It has been demonstrated that the development of NKT cells requires CD1d. The contribution of costimulatory molecules in this process has not been studied. Here we show that in mice with targeted mutations of B7-1/2 and CD28, the TCRbeta(+)alpha-Galcer/CD1d(+) (iValpha14 NKT) subset is significantly reduced in the thymus, spleen and liver. This is mainly due to decreased cell proliferation; although increased cell death in the thymi of CD28-deficient mice was also observed. Moreover, in the B7-1/2- and CD28-deficient mice, we found a decreased percentage of the CD4(-)NK1.1(+) subset and a correspondingly increased portion of the CD4(+)NK1.1(-) subset. In addition, the mice with a targeted mutation of either B7 or CD28 had a reduced susceptibility to Con A induced hepatitis, which is known to be mediated by NKT cells. Our results demonstrate that the development, maturation and function of NKT cell are modulated by the costimulatory pathway and thus expand the horizon of costimulation into NKT, which is widely viewed as a bridge between innate and adaptive immunity. As such, costimulation may modulate all major branches of cell-mediated immunity, including T cells, NK cells and NKT cells.

In our previous study we found that miR-612 negatively regulated stem cell-like property and tumor metastasis of hepatocellular carcinoma cells (HCC). In this study, we try to elucidate underlying mechanism of the regulation, and find that miR-612 inversely modulate the mRNA and protein level of epithelial cell adhesion molecule as well as CD133, negatively regulate the numbers and sizes of tumor spheres, directly inhibit the protein level of Sp1, and subsequently reduce transcription activity of Nanog. Of importance, the higher levels of Sp1 and Nanog in biopsies are the more unfavorable prognoses of HCC patients are found after tumor resection. Taken together, miR-612 has a suppressive role on HCC stemness via Sp1/Nanog signaling pathway.

In response to a lymphopenic cue, T lymphocytes undergo a slow-paced homeostatic proliferation in an attempt to restore T cell cellularity. The molecular interaction that maintains the pace of homeostatic proliferation is unknown. In this study, we report that in lymphopenic CD24-deficient mice, T cells launch a massive proliferation that results in the rapid death of the recipient mice. The dividing T cells have phenotypes similar to those activated by cognate antigens. The rapid homeostatic proliferation is caused by a lack of CD24 on dendritic cells (DCs). Interestingly, although CD24 expression in T cells is required for optimal homeostatic proliferation in the wild-type (WT) host, mice lacking CD24 on all cell types still mount higher homeostatic proliferation than the WT mice. Thus, a lack of CD24 in the non-T host cells bypassed the requirement for T cell expression of CD24 in homeostatic proliferation in the WT host. Our data demonstrate that CD24 expressed on the DCs limits T cell response to homeostatic cue and prevents fatal damage associated with uncontrolled homeostatic proliferation.

Our previous study demonstrated a progressive glycolytic perturbation during the course of DMBA-induced hamster oral carcinogenesis, which was attenuated by salvianolic acid B (Sal-B) treatment along with decreased incidences of oral squamous cell carcinoma (OSCC) formation. It was proposed that metabolic modulation should be an additional mode of action attributable to Sal-B's anti-carcinogenic activity. However, the molecular mechanisms underlying Sal-B-induced metabolic modulation function remained elusive. In the present study, we performed next-generation sequencing (NGS) profiling in the same animal model and found Sal-B treatment evoked a general downregulation of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and hypoxia inducible factor 1α subunit (HIF-1α) signaling pathways, which might contribute to Sal-B's metabolic modulation activity. The inhibitory effects of Sal-B on aerobic glycolysis, as well as PI3K/AKT and HIF-1α signaling pathways, were validated in two well-characterized OSCC cell lines (Cal27 and HN4), and premalignant oral Leuk1 cells and Sal-B treatment led to elevation of the loss of mitochondrial membrane potential (MMP), increased cell apoptosis, and reduced abilities of colony formation. Rescue assays suggested that compared with Sal-B treatment group, Akt or hif-1a overexpression attenuated the inhibitory effect of Sal-B on glucose uptake and intracellular lactate level. Taken together, our results suggested that Sal-B modulated aberrant glucose metabolism via the PI3K/AKT/HIF-1α signaling pathways, which might contribute to the anti-carcinogenic activity of Sal-B.

