CD86 is an activation receptor for NK cell cytotoxicity against tumor cells

CAST Regimen for GvHD Prophylaxis: A CIBMTR Propensity Score-Matched Analysis

Previously, we reported excellent results with the combination of post-transplant cyclophosphamide (PTCy), abatacept, and a short course of tacrolimus (CAST) for the prevention of graft-versus-host disease (GvHD) following peripheral blood haploidentical transplantation. To further substantiate these results, we performed a propensity score-matched analysis. Patients enrolled in the CAST trial were matched with patients from a contemporaneous cohort from the Center for International Blood and Marrow Transplant Research database who received PTCy, tacrolimus, and mycophenolate mofetil, using nearest neighbor propensity score matching. An excellent balance between pairs was achieved as measured by the density distribution and standardized differences of covariates (median 0.09). The rates of acute GvHD grades II to IV at day +120 and 1-year GvHD- and relapse-free survival were 16.7% and 66.7% in the CAST cohort versus 28.6% and 47.6% in the control group, respectively. This trend did not reach statistical significance (P = .14 and .07), possibly due to the small numbers of patients and events. On the other hand, CAST was associated with a statistically significant reduction in the incidence of relapse (9.5% versus 26.2%, P = .045) with improved disease-free survival (85.7% versus 61.9%, P = .01). Our data provides a strong impetus to examine CAST in a randomized clinical trial.

The role and novel use of natural killer cells in graft-versus-leukemia reactions after allogeneic transplantation

Allogeneic hematopoietic cell transplantation (HCT) has transformed over the past several decades through enhanced supportive care, reduced intensity conditioning (RIC), improved human leukocyte antigen (HLA) typing, and novel graft-versus-host disease (GVHD)-prevention and treatment strategies. Most notably, the implementation of post-transplantation cyclophosphamide (PTCy) has dramatically increased the safety and availability of this life-saving therapy. Given reductions in nonrelapse mortality (NRM) with these advances, the HCT community has placed even greater emphasis on developing ways to reduce relapse - the leading cause of death after HCT. When using RIC HCT, protection from relapse relies predominantly on graft-versus-leukemia (GVL) reactions. Donor lymphocyte infusion (DLI), adoptive cellular therapy, checkpoint inhibition, and post-HCT maintenance strategies represent approaches under study that aim to augment or synergize with the GVL effects of HCT. Optimizing donor selection algorithms to leverage GVL represents another active area of research. Many of these strategies seek to harness the effects of T cells, which for decades were felt to be the primary mediators of GVL and the focus of investigation in relapse reduction. However, there is growing interest in capitalizing on the ability of natural killer (NK) cells to yield potent anti-tumor effects. A potential advantage of NK cell-based approaches over T cell-mediated is the potential to reduce NRM in addition to relapse. By decreasing infection, without increasing the risk of GVHD, NK cells may mitigate NRM, while still yielding relapse reduction through identification and clearance of cancer cells. Most T cell-focused relapse-prevention strategies must weigh the benefits of relapse reduction against the increased risk of NRM from GVHD. In contrast, NK cells have the potential to reduce both, potentially tipping the scales significantly in favor of survival. Here, we will review the role of NK cells in GVL, optimization of NK cell match or mismatch, and burgeoning areas of research in NK cell therapy such as adoptive transfer and chimeric antigen receptor (CAR) NK cells.

Integrated analysis reveals the potential of cluster of differentiation 86 as a key biomarker in high-grade glioma

This study aimed to evaluate the potential of cluster of differentiation 86 (CD86) as a biomarker in high-grade glioma (HGG). The TCGA and TCIA databases were used to obtain the CD86 expression value, clinical data, and MRI images of HGG patients. Prognostic values were assessed by the Kaplan-Meier method, Receiver operating characteristic curve (ROC), Cox regression, logistic regression, and nomogram analyses. CD86-associated pathways were also explored. We found that CD86 was significantly upregulated in HGG compared with the normal group. Survival analysis showed a significant association between CD86 high expression and shorter overall survival time. Its independent prognostic value was also confirmed. These results suggested the possibility of CD86 as a biomarker in HGG. We also innovatively established 2 radiomics models with Support Vector Machine (SVM) and Logistic regression (LR) algorithms to predict the CD86 expression. The 2 models containing 5 optimal features by SVM and LR methods showed similar favorable performance in predicting CD86 expression in the training set, and their performance were also confirmed in validation set. These results indicated the successful construction of a radiomics model for non-invasively predicting biomarker in HGG. Finally, pathway analysis indicated that CD86 might be involved in the natural killer cell-mediated cytotoxicity in HGG progression.

