A role of gut microbiota metabolites in HLA-E and NKG2 blockage immunotherapy against tumors: new insights for clinical application.

One of major breakthroughs in immunotherapy against tumor is from blocking immune checkpoint molecules on tumor and reactive T cells. The development of CTLA-4 and PD-1 blockage antibodies has triggered to search for additional effective therapeutic strategies. This causes recent findings that blocking the interaction of checkpoint molecule NKG2A in NK and CD8 T cells with HLA-E in tumors is effective in defensing tumors. Interestingly, gut microbiota also affects this immune checkpoint immunotherapy against tumor. Gut microbiota such as bacteria can contribute to the regulation of host immune response and homeostasis. They not only promote the differentiation and function of immunosuppressive cells but also the inflammatory cells through the metabolites such as tryptophan (Trp) and bile acid (BA) metabolites as well as short chain fatty acids (SCFAs). These gut microbiota metabolites (GMMs) educated immune cells can affect the differentiation and function of effective CD8 and NK cells. Notably, these metabolites also directly affect the activity of CD8 and NK cells. Furthermore, the expression of CD94/NKG2A in the immune cells and/or their ligand HLA-E in the tumor cells is also regulated by gut microbiota associated immune factors. These findings offer new insights for the clinical application of gut microbiota in precise and/or personalized treatments of tumors. In this review, we will discuss the impacts of GMMs and GMM educated immune cells on the activity of effective CD8 and NK cells and the expression of CD94/NKG2A in immune cells and/or their ligand HLA-E in tumor cells.

Torque teno viruses exhaust and imprint the human immune system via the HLA-E/NKG2A axis.

The ubiquitous Torque teno virus (TTV) establishes a chronically persistent infection in the human host. TTV has not been associated with any apparent disease, but, as part of the human virome, it may confer a regulatory imprint on the human immune system with as yet unclear consequences. However, so far, only few studies have characterized the TTV-specific immune responses or the overall immunological imprints by TTV. Here, we reveal that TTV infection leads to a highly exhausted TTV-specific CD8+ T-cell response, hallmarked by decreased IFN-γ production and the expression of the inhibitory NKG2A-receptor. On a functional level, we identified a panel of highly polymorphic TTV-encoded peptides that lead to an expansion of regulatory NKG2A+ natural killer, NKG2A+CD4+, and NKG2A+CD8+ T cells via the stabilization of the non-classical HLA-E molecule. Our results thus demonstrate that TTV leads to a distinct imprint on the human immune system that may further regulate overall human immune responses in infectious, autoimmune, and malignant diseases.

Is HLA-E with its receptors an immune checkpoint or an antigenic determinant in allo-HCT?

Hematopoietic cell transplantation (HCT) represents a potentially curative therapeutic approach for various hematologic and non-hematologic malignancies. Human leukocyte antigen (HLA) matching is still the central selection criterion for HCT donors. Nevertheless, post-transplant complications, in particular graft-versus-host disease (GvHD), relapse of disease and infectious complications, represent a major challenge and contribute significantly to morbidity and mortality. Recently, non-classical HLA class I molecules, especially HLA-E, have gained increasing attention in the context of allogeneic HCT. This review aims to summarize the latest findings on the immunomodulatory role of HLA-E, which serves as a ligand for receptors of the innate and adaptive immune system. In particular, we aim to elucidate how (i) polymorphisms within HLA-E, (ii) the NKG2A/C axis and (iii) the repertoire of peptides presented by HLA-E jointly influence the functionality of immune effector cells. Understanding this intricate network of interactions is crucial as it significantly affects NK and T cell responses and thus clinical outcomes after HCT.

LAG-3 and PD-1 synergize on CD8+ T cells to drive T cell exhaustion and hinder autocrine IFN-γ-dependent anti-tumor immunity.

