cholangiocarcinoma Cells to Be Killed by Natural Killer-92 (NK-92) Cells

Immunotherapy harnessing immune functions is a promising strategy for cancer treatment. Tumor sensitization is one approach to enhance tumor cell susceptibility to immune cell cytotoxicity that can be used in combination with immunotherapy to achieve therapeutic efficiency. Cordycepin, a bioactive compound that can be extracted from some Cordyceps spp. has been reported to effectively inhibit tumor growth, however, the mechanism of its tumor sensitization activity that enhances immune cell cytotoxicity is unknown. In the present study, we investigated the potency of cordycepin to sensitize a lethal cancer, cholangiocarcinoma (CCA), to natural killer (NK) cells. Treatment with cordycepin prior to and during co-culturing with NK-92 cells significantly increased cell death of KKU-213A as compared to solitary cordycepin or NK treatment. Moreover, sensitization activity was also observed in the combination of NK-92 cells and Cordyceps militaris extract that contained cordycepin as a major component. The cordycepin treatment remarkably caused an increase in TRAIL receptor (DR4 and DR5) expression in KKU-213A, suggesting the possible involvement of TRAIL signaling in KKU-213A sensitization to NK-92 cells. In conclusion, this is the first report on the sensitization activity of cordycepin on CCA cells to NK cytotoxicity, which supports that cordycepin can be further developed as an alternate immunomodulating agent.

A History of Endometriosis Is Associated With Decreased Peripheral NK Cytotoxicity and Increased Infiltration of Uterine CD68+ Macrophages

Women with endometriosis may have a defective immune system. However, evidence of the immune responses of endometriosis patients with a history of endometriosis surgery is lacking, and the association between the location of endometriosis lesions and immune responses is unclear. This retrospective study included 117 females with reproductive failure and a history of endometriosis and 200 females with reproductive failure but without endometriosis to analyze their endometrial and peripheral immune responses. The results show that endometriosis was associated with decreased peripheral natural killer (NK) cytotoxicity and increased uterine macrophages. Peripheral NK cytotoxicity at effector-to-target ratios of 25:1 and 50:1 was significantly reduced in women with a history of endometriosis from that of the control group (26.6% versus 33.3% and 36.1% versus 43.3%, respectively, both P < 0.001). Furthermore, after further division of patients into three subgroups according to the location of endometriosis lesions, we observed that NK cytotoxicity in the endometriosis subgroups, especially the mixed endometriosis group, was strongly decreased from that of the controls (P = 0.001). The endometrial CD68+ macrophage proportion in the mixed endometriosis subgroup was higher than that in the control group (2.8% versus 2.1%, P = 0.043). In addition, the baseline estradiol (E2) level was weakly correlated with the percentage of endometrial macrophages (r = 0.251, P = 0.009), indicating a potential association among the endocrine system, endometrial immune environment, and endometriosis. This study indicated that peripheral NK cytotoxicity and endometrial immune cell profiles could be useful for diagnosing and treating endometriosis and endometriosis-related reproductive diseases.

P–423 Lower cytotoxicity: Altered natural killer cell activation in recurrent implantation failure