The expression of CD86 in CD3+CD56+ NKT cells is associated with the occurrence and prognosis of sepsis-associated encephalopathy in sepsis patients: a prospective observational cohort study

The role of CD3+CD56+ natural killer T (NKT) cells and its co-signaling molecules in patients with sepsis-associated encephalopathy (SAE) is unknown. In this prospective observational cohort study, we initially recruited 260 septic patients and eventually analyzed 90 patients, of whom 57 were in the SAE group and 37 were in the non-SAE group. Compared to the non-SAE group, 28-day mortality was significantly increased in the SAE group (33.3% vs. 12.1%, p = 0.026), while the mean fluorescence intensity (MFI) of CD86 in CD3+CD56+ NKT cells was significantly lower (2065.8 (1625.5 ~ 3198.8) vs. 3117.8 (2278.1 ~ 5349), p = 0.007). Multivariate analysis showed that MFI of CD86 in NKT cells, APACHE II score, and serum albumin were independent risk factors for SAE. Furthermore, the Kaplan-Meier survival analysis indicated that the mortality rate was significantly higher in the high-risk group than in the low-risk group (χ2 = 14.779, p < 0.001). This study showed that the decreased expression of CD86 in CD3+CD56+ NKT cells is an independent risk factor of SAE; thus, a prediction model including MFI of CD86 in NKT cells, APACHE II score, and serum albumin can be constructed for diagnosing SAE and predicting prognosis.

Natural Killer Cell Activation by Ubiquitin-specific Protease 6 Mediates Tumor Suppression in Ewing Sarcoma

Ewing sarcoma is a rare and deadly pediatric bone cancer for which survival rates and treatment options have stagnated for decades. Ewing sarcoma has not benefited from immunotherapy due to poor understanding of how its immune landscape is regulated. We recently reported that ubiquitin-specific protease 6 (USP6) functions as a tumor suppressor in Ewing sarcoma, and identified it as the first cell-intrinsic factor to modulate the Ewing sarcoma immune tumor microenvironment (TME). USP6 induces intratumoral infiltration and activation of multiple innate immune lineages in xenografted nude mice. Here we report that natural killer (NK) cells are essential for its tumor-inhibitory functions, as NK cell depletion reverses USP6-mediated suppression of Ewing sarcoma xenograft growth. USP6 expression in Ewing sarcoma cells directly stimulates NK cell activation and degranulation in vitro, and functions by increasing surface levels of multiple NK cell-activating ligands. USP6 also induces surface upregulation of the receptor for the apoptosis-inducing ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), providing an additional route for enhanced sensitivity to NK cell killing. Furthermore, USP6-expressing Ewing sarcoma and NK cells participate in a paracrine immunostimulatory feedforward loop, wherein IFNγ secreted by activated NK cells feeds back on USP6/Ewing sarcoma cells to induce synergistic expression of chemokines CXCL9 and CXCL10. Remarkably, expression of USP6 in subcutaneous Ewing sarcoma xenografts induces systemic activation and maturation of NK cells, and induces an abscopal response in which growth of distal tumors is inhibited, coincident with increased infiltration and activation of NK cells. This work reveals how USP6 reprograms the Ewing sarcoma TME to enhance antitumor immunity, and may be exploited for future therapeutic benefit.

Significance

This study provides novel insights into the immunomodulatory functions of USP6, the only cancer cell-intrinsic factor demonstrated to regulate the immune TME in Ewing sarcoma. We demonstrate that USP6-mediated suppression of Ewing sarcoma tumorigenesis is dependent on NK cells. USP6 directly activates NK cell cytolytic function, inducing both intratumoral and systemic activation of NK cells in an Ewing sarcoma xenograft model.