Overcoming immune-mediated resistance to PD-1 blockade remains a major clinical challenge. Enhanced efficacy has been demonstrated in melanoma patients with combined nivolumab (anti-PD-1) and relatlimab (anti-LAG-3) treatment, the first in its class to be FDA approved. However, how these two inhibitory receptors synergize to hinder anti-tumor immunity remains unknown. Here, we show that CD8+ T cells deficient in both PD-1 and LAG-3, in contrast to CD8+ T cells lacking either receptor, mediate enhanced tumor clearance and long-term survival in mouse models of melanoma. PD-1- and LAG-3-deficient CD8+ T cells were transcriptionally distinct, with broad TCR clonality and enrichment of effector-like and interferon-responsive genes, resulting in enhanced IFN-γ release indicative of functionality. LAG-3 and PD-1 combined to drive T cell exhaustion, playing a dominant role in modulating TOX expression. Mechanistically, autocrine, cell-intrinsic IFN-γ signaling was required for PD-1- and LAG-3-deficient CD8+ T cells to enhance anti-tumor immunity, providing insight into how combinatorial targeting of LAG-3 and PD-1 enhances efficacy.

LAG-3 sustains TOX expression and regulates the CD94/NKG2-Qa-1b axis to govern exhausted CD8 T cell NK receptor expression and cytotoxicity.

Exhausted CD8 T (Tex) cells in chronic viral infection and cancer have sustained co-expression of inhibitory receptors (IRs). Tex cells can be reinvigorated by blocking IRs, such as PD-1, but synergistic reinvigoration and enhanced disease control can be achieved by co-targeting multiple IRs including PD-1 and LAG-3. To dissect the molecular changes intrinsic when these IR pathways are disrupted, we investigated the impact of loss of PD-1 and/or LAG-3 on Tex cells during chronic infection. These analyses revealed distinct roles of PD-1 and LAG-3 in regulating Tex cell proliferation and effector functions, respectively. Moreover, these studies identified an essential role for LAG-3 in sustaining TOX and Tex cell durability as well as a LAG-3-dependent circuit that generated a CD94/NKG2+ subset of Tex cells with enhanced cytotoxicity mediated by recognition of the stress ligand Qa-1b, with similar observations in humans. These analyses disentangle the non-redundant mechanisms of PD-1 and LAG-3 and their synergy in regulating Tex cells.

PACIFIC-9: Phase III trial of durvalumab + oleclumab or monalizumab in unresectable stage III non-small-cell lung cancer.

Evidence from the Phase III PACIFIC trial established durvalumab, a monoclonal antibody (mAb) targeting PD-L1, following concurrent chemoradiotherapy (cCRT) as a global standard of care for patients with unresectable, stage III non-small-cell lung cancer (NSCLC). There remains an unmet need to improve upon the outcomes achieved with the PACIFIC regimen. Combining durvalumab with other immunotherapies may improve outcomes further. Two such immunotherapies include oleclumab, an mAb targeting CD73, and monalizumab, an mAb targeting NKG2A. Both agents demonstrated antitumor activity in early-phase trials. PACIFIC-9 (NCT05221840) is an international, double-blind, randomized, placebo-controlled, Phase III trial comparing durvalumab plus either oleclumab or monalizumab with durvalumab plus placebo in patients with unresectable, stage III NSCLC and no disease progression following cCRT.Clinical Trial Registration: NCT05221840 (ClinicalTrials.gov).

Durvalumab is a treatment that helps the body's immune system to identify and attack cancer cells by binding to a protein called PD-L1. Studies show that durvalumab lowers the risk of cancer growing or spreading, and prolongs survival, when administered after chemotherapy and radiation therapy ('chemoradiotherapy') in patients with a type of lung cancer called stage III non-small-cell lung cancer (NSCLC) for whom surgery is not an option.Two antibody treatments have been developed that may help a patient's immune system to identify and attack cancer cells. Oleclumab binds to a protein on cancer cells called CD73, which prevents the production of adenosine, a chemical that obstructs the immune system from attacking the cancer. Monalizumab binds to NKG2A, a protein on immune cells that inhibits their ability to destroy cancer cells. Early studies suggest that combining either of these treatments with durvalumab may be better than durvalumab alone for slowing the growth and spread of cancer in patients with NSCLC.PACIFIC-9 is a study that aims to recruit approximately 999 patients with stage III NSCLC for whom surgery is not an option and who have completed chemoradiotherapy without the cancer growing or spreading. Patients will be randomly assigned in equal numbers to receive up to a year of treatment with durvalumab plus oleclumab, durvalumab plus monalizumab or durvalumab plus placebo. The primary measure of efficacy is the length of time that patients remain alive without the cancer growing or spreading for each combination versus durvalumab plus placebo.

