Positive & Negative Roles of Innate Effector Cells in Controlling Cancer Progression

T cells in the microenvironment of solid pediatric tumors: the case of neuroblastoma

Neuroblastoma (NB) is an immunologically "cold" tumor with poor or no inflamed substrates as most of solid pediatric tumors (SPT). Consistent data indicate that NB tumor microenvironment (TME) is dominated by myeloid cells, with little (but variable) T cell infiltration. The obstacles to lymphocyte infiltration and to their anti-tumor activity are due to different tumor immune evasion strategies, including loss of HLA Class I molecules, high expression of immune checkpoint molecular ligands leading to exhaustion of T effector (and NK) cells, induction of T regulatory, myeloid and stromal cells and secretion of immunosuppressive mediators. In odds with adult solid tumors, NB displays weak immunogenicity caused by intrinsic low mutational burden and scant expression of neoepitopes in the context of MHC-class I antigens which, in turn, are particularly poorly expressed on NB cells, thus inducing low anti-tumor T cell responses. In addition, NB is generated from embryonal cells and is the result of transcriptional abnormalities and not of the accumulation of genetic mutations over time, thus further explaining the low immunogenicity. The poor expression of immunogenic molecules on tumor cells is associated with the high production of immunosuppressive factors which further downregulate lymphocyte infiltration and activity, thus explaining the limited efficacy of new drugs in NB, as immune checkpoint inhibitors. This review is focused on examining the role of T effector and regulatory cells infiltrating TME of NB, taking into account their repertoire, phenotype, function, plasticity and, importantly, predictive value for defining novel targets for therapy.

T cell landscape in the microenvironment of human solid tumors

T cells are the main effectors involved in anti-tumor immunity, mediating most of the adaptive response towards cancer. After priming in lymph nodes, tumor antigens-specific naïve T lymphocytes proliferate and differentiate into effector CD4+ and CD8+ T cells that migrate from periphery into tumor sites aiming to eliminate cancer cells. Then while most effector T cells die, a small fraction persists and recirculates as long-lived memory T cells which generate enhanced immune responses when re-encountering the same antigen. A number of T (and non-T) cell subsets, stably resides in non-lymphoid peripheral tissues and may provide rapid immune response independently of T cells recruited from blood, against the reemergence of cancer cells. When tumor grows, however, tumor cells have evaded immune surveillance of effector cells (NK and CTL cells) which are exhausted, thus favoring the local expansion of T (and non-T) regulatory cells. In this review, the current knowledge of features of T cells present in the tumor microenvironment (TME) of solid adult and pediatric tumors, the mechanisms upregulating immune-checkpoint molecules and transcriptional and epigenetic landscapes leading to dysfunction and exhaustion of T effector cells are reviewed. The interaction of T cells with cancer- or TME non-neoplastic cells and their secreted molecules shape the T cell profile compromising the intrinsic plasticity of T cells and, therefore, favoring immune evasion. In this phase regulatory T cells contribute to maintain a high immunosuppressive TME thus facilitating tumor cell proliferation and metastatic spread. Despite the advancements of cancer immunotherapy, many tumors are unresponsive to immune checkpoint inhibitors, or therapeutical vaccines or CAR T cell-based adoptive therapy: some novel strategies to improve these T cell-based treatments are lastly proposed.

Role of innate T cells in necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a destructive gastrointestinal disease primarily affecting preterm babies. Despite advancements in neonatal care, NEC remains a significant cause of morbidity and mortality in neonatal intensive care units worldwide and the etiology of NEC is still unclear. Risk factors for NEC include prematurity, very low birth weight, feeding with formula, intestinal dysbiosis and bacterial infection. A review of the literature would suggest that supplementation of prebiotics and probiotics prevents NEC by altering the immune responses. Innate T cells, a highly conserved subpopulation of T cells that responds quickly to stimulation, develops differently from conventional T cells in neonates. This review aims to provide a succinct overview of innate T cells in neonates, encompassing their phenotypic characteristics, functional roles, likely involvement in the pathogenesis of NEC, and potential therapeutic implications.

Characterization of candidate factors associated with the metastasis and progression of high-grade serous ovarian cancer

BACKGROUND

High-grade serous ovarian cancer (HGSOC) is the biggest cause of gynecological cancer-related mortality because of its extremely metastatic nature. This study aimed to explore and evaluate the characteristics of candidate factors associated with the metastasis and progression of HGSOC.