Addressing Natural Killer Cell Dysfunction and Plasticity in Cell-Based Cancer Therapeutics

Natural killer (NK) cells are cytotoxic group 1 innate lymphoid cells (ILC), known for their role as killers of stressed, cancerous, and virally infected cells. Beyond this cytotoxic function, NK cell subsets can influence broader immune responses through cytokine production and have been linked to central roles in non-immune processes, such as the regulation of vascular remodeling in pregnancy and cancer. Attempts to exploit the anti-tumor functions of NK cells have driven the development of various NK cell-based therapies, which have shown promise in both pre-clinical disease models and early clinical trials. However, certain elements of the tumor microenvironment, such as elevated transforming growth factor (TGF)-β, hypoxia, and indoalemine-2,3-dioxygenase (IDO), are known to suppress NK cell function, potentially limiting the longevity and activity of these approaches. Recent studies have also identified these factors as contributors to NK cell plasticity, defined by the conversion of classical cytotoxic NK cells into poorly cytotoxic, tissue-resident, or ILC1-like phenotypes. This review summarizes the current approaches for NK cell-based cancer therapies and examines the challenges presented by tumor-linked NK cell suppression and plasticity. Ongoing efforts to overcome these challenges are discussed, along with the potential utility of NK cell therapies to applications outside cancer.

Cytometric analysis reveals an association between allergen-responsive natural killer cells and human peanut allergy

Food allergies are a leading cause of anaphylaxis, and allergen-specific immune responses in both the innate and the adaptive immune system play key roles in its pathogenesis. We conducted a comprehensive phenotypic and functional investigation of immune cell responses from nonallergic (NA) and peanut allergic (PA) participants cultured with media alone or peanut protein and found, surprisingly, that NK cell activation was strongly associated with the immune response to allergen in PA participants. Peanut-responsive NK cells manifested a distinct expression pattern in PA participants compared with NA participants. Allergen-activated NK cells expressed both Th2 and immune regulatory cytokines, hinting at a potential functional role in mediating and regulating the Th2 allergic response. Depletion of CD3⁺ T cells attenuated the response of NK cells to peanut-allergen stimulation, suggesting that peanut-responsive NK cells are T cell dependent. We also showed that oral immune therapy was associated with decreased NK responses to peanut allergen stimulation in vitro. These results demonstrate that NK cells are associated with the food-allergic immune response, and the magnitude of this mobilized cell population suggests that they play a functional role in allergic immunity.

Development of a Risk Predictive Model for Evaluating Immune Infiltration Status in Invasive Thyroid Carcinoma

Aims

This study aimed to reveal the molecular characteristics and potential biomarker of immune-activated and immunosuppressive invasive thyroid carcinoma.

Methods

Expression and clinical data for invasive thyroid carcinoma were obtained from the TCGA database. Tumor samples were divided into immune-activated or immunosuppressive groups based on the immune enrichment score calculated by ssGSEA. Differentially expressed genes (DEGs) between tumor vs. normal groups or between immune-activated vs. immunosuppressive groups were screened, followed by functional enrichment. Immune infiltration was evaluated using the ESTIMATE, CIBERSORTx, and EPIC algorithms, respectively. A random forest algorithm and Lasso cox analysis were used to identify gene signatures for risk model construction.

Results

Totally 1171 DEGs were screened between tumor vs. normal groups, and multiple tumorigenesis-associated pathways were significantly activated in invasive thyroid carcinoma. Compared to immune-activated samples, immunosuppressive samples showed higher tumor purity, lower immune/stromal scores, and lower expression of immune markers, as well as lower infiltration abundance of CD4+ T cells and CD8+ T cells. A risk model based on a 12-immune signature (CCR7, CD1B, CD86, CSF2RB, HCK, HLA-DQA1, LTA, LTB, LYZ, NOD2, TNFRSF9, and TNFSF11) was developed to evaluate the immune infiltration status (AUC = 0.998; AUC of 0.958 and 0.979 in the two external validation datasets), which showed a higher clinical benefit and high accuracy. Immune-activated samples presented lower IC50 value for bortezomib, MG.132, staurosporine, and AZD8055, indicating sensitivity to these drugs.

Conclusion

A 12-gene-based immune signature was developed to predict the immune infiltration status for invasive thyroid carcinoma patients and then to identify the subsets of invasive thyroid carcinoma patients who might benefit from immunotherapy.