Under lymphopenic conditions, the rapid spontaneous proliferation produces cells that robustly differentiate into effector memory T (TEM) cells, and the aberrant expansion is preferentially driven by self-antigens. The pool size of effector memory T-cell is governed by a complex homeostatic balance between proliferation and death. Perp is a critical effector involved in the p53-dependent apoptotic pathway and widely expressed in mammalian tissues. We have previously shown that Perp has a prominent role in activation-induced cell death of peripheral Th17 cells. Here, we show that Peripheral Perp-/-CD4+ TEM cells outcompete wild type TEM cells for access to splenic niches in vivo. The skewing of the Perp-/- TEM cells compartment was not the result of a difference in lymphopenia-induced proliferation, but the resistance to apoptosis, particularly after anti-Fas treatment. Data presented in this work indicate that Perp mediates the persistence of CD4+ TEM cells in irradiation-induced lymphopenic settings.

Understanding the mechanism that leads to immune dysfunction in severe coronavirus disease 2019 (COVID-19) is crucial for the development of effective treatment. Here, using single-cell RNA sequencing, we characterized the peripheral blood mononuclear cells (PBMCs) from uninfected controls and COVID-19 patients and cells in paired broncho-alveolar lavage fluid (BALF). We found a close association of decreased dendritic cells (DCs) and increased monocytes resembling myeloid-derived suppressor cells (MDSCs), which correlated with lymphopenia and inflammation in the blood of severe COVID-19 patients. Those MDSC-like monocytes were immune-paralyzed. In contrast, monocyte-macrophages in BALFs of COVID-19 patients produced massive amounts of cytokines and chemokines, but secreted little interferons. The frequencies of peripheral T cells and NK cells were significantly decreased in severe COVID-19 patients, especially for innate-like T and various CD8+ T cell subsets, compared to healthy controls. In contrast, the proportions of various activated CD4+ T cell subsets among the T cell compartment, including Th1, Th2, and Th17-like cells were increased and more clonally expanded in severe COVID-19 patients. Patients' peripheral T cells showed no sign of exhaustion or augmented cell death, whereas T cells in BALFs produced higher levels of IFNG, TNF, CCL4, CCL5, etc. Paired TCR tracking indicated abundant recruitment of peripheral T cells to the severe patients' lung. Together, this study comprehensively depicts how the immune cell landscape is perturbed in severe COVID-19.

Cell-based immunotherapy for the treatment of hematologic malignancies, such as leukemia and lymphoma, has seen much success and played an increasingly important role in clinical studies. Nevertheless, the efficacy of immunotherapy in solid tumors still needs improvements due to the immunosuppressive properties of tumor cells and the microenvironment. To overcome these limitations, we prepared a novel tumor-targeting delivery system based on the underlying mechanism of immune-targeted cell death that encapsulated granzyme B protein within a porous polymeric nanocapsule. Methods: A cell-penetrating peptide TAT was attached onto granzyme B (GrB) to enhance its transmembrane transport efficiency and potency to induce cell apoptosis. The endocytosis and internalization pathways of GrB-TAT (GrB-T) were analyzed in comparison with perforin by confocal microscopy and flow cytometry. Furthermore, the positively charged GrB-T was wrapped into nanoparticles by p-2-methacryloyloxy ethyl phosphorylcholine (PMPC)-modified HA (hyaluronic acid). The nanoparticles (called TCiGNPs) were characterized in terms of zeta potential and by transmission electron microscopy (TEM). The in vitro anti-tumor effects of GrB-T were examined by cell apoptosis assay and Western blotting analysis. The in vivo anti-tumor therapeutic efficacy of TCiGNPs was evaluated in a mouse tumor model. Results: The TAT peptide could play a role similar to perforin to mediate direct transmembrane transfer of GrB and improve GrB-induced cell apoptosis. The TCiGNPs were successfully synthesized and accumulated in the solid tumor through enhanced permeability and retention (EPR) effect. In the tumor microenvironment, TCiGNPs could be degraded by hyaluronidase and triggered the release of GrB-T. The TAT peptide enabled the translocation of GrB across the plasma membrane to induce tumor cell apoptosis in vivo.Conclusion: We successfully developed a granzyme B delivery system with a GrB-T core and a PMPC/HA shell that simulated CTL/NK cell-mediated cancer immunotherapy mechanism. The GrB delivery system holds great promise for cancer treatment analogous to the CTL/NK cell-induced immunotherapy.