Study question Within this prospective study, we aim to differentiate immune cell subpopulations in recurrent implantation failure (RIF) patients and fertile controls. Summary answer A misbalanced immune profile of NK cell subpopulations is present in RIF patients and might be a potential risk factor that requires further detailed analysis. What is known already So far, there is no conclusive opinion on the prognostic value of testing immune cell populations in women with RIF. Increased numbers of cytotoxic (CD56dimCD16bright) peripheral natural killer (pNK)-cells and CD56brightCD16dim mainly in the uterus occurring NK cells (uNK) seemed to be more prevalent in RIF patients. NK cell cytotoxicity is regulated by a complex interaction of activating and inhibiting receptors, such as the NKGD2 and natural cytotoxicity receptors including NKp46, NKp30 and NKp44. Dysregulated pNK cells could affect the adhesion and implantation of the embryo thereby contributing to RIF. Study design, size, duration Within this prospective study between March 2018 and August 2020 immune diagnostics of pNK cells and subpopulations as well as regulatory T-cells in RIF patients (defined as ≥ 3 failed fresh or frozen embryo transfers of good quality embryos (Istanbul criteria) and non-pregnant controls (nulli- and multipara) were performed using flow cytometry analysis. Participants/materials, setting, methods In total, n = 42 RIF and n = 85 controls were included. Absolute numbers and percentages of total lymphocytes of CD56dimCD16bright, CD56brightCD16dim NK cells, CD45+CD25+FoxP3+-regulatory T-cells and activation markers (CD57+, CD62L+, NKGD2+, NKp46+) were measured in patients and controls (n = 60 nulligravida, n = 25 para) in the mid-luteal phase. Statistical analysis was performed using SPSS Version 26 considering p < 0.05 statistically significant. Main results and the role of chance RIF patients showed significantly lower numbers and percentages of CD56dimCD16bright pNK cells (mean±SD per µl: 187,5±113,3 vs. 281,9±163,4 p = 0.001;%: 87,4±8,8 vs. 90,6±6,0 p = 0.017) and higher levels of CD56brightCD16dim pNK cells (mean±SD per%: 10,5±8,3 vs. 7,6±5,5 p = 0.021) compared to controls. Further, lower percentages of CD56dimCD16brightCD62L + (mean±SD per%: 23,5±11,1 vs. 32,0±14,0 p = 0.001), CD56dimCD16brightNKGD2 + (mean±SD per%: 94,0±6,8 vs. 96,4±4,2 p = 0.014) and CD56dimCD16brightNKp46 + (mean±SD per%: 65,8±19,5 vs. 76,1±14,0 p = 0.001) were observed in RIF patients (p < 0.05). A different activation of pNK cells represented by high levels of CD62L+, NKGD2+, NKp46+ surface markers in controls and higher levels of CD56brightCD16dim pNK cells in RIF patients could contribute to RIF. No difference was present in levels of CD45+CD25+FoxP3+-regulatory T-cells within the study population. Limitations, reasons for caution As controls composed out of not only nulli- but also multipara, higher levels of pNK cells in controls, could be induced by fetal microchimerism in multiparas, however, results remained significant after removing multipara from statistical analysis. Wider implications of the findings: These findings condense into the assumption of a non-linear association between NK cytotoxicity and successful pregnancy. A lower NK cytotoxicity in RIF patients could potentially lead to an altered immune environment impeding a successful implantation process. Trial registration number Drks00020803

Coexistence of inhibitory and activating killer-cell immunoglobulin-like receptors to the same cognate HLA-C2 and Bw4 ligands confer breast cancer risk

Human leukocyte antigen (HLA) class I-specific killer-cell immunoglobulin-like receptors (KIR) regulate natural killer (NK) cell function in eliminating malignancy. Breast cancer (BC) patients exhibit reduced NK-cytotoxicity in peripheral blood. To test the hypothesis that certain KIR-HLA combinations impairing NK-cytotoxicity predispose to BC risk, we analyzed KIR and HLA polymorphisms in 162 women with BC and 278 controls. KIR-Bx genotypes increased significantly in BC than controls (83.3% vs. 71.9%, OR 1.95), and the increase was more pronounced in advanced-cancer (OR 5.3). No difference was observed with inhibitory KIR (iKIR) and HLA-ligand combinations. The activating KIR (aKIR) and HLA-ligand combinations, 2DS1 + C2 (OR 2.98) and 3DS1 + Bw4 (OR 2.6), were significantly increased in advanced-BC. All patients with advanced-cancer carrying 2DS1 + C2 or 3DS1 + Bw4 also have their iKIR counterparts 2DL1 and 3DL1, respectively. Contrarily, the 2DL1 + C2 and 3DL1 + Bw4 pairs without their aKIR counterparts are significantly higher in controls. These data suggest that NK cells expressing iKIR to the cognate HLA-ligands in the absence of putative aKIR counterpart are instrumental in antitumor response. These data provide a new framework for improving the utility of genetic risk scores for individualized surveillance.