Morbid Obesity in Women Is Associated with an Altered Intestinal Expression of Genes Related to Cancer Risk and Immune, Defensive, and Antimicrobial Response

Background: Little is known about the relation between morbid obesity and duodenal transcriptomic changes. We aimed to identify intestinal genes that may be associated with the development of obesity regardless of the degree of insulin resistance (IR) of patients. Material and Methods: Duodenal samples were assessed by microarray in three groups of women: non-obese women and women with morbid obesity with low and high IR. Results: We identified differentially expressed genes (DEGs) associated with morbid obesity, regardless of IR degree, related to digestion and lipid metabolism, defense response and inflammatory processes, maintenance of the gastrointestinal epithelium, wound healing and homeostasis, and the development of gastrointestinal cancer. However, other DEGs depended on the IR degree. We mainly found an upregulation of genes involved in the response to external organisms, hypoxia, and wound healing functions in women with morbid obesity and low IR. Conclusions: Regardless of the degree of IR, morbid obesity is associated with an altered expression of genes related to intestinal defenses, antimicrobial and immune responses, and gastrointestinal cancer. Our data also suggest a deficient duodenal immune and antimicrobial response in women with high IR.

Early and Sustained Expansion of Adaptive Natural Killer Cells Following Haploidentical Transplantation and CTLA4Ig-Primed Donor Lymphocyte Infusions Dissociate Graft-versus-Leukemia and Graft-versus-Host Effects

BACKGROUND

Adaptive or memory natural killer (NK) cells with epigenetic imprints similar to memory T cells have been shown to develop in response to cytomegalovirus (CMV) infection with upregulation of activating receptor NKG2C. These cells have been shown to possess strong anti-tumour efficacy both in-vitro as well as in-vivo.

OBJECTIVES

To determine if reconstitution of adaptive NK cells (CD56^dimNKG2C⁺NKG2A^-) in patients with advanced leukemia undergoing haploidentical HCT had any impact on disease progression (DP).

STUDY DESIGN

The study cohort comprised of 60 patients with advanced acute leukemia, aged 2-65 years, receiving myeloablative PTCy based haploidentical transplantation from CMV seropositive donors, followed by CTLA4Ig-primed donor lymphocyte infusions (DLI). They were evaluated for the kinetics of reconstitution of adaptive NK cells, both phenotypic and functional, at days +30,+60, +90 and at regular intervals, to 3 years of follow-up, in relation to DP. Reconstitution of adaptive NK cells was compared with a retrospective cohort of patients in the same protocol receiving DLI without CTLA4Ig.

RESULTS

Non-relapse mortality, acute and chronic GVHD were 5.1%, 10.3% and 14.5%. DP was 17.5% at a median follow-up of 28 months. Adaptive NK cells were significantly higher in patients without DP at days+30, +60 and +90 (p = 0.0001), irrespective of CMV reactivation and remained elevated until 36 months post-HCT. These cells maintained their functional competence as measured by robust interferon-gamma production with higher expressions of KIR, NKG2D and CD57, without any increase in PD1 expression. Grafts from donors with higher adaptive NK cells were associated with a lower risk of DP (p = 0.0001). In multivariate analysis, adaptive NK cell recovery at day +90 had the most favorable impact on DP (HR-0.7). Tregs reconstituted briskly along with the adaptive NK cells and were sustained as well, without compromising the GVL effect. Comparison with a retrospective cohort receiving the same protocol with DLI without CTLA4Ig, showed a superior reconstitution of adaptive NK cells in those receiving CTLA4Ig-DLI (p < 0.0001).

CONCLUSION

Our study suggests that myeloablative transplantation from CMV seropositive haploidentical donors augmented with CTLA4Ig-primed DLI might favor early and sustained expansion of functionally competent adaptive NK cells irrespective of CMV reactivation, with a favorable outcome.

The Immune Profile of Pituitary Adenomas and a Novel Immune Classification for Predicting Immunotherapy Responsiveness

CONTEXT

The tumor immune microenvironment is associated with clinical outcomes and immunotherapy responsiveness.

OBJECTIVE

To investigate the intratumoral immune profile of pituitary adenomas (PAs) and its clinical relevance and to explore a novel immune classification for predicting immunotherapy responsiveness.

DESIGN, PATIENTS, AND METHODS

The transcriptomic data from 259 PAs and 20 normal pituitaries were included for analysis. The ImmuCellAI algorithm was used to estimate the abundance of 24 types of tumor-infiltrating immune cells (TIICs) and the expression of immune checkpoint molecules (ICMs).