METHODS

Transcriptomic data of HGSOC patients' samples collected from primary tumors and matched omental metastatic tumors were obtained from three independent studies in the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were selected to evaluate the effects on the prognosis and progression of ovarian cancer using data from The Cancer Genome Atlas (TCGA) database. Hub genes' immune landscapes were estimated by the Tumor Immune Estimation Resource (TIMER) database. Finally, using 25 HGSOC patients' cancer tissues and 10 normal fallopian tube tissues, immunohistochemistry (IHC) was performed to quantify the expression levels of hub genes associated with International Federation of Gynecology and Obstetrics (FIGO) stages.

RESULTS

Fourteen DEGs, ADIPOQ , ALPK2 , BARX1 , CD37 , CNR2 , COL5A3 , FABP4 , FAP , GPR68 , ITGBL1 , MOXD1 , PODNL1 , SFRP2 , and TRAF3IP3 , were upregulated in metastatic tumors in every database while CADPS , GATA4 , STAR , and TSPAN8 were downregulated. ALPK2 , FAP , SFRP2 , GATA4 , STAR , and TSPAN8 were selected as hub genes significantly associated with survival and recurrence. All hub genes were correlated with tumor microenvironment infiltration, especially cancer-associated fibroblasts and natural killer (NK) cells. Furthermore, the expression of FAP and SFRP2 was positively correlated with the International Federation of Gynecology and Obstetrics (FIGO) stage, and their increased protein expression levels in metastatic samples compared with primary tumor samples and normal tissues were confirmed by IHC ( P = 0.0002 and P = 0.0001, respectively).

CONCLUSIONS

This study describes screening for DEGs in HGSOC primary tumors and matched metastasis tumors using integrated bioinformatics analyses. We identified six hub genes that were correlated with the progression of HGSOC, particularly FAP and SFRP2 , which might provide effective targets to predict prognosis and provide novel insights into individual therapeutic strategies for HGSOC.

Exploiting innate immunity for cancer immunotherapy

Immunotherapies have revolutionized the treatment paradigms of various types of cancers. However, most of these immunomodulatory strategies focus on harnessing adaptive immunity, mainly by inhibiting immunosuppressive signaling with immune checkpoint blockade, or enhancing immunostimulatory signaling with bispecific T cell engager and chimeric antigen receptor (CAR)-T cell. Although these agents have already achieved great success, only a tiny percentage of patients could benefit from immunotherapies. Actually, immunotherapy efficacy is determined by multiple components in the tumor microenvironment beyond adaptive immunity. Cells from the innate arm of the immune system, such as macrophages, dendritic cells, myeloid-derived suppressor cells, neutrophils, natural killer cells, and unconventional T cells, also participate in cancer immune evasion and surveillance. Considering that the innate arm is the cornerstone of the antitumor immune response, utilizing innate immunity provides potential therapeutic options for cancer control. Up to now, strategies exploiting innate immunity, such as agonists of stimulator of interferon genes, CAR-macrophage or -natural killer cell therapies, metabolic regulators, and novel immune checkpoint blockade, have exhibited potent antitumor activities in preclinical and clinical studies. Here, we summarize the latest insights into the potential roles of innate cells in antitumor immunity and discuss the advances in innate arm-targeted therapeutic strategies.

A new method for the treatment of myocardial ischemia-reperfusion injury based on γδT cell-mediated immune response

Acute myocardial ischemia is a disease with high morbidity and mortality, and re-perfusion is currently the best intervention. However, re-perfusion may lead to further myocardial injury and increase the area of myocardial infarction. The mechanism of myocardial ischemia-re-perfusion injury is complex, but with more in-depth study, it has been proved that the immune system plays an important role in the process of MIRI. Among them, the γδT cell population has received increasing attention as the main early source of IL-17A in many immune response models. Because γδT cells have the characteristics of linking innate immunity and adaptive immunity,they can rapidly produce IL-17A and produce subsequent immune killing of cardiomyocytes. It can be seen that γδT cells play an important role in MIRI. Therefore, here we review the research progress of immune response in myocardial ischemia-re-perfusion injury, the key characteristics of γδT cells and the role of rapidly produced IL-17 in myocardial ischemia-re-perfusion injury, and propose relevant treatment strategies and prospects for myocardial repair, in order to provide new ideas and methods for clinical treatment of myocardial ischemia-re-perfusion injury.

