CD39 identifies a specific CD8 + T cell population in lung adenocarcinoma-related metastatic pleural effusion.

Malignant pleural effusion (MPE), which is a complex microenvironment that contains numerous immune and tumour signals, is common in lung cancer. Gene alterations, such as driver gene mutations, are believed to affect the components of tumour immunity in the microenvironment (TIME) of non-small-cell lung cancer. In this study, we have shown that pleural CD39 + CD8 + T cells are selectively elevated in lung adenocarcinoma (LUAD) with wild-type epidermal growth factor receptor (EGFRwt) compared to those with newly diagnosed mutant EGFR (EGFRmu). Furthermore, these CD39 + CD8 + T cells are more prevalent in MPE with acquired resistance to EGFR-tyrosine kinase inhibitors (AR-EGFR-TKIs). Our analysis reveals that pleural CD39 + CD8 + T cells exhibit an exhausted phenotype while still retaining cytolytic function. Additionally, they have a higher T cell receptor (TCR) repertoire clonality compared to CD39-CD8 + T cells, which is a unique characteristic of LUAD-related MPE. Further investigation has shown that TCR-Vß clonality tends to be more enhanced in pleural CD39 + CD8 + T cells from MPE with AR-EGFR-TKIs. In summary, we have identified a subset of CD8 + T cells expressing CD39 in MPE, which may potentially be tumour-reactive CD8 + T cells. This study provides new insights into the dynamic immune composition of the EGFRmu tumour microenvironment.

MiR-106b inhibition suppresses inflammatory bone destruction of wear debris-induced periprosthetic osteolysis in rats.

Aseptic loosening caused by periprosthetic osteolysis (PPO) is the main reason for the primary artificial joint replacement. Inhibition of inflammatory osteolysis has become the main target of drug therapy for prosthesis loosening. MiR-106b is a newly discovered miRNA that plays an important role in tumour biology, inflammation and the regulation of bone mass. In this study, we analysed the in vivo effect of miR-106b on wear debris-induced PPO. A rat implant loosening model was established. The rats were then administrated a lentivirus-mediated miR-106b inhibitor, miR-106b mimics or an equivalent volume of PBS by tail vein injection. The expression levels of miR-106b were analysed by real-time PCR. Morphological changes in the distal femurs were assessed via micro-CT and histopathological analysis, and cytokine expression levels were examined via immunohistochemical staining and ELISA. The results showed that treatment with the miR-106b inhibitor markedly suppressed the expression of miR-106b in distal femur and alleviated titanium particle-induced osteolysis and bone loss. Moreover, the miR-106b inhibitor decreased TRAP-positive cell numbers and suppressed osteoclast formation, in addition to promoting the activity of osteoblasts and increasing bone formation. MiR-106b inhibition also significantly regulated macrophage polarization and decreased the inflammatory response as compared to the control group. Furthermore, miR-106b inhibition blocked the activation of the PTEN/PI3K/AKT and NF-κB signalling pathways. Our findings indicated that miR-106b inhibition suppresses wear particles-induced osteolysis and bone destruction and thus may serve as a potential therapy for PPO and aseptic loosening.

Investigating the role of circulating CXCR5-expressing CD8+ T-cells as a biomarker for bacterial infection in subjects with pneumonia.