Non-small cell lung cancer (NSCLC) is the most commonly diagnosed cancer and the leading cause of cancer death worldwide. More than half of patients with NSCLC die after developing distant metastases, so rapid, minimally invasive prognostic biomarkers are needed to reduce mortality. We used proteomics to identify proteins differentially expressed on extracellular vesicles (EVs) of nonmetastatic 393P and metastatic 344SQ NSCLC cell lines and found that tetraspanin-8 (Tspan8) was selectively enriched on 344SQ EVs. NSCLC cell lines treated with EVs overexpressing Tspan8 also exhibited increased Matrigel invasion. Elevated Tspan8 expression on serum EVs of individuals with stage III premetastatic NSCLC tumors was also associated with reduced distant metastasis-free survival, suggesting that Tspan8 levels on serum EVs may predict future metastasis. This result suggests that a minimally invasive blood test to analyze EV expression of Tspan8 may be of potential value to guide therapeutic decisions for patients with NSCLC and merits further study.

Programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) blocking therapy has become a major pillar of cancer immunotherapy. Compared with antibodies targeting, small-molecule checkpoint inhibitors which have favorable pharmacokinetics are urgently needed. Here we identified berberine (BBR), a proven anti-inflammation drug, as a negative regulator of PD-L1 from a set of traditional Chinese medicine (TCM) chemical monomers. BBR enhanced the sensitivity of tumour cells to co-cultured T-cells by decreasing the level of PD-L1 in cancer cells. In addition, BBR exerted its antitumor effect in Lewis tumor xenograft mice through enhancing tumor-infiltrating T-cell immunity and attenuating the activation of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T-cells (Tregs). BBR triggered PD-L1 degradation through ubiquitin (Ub)/proteasome-dependent pathway. Remarkably, BBR selectively bound to the glutamic acid 76 of constitutive photomorphogenic-9 signalosome 5 (CSN5) and inhibited PD-1/PD-L1 axis through its deubiquitination activity, resulting in ubiquitination and degradation of PD-L1. Our data reveals a previously unrecognized antitumor mechanism of BBR, suggesting BBR is small-molecule immune checkpoint inhibitor for cancer treatment.

Ant colonies with permanent division of labour between castes and highly distinct roles of the sexes have been conceptualized to be superorganisms, but the cellular and molecular mechanisms that mediate caste/sex-specific behavioural specialization have remained obscure. Here we characterized the brain cell repertoire of queens, gynes (virgin queens), workers and males of Monomorium pharaonis by obtaining 206,367 single-nucleus transcriptomes. In contrast to Drosophila, the mushroom body Kenyon cells are abundant in ants and display a high diversity with most subtypes being enriched in worker brains, the evolutionarily derived caste. Male brains are as specialized as worker brains but with opposite trends in cell composition with higher abundances of all optic lobe neuronal subtypes, while the composition of gyne and queen brains remained generalized, reminiscent of solitary ancestors. Role differentiation from virgin gynes to inseminated queens induces abundance changes in roughly 35% of cell types, indicating active neurogenesis and/or programmed cell death during this transition. We also identified insemination-induced cell changes probably associated with the longevity and fecundity of the reproductive caste, including increases of ensheathing glia and a population of dopamine-regulated Dh31-expressing neurons. We conclude that permanent caste differentiation and extreme sex-differentiation induced major changes in the neural circuitry of ants.