HLA-E-expressing macrophage polarization and increased NKG2A/CD94 expression in adult-onset Still's disease.

We investigated the phenotypic characteristics of human leukocyte antigen (HLA)-E-expressing macrophages, NKG2A/CD94 expression in T and natural killer (NK) cells, and their interactions in patients with adult-onset Still's disease (AOSD). Peripheral blood mononuclear cells from 22 patients with AOSD and 22 healthy controls (HC) were used. Isolated monocytes were cultured first with macrophage colony-stimulating factor to differentiate into M0 macrophages and subsequently with lipopolysaccharide/interferon-γ or interleukin-4 to differentiate into M1 or M2 macrophages, respectively. HLA-E and NKG2A/CD94 expression levels were evaluated using quantitative RT-PCR and flow cytometry. HLA-E expression in M0 and M2 macrophages was significantly higher in patients with AOSD than in HC, and was positively correlated with serum C-reactive protein levels and erythrocyte sedimentation rate. NKG2A/CD94 expression in CD4 + and CD8 + T cells was significantly higher in patients with AOSD than in HC, but that in NK cells was not significantly different. In patients with AOSD, NKG2A expression in CD4 + T cells positively correlated with HLA-E expression in M0, M1, and M2 macrophages. CD94 expression in CD8 + T cells inversely correlated with HLA-E expression in M1 and M2 macrophages. NKG2A and CD94 expression in NK cells inversely correlated with HLA-E expression in M0, M1, and M2 macrophages. No significant correlation was observed between HLA-E and NKG2A/CD94 expression in HC. Increased expression of HLA-E in macrophages and NKG2A/CD94 in T cells can be observed in the inflammatory condition of AOSD. HLA-E-expressing macrophages may be associated with NKG2A/CD94 expression in T and NK cells with different correlations.

Expression and clinical significance of NKG2A and HLA-E in advanced laryngeal carcinoma.

OBJECTIVES: The purpose was to detected features of the expression levels of NKG2A and its ligand HLA-E, a new member of the immune checkpoints, in advanced laryngeal carcinoma and their clinicopathologic significance. MATERIAL AND METHODS: We analyzed the expression levels of HLA-E and NKG2A in multiple types of tumors utilizing the Tumor Immune Estimation Resource (TIMER) database and immunohistochemistry and qRT-PCR analysis of paraffin embedded tissue samples to reveal the correlations of the clinicopathological factors with the expression of these two proteins in advanced laryngeal carcinoma as well as their prognostic significance. RESULTS: KLRC1 (the coding gene of NKG2A) and HLA-E are substantially overexpressed in various human cancers than normal tissues. HNSCC is also included. KLRC1 is differentially expressed in different HPV subgroups of patients, with higher expression in the HPV-positive group. Consistent with this, immunohistochemical results also revealed the high expression of these two proteins in tumor tissue. In addition, immunohistochemical staining also displayed a preference for the distribution of NKG2A-positive cells in tumor tissue. Clinicopathological analyses also displayed that the density of NKG2A-positive cells of the HPV-positive group infiltrating laryngeal carcinoma tissue was larger than that in the HPV-negative group. Prognostic analyses indicated that the expression of this immune checkpoint does not affect the overall survival length of patients, but the highly expressed HLA-E is significantly correlated with local recurrence in the patients. CONCLUSIONS: The findings suggest that the expression levels of HLA-E and NKG2A is upregulated in advanced laryngeal carcinoma. The NKG2A-positive cells infiltrating the tumor are mainly distributed in the cancer nest, while infiltrating cell number may be regulated by HPV. The highly expressed HLA-E may promote local recurrence in patients with advanced laryngeal carcinoma.

NKG2A genetic deletion promotes human primary NK cell anti-tumor responses better than an anti-NKG2A monoclonal antibody.