MITF induces escape from innate immunity in melanoma

Background The application of immune-based therapies has revolutionized cancer treatment. Yet how the immune system responds to phenotypically heterogeneous populations within tumors is poorly understood. In melanoma, one of the major determinants of phenotypic identity is the lineage survival oncogene MITF that integrates diverse microenvironmental cues to coordinate melanoma survival, senescence bypass, differentiation, proliferation, invasion, metabolism and DNA damage repair. Whether MITF also controls the immune response is unknown. Methods By using several mouse melanoma models, we examine the potential role of MITF to modulate the anti-melanoma immune response. ChIP-seq data analysis, ChIP-qPCR, CRISPR-Cas9 genome editing, and luciferase reporter assays were utilized to identify ADAM10 as a direct MITF target gene. Western blotting, confocal microscopy, flow cytometry, and natural killer (NK) cytotoxicity assays were used to determine the underlying mechanisms by which MITF-driven phenotypic plasticity modulates melanoma NK cell-mediated killing. Results Here we show that MITF regulates expression of ADAM10, a key sheddase that cleaves the MICA/B family of ligands for NK cells. By controlling melanoma recognition by NK-cells MITF thereby controls the melanoma response to the innate immune system. Consequently, while melanoma MITFLow cells can be effectively suppressed by NK-mediated killing, MITF-expressing cells escape NK cell surveillance. Conclusion Our results reveal how modulation of MITF activity can impact the anti-melanoma immune response with implications for the application of anti-melanoma immunotherapies.

Natural-killer cell cytotoxicity as a diagnostic and prognostic marker for adult patients with secondary hemophagocytic lymphohistiocytosis: a prospective phase II observational study

Background: Hemophagocytic lymphohistiocytosis (HLH) can be life-threatening if not detected and treated appropriately. The diagnosis of HLH can be confusing due to other similar febrile diseases that present with cytopenia. Natural-killer cell (NK)-cytotoxicity is an important diagnostic parameter for primary HLH; however, its role in secondary HLH in adults has not been well-elucidated. Methods: We prospectively enrolled 123 adult patients with febrile conditions accompanied by cytopenia or marrow hemophagocytosis. A diagnosis of HLH was based on HLH-2004 criteria and treated based on HLH-94 protocol. NK-cytotoxicity was calculated at the time of diagnosis by K562-cell direct lysis using flow-cytometry. Results: HLH ( n = 60) was determined to be caused by Epstein–Barr virus (EBV) ( n = 11), infection other than EBV ( n = 16), malignancies ( n = 19), and unknown ( n = 14). Febrile diseases other than HLH ( n = 63) were diagnosed as autoimmune disease ( n = 22), malignancies ( n = 21), infection ( n = 12), non-malignant hematological diseases ( n = 6), and unknown ( n = 2). A lower NK-cytotoxicity level was observed at diagnosis in patients with HLH, compared with other causes of febrile disease (12.1% versus 26.2%, p < 0.001). However, NK-cytotoxicity had a borderline effect on diagnosis of HLH, with an area under receiver operation characteristic curve of 0.689. It also showed no significant role for the prediction of survival outcome. Multivariate analysis revealed that malignant disease and high ferritin level were related with poor survival outcome. In non-malignant disease subgroups, old age, EBV-association, and low NK-cytotoxicity were related with poor survival. Conclusions: Febrile disease with cytopenia was associated with decreased NK-cytotoxicity, especially in adults with HLH; however, its diagnostic role for adult HLH is still arguable. The diagnostic criteria for adult HLH should be further discussed. Trial registration: Clinical Research Information Service [Internet]; Osong (Chungcheongbuk-do), Korea, Centers for Disease Control and Prevention, Ministry of Health and Welfare (Republic of Korea); https://cris.nih.go.kr/cris/index.jsp ; Feb, 16th 2016; KCT0001886 (KC15TISE0936);