RESULTS

The distributions of TIICs differed between PAs and normal pituitaries and varied among PA subtypes. T cells dominated the immune microenvironment across all subtypes of PAs. The tumor size and patient age were correlated with the TIIC abundance, and the ubiquitin-specific protease 8 (USP8) mutation in corticotroph adenomas influenced the intratumoral TIIC distributions. Three immune clusters were identified across PAs based on the TIIC distributions. Each cluster of PAs showed unique features of ICM expression that were correlated with distinct pathways related to tumor development and progression. CTLA4/CD86 expression was upregulated in cluster 1, whereas programmed cell death protein 1/programmed cell death 1 ligand 2 (PD1/PD-L2) expression was upregulated in cluster 2. Clusters 1 and 2 exhibited a "hot" immune microenvironment and were predicted to exhibit higher immunotherapy responsiveness than cluster 3, which exhibited an overall "cold" immune microenvironment.

CONCLUSIONS

We summarized the immune profile of PAs and identified 3 novel immune clusters. These findings establish a foundation for further immune studies on PAs and provide new insights into immunotherapy strategies for PAs.

CTLA4Ig-primed donor lymphocyte infusions following haploidentical transplantation improve outcome with a distinct pattern of early immune reconstitution as compared to conventional donor lymphocyte infusions in advanced hematological malignancies

CTLA4Ig has a unique property to spare or even potentiate natural killer (NK) cell-mediated cytotoxicity, whilst inhibiting T cell activation. We explored the efficacy of prophylactic DLI following CTLA4Ig (CTLA4Ig-DLI group, n = 75), compared to conventional DLI (DLI group, n = 50), in patients with advanced hematological malignancies receiving PTCy-based haploidentical transplantation. Acute and chronic GVHD in the CTLA4Ig-DLI group were 9.6% and 15.3% compared to 18.8% [p = 0.09] and 36.5% [p = 0.01] in the DLI group. Both non-relapse mortality (4% vs 14.4%) and disease progression (DP) (15.7% vs 31.1%) were lower in CTLA4Ig-DLI group (p = 0.04). GVHD and progression-free survival was significantly improved in the CTLA4Ig-DLI group (p = 0.001). The recovery of CD56^dimNK cells, NKG2A-KIR + NK subsets and Tregs was significantly better in the CTLA4Ig-DLI group at all time points and memory T cells at day +90. Immune recovery in relation to DP showed distinct patterns, with T cell subsets in the DLI group and NKG2A^-KIR⁺NK cells in CTLA4Ig-DLI group having favorable impact. CTLA4Ig-DLI was thus associated with an improved outcome, possibly on account of the distinct pattern of immune recovery shown with this novel approach.

Natural killer cell-based immunotherapy with CTLA4Ig-primed donor lymphocytes following haploidentical transplantation

NK cell-based immunotherapy is one of the more exciting propositions in the field of cellular therapy for hematological malignancies. Current protocols are largely based on expanded and activated NK cells which are used both with and without allogeneic transplantation. Based on our recent findings, we discuss the concept of CTLA4Ig-primed donor lymphocyte infusions following haploidentical transplantation as an effective tool to garner NK cell-mediated antitumor effect with abrogation of T cell-mediated alloreactivity. This approach might widen the possibility of immunotherapy following haploidentical transplantation without increase in graft-versus-host disease. Further studies would be needed to establish the veracity of this concept with better understanding of the antitumor effect via this pathway. Future studies would decide if CTLA4Ig might be used to augment NK-cell activation in vitro as well.

Allogeneic Hematopoietic Stem Cell Transplantation for Myeloma: Time for an Obituary or Not Just Yet!