New insights on IL‑36 in intestinal inflammation and colorectal cancer (Review)

Interleukin (IL)-36 is a member of the IL-1 superfamily, which includes three receptor agonists and one antagonist and exhibits a familial feature of inflammatory regulation. Distributed among various tissues, such as the skin, lung, gut and joints, the mechanism of IL-36 has been most completely investigated in the skin and has been used in clinical treatment of generalized pustular psoriasis. Meanwhile, the role of IL-36 in the intestine has also been under scrutiny and has been shown to be involved in the regulation of various intestinal diseases. Inflammatory bowel disease and colorectal cancer are the most predominant inflammatory and neoplastic diseases of the intestine, and multiple studies have identified a complex role for IL-36 in both of them. Indeed, inhibiting IL-36 signaling is currently regarded as a promising therapeutic approach. Therefore, the present review briefly describes the composition and expression of IL-36 and focuses on the role of IL-36 in intestinal inflammation and colorectal cancer. The targeted therapies that are currently being developed for the IL-36 receptor are also discussed.

Preliminary analysis of double-negative T, double-positive T, and natural killer T-like cells in B-cell chronic lymphocytic leukemia

BACKGROUND

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the expansion of CD5⁺ malignant B lymphocytes. Recent discoveries have shown that double-negative T (DNT) cells, double-positive T (DPT) cells, and natural killer T (NKT)-cells may be involved in tumor surveillance.

METHODS

A detailed immunophenotypic analysis of the peripheral blood T-cell compartment of 50 patients with B-CLL (classified in three prognostic groups) and 38 healthy donors (as controls) matched for age was performed. The samples were analyzed by flow cytometry using a stain-lyse-no wash technique and a comprehensive six-color antibody panels.

RESULTS

Our data confirmed a reduction in percentage values and an increase in absolute values of T lymphocytes in patients with B-CLL, as already reported. In particular, DNT, DPT, and NKT-like percentages were significantly lower than in the controls, except for NKT-like in the low-risk prognostic group. Moreover, a significant rise in the absolute counts of DNT cells in each prognostic group and in the low-risk prognostic group of NKT-like cells was found. A significant correlation of the absolute values of NKT-like cells in the intermediate-risk prognostic group versus B cells was observed. Furthermore, we analyzed whether the increase in T cells was related to the subpopulations of interest. Only DNT cells were positively correlated with the increase in CD3⁺ T lymphocytes, regardless of the stage of the disease, supporting the hypothesis that this T-cell subset plays a key role in the immune T response in B-CLL.

CONCLUSION

These early results supported that DNT, DPT, and NKT-like subsets may be related to disease progression and should encourage further studies aimed at identifying the potential immune surveillance role of these minority T subpopulations.

Natural Killer T and Natural Killer Cell-Based Immunotherapy Strategies Targeting Cancer

Both natural killer T (NKT) and natural killer (NK) cells are innate cytotoxic lymphoid cells that produce inflammatory cytokines and chemokines, and their role in the innate immune response to tumors and microorganisms has been investigated. Especially, emerging evidence has revealed their status and function in the tumor microenvironment (TME) of tumor cells. Some bacteria producing NKT cell ligands have been identified to exert antitumor effects, even in the TME. By contrast, tumor-derived lipids or metabolites may reportedly suppress NKT and NK cells in situ. Since NKT and NK cells recognize stress-inducible molecules or inhibitory molecules on cancer cells, their status or function depends on the balance between inhibitory and activating receptor signals. As a recent strategy in cancer immunotherapy, the mobilization or restoration of endogenous NKT or NK cells by novel vaccines or therapies has become a focus of research. As a new biological evidence, after activation, effector memory-type NKT cells lasted in tumor-bearing models, and NK cell-based immune checkpoint inhibition potentiated the enhancement of NK cell cytotoxicity against cancer cells in preclinical and clinical trials. Furthermore, several new modalities based on the characteristics of NKT and NK cells, including artificial adjuvant vector cells, chimeric antigen receptor-expressing NK or NKT cell therapy, or their combination with immune checkpoint blockade have been developed. This review examines challenges and future directions for improving these therapies.

Improved MAIT cell functions following fecal microbiota transplantation for metastatic renal cell carcinoma

Strategies to modify the gut microbiome in cancer patients using fecal microbiota transplantation (FMT) have gained momentum as a therapeutic intervention. However, how FMT impacts innate-like, antimicrobial T lymphocytes is unclear. In this study, we assessed peripheral blood (PB) mucosa-associated invariant T (MAIT) cell frequencies and functions in patients with metastatic renal cell carcinoma (mRCC) before and seven days after they received FMT as part of a clinical trial. We found comparable MAIT cell frequencies in healthy controls and mRCC patients. In contrast, γδ T cells exhibited a numerical decline in mRCC, which was partially reversed by FMT. We also found a significant increase in the PB CD4⁺ MAIT cell compartment of mRCC patients with or without FMT. Paired sample analyses revealed CD69 upregulation on MAIT cells accompanied by decreased PD-1 levels post-FMT. These changes were unique to MAIT cells as non-MAIT T lymphocytes showed either no trend or a trend in the opposite direction. Importantly, FMT did not render MAIT cells exhausted as also judged by their stable expression of TIM-3, LAG-3, BTLA, CTLA-4, TIGIT and VISTA. These findings were corroborated in functional assays in which MAIT cells were stimulated with MR1 ligands or with a combination of IL-12 and IL-18 to produce inflammatory cytokines and granzyme B. Indeed, when stimulated ex vivo with IL-12 and IL-18, MAIT cells mounted a more rigorous TNF-α response post-FMT. In conclusion, FMT improves MAIT cell functions, which should serve patients well in subsequent microbial challenges in the face of cancer-elicited immunosuppression. Trial Registration: https://clinicaltrials.gov/ Identifier: NCT04163289 (registration date: November 14, 2019).