Glioblastoma multiforme (GBM) is the most prevalent form of malignant brain tumor. Amlexanox, a novel compound, has been shown to have anti-cancer potential. In this study, the anti-tumoral effects and the underlying mechanisms of amlexanox were investigated. Amlexanox significantly suppressed proliferation and invasion and induced apoptosis in glioblastoma cells. Furthermore, we found that amlexanox altered the protein expression of the Hippo pathway by downregulating IKBKE. Our data indicates that IKBKE directly targets LATS1/2 and induces degradation of LATS1/2, thereby inhibiting the activity of the Hippo pathway. In vivo results further confirmed the tumor inhibitory effect of amlexanox via the downregulation of IKBKE, and amlexanox induced no apparent toxicity. Collectively, our studies suggest that amlexanox is a promising therapeutic agent for the treatment of GBM.

Esophageal Squamous Cell Carcinoma (ESCC) is one of the most common malignant cancers worldwide with a high death rate worldwide. Long non-coding RNA (LncRNA) has been recently demonstrated to play a critical role in ESCC. LncRNA HOTAIR played important regulatory roles in ESCC. We highlight the molecular mechanisms by which HOTAIR could influence the expression of Hexokinase 2 (HK2) in ESCC through binding miR-125 and miR-143 directly. Taken together, this study identified a functional lncRNA HOTAIR involved with regulation of glycolysis via miRNA-125/miRNA-143-HK2 in ESCC cells. The "competitive endogenous RNA" (ceRNA) model of HOTAIR/miR-125 and miR143/HK2 interaction might serve as important targets for ESCC diagnosis and therapy.

Radiotherapy may work synergistically with immunotherapy and targeted agents. We aimed to assess the safety and outcomes of stereotactic body radiotherapy (SBRT) plus non-first-line programmed death-1 (PD-1) inhibitors and targeted agents (TA) in metastatic renal cell carcinoma (mRCC).

Bruton's tyrosine kinase inhibitors (BTKi) and CAR T-cell therapy have demonstrated tremendous clinical benefits in mantle cell lymphoma (MCL) patients, but intrinsic or acquired resistance inevitably develops. In this study, we assessed the efficacy of the highly potent and selective MCL-1 inhibitor AZD5991 in various therapy-resistant MCL cell models. AZD5991 markedly induced apoptosis in these cells. In addition to liberating BAK from the antiapoptotic MCL-1/BAK complex for the subsequent apoptosis cascade, AZD5991 downregulated inhibitor of apoptosis proteins (IAPs) through a BAK-dependent mechanism to amplify the apoptotic signal. The combination of AZD5991 with venetoclax enhanced apoptosis and reduced mitochondrial oxygen consumption capacity in MCL cell lines irrespective of their BTKi or venetoclax sensitivity. This combination also dramatically inhibited tumor growth and prolonged mouse survival in two aggressive MCL patient-derived xenograft models. Mechanistically, the augmented cell lethality was accompanied by the synergistic suppression of IAPs. Supporting this notion, the IAP antagonist BV6 induced dramatic apoptosis in resistant MCL cells and sensitized the resistant MCL cells to venetoclax. Our study uncovered another unique route for MCL-1 inhibitor to trigger apoptosis, implying that the pro-apoptotic combination of IAP antagonists and apoptosis inducers could be further exploited for MCL patients with multiple therapeutic resistance.