The management of myeloma has evolved dramatically in the last two decades. High dose melphalan and autologous hematopoietic stem cell transplantation (HSCT) marked the beginning of this journey. This was followed by an explosion of novel agents which were approved for management of myeloma. Allogeneic HSCT which was deemed as the only curative option was largely abhorred due to high transplant-related mortality (TRM) until the advent of reduced intensity conditioning (RIC). An approach of tandem autologous and RIC-allogeneic transplantations has showed the best promise for cure for this condition, particularly for those with high-risk cytogenetics. Yet, allogeneic HSCT seems to have fallen out of favor due to the projected high TRM and late relapses, even though the alternatives do not offer a cure, but merely prolong survival. Offering an allogeneic HSCT as a final resort in unlikely to yield gratifying results. At the same time, allogeneic HSCT needs to evolve in a disease-specific manner to address the relevant concerns regarding TRM and relapse. With the introduction of effective GVHD prophylaxis in the form of post-transplantation cyclophosphamide, transplantation from a haploidentical family donor has become a reality. The challenge lies in segregating graft-vs-myeloma effect from a graft-versus-host effect. We discuss the pro-survival and anti-apoptotic pathways via CD28-CD86 interactions which confer survival advantages to myeloma cells and the possibility of disruption of this pathway in the context of haploidentical transplantation through the use of CTLA4Ig without incurring T cell alloreactivity.

PRL3-zumab as an immunotherapy to inhibit tumors expressing PRL3 oncoprotein

Tumor-specific antibody drugs can serve as cancer therapy with minimal side effects. A humanized antibody, PRL3-zumab, specifically binds to an intracellular oncogenic phosphatase PRL3, which is frequently expressed in several cancers. Here we show that PRL3-zumab specifically inhibits PRL3⁺ cancer cells in vivo, but not in vitro. PRL3 antigens are detected on the cell surface and outer exosomal membranes, implying an 'inside-out' externalization of PRL3. PRL3-zumab binds to surface PRL3 in a manner consistent with that in classical antibody-dependent cell-mediated cytotoxicity or antibody-dependent cellular phagocytosis tumor elimination pathways, as PRL3-zumab requires an intact Fc region and host FcγII/III receptor engagement to recruit B cells, NK cells and macrophages to PRL3⁺ tumor microenvironments. PRL3 is overexpressed in 80.6% of 151 fresh-frozen tumor samples across 11 common cancers examined, but not in patient-matched normal tissues, thereby implicating PRL3 as a tumor-associated antigen. Targeting externalized PRL3 antigens with PRL3-zumab may represent a feasible approach for anti-tumor immunotherapy.

αβ T Cell-Depleted Haploidentical Hematopoietic Stem Cell Transplantation without Antithymocyte Globulin in Children with Chemorefractory Acute Myelogenous Leukemia

We evaluated the outcome of αβ T cell-depleted haploidentical hematopoietic stem cell transplantation (HSCT) in a cohort of children with chemorefractory acute myelogenous leukemia (AML). Twenty-two patients with either primary refractory (n = 10) or relapsed refractory (n = 12) AML in active disease status received a transplant from haploidentical donors. The preparative regimen included cytoreduction with fludarabine and cytarabine and subsequent myeloablative conditioning with treosulfan and thiotepa. Antithymocyte globulin was substituted with tocilizumab in all patients and also with abatacept in 10 patients. Grafts were peripheral blood stem cells engineered by αβ T cell and CD19 depletion. Post-transplantation prophylactic therapy included infusion of donor lymphocytes, composed of a CD45RA-depleted fraction with or without a hypomethylating agent. Complete remission was achieved in 21 patients (95%). The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 18%, and the cumulative incidence of chronic GVHD was 23%. At 2 years, transplantation-related mortality was 9%, relapse rate was 42%, event-free survival was 49%, and overall survival was 53%. Our data suggest that αβ T cell-depleted haploidentical HSCT provides a reasonable chance of long-term survival in a cohort of children with chemorefractory AML and creates a solid basis for further improvement.

Thymosin Alpha1-Fc Modulates the Immune System and Down-regulates the Progression of Melanoma and Breast Cancer with a Prolonged Half-life

Thymosin alpha 1 (Tα1) is a biological response modifier that has been introduced into markets for treating several diseases. Given the short serum half-life of Tα1 and the rapid development of Fc fusion proteins, we used genetic engineering method to construct the recombinant plasmid to express Tα1-Fc (Fc domain of human IgG4) fusion protein. A single-factor experiment was performed with different inducers of varying concentrations for different times to get the optimal condition of induced expression. Pure proteins higher than 90.3% were obtained by using 5 mM lactose for 4 h with a final production about 160.4 mg/L. The in vivo serum half-life of Tα1-Fc is 25 h, almost 13 times longer than Tα1 in mice models. Also, the long-acting protein has a stronger activity in repairing immune injury through increasing number of lymphocytes. Tα1-Fc displayed a more effective antitumor activity in the 4T1 and B16F10 tumor xenograft models by upregulating CD86 expression, secreting IFN-γ and IL-2, and increasing the number of tumor-infiltrating CD4+ T and CD8+ T cells. Our study on the novel modified Tα1 with the Fc segment provides valuable information for the development of new immunotherapy in cancer.