Melatonin as an oncostatic agent: Review of the modulation of tumor microenvironment and overcoming multidrug resistance

Multi drug resistance (MDR) generally limits the efficacy of chemotherapy in cancer patients and can be categorized into primary or acquired resistance. Melatonin (MLT), a lipophilic hormone released from pineal gland, is a molecule with oncostatic effects. Here, we will briefly review the contribution of different microenvironmental components including fibroblasts, immune and inflammatory cells, stem cells and vascular endothelial cells in tumor initiation, progression and development. Then, the mechanisms by which MLT can potentially affect these elements and regulate drug resistance will be presented. Finally, we will explain how different studies have used novel strategies incorporating MLT to suppress cancer resistance against therapeutics.

Enhanced development of functional human NK cells in NOD-scid-IL2rgnull mice expressing human IL15

Human innate immunity plays a critical role in tumor surveillance and in immunoregulation within the tumor microenvironment. Natural killer (NK) cells are innate lymphoid cells that have opposing roles in the tumor microenvironment, including NK cell subsets that mediate tumor cell cytotoxicity and subsets with regulatory function that contribute to the tumor immune suppressive environment. The balance between effector and regulatory NK cell subsets has been studied extensively in murine models of cancer, but there is a paucity of models to study human NK cell function in tumorigenesis. Humanized mice are a powerful alternative to syngeneic mouse tumor models for the study of human immuno-oncology and have proven effective tools to test immunotherapies targeting T cells. However, human NK cell development and survival in humanized NOD-scid-IL2rg^null (NSG) mice are severely limited. To enhance NK cell development, we have developed NSG mice that constitutively expresses human Interleukin 15 (IL15), NSG-Tg(Hu-IL15). Following hematopoietic stem cell engraftment of NSG-Tg(Hu-IL15) mice, significantly higher levels of functional human CD56+ NK cells are detectable in blood and spleen, as compared to NSG mice. Hematopoietic stem cell (HSC)-engrafted NSG-Tg(Hu-IL15) mice also supported the development of human CD3+ T cells, CD20+ B cells, and CD33+ myeloid cells. Moreover, the growth kinetics of a patient-derived xenograft (PDX) melanoma were significantly delayed in HSC-engrafted NSG-Tg(Hu-IL15) mice as compared to HSC-engrafted NSG mice demonstrating that human NK cells have a key role in limiting the tumor growth. Together, these data demonstrate that HSC-engrafted NSG-Tg(Hu-IL15) mice support enhanced development of functional human NK cells, which limit the growth of PDX tumors.

Identification of lncRNA Signature Associated With Pan-Cancer Prognosis

Long noncoding RNAs (lncRNAs) have emerged as potential prognostic markers in various human cancers as they participate in many malignant behaviors. However, the value of lncRNAs as prognostic markers among diverse human cancers is still under investigation, and a systematic signature based on these transcripts that related to pan-cancer prognosis has yet to be reported. In this study, we proposed a framework to incorporate statistical power, biological rationale, and machine learning models for pan-cancer prognosis analysis. The framework identified a 5-lncRNA signature (ENSG00000206567, PCAT29, ENSG00000257989, LOC388282, and LINC00339) from TCGA training studies (n = 1,878). The identified lncRNAs are significantly associated (all P ≤ 1.48E-11) with overall survival (OS) of the TCGA cohort (n = 4,231). The signature stratified the cohort into low- and high-risk groups with significantly distinct survival outcomes (median OS of 9.84 years versus 4.37 years, log-rank P = 1.48E-38) and achieved a time-dependent ROC/AUC of 0.66 at 5 years. After routine clinical factors involved, the signature demonstrated better performance for long-term prognostic estimation (AUC of 0.72). Moreover, the signature was further evaluated on two independent external cohorts (TARGET, n = 1,122; CPTAC, n = 391; National Cancer Institute) which yielded similar prognostic values (AUC of 0.60 and 0.75; log-rank P = 8.6E-09 and P = 2.7E-06). An indexing system was developed to map the 5-lncRNA signature to prognoses of pan-cancer patients. In silico functional analysis indicated that the lncRNAs are associated with common biological processes driving human cancers. The five lncRNAs, especially ENSG00000206567, ENSG00000257989 and LOC388282 that never reported before, may serve as viable molecular targets common among diverse cancers.

