Expansion and activation of natural killer cells from PBMC for immunotherapy of hepatocellular carcinoma

Exploiting the immune system in hepatic tumor targeting: Unleashing the potential of drugs, natural products, and nanoparticles

Hepatic tumors present a formidable challenge in cancer therapeutics, necessitating the exploration of novel treatment strategies. In recent years, targeting the immune system has attracted interest to augment existing therapeutic efficacy. The immune system in hepatic tumors includes numerous cells with diverse actions. CD8+ T lymphocytes, T helper 1 (Th1) CD4+ T lymphocytes, alternative M1 macrophages, and natural killer (NK) cells provide the antitumor immunity. However, Foxp3+ regulatory CD4+ T cells (Tregs), M2-like tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs) are the key immune inhibitor cells. Tumor stroma can also affect these interactions. Targeting these cells and their secreted molecules is intriguing for eliminating malignant cells. The current review provides a synopsis of the immune system components involved in hepatic tumor expansion and highlights the molecular and cellular pathways that can be targeted for therapeutic intervention. It also overviews the diverse range of drugs, natural products, immunotherapy drugs, and nanoparticles that have been investigated to manipulate immune responses and bolster antitumor immunity. The review also addresses the potential advantages and challenges associated with these approaches.

Adoptive NK-cell transfer as a potential treatment paradigm for Wilms tumor: A preclinical study

BACKGROUND

Natural killer (NK) cell therapy has been shown to be effective in the treatment of some cancers. However, the effects of this adoptive immunotherapy have not been investigated for Wilms tumor (WT). In this study, the effects of adoptive NK-cell transfer on a patient-derived xenograft (PDX) model of anaplastic WT were evaluated, and the impacts of cell source and ex vivo activation strategy on the therapeutic efficacy of NK-cell product were appraised.

METHODS

NK cells were isolated from human peripheral blood mononuclear cells (NK_PB ) and human cord blood (NK_CB ), and were expanded and activated using a cytokine cocktail. Another group of NK cells (NK_ET ) was produced through activation with the exosomes extracted from previously challenged NK_PB cells with WT. PDX-bearing mice were treated with clinically relevant doses of NK_PB , NK_CB , NK_ET , standard chemotherapy, and placebo (phosphate-buffered saline).

RESULTS

PDX models treated with NK_CB showed a better survival rate, though the difference among the study groups was not significant. Compared with the placebo control group, NK_CB significantly improved the histopathologic response, NK_PB significantly inhibited the proliferation of neoplastic cells, and NK_ET led to a significant decrease in the metastasis score (all p-values <.05). Standard chemotherapy provided the greatest tumor growth inhibition and the lowest mitotic count, though it did not show any significant advantage over NK-cell therapies in any of the outcome parameters in two-by-two comparisons.

CONCLUSIONS

This study spotlights the efficacy of adoptive NK-cell transfer as a potential treatment candidate for high-risk WT.

[Construction and evaluation of dual-effect cord blood natural killer cells expressing highaffinity PD-1 and chimeric antigen CD19 receptor]

OBJECTIVE

To obtain novel dual-effect cord blood natural killer cells (CBNKCs) expressing high-affinity PD-1 (HAPD1) and chimeric antigen CD19 receptor (CAR) to improve the effect of CAR-based immunotherapy.

METHODS

A dual-effect lentiviral vector expressing both HAPD1 and CAR targeting CD19 was constructed. CBNKCs were infected with the vector to obtain HAPD1 CAR19 CBNKCs. The surface markers of the cells including CD3-/CD16+CD56+, CD3+/CD16+CD56+, CD3+/CD4+, and CD3+/CD8+ were tested during cell proliferation. The cytotoxicity of CBNKCs, CAR19 CBNKCs and HAPD1 CAR19 CBNKCs incubated with CD19-positive target cells at the effector-target ratios of 5∶1, 10∶1 and 20∶1 was tested on days 7, 9, 12, and 15 of cell culture. The cytotoxicity of the cells against the target cells was also tested in NPG mice.