Analysis of the regulatory function of natural killer cells from patients with systemic lupus erythematosus

Natural killer (NK) cells participate in the regulation of the immune response. However, the immunomodulatory function of NK cells in systemic lupus erythematosus (SLE) is not well understood. The aim of this study was to evaluate the regulatory function of NK cells in SLE patients and to identify the NK cells involved in the pathogenesis of this complex disease. We analysed the expression of NK receptors and co-stimulatory molecules in peripheral NK cells (CD3^- CD56⁺ ) from SLE patients, as well as the numbers of human leucocyte antigen D-related (HLA-DR)/CD11c⁺ NK cells. In addition, NK cell regulatory function was assessed by the detection of NK cell-mediated dendritic cell (DC) lysis. We found that SLE patients showed increased numbers of immunoglobulin-like transcript 2 (ILT2)⁺ , CD86⁺ and CD134⁺ NK cells. Furthermore, NK cells from SLE patients induced higher levels of DC lysis. We were able to identify a new subset of NK cells co-expressing CD11c and HLA-DR. These atypical NK cells were increased in SLE patients when compared with controls. We have identified an expanded new subset of NK cells in SLE patients. This is the first study, to our knowledge, which demonstrates that NK cells in SLE patients have an altered phenotype with a high expression of receptors characteristic of dendritic cells. Our results suggest that the impairment in the regulatory function of NK cells, together with the increased number of DC-like NK cells, could play an important role in the development of SLE and highlight the importance of NK cells as a future therapeutic target.

Two immune-enhanced molecular subtypes differ in inflammation, checkpoint signaling and outcome of advanced head and neck squamous cell carcinoma

The immune environment of primary tumor is associated with the clinical response and benefit of immunotherapy. This study aims to investigate the intratumoral immune profile and its clinical relevance in advanced head and neck squamous cell carcinoma (HNSCC). Gene expression profiles of 401 HNSCCs at stage III-IVB from two cohorts (The Cancer Genome Atlas, TCGA, n = 203; the Leipzig Head and Neck Group, LHNG, n = 198) were involved in this analysis. Based on the global immune-related genes, four gene expression subtypes (C1-4) were identified in HNSCCs. Overall, subtypes C2 and C3 showed upregulation of immune profiles and increased tumor lymphocyte infiltration, exhibiting an enhanced immune microenvironment (EIME). However, the two EIME subtypes revealed differences in immune markers and clinical features. Subtype C2 showed higher expression of macrophage signature, whereas subtype C3 was more associated with B cell infiltration. T cell and NK cell infiltration was not different between C2 and C3 subtypes. The subtype C2 tumors were characterized by inflammation compared with subtype C3. Although the checkpoint receptors PD1 and CTLA4 expressed equally between the EIME subtypes, their ligands (PD-L1/PD-L2, CD86/CD80) were significantly upregulated in subtype C2 compared with C3. HPV-positive tumors were predominantly enriched in subtype C3 but not in C2. Furthermore, patients in subtype C2 had a worse outcome than those in C3. In summary, two immune-enhanced subtypes with different immune characteristics and clinical features were identified in advanced HNSCC. The different immune microenvironments among HNSCC subgroups may provide new insights into the strategy of immunotherapy.

Macrophages are necessary for epimorphic regeneration in African spiny mice

How the immune system affects tissue regeneration is not well understood. In this study, we used an emerging mammalian model of epimorphic regeneration, the African spiny mouse, to examine cell-based inflammation and tested the hypothesis that macrophages are necessary for regeneration. By directly comparing inflammatory cell activation in a 4 mm ear injury during regeneration (Acomys cahirinus) and scarring (Mus musculus), we found that both species exhibited an acute inflammatory response, with scarring characterized by stronger myeloperoxidase activity. In contrast, ROS production was stronger and more persistent during regeneration. By depleting macrophages during injury, we demonstrate a functional requirement for these cells to stimulate regeneration. Importantly, the spatial distribution of activated macrophage subtypes was unique during regeneration with pro-inflammatory macrophages failing to infiltrate the regeneration blastema. Together, our results demonstrate an essential role for inflammatory cells to regulate a regenerative response.