Prognostic Signature of Immune Genes and Immune-Related LncRNAs in Neuroblastoma: A Study Based on GEO and TARGET Datasets

Background

The prognostic value of immune-related genes and lncRNAs in neuroblastoma has not been elucidated, especially in subgroups with different outcomes. This study aimed to explore immune-related prognostic signatures.

Materials and Methods

Immune-related prognostic genes and lncRNAs were identified by univariate Cox regression analysis in the training set. The top 20 C-index genes and 17 immune-related lncRNAs were included in prognostic model construction, and random forest and the Least Absolute Shrinkage and Selection Operator (LASSO) regression algorithms were employed to select features. The risk score model was constructed and assessed using the Kaplan-Meier plot and the receiver operating characteristic curve. Functional enrichment analysis of the immune-related lncRNAs was conducted using the STRING database.

Results

In GSE49710, five immune genes (CDK4, PIK3R1, THRA, MAP2K2, and ULBP2) were included in the risk score five genes (RS5_G) signature, and eleven immune-related lncRNAs (LINC00260, FAM13A1OS, AGPAT4-IT1, DUBR, MIAT, TSC22D1-AS1, DANCR, MIR137HG, ERC2-IT1, LINC01184, LINC00667) were brought into risk score LncRNAs (RS_Lnc) signature. Patients were divided into high/low-risk score groups by the median. Overall survival and event/progression-free survival time were shortened in patients with high scores, both in training and validation cohorts. The same results were found in subgroups. In grouping ability assessment, the area under the curves (AUCs) in distinguishing different groups ranged from 0.737 to 0.94, better in discriminating MYCN status and high risk in training cohort (higher than 0.9). Multivariate Cox analysis demonstrated that RS5_G and RS_Lnc were the independent risk factors for overall and event/progression-free survival (all p-values <0.001). Correlation analysis showed that RS5_G and RS_Lnc were negatively associated with aDC, CD8+ T cells, but positively correlated with Th2 cells. Functional enrichment analyzes demonstrated that immune-related lncRNAs are mainly enriched in cancer-related pathways and immune-related pathways.

Conclusion

We identified the immune-related prognostic signature RS5_G and RS_Lnc. The predicting and grouping ability is close to being even better than those reported in other studies, especially in subgroups. This study provided prognostic signatures that may help clinicians to choose optimal treatment strategies and showed a new insight for NB treatment. These results need further biological experiments and clinical validation.

Exploiting CD1-restricted T cells for clinical benefit

CD1-restricted T cells were first described over 30 years ago along with the cloning of the CD1 family. Around the same time, invariant Natural Killer cells (iNKT) were identified based on invariant TCR-alpha chains with additional expression of natural killer (NK) cell markers. About 5 years later, iNKT were shown to react with CD1d. Since then, iNKT have been shown to be a major population of CD1d-restricted T cells in humans and many animals. Like NK cells, iNKT are innate lymphocytes with rapid and wide-ranging effector potential. These activities include cytotoxicity and an unusually broad and high-level cytokine production. The development of highly-specific methods of isolating, stimulating, expanding or depleting these relatively rare cells and controlling their potent activities has stimulated considerable interest in therapeutic targeting of iNKT cells. Potential applications include cancers, inflammatory, infectious and autoimmune among other diseases. To date, most trials have targeted various cancers, there are 2 published trials in viral hepatitis and one in sickle cell lung disease. Uniform safety, evidence of immunologic activity and increasingly clinical efficacy have been seen. Approaches to targeting iNKT cells in clinical development include highly specific natural glycolipid ligands presented by CD1d and chemical analogues thereof and monoclonal antibody-based targeting of iNKT cells. In the case of iNKT cell-based therapies, novel approaches include arming them with Chimeric Antigen Receptors (CARs) and recombinant TCRs (rTCR), gene editing and allogeneic use. Controlling the iTCR:CD1d molecular interaction and consequences is a unique and promising therapeutic technology.