Natural killer (NK) cells eliminate infected or cancer cells via their cytotoxic capacity. NKG2A is an inhibitory receptor on NK cells and cancer cells often overexpress its ligand HLA-E to evade NK cell surveillance. Given the successes of immune checkpoint blockade in cancer therapy, NKG2A is an interesting novel target. However, anti-NKG2A antibodies have shown limited clinical response. In the pursuit of enhancing NK cell-mediated anti-tumor responses, we devised a Cas9-based strategy to delete KLRC1, encoding NKG2A, in human primary NK cells. Our approach involved electroporation of KLRC1-targeting Cas9 ribonucleoprotein resulting in effective ablation of NKG2A expression. Compared with anti-NKG2A antibody blockade, NKG2AKO NK cells exhibited enhanced activation, reduced suppressive signaling, and elevated expression of key transcription factors. NKG2AKO NK cells overcame inhibition from HLA-E, significantly boosting NK cell activity against solid and hematologic cancer cells. We validated this efficacy across multiple cell lines, a xenograft mouse model, and primary human leukemic cells. Combining NKG2A knockout with antibody coating of tumor cells further enhanced cytotoxicity through ADCC. Thus, we provide a comprehensive comparison of inhibition of the NKG2A pathway using genetic ablation and antibodies and provide novel insight in the observed differences in molecular mechanisms, which can be translated to enhance adoptive NK cell immunotherapy.

Bimodal Effect of NKG2A Blockade on Intratumoral and Systemic CD8 T Cell Response Induced by Cancer Vaccine.

Immune check-point blockade (ICB) has revitalized cancer immunotherapy, showing unprecedented efficacy despite only a narrow number of indications and with limited long-term protection. Cancer vaccines are promising combination partners for ICB to widen the patient population profiting from these treatments. Therapeutic heterologous prime-boost vaccination with KISIMATM protein vaccine and VSV-GP-TAg oncolytic virus was shown to inflame the tumor microenvironment, promoting significant infiltration of antigen-specific CD8 T cells resulting in robust antitumoral efficacy in mouse tumor models, and clinical trials are currently ongoing. Here, we report the impact of NKG2A blockade on antitumoral CD8 T cell immune response elicited by KISIMA-VSV-GP-TAg vaccination in tumor mouse models. Combination therapy significantly reduced the amount of vaccine-induced exhausted CD8 T cells infiltrating the tumor, resulting in short-term improved tumor growth control and prolonged mouse survival, while it also influenced the establishment of systemic effector memory CD8 T cell response. Taken together, these data show a compartment-dependent effect of NKG2A blockade on cancer vaccine-induced T cell immunity, increasing intratumoral T cell efficacy and attenuating the development of peripheral effector memory CD8 T cell response.

SARS-CoV-2 infection induces adaptive NK cell responses by spike protein-mediated induction of HLA-E expression.

HLA-E expression plays a central role for modulation of NK cell function by interaction with inhibitory NKG2A and stimulatory NKG2C receptors on canonical and adaptive NK cells, respectively. Here, we demonstrate that infection of human primary lung tissue with SARS-CoV-2 leads to increased HLA-E expression and show that processing of the peptide YLQPRTFLL from the spike protein is primarily responsible for the strong, dose-dependent increase of HLA-E. Targeting the peptide site within the spike protein revealed that a single point mutation was sufficient to abrogate the increase in HLA-E expression. Spike-mediated induction of HLA-E differentially affected NK cell function: whereas degranulation, IFN-γ production, and target cell cytotoxicity were enhanced in NKG2C+ adaptive NK cells, effector functions were inhibited in NKG2A+ canonical NK cells. Analysis of a cohort of COVID-19 patients in the acute phase of infection revealed that adaptive NK cells were induced irrespective of the HCMV status, challenging the paradigm that adaptive NK cells are only generated during HCMV infection. During the first week of hospitalization, patients exhibited a selective increase of early NKG2C+CD57- adaptive NK cells whereas mature NKG2C+CD57+ cells remained unchanged. Further analysis of recovered patients suggested that the adaptive NK cell response is primarily driven by a wave of early adaptive NK cells during acute infection that wanes once the infection is cleared. Together, this study suggests that NK cell responses to SARS-CoV-2 infection are majorly influenced by the balance between canonical and adaptive NK cells via the HLA-E/NKG2A/C axis.