RESULTS

CBNKCs were successfully transduced with T-cell designed CAR19 and HAPD1 CAR19 with an efficiency of (18.63±1.88)%. Infection with the lentiviral vector significantly reduced the cell expansion efficiency of the CBNKCs (10.97±2.77 vs 24.84±3.17, P < 0.05) but did not significantly affect the expressions of the surface markers (P>0.05). HAPD1 CAR CBNKCs showed stronger anti-tumor effect than CAR19 CBNKCs [(68.38±8.08)% vs (49.65±13.60)% at the effector-target ratios of 5∶1 and (79.11±7.42)% vs (59.78 ± 9.32)% at 10∶1; P < 0.05]. The infected CBNKCs showed the strongest cytotoxicity at 9 and 12 days after lentivirus infection. In the mouse models, transplantation of the dual-effect cells resulted in a significantly lower percentage of tumor cells in white blood cells than transplantation CAR-CBNKCs [(19.21 ± 3.07%) vs (29.08 ± 3.15)%, P < 0.05].

CONCLUSION

We obtained a novel dual-effect CBNKC co-expressing HAPD1 and CAR. The cells show strong cytotoxicity against the target tumor cells both in vitro and in vivo, which sheds light on a new strategy of immunotherapy against tumor cells.

Adoptive transfer of placental ischemia-stimulated natural killer cells causes a preeclampsia-like phenotype in pregnant rats

PROBLEM

The Reduced Uterine Perfusion Pressure (RUPP) rat model of placental ischemia recapitulates many characteristics of preeclampsia including maternal hypertension, intrauterine growth restriction (IUGR), and increased cytolytic natural killer cells (cNKs). While we have previously shown a 5-fold higher cytotoxicity of RUPP NKs versus normal pregnant NKs, their role in RUPP pathophysiology remains unclear. In this study, we tested the hypotheses that (1) adoptive transfer of RUPP-stimulated NKs will induce maternal hypertension and IUGR in normal pregnant control (Sham) rats and (2) adoptive transfer of Sham NKs will attenuate maternal hypertension and IUGR in RUPP rats.

METHOD OF STUDY

On gestation day (GD)14, vehicle or 5 × 106 RUPP NKs were infused i.v. into a subset of Sham rats (Sham+RUPP NK), and vehicle or 5 × 106 Sham NKs were infused i.v. into a subset of RUPP rats (RUPP+Sham NK; n = 12/group). On GD18, Uterine Artery Resistance Index (UARI) was measured. On GD19, mean arterial pressure (MAP) was measured, animals were sacrificed, and blood and tissues were collected for analysis.

RESULTS

Adoptive transfer of RUPP NKs into Sham rats resulted in elevated NK activation, UARI, placental oxidative stress, and preproendothelin expression as well as reduced circulating nitrate/nitrite. This led to maternal hypertension and IUGR. RUPP recipients of Sham NKs demonstrated normalized NK activation, sFlt-1, circulating and placental VEGF, and UARI, which led to improved maternal blood pressure and normal fetal growth.

CONCLUSION

These data suggest a direct role for cNKs in causing preeclampsia pathophysiology and a role for normal NKs to improve maternal outcomes and IUGR during late gestation.

Adult peripheral blood and umbilical cord blood NK cells are good sources for effective CAR therapy against CD19 positive leukemic cells

Among hematological cancers, Acute Lymphoblastic Leukemia (ALL) and Chronic Lymphocytic Leukemia (CLL) are the most common leukemia in children and elderly people respectively. Some patients do not respond to chemotherapy treatments and it is necessary to complement it with immunotherapy-based treatments such as chimeric antigen receptor (CAR) therapy, which is one of the newest and more effective treatments against these cancers and B-cell lymphoma. Although complete remission results are promising, CAR T cell therapy presents still some risks for the patients, including cytokine release syndrome (CRS) and neurotoxicity. We proposed a different immune cell source for CAR therapy that might prevent these side effects while efficiently targeting malignant cells. NK cells from different sources are a promising vehicle for CAR therapy, as they do not cause graft versus host disease (GvHD) in allogenic therapies and they are prompt to attack cancer cells without prior sensitization. We studied the efficacy of NK cells from adult peripheral blood (AB) and umbilical cord blood (CB) against different target cells in order to determine the best source for CAR therapy. AB CAR-NK cells are slightly better at killing CD19 presenting target cells and CB NK cells are easier to stimulate and they have more stable number from donor to donor. We conclude that CAR-NK cells from both sources have their advantages to be an alternative and safer candidate for CAR therapy.