Liposomal Nanovaccine Containing α-Galactosylceramide and Ganglioside GM3 Stimulates Robust CD8+ T Cell Responses via CD169+ Macrophages and cDC1

Successful anti-cancer vaccines aim to prime and reinvigorate cytotoxic T cells and should therefore comprise a potent antigen and adjuvant. Antigen targeting to splenic CD169⁺ macrophages was shown to induce robust CD8⁺ T cell responses via antigen transfer to cDC1. Interestingly, CD169⁺ macrophages can also activate type I natural killer T-cells (NKT). NKT activation via ligands such as α-galactosylceramide (αGC) serve as natural adjuvants through dendritic cell activation. Here, we incorporated ganglioside GM3 and αGC in ovalbumin (OVA) protein-containing liposomes to achieve both CD169⁺ targeting and superior DC activation. The systemic delivery of GM3-αGC-OVA liposomes resulted in specific uptake by splenic CD169⁺ macrophages, stimulated strong IFNγ production by NKT and NK cells and coincided with the maturation of cDC1 and significant IL-12 production. Strikingly, superior induction of OVA-specific CD8⁺ T cells was detected after immunization with GM3-αGC-OVA liposomes. CD8⁺ T cell activation, but not B cell activation, was dependent on CD169⁺ macrophages and cDC1, while activation of NKT and NK cells were partially mediated by cDC1. In summary, GM3-αGC antigen-containing liposomes are a potent vaccination platform that promotes the interaction between different immune cell populations, resulting in strong adaptive immunity and therefore emerge as a promising anti-cancer vaccination strategy.

Regulating innovation in the early development of cell therapies

Clinical need for paradigm shifts in efficacy and safety is driving the rapid and wide-ranging innovation in cell therapies for cancer beyond existing regulatory frameworks. Critical issues emerging during clinical trials frequently reflect unresolved elements of the regulation of innovation conundrum from earlier stages of development. We address this challenge using a global regulators’ perspective on the preclinical development of cell therapies, as a navigational aid to intended commercial use which maximises the clinical relevance of developmental data. We examine the implications of tumour targeting based on B cell, natural killer cell, conventional and unconventional T cell receptor domains; multiplex approaches; genetic manipulation strategies; and autologous versus allogeneic cell sources. We propose that detailed characterisation of both the cell source and final product is critical to optimising manufacture of individualised autologous or off the shelf allogeneic cell therapies, enabling product consistency to underpin extrapolation of clinical trial data to the expected commercial use. We highlight preclinical approaches to characterising target antigens including the Human Cell Atlas initiative, multi-dimensional cell culture, and safety testing against activated, proliferating or stressed control cells. Practical solutions are provided for preclinical toxicity studies when cell therapies target uniquely human tumour antigens, including illustrative mitigation measures for potential toxicity likely to support timely approval of first-in-human clinical trials. We recommend addressing the regulation of innovation conundrum through serial engagement between innovators and regulators early in the development of cell therapies for cancer, accelerating patient access while safeguarding against unacceptable toxicities.

Ex vivo rectal explant model reveals potential opposing roles of Natural Killer cells and Marginal Zone-like B cells in HIV-1 infection

Our understanding of innate immune responses in human rectal mucosal tissues (RM) and their contributions to promoting or restricting HIV transmission is limited. We defined the RM composition of innate and innate-like cell subsets, including plasmacytoid dendritic cells; CD1c + myeloid DCs; neutrophils; macrophages; natural killer cells (NK); Marginal Zone-like B cells (MZB); γδ T cells; and mucosal-associated invariant T cells in RM from 69 HIV-negative men by flow cytometry. Associations between these cell subsets and HIV-1 replication in ex vivo RM explant challenge experiments revealed an inverse correlation between RM-NK and p24 production, in contrast to a positive association between RM-MZB and HIV replication. Comparison of RM and blood-derived MZB and NK illustrated qualitative and quantitative differences between tissue compartments. Additionally, 22 soluble molecules were measured in a subset of explant cultures (n = 26). Higher production of IL-17A, IFN-γ, IL-10, IP-10, GM-CSF, sFasL, Granzyme A, Granzyme B, Granulysin, and Perforin following infection positively correlated with HIV replication. These data show novel associations between MZB and NK cells and p24 production in RM and underscore the importance of inflammatory cytokines in mucosal HIV infection, demonstrating the likely critical role these innate immune responses play in early mucosal HIV replication in humans.