Rationale: Multidrug resistance (MDR) and metastasis of breast cancer remain major hurdles in clinical anticancer therapy. The unsatisfactory outcome is largely due to insufficient cytotoxicity of chemotherapeutic agents and limited immunogenic cell death (ICD). On the other hand, efflux proteins, especially P-glycoprotein (P-gp), can recognize and promote the efflux of drugs from tumor cells. Methods: In this study, silver nanoparticles (Ag NPs) and peptide- functionalized doxorubicin (PDOX) were used to prepare a theranostic nanocomposite (Ag-TF@PDOX), which induced organelle-mediated immunochemotherapy and drug efflux protein inhibition in drug-resistant breast cancer cells (MCF-7/ADR) via a strategy based on endoplasmic reticulum (ER) stress and cell-nucleus penetration. Results: The silver nanoparticle-triggered persistent activation of ER stress synergizes with chemotherapy to enhance cytotoxicity and stimulate the ICD effect. It has the potential to enhance chemosensitivity by downregulating of P-gp expression due to the increased production of ATP-consuming chaperones. In addition, the novel peptide (CB5005), which not only penetrates the cell membrane but also has a nuclear localization sequence, is conjugated to DOX to improve both cellular internalization and intranuclear accumulation. Moreover, surface TA-Fe3+ engineering endows the nanocomposite with ATP-responsive disassembly and ATP depletion properties to improve biocompatibility and decrease ATP-dependent drug efflux. Ag-TF@PDOX has potential as a dual-mode (PAI/MRI) contrast-enhanced agent for realizing theranostic guidance. Conclusion: This theranostic nanocomposite greatly restricts the growth of drug-resistant breast tumors and activates a strong immune response as well, providing an opportunity for the development of therapeutics that reverse tumor MDR and metastasis at the subcellular level.

Cerebral infarction is one of the leading causes of death worldwide, in which angiogenesis plays a critical role. On the other hand, accumulating evidence has demonstrated that microRNAs (miRNAs) function as key modulators in the formation and progression of cerebral infarction. However, the molecular mechanisms of miRNAs underlying cerebral infarction-associated angiogenesis remain unclear. In the present study, we indicated that the expression of miR-203 was significantly downregulated in serum samples derived from patients with cerebral infarction and in mice brain samples following middle cerebral artery occlusion (MCAO) compared with healthy controls. In vitro, the expression of miR-203 was obviously downregulated in hypoxia-induced human umbilical vein vascular endothelial cells (HUVECs). Functionally, ectopic expression of miR-203 drastically suppressed HUVEC proliferation, invasion, and migration. In addition, SLUG, a zinc finger transcriptional repressor, was identified as a direct target of miR-203 and was negatively correlated with miR-203 expression in MCAO mice and in hypoxia-induced HUVECs. Furthermore, overexpression of SLUG reversed the inhibitory effect of miR-203 on proliferation, invasion, and migration abilities of HUVECs. Taken together, our research provides a novel insight of the miR-203-SLUG axis into cerebral infarction-associated endothelial behaviors and may offer a powerful therapeutic target of cerebral ischemia.

The aim of this study was to investigate the in vitro release and the effect of RAW 264.7 macrophages of critical-sized wear particles of ultra-high molecular weight polyethylene (UHMWPE) loaded with alendronate sodium (ALN), one of the most effective drugs to treat osteoporosis in clinic. The critical-sized UHMWPE-ALN 0.5 wt.% wear particles were prepared by vacuum gradient filtration combined with Pluronic F-68. In vitro release of ALN from critical-sized UHMWPE-ALN wear particles was investigated in phosphate buffered saline (PBS) at 37 °C with a shaker. Cell morphology, proliferation, lactate dehydrogenase (LDH) leakage and secretions of cytokines were evaluated after co-cultured with critical-sized UHMWPE-ALN wear particles in vitro. Results showed that ALN released from critical-sized UHMWPE-ALN wear particles included burst release and slow release in vitro. Macrophages would be chemotaxis and aggregated around the critical-sized UHMWPE-ALN or UHMWPE wear particle, which was phagocytosed with time. The proliferation of macrophages co-cultured with critical-sized UHMWPE-ALN wear particles was significantly decreased compared with that of critical-sized UHMWPE group. Meanwhile, the critical-sized UHMWPE-ALN wear particles significantly induced the LDH leakage of macrophages, which indicated the cell death. The death of macrophages induced by ALN was one of pathways to inhibit their proliferation. The secretions of cytokines (interleukin-6 and tumor necrosis factor-alpha) in critical-sized UHMWPE-ALN group were significantly lower than those in critical-sized UHMWPE group due to the released ALN. The present results suggested that UHMWPE-ALN had the potential application in clinic to treat osteolysis induced by wear particles.