Natural Killer Cell Expansion with Autologous Feeder Layer and Anti-CD3 Antibody for Immune Cell Therapy of Hepatocellular Carcinoma

Background:

one of the promising approaches for treatment of some cancers is adoptive cell therapy using natural killer (NK) cells. Various methods have been investigated for ex vivo expansion of NK cells in large-scale, but most of them involved cancer or genetically modified cells as feeder layer and also some of them have the risk of T cell contamination and graft-versus-host disease (GVHD).

Method:

In this study, irradiated autologous peripheral blood mononuclear cells (PBMCs) as feeder layer with an anti-CD3 monoclonal antibody (mAb) were used. For activation and expansion of NK cells, human recombinant IL2 and IL15 were used. After co-culturing of expanded NK cells (eNKC) and isolated NK cells (iNKC) with hepatocellular carcinoma (HCC) cells, the viability of eNKC in compared to iNKC were analyzed by CCK-8 assay and degranulation of NK cells after co-culturing was assayed by measuring CD107a expression. Enzyme-Linked Immunosorbent Assay (ELISA) assay was used for the ability of NK cells to secretion of IFN-γ (interferon-γ) and TNF-α (Tumor Necrosis Factor-α) after co-culture with HCC cells. Real Time PCR analysis was used for expression of human Perforin and Granzyme B genes in the NK cells exposed to target HepG2 cells.

Result:

This method strongly expanded highly purified NK cells with powerful cytotoxicity against HCC cells. The expanded NK cells showed high level of expression of degranulation marker and human Perforin and Granzyme B genes, and also was secreted larger amounts of TNF-α and IFN-γ compared with fresh isolated NK cells.

Conclusion:

we proposed an effective method for expansion of cytotoxic NK cells using irradiated autologous PBMC as feeder layer for more successful transfer of allogeneic NK cell in immuno cell therapy of HCC.

Phenotypic and functional stability of leukocytes from human peripheral blood samples: considerations for the design of immunological studies

Background

Human peripheral blood mononuclear cells (PBMCs) are extensively used for research of immune cell functions, identification of biomarkers and development of diagnostics and therapeutics for human diseases, among others. The assumption that “old blood samples” are not appropriate for isolation of PBMCs for functional assays has been a dogma in the scientific community. However, partial data on the impact of time after phlebotomy on the quality and stability of human PBMCs preparations impairs the design of studies in which time-controlled blood sampling is challenging such as field studies involving multiple sampling centers/sites. In this study, we evaluated the effect of time after phlebotomy over a 24 h time course, on the stability of human blood leukocytes used for immunological analyses. Blood samples from eight healthy adult volunteers were obtained and divided into four aliquots, each of which was left in gentle agitation at room temperature (24 °C) for 2 h (control), 7 h, 12 h and 24 h post phlebotomy. All samples at each time point were independently processed for quantification of mononuclear cell subpopulations, cellular viability, gene expression and cytokine secretion.

Results

A 24 h time delay in blood sample processing did not affect the viability of PBMCs. However, a significantly lower frequency of CD3+ T cells (p < 0.05) and increased LPS-induced CXCL10 secretion were observed at 12 h post-phlebotomy. Alterations in TNFα, CCL8, CCR2 and CXCL10 gene expression were found as early as 7 h after blood sample procurement.

Conclusions

These data reveal previously unrecognized early time-points for sample processing control, and provide an assay-specific time reference for the design of studies that involve immunological analyses of human blood samples.

Electronic supplementary material

The online version of this article (10.1186/s12865-019-0286-z) contains supplementary material, which is available to authorized users.