Distinct immune composition in lymph node and peripheral blood of CLL patients is reshaped during venetoclax treatment

Morbidity and mortality due to immunosuppression remain among the foremost clinical challenges in chronic lymphocytic leukemia (CLL). Although immunosuppression is considered to originate within the lymph node (LN) microenvironment, alterations in T and natural killer (NK) cells have almost exclusively been studied in peripheral blood (PB). Whereas chemoimmunotherapy further deteriorates immune function, novel targeted agents like the B-cell lymphoma 2 inhibitor venetoclax potentially spare nonmalignant lymphocytes; however, the effects of venetoclax on nonleukemic cells have not been explored. We address these unresolved issues using a comprehensive analysis of nonmalignant lymphocytes in paired LN and PB samples from untreated CLL patients, and by analyzing the effects of venetoclax-based treatment regimens on the immune system in PB samples from previously untreated and relapsed/refractory patients. CLL-derived LNs contained twice the amount of suppressive regulatory T cells (T_regs) and CLL supportive follicular T helper (T_fh) cells compared with PB. This was accompanied by a low frequency of cytotoxic lymphocytes. The expression of PD-1 by CD8⁺ T cells was significantly higher in LN compared with PB. Venetoclax-based treatment led to deep responses in the majority of patients, but also to decreased absolute numbers of B, T, and NK cells. T_fh cell, T_reg, and PD-1⁺ CD8⁺ T cell numbers were reduced more than fivefold after venetoclax-based therapy, and overproduction of inflammatory cytokines was reduced. Furthermore, we observed restoration of NK cell function. These data support the notion that the immunosuppressive state in CLL is more prominent within the LN. Venetoclax-based regimens reduced the immunosuppressive footprint of CLL, suggesting immune recovery after the elimination of leukemic cells.

Unravelling the heterogeneity and dynamic relationships of tumor-infiltrating T cells by single-cell RNA sequencing analysis

T cells are crucial for the success of immune-based cancer therapy. Reinvigorating antitumor T cell activity by blocking checkpoint inhibitory receptors has provided clinical benefits for many cancer patients. However, the efficacy of these treatments varies in cancer patients and the mechanisms underlying these diverse responses remain elusive. The density and status of tumor-infiltrating T cells have been shown to positively correlate with patient response to checkpoint blockades. Therefore, further understanding of the heterogeneity, clonal expansion, migration, and effector functions of tumor-infiltrating T cells will provide fundamental insights into antitumor immune responses. To this end, recent advances in single-cell RNA sequencing technology have enabled profound and extensive characterization of intratumoral immune cells and have improved our understanding of their dynamic relationships. Here, we summarize recent progress in single-cell RNA sequencing technology and current strategies to uncover heterogeneous tumor-infiltrating T cell subsets. In particular, we discuss how the coupling of deep transcriptome information with T cell receptor (TCR)-based lineage tracing has furthered our understanding of intratumoral T cell populations. We also discuss the functional implications of various T cell subsets in tumors and highlight the identification of novel T cell markers with therapeutic or prognostic potential.

Navigating the Role of CD1d/Invariant Natural Killer T-cell/Glycolipid Immune Axis in Multiple Myeloma Evolution: Therapeutic Implications

Multiple myeloma (MM) is an incurable B-cell malignancy. The immunotherapeutic approach for MM therapy is evolving. The Cd1d/invariant natural killer T-cell/glycolipid immune axis belongs to the innate immunity, and we have highlighted role in myeloma pathogenesis in the present study. The recent development of the chimeric antigen receptor (CAR19)-invariant natural killer T-cells resulted in our renewed interest in this immune system and offer new perspectives for future anti-MM immunotherapies.

NK and NKT Cell-Mediated Immune Surveillance against Hematological Malignancies

Recent cancer treatment modalities have been intensively focused on immunotherapy. The success of chimeric antigen receptor T cell therapy for treatment of refractory B cell acute lymphoblastic leukemia has pushed forward research on hematological malignancies. Among the effector types of innate lymphocytes, natural killer (NK) cells show great importance in immune surveillance against infectious and tumor diseases. Particularly, the role of NK cells has been argued in either elimination of target tumor cells or escape of tumor cells from immune surveillance. Therefore, an NK cell activation approach has been explored. Recent findings demonstrate that invariant natural killer T (iNKT) cells capable of producing IFN-γ when optimally activated can promptly trigger NK cells. Here, we review the role of NKT and/or NK cells and their interaction in anti-tumor responses by highlighting how innate immune cells recognize tumors, exert effector functions, and amplify adaptive immune responses. In addition, we discuss these innate lymphocytes in hematological disorders, particularly multiple myeloma and acute myeloid leukemia. The immune balance at different stages of both diseases is explored in light of disease progression. Various types of innate immunity-mediated therapeutic approaches, recent advances in clinical immunotherapies, and iNKT-mediated cancer immunotherapy as next-generation immunotherapy are then discussed.