Glioblastoma Eradication Following Immune Checkpoint Blockade in an Orthotopic, Immunocompetent Model

Inhibition of immune checkpoints, including cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), and its ligand PD-L1, has demonstrated exciting and durable remissions across a spectrum of malignancies. Combinatorial regimens blocking complementary immune checkpoints further enhance the therapeutic benefit. The activity of these agents for patients with glioblastoma, a generally lethal primary brain tumor associated with significant systemic and microenvironmental immunosuppression, is not known. We therefore systematically evaluated the antitumor efficacy of murine antibodies targeting a broad panel of immune checkpoint molecules, including CTLA-4, PD-1, PD-L1, and PD-L2 when administered as single-agent therapy and in combinatorial regimens against an orthotopic, immunocompetent murine glioblastoma model. In these experiments, we observed long-term tumor-free survival following single-agent anti-PD-1, anti-PD-L1, or anti-CTLA-4 therapy in 50%, 20%, and 15% of treated animals, respectively. Combination therapy of anti-CTLA-4 plus anti-PD-1 cured 75% of the animals, even against advanced, later-stage tumors. In long-term survivors, tumor growth was not seen upon intracranial tumor rechallenge, suggesting that tumor-specific immune memory responses were generated. Inhibitory immune checkpoint blockade quantitatively increased activated CD8(+) and natural killer cells and decreased suppressive immune cells in the tumor microenvironment and draining cervical lymph nodes. Our results support prioritizing the clinical evaluation of PD-1, PD-L1, and CTLA-4 single-agent targeted therapy as well as combination therapy of CTLA-4 plus PD-1 blockade for patients with glioblastoma.

Infusions of allogeneic natural killer cells as cancer therapy

Natural killer (NK) cells are normal white blood cells capable of killing malignant cells without prior sensitization. Allogeneic NK cell infusions are attractive for cancer therapy because of non-cross-resistant mechanisms of action and minimal overlapping toxicities with standard cancer treatments. Although NK therapy is promising, many obstacles will need to be overcome, including insufficient cell numbers, failure of homing to tumor sites, effector dysfunction, exhaustion, and tumor cell evasion. Capitalizing on the wealth of knowledge generated by recent NK cell biology studies and the advancements in biotechnology, substantial progress has been made recently in improving therapeutic efficiency and reducing side effects. A multipronged strategy is essential, including immunogenetic-based donor selection, refined NK cell bioprocessing, and novel augmentation techniques, to improve NK function and to reduce tumor resistance. Although data from clinical trials are currently limited primarily to hematologic malignancies, broader applications to a wide spectrum of adult and pediatric cancers are under way. The unique properties of human NK cells open up a new arena of novel cell-based immunotherapy against cancers that are resistant to contemporary therapies.

NK cell phenotypic modulation in lung cancer environment

Background

Nature killer (NK) cells play an important role in anti-tumor immunotherapy. But it indicated that tumor cells impacted possibly on NK cell normal functions through some molecules mechanisms in tumor microenvironment.

Materials and methods

Our study analyzed the change about NK cells surface markers (NK cells receptors) through immunofluorescence, flow cytometry and real-time PCR, the killed function from mouse spleen NK cell and human high/low lung cancer cell line by co-culture. Furthermore we certificated the above result on the lung cancer model of SCID mouse.

Results

We showed that the infiltration of NK cells in tumor periphery was related with lung cancer patients' prognosis. And the number of NK cell infiltrating in lung cancer tissue is closely related to the pathological types, size of the primary cancer, smoking history and prognosis of the patients with lung cancer. The expression of NK cells inhibitor receptors increased remarkably in tumor micro-environment, in opposite, the expression of NK cells activated receptors decrease magnificently.

Conclusions

The survival time of lung cancer patient was positively related to NK cell infiltration degree in lung cancer. Thus, the down-regulation of NKG2D, Ly49I and the up-regulation of NKG2A may indicate immune tolerance mechanism and facilitate metastasis in tumor environment. Our research will offer more theory for clinical strategy about tumor immunotherapy.