The combination of elevated glucose and free-fatty acids (FFA), prevalent in diabetes, has been suggested to be a major contributor to pancreatic β-cell death. This study examines the synergistic effects of glucose and FFA on β-cell apoptosis and the molecular mechanisms involved. Mouse insulinoma cells and primary islets were treated with palmitate at increasing glucose and effects on apoptosis, endoplasmic reticulum (ER) stress and insulin receptor substrate (IRS) signaling were examined.

PLEKHH2 is an important FERM domain containing-protein. However, the role of PLEKHH2 in human solid tumors has not been reported yet. We report that PLEKHH2 showed enhanced cytoplasmic expression in non-small cell lung cancer (NSCLC). Its overexpression was positively correlated with high TNM stage, low differentiation, lymphatic node metastasis, and poor prognosis. In A549 and H1299 cells, high expression of PLEKHH2 significantly promoted cell proliferation, migration, invasion, and increased the expression of proliferation- and invasion-related proteins. It also enhanced the phosphorylation of FAK and promoted the activity of the PI3K/AKT pathway. Immunofluorescence and co-immunoprecipitation analyses were performed to elucidate the molecular mechanism underlying PLEKHH2-mediated regulation of proliferation and invasion in lung cancer cells. Upon transfection of full length PLEKHH2 or its FERM domain, we observed enhanced binding of PLEKHH2 to β-arrestin1, whereas FAK- β-arrestin1 binding was diminished and this led to an increase in FAK phosphorylation. PLEKHH2-mutant plasmids without the FERM domain could not effectively promote its binding to β-arrestin1, activation of FAK phosphorylation, PI3K/AKT activation, or the malignant phenotype. Our findings suggested that PLEKHH2 is an important oncogene in NSCLC. PLEKHH2 binding to β-arrestin1 through the FERM domain competitively inhibits β-arrestin1 binding to FAK, which causes the dissociation of FAK from the FAK-β-arrestin1 complex. Furthermore, the dissociation of FAK promotes its autophosphorylation, activates the PI3K/AKT signaling pathway, and subsequently promotes lung cancer cell proliferation, migration, and invasion. These results provide evidence for the potential use of PLEKHH2 inhibition as an anticancer therapy.

Glioblastoma is the most common malignant primary brain tumor, and it is one of the causes of cancer fatality in both adult and pediatric populations. Patients with glioblastoma require chemotherapy after surgical resection and radiotherapy. Therefore, chemotherapy constitutes a viable approach for the eradication of glioblastoma cells. In this study, the anti-tumor activity of sinomenine hydrochloride (SH) was evaluated in U87 and SF767 cells in vitro and in vivo. The results showed that SH potently inhibited U87 and SF767 cell viability and did not cause caspase-dependent cell death, as demonstrated by the absence of significant early apoptosis and caspase-3 cleavage. Instead, SH activated an autophagy-mediated cell death pathway, as indicated by the accumulated microtubule-associated protein light chain 3B (LC3B)-II, triggered autophagic flux and enhanced cell viability after pretreatment with autophagy inhibitors. SH-mediated autophagy in the two cell lines was implicated in reactive oxygen species (ROS) generation, protein kinase B (Akt)-mammalian target of rapamycin (mTOR) pathway suppression and c-Jun NH2-terminal kinase (JNK) pathway activation. The ROS antioxidant N-acetylcysteine (NAC), the Akt-specific activator insulin-like growth factor-1 (IGF-1) and the JNK-specific inhibitor SP600125 attenuated SH-induced autophagy. Moreover, ROS activated autophagy via the Akt-mTOR and JNK pathways. Additionally, SH treatment may promote lysosome biogenesis through activating transcription factor EB (TFEB). The in vivo study found that SH effectively suppressed glioblastoma growth without exhibiting significant toxicity. In conclusion, our findings reveal a novel mechanism of action of SH in cancer cells via the induction of autophagy through ROS generation and autophagy-lysosome pathway activation; these findings also supply a new potential therapeutic agent for the treatment of human glioblastoma.