[Effect of Spatholobi Caulis extract from ethyl acetate on immune killing function of NK cells].

This study aims to investigate the regulatory effect of the Spatholobi Caulis extract from ethyl acetate(SEA) on natural killer(NK) cells under physiological conditions and elucidate the underlying mechanism. The C57BL/6 mice were randomized into NC and SEA groups, and NK-92 cells were respectively treated with 0, 25, 50, and 100 µg·mL~(-1) SEA. The body weight and immune organ index of the mice were compared between groups. The lactate dehydrogenase(LDH) assay was employed to examine the cytotoxicity of NK-92 cells treated with SEA and the killing activity of mouse NK cells against YAC-1 cells. The cell-counting kit-8(CCK-8) was used to examine the impact of SEA on the proliferation of NK-92 cells. Flow cytometry was employed to measure the number of NK cells in the peripheral blood as well as the expression levels of natural killer group 2 member A(NKG2A) and natural killer group 2 member D(NKG2D). The enzyme-linked immunosorbent assay(ELISA) was performed to determine the interferon(IFN)-γ secretion in the serum. Semi-quantitative PCR was conducted to determine the mRNA levels of NKG2A, NKG2D, and IFN-γ in spleen cells. Western blot was employed to investigate the involvement of phosphoinositide 3-kinase(PI3K)/extracellular regulated protein kinase 1(ERK1) signaling pathway. The results showed that SEA exhibited no adverse effects on the body, while significantly enhance the number of NK cells and augment the cytotoxicity of NK-92 cells against YAC-1 cells. Moreover, it suppressed the expression of NKG2A, enhanced the expression of NKG2D, promoted IFN-γ secretion, and upregulated the protein levels of PI3K and ERK. The findings suggest that SEA has the potential to enhance the immune recognition and effector function of NK cells by increasing the cell number, modulating the expression of functional receptors, and promoting IFN-γ secretion via the PI3K/ERK signaling pathway.

Long-term dynamics of natural killer cells in response to SARS-CoV-2 vaccination: Persistently enhanced activity postvaccination.

Natural Killer (NK) cells play a significant role in the early defense against virus infections and cancer. Recent studies have demonstrated the involvement of NK cells in both the induction and effector phases of vaccine-induced immunity in various contexts. However, their role in shaping immune responses following SARS-CoV-2 vaccination remains poorly understood. To address this matter, we conducted a comprehensive analysis of NK cell phenotype and function in SARS-CoV-2 unexposed individuals who received the BNT162b2 vaccine. We employed a longitudinal study design and utilized a panel of 53 15-mer overlapping peptides covering the receptor binding domain (RBD) of the SARS-CoV-2 Spike protein to assess NK cell function at 0 and 20 days following the first vaccine, and 30 and 240 days following booster. Additionally, we evaluated the levels of total IgG anti-Spike antibodies and their potential neutralizing ability. Our findings revealed an increased NK cell activity upon re-exposure to RBD when combined with IL12 and IL18 several months after booster. Concurrently, we observed that the frequencies of NKG2A + NK cells declined over the course of the follow-up period, while NKG2C increased only in CMV positive subjects. The finding that NK cell functions are inducible 9 months after vaccination upon re-exposure to RBD and cytokines, sheds light on the role of NK cells in contributing to SARS-CoV-2 vaccine-induced immune protection and pave the way to further studies in the field.

Integrative systems biology reveals NKG2A-biased immune responses correlate with protection in infectious disease, autoimmune disease, and cancer.

Infection, autoimmunity, and cancer are principal human health challenges of the 21st century. Often regarded as distinct ends of the immunological spectrum, recent studies hint at potential overlap between these diseases. For example, inflammation can be pathogenic in infection and autoimmunity. T resident memory (TRM) cells can be beneficial in infection and cancer. However, these findings are limited by size and scope; exact immunological factors shared across diseases remain elusive. Here, we integrate large-scale deeply clinically and biologically phenotyped human cohorts of 526 patients with infection, 162 with lupus, and 11,180 with cancer. We identify an NKG2A+ immune bias as associative with protection against disease severity, mortality, and autoimmune/post-acute chronic disease. We reveal that NKG2A+ CD8+ T cells correlate with reduced inflammation and increased humoral immunity and that they resemble TRM cells. Our results suggest NKG2A+ biases as a cross-disease factor of protection, supporting suggestions of immunological overlap between infection, autoimmunity, and cancer.