YY1lo NKT cells are dedicated IL-10 producers

Co-expression of Yin Yang 1 (YY1) is required for the full function of the transcription factor, PLZF, which is essential for the development of natural killer T cell (NKT cell) effector functions. Discordant expression of YY1 and PLZF, therefore, might define NKT cell subsets with distinct effector functions. A subset of NKT cells was identified that expressed low levels of YY1. YY1lo NKT cells were found in all tissues, had a mature phenotype and, distinct from other NKT cells, expressed almost no ThPOK or Tbet. When activated, YY1lo NKT cells produced little IL-4 or IFN-γ. YY1lo NKT cells were found to constitutively transcribe IL-10 mRNA and, accordingly, produced IL-10 upon primary activation. Finally, we find that tumor infiltrating NKT cells are highly enriched for the YY1lo subset. Low YY1 expression, therefore, defines a previously unrecognized NKT cell subset that is committed to producing IL-10.

Heterogeneity of Human γδ T Cells and Their Role in Cancer Immunity

The γδ T cells are unconventional lymphocytes that function in both innate and adaptive immune responses against various intracellular and infectious stresses. The γδ T cells can be exploited as cancer-killing effector cells since γδ TCRs recognize MHC-like molecules and growth factor receptors that are upregulated in cancer cells, and γδ T cells can differentiate into cytotoxic effector cells. However, γδ T cells may also promote tumor progression by secreting IL-17 or other cytokines. Therefore, it is essential to understand how the differentiation and homeostasis of γδ T cells are regulated and whether distinct γδ T cell subsets have different functions. Human γδ T cells are classified into Vδ2 and non-Vδ2 γδ T cells. The majority of Vδ2 γδ T cells are Vγ9δ2 T cells that recognize pyrophosphorylated isoprenoids generated by the dysregulated mevalonate pathway. In contrast, Vδ1 T cells expand from initially diverse TCR repertoire in patients with infectious diseases and cancers. The ligands of Vδ1 T cells are diverse and include the growth factor receptors such as endothelial protein C receptor. Both Vδ1 and Vδ2 γδ T cells are implicated to have immunotherapeutic potentials for cancers, but the detailed elucidation of the distinct characteristics of 2 populations will be required to enhance the immunotherapeutic potential of γδ T cells. Here, we summarize recent progress regarding cancer immunology of human γδ T cells, including their development, heterogeneity, and plasticity, the putative mechanisms underlying ligand recognition and activation, and their dual effects on tumor progression in the tumor microenvironment.

The renal adverse effects of cancer immunotherapy

Over the past decade, the development and clinical use of immunotherapy agents has increased exponentially. As clinical experience builds with these agents so too does our understanding of the associated adverse effects. In particular, the effects of immunotherapy on the kidneys, individual nephrons, and kidney function remain less well described than the adverse effects on barrier organ systems such as the gastrointestinal tract and skin. However, phase IV post-marketing surveillance and clinical case studies together with basic research has begun to reveal mechanisms by which immunotherapy mediates renal adverse effects. This work may lead to improvements in treatment guidelines and therapy. These advances are particularly important as post-cancer survival increases leaving patients to cope with the consequences of not only the cancer, but the short- and long-term adverse effects of treatment. Here we discuss the major renal adverse effects encountered with individual immunotherapeutic agents, putative mechanisms, their current management, and how cancer survivorship programs can help patients who have been treated with immunotherapy.

Nano-immunotherapy: Overcoming tumour immune evasion

Immunotherapy is emerging as a groundbreaking cancer treatment, offering the unprecedented opportunity to effectively treat and in several cases, even cure previously untreatable malignancies. Anti-tumour immunotherapies designed to amplify T cell responses against defined tumour antigens have long been considered effective approaches for cancer treatment. Despite a clear rationale behind such immunotherapies, extensive past efforts were unsuccessful in mediating clinically relevant anti-tumour activity in humans. This is mainly because tumours adopt specific mechanisms to circumvent the host´s immunity. Emerging data suggest that the full potential of cancer immunotherapy will be only achieved by combining immunotherapies designed to generate or amplify anti-tumour T cell responses with strategies able to impair key tumour immune-evasion mechanisms. However, many approaches aimed to re-shape the tumour immune microenvironment (TIME) are commonly associated with severe systemic toxicity, require frequent administration, and only show modest efficacy in clinical settings. The use of nanodelivery systems is revealing as a valid means to overcome these limitations by improving the targeting efficiency, minimising systemic exposure of immunomodulatory agents, and enabling the development of novel combinatorial immunotherapies. In this review, we examine the emerging field of therapeutic modulation of TIME by the use of nanoparticle-based immunomodulators and potential future directions for TIME-targeting nanotherapies.