The Notch Signaling Pathway Is Balancing Type 1 Innate Lymphoid Cell Immune Functions

The Notch pathway is one of the canonical signaling pathways implicated in the development of various solid tumors. During carcinogenesis, the Notch pathway dysregulation induces tumor expression of Notch receptor ligands participating to escape the immune surveillance. The Notch pathway conditions both the development and the functional regulation of lymphoid subsets. Its importance on T cell subset polarization has been documented contrary to its action on innate lymphoid cells (ILC). We aim to analyze the effect of the Notch pathway on type 1 ILC polarization and functions after disruption of the RBPJk-dependent Notch signaling cascade. Indeed, type 1 ILC comprises conventional NK (cNK) cells and type 1 helper innate lymphoid cells (ILC1) that share Notch-related functional characteristics such as the IFNg secretion downstream of T-bet expression. cNK cells have strong antitumor properties. However, data are controversial concerning ILC1 functions during carcinogenesis with models showing antitumoral capacities and others reporting ILC1 inability to control tumor growth. Using various mouse models of Notch signaling pathway depletion, we analyze the effects of its absence on type 1 ILC differentiation and cytotoxic functions. We also provide clues into its role in the maintenance of immune homeostasis in tissues. We show that modulating the Notch pathway is not only acting on tumor-specific T cell activity but also on ILC immune subset functions. Hence, our study uncovers the intrinsic Notch signaling pathway in ILC1/cNK populations and their response in case of abnormal Notch ligand expression. This study help evaluating the possible side effects mediated by immune cells different from T cells, in case of multivalent forms of the Notch receptor ligand delta 1 treatments. In definitive, it should help determining the best novel combination of therapeutic strategies in case of solid tumors.

Shaping of Natural Killer Cell Antitumor Activity by Ex Vivo Cultivation

Natural killer (NK) cells are a promising tool for the use in adoptive immunotherapy, since they efficiently recognize and kill tumor cells. In this context, ex vivo cultivation is an attractive option to increase NK cells in numbers and to improve their antitumor potential prior to clinical applications. Consequently, various strategies to generate NK cells for adoptive immunotherapy have been developed. Here, we give an overview of different NK cell cultivation approaches and their impact on shaping the NK cell antitumor activity. So far, the cytokines interleukin (IL)-2, IL-12, IL-15, IL-18, and IL-21 are used to culture and expand NK cells. The selection of the respective cytokine combination is an important factor that directly affects NK cell maturation, proliferation, survival, distribution of NK cell subpopulations, activation, and function in terms of cytokine production and cytotoxic potential. Importantly, cytokines can upregulate the expression of certain activating receptors on NK cells, thereby increasing their responsiveness against tumor cells that express the corresponding ligands. Apart from using cytokines, cocultivation with autologous accessory non-NK cells or addition of growth-inactivated feeder cells are approaches for NK cell cultivation with pronounced effects on NK cell activation and expansion. Furthermore, ex vivo cultivation was reported to prime NK cells for the killing of tumor cells that were previously resistant to NK cell attack. In general, NK cells become frequently dysfunctional in cancer patients, for instance, by downregulation of NK cell activating receptors, disabling them in their antitumor response. In such scenario, ex vivo cultivation can be helpful to arm NK cells with enhanced antitumor properties to overcome immunosuppression. In this review, we summarize the current knowledge on NK cell modulation by different ex vivo cultivation strategies focused on increasing NK cytotoxicity for clinical application in malignant diseases. Moreover, we critically discuss the technical and regulatory aspects and challenges underlying NK cell based therapeutic approaches in the clinics.

IL-17C/IL-17RE Augments T Cell Function in Autoimmune Hepatitis

Autoimmune hepatitis is a worldwide health problem and significant cause of mortality. However, the disease etiology is largely unknown, which accounts for ineffective treatment and uncontrolled disease progression. In this study, we demonstrated the functional importance of the IL-17C/IL-17RE axis in Con A-induced hepatitis. Elevated IL-17C expression was detected in liver samples of both human and mouse autoimmune hepatitis. IL-17C, produced by hepatocytes, and its specific receptor IL-17RE on liver-resident T cells were both found to be required in Con A-induced liver damage. Mechanistically, IL-17C augmented the expression of IL-2 by intrahepatic CD4+ T cells to promote NK cell activation and liver damage. To our knowledge, our findings thus for the first time defined the indispensable role of IL-17C/IL-17RE in autoimmune hepatitis; this axis may serve as a novel drug target for the treatment of this disease.