Dual Checkpoint Aptamer Immunotherapy: Unveiling Tailored Cancer Treatment Targeting CTLA-4 and NKG2A.

Recent strides in immunotherapy have illuminated the crucial role of CTLA-4 and PD-1/PD-L1 pathways in contemporary oncology, presenting both promises and challenges in response rates and adverse effects. This study employs a computational biology tool (in silico approach) to craft aptamers capable of binding to dual receptors, namely, inhibitory CTLA4 and NKG2A, thereby unleashing both T and NK cells and enhancing CD8+ T and NK cell functions for tumor cell lysis. Computational analysis highlighted AYA22T-R2-13 with HADDOCK scores of -78.2 ± 10.2 (with CTLA4), -60.0 ± 4.2 (with NKG2A), and -77.5 ± 5.6 (with CD94/NKG2A). Confirmation of aptamer binding to targeted proteins was attained via ELISA and flow cytometry methods. In vitro biological functionality was assessed using lactate dehydrogenase (LDH) cytotoxicity assay. Direct and competitive assays using ELISA and flow cytometry demonstrated the selective binding of AYA22T-R2-13 to CTLA4 and NKG2A proteins, as well as to the cell surface receptors of IL-2-stimulated T cells and NK cells. This binding was inhibited in the presence of competition from CTLA4 or NKG2A proteins. Remarkably, the blockade of CTLA4 or NKG2A by AYA22T-R2-13 augmented human CD8 T cell- and NK cell-mediated tumor cell lysis in vitro. Our findings highlight the precise binding specificity of AYA22T-R2-13 for CTLA4-B7-1/B7-2 (CD80/CD86) or CD94/NKG2A-HLA-E interactions, positioning it as a valuable tool for immune checkpoint blockade aptamer research in murine tumor models. These in vitro studies establish a promising foundation for further enhancing binding capacity and establishing efficacy and safety in animal models. Consequently, our results underscore the potential of AYA22T-R2-13 in cancer immunotherapy, offering high specificity, low toxicity, and the potential for cost-effective production.

Phenotypic and functional exhaustion of circulating CD3+ CD56+ NKT-like cells in colorectal cancer patients.

CD3+ CD56+ NKT-like cells are crucial to antitumor immune surveillance and defense. However, research on circulating NKT-like cells in colorectal cancer (CRC) patients is limited. This investigation selected 113 patients diagnosed with primary CRC for preoperative peripheral blood collection. The blood from 106 healthy donors at the physical examination center was acquired as a healthy control (HC). The distribution of lymphocyte subsets, immunophenotype, and functional characteristics of NKT-like cells was comprehensively evaluated. Compared to HC, primary CRC patients had considerably fewer peripheral NKT-like cells in frequency and absolute quantity, and the fraction of NKT-like cells was further reduced in patients with vascular invasion compared to those without. The NKT-like cells in CRC patients had a reduced fraction of the activating receptor CD16, up-regulated expression of inhibitory receptors LAG-3 and NKG2A, impaired production of TNF-α and IFN-γ, as well as degranulation capacity. Moreover, the increased frequency of NKG2A+ NKT-like cells and the decreased expression of activation-related molecules were significantly correlated with tumor progression. In detail, NKG2A+ NKT-like cells indicated increased PD-1 and Tim-3 and reduced TNF-α than NKG2A- subgroup. Blocking NKG2A in vitro restored cytokine secretion capacity in NKT-like cells from CRC patients. Altogether, this research revealed that circulating NKT-like cells in CRC patients exhibited suppressive phenotype and functional impairment, which was more pronounced in NKG2A+ NKT-like cells. These findings suggest that NKG2A blockade may restore anti-tumor effector function in NKT-like cells, which provides a potential target for immunotherapy in CRC patients.

Exploring NK cell receptor dynamics in paediatric leukaemias: implications for immunotherapy and prognosis.

Objectives: Immunotherapies targeting natural killer (NK) cell receptors have shown promise against leukaemia. Unfortunately, cancer immunosuppressive mechanisms that alter NK cell phenotype prevent such approaches from being successful. The study utilises advanced cytometry to examine how cancer immunosuppressive pathways affect NK cell phenotypic changes in clinical samples. Methods: In this study, we conducted a high-dimensional examination of the cell surface expression of 16 NK cell receptors in paediatric patients with acute myeloid leukaemia and acute lymphoblastic leukaemia, as well as in samples of non-age matched adult peripheral blood (APB) and umbilical cord blood (UCB). An unsupervised analysis was carried out in order to identify NK cell populations present in paediatric leukaemias. Results: We observed that leukaemia NK cells clustered together with UCB NK cells and expressed relatively higher levels of the NKG2A receptor compared to APB NK cells. In addition, CD56dimCD16+CD57- NK cells lacking NKG2A expression were mainly absent in paediatric leukaemia patients. However, CD56br NK cell populations expressing high levels of NKG2A were highly represented in paediatric leukaemia patients. NKG2A expression on leukaemia NK cells was found to be positively correlated with the expression of its ligand, suggesting that the NKG2A-HLA-E interaction may play a role in modifying NK cell responses to leukaemia cells. Conclusion: We provide an in-depth analysis of NK cell populations in paediatric leukaemia patients. These results support the development of immunotherapies targeting immunosuppressive receptors, such as NKG2A, to enhance innate immunity against paediatric leukaemia.

Novel immune checkpoint targets: A promising therapy for cancer treatments.

The immune system frequently comprises immunological checkpoints. They serve as a barrier to keep the immune system from overreacting and damaging cells that are robust. Immune checkpoint inhibitors (ICIs) are utilized in immunotherapy to prevent the synergy of partner proteins of checkpoint proteins with auxiliary proteins. Moreover, the T cells may target malignant cells since the "off" signal cannot be conveyed. ICIs, which are mostly composed of monoclonal antibodies (mAbs) against cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and anti- programmed death-1/programmed ligand 1 (anti-PD-1/PD-L1), might transform the context of cancer therapy. Further, more patients continued to exhibit adaptive resistance, even though several ICIs demonstrated convincing therapeutic benefits in selective tumor types. Immune checkpoint therapy's overall effectiveness is still lacking at this time. A popular area of study involves investigating additional immune checkpoint molecules. Recent research has found a number of fresh immune checkpoint targets, including NKG2A ligands, TIGIT, B7-H6 ligands, Galectin 3, TIM3, and so on. These targets have been focus of the study, and recent investigational approaches have shown encouraging outcomes. In this review article, we covered the development and present level understanding of these recently identified immune checkpoint molecules, its effectiveness and limitations.

Integrated multi-omics profiling to dissect the spatiotemporal evolution of metastatic hepatocellular carcinoma.

Comprehensive molecular analyses of metastatic hepatocellular carcinoma (HCC) are lacking. Here, we generate multi-omic profiling of 257 primary and 176 metastatic regions from 182 HCC patients. Primary tumors rich in hypoxia signatures facilitated polyclonal dissemination. Genomic divergence between primary and metastatic HCC is high, and early dissemination is prevalent. The remarkable neoantigen intratumor heterogeneity observed in metastases is associated with decreased T cell reactivity, resulting from disruptions to neoantigen presentation. We identify somatic copy number alterations as highly selected events driving metastasis. Subclones without Wnt mutations show a stronger selective advantage for metastasis than those with Wnt mutations and are characterized by a microenvironment rich in activated fibroblasts favoring a pro-metastatic phenotype. Finally, metastases without Wnt mutations exhibit higher enrichment of immunosuppressive B cells that mediate terminal exhaustion of CD8+ T cells via HLA-E:CD94-NKG2A checkpoint axis. Collectively, our results provide a multi-dimensional dissection of the complex evolutionary process of metastasis.