Potential immunotherapeutic role of interleukin-2 and interleukin-12 combination in patients with hepatocellular carcinoma

Background

Many recent therapeutic interventions are necessary to improve the treatment of hepatocellular carcinoma (HCC), including immunotherapy, which seems to offer one of the new realistic therapeutic modalities. This study aims to investigate the optimization of immunotherapy for HCC patients by appraisal of both interferon (IFN)-γ levels and phenotyping of lymphocytes obtained from peripheral blood and fine-needle aspirates.

Methods

The isolated lymphocytes were cultured in the presence of interleukins (IL)-2, IL-4, and IL-12. Enzyme-linked immunosorbent assay and flow cytometric techniques were used for the assessment of human IFN-γ production and the studied T-cell subpopulations, respectively.

Results

Mixed cell populations of peripheral blood lymphocytes and tumor infiltrating lymphocytes treated with IL-2 plus IL-12 showed a marked and significant elevation in IFN-γ levels in their culture media, a significant decrease in the percentage of cluster of differentiation (CD)4⁺CD25⁺ regulatory T-cells, and a nonsignificant increase in the percentage of CD8⁺ cytotoxic T-cells. Meanwhile, IL-2 plus IL-4 treatment demonstrated nonsignificant effects.

Conclusion

Our data suggested that IL-12 together with IL-2 caused a suppression of CD4⁺CD25⁺ regulatory T-cells and an elevation of IFN-γ levels, which play a crucial immunotherapeutic role in the management of HCC patients.

Dynamic and label-free monitoring of natural killer cell cytotoxic activity using electronic cell sensor arrays

A microelectronic sensor-based platform, the RT-CES (real time electronic sensing) system, is introduced for label free assessment of natural killer (NK) cell-mediated cytotoxic activity. The RT-CES system was used to dynamically and quantitatively monitor NK-mediated cytotoxic activity towards 8 different adherent target cell lines, including cancer cell lines commonly used in laboratories. The cytotoxic activity monitored by RT-CES system was compared with standard techniques such as MTT measurement and shows good correlation and sensitivity. To test the specificity of the assay, pharmacological agents that inhibit NK cell degranulation and cytotoxic activity were employed and were shown to selectively and dose-dependently inhibit NK-mediated cytotoxic activity toward target cells. In summary, the RT-CES system offers fully automated measurement of cytotoxic activity in real time, which enables large-scale screening of chemical compounds or genes responsible for the regulation of NK-mediated cytotoxic activity.

Immune restoration following hematopoietic stem cell transplantation: an evolving target

Hematopoietic stem cell transplantation (HSCT) is the definitive cure for many malignant and nonmalignant diseases. However, delays in immune reconstitution (IR) following HSCT significantly limit the success of transplantation and increase the risk for infection and disease relapse in the transplant recipient. Therefore, ways to measure and to manipulate immune recovery following HSCT are emerging and their success depends directly upon an enhanced understanding for the underlying mechanisms responsible for reconstituted immunity and hematopoiesis. Recent discoveries in the activation, function, and regulation of dendritic cell (DC), natural killer (NK) cell, and T-lymphocyte subtypes have been critical in developing immunotherapies used to prevent graft-versus-host disease and to enhance graft-versus-leukemia. For example, regulatory T cells that induce tolerance and NK receptor-tumor ligand disparities that result in tumor lysis are being used to minimize GVHD and tumor burden, respectively. Furthermore, expansion and modulation of immune effector cells are being used to augment hematopoietic and immune recovery and to decrease transplant-related toxicity in the transplant recipient. Specifically, DC expansion and incorporation into antitumor and anti-microbial vaccines is fast approaching application into clinical trials. This paper will review our current understanding for IR following HSCT and the novel ways in which to restore immune function and decrease transplant-related toxicity in the transplant recipient.