BACKGROUND: Recently, lymphoid follicle-confined and circulating CD8+ T-cells expressing the C-X-C chemokine receptor type 5 (CXCR5) were described, which was involved in anti-virus immune response. However, the dynamics and role of circulating CXCR5-expressing CD8+ T-cells during bacterial infection is unknown. So, we asked whether CXCR5+ CD8+ T cells were also generated during bacterial infections in lower respiratory tract. METHODS: The clinical data of 65 pneumonia patients were analyzed. The patients were divided into groups as tuberculosis, bronchiectasis and community or hospital acquired pneumonia (CAP, HAP). The sputum/bronchial secretion or bronchoalveolar lavage fluid (BALF) samples were taken for microbiological examination. The procalcitonin (PCT) was used to evaluate disease severity of these groups and compared among patients. We characterized the number and phenotype (PD-1 and CD103) of CXCR5 + CD8+ T cells in the peripheral circulation by flow cytometry in all individuals and analyzed their association with the serum PCT level and disease severity. RESULTS: Patients were mainly infected with Escherichia coli, Acinetobacter baumannii, Klebsiella pneumonia (K.p), Pseudomonas aeruginosa, and Staphylococcus aureus. Of note is the finding that PCT was weakly correlated with severity of respiratory infections. Furthermore, it was revealed an increase of CXCR5-expressing CD8+ T cells in peripheral blood of un-controlled CAP and progressive HAP compared controlled CAP and HAP, respectively (P < 0.05). Strikingly, the circulating CXCR5-expressing CD8+ T-cells in K.p-infected group was higher than that non-K.p-infected group (P < 0.05). Meanwhile, the ratio of CXCR5 + CD8+/CD8 was positively correlated with PCT level (P < 0.05). In clinic, the determination of CXCR5-expressing CD8+ T-cells showed better results compared to PCT and can be useful for the prediction of exacerbation of CAP or HAP. Phenotypically, CXCR5+ CD8 + T cell expressed comparable level of inhibitory molecules PD-1 and lower CD103 compared to their CXCR5- counterparts. CONCLUSION: The circulating CXCR5-expressing CD8+ T-cell has diagnostic value for current pneumonia severity, and could act as a biomarker for identifying a bacteria-associated exacerbation. These cells may provide novel insight for the pathogenesis of pneumonia.

Membranous and Cytoplasmic Expression of PD-L1 in Ovarian Cancer Cells.

BACKGROUND: Expression of programmed death-ligand 1 (PD-L1) on tumor cells represents a powerful immune evasion pathway, but the role of intracellular or cytoplasmic PD-L1 has not been investigated in ovarian cancer cells. METHODS: Flow cytometry (FCM), Real-time PCR (qPCR), immunohistochemistry (IHC) and western blot were used to determine the expression of PD-L1 in ovarian cancer cells. The cytokines detected in the tumor or tumor associated macrophage (TAM) were used to treat cancer cells. PD-L1 blockade and silencing were used to elucidate the functional significance of cancer-related PD-L1 expression. RESULTS: Based on the results presented, PD-L1 was found variably expressed in the cytoplasm and the cell surface of both HO8910 and SKOV3 cells. TAM or IFN-γ, TNF-α, IL-10 and IL-6 released from TAM stimulated the expression of PD-L1 at the surface of the cancer cells. The IHC results were consistent with the data in vitro showing infiltration of TAM correlated with membranous PD-L1. The increases of PD-L1 at the surface were not due to a shift in the proportion of surface versus intracellular protein, but the contribution of extracellular signal-regulated kinase (ERK)1/2 and phosphoinositide 3-kinase (PI3K) pathway activation. As a consequence, inducible membranous PD-L1 expression on SKOV3 inhibited CD8+ T cell function, and cytoplasmic PD-L1 promoted cancer cell growth. Additionally, in mouse models, both PD-L1 and PD-1 mAb resulted in tumor growth inhibition and demonstrated a potential to decrease the number of PD-1+CD8+T cells. CONCLUSION: We conclude that TAM induced PD-L1 on the cancer cells represents an immune evasion mechanism. The observations confirm the therapeutic potential of PD-L1/PD-1 mAb to reactivate anti-tumor immunity in ovarian cancer.

Analysis of B7-H4 expression in metastatic pleural adenocarcinoma and therapeutic potential of its antagonists.

BACKGROUND: The increasing incidence and poor outcome associated with malignant pleural effusion (MPE) requires finding an effective treatment for this disease. Inhibitory B7-H4 is expressed in many different human cancers but its role in malignant pleural tissue has yet to be established. METHODS: Here, patients with metastatic pleural adenocarcinoma (MPA) or with early-stage lung adenocarcinoma were clinically and statistically analyzed. Immunohistochemistry and confocal microscopy were used to determinate the expression of B7-H4 in the cancer cells. By using MPE model, we sought to a potential immunotherapy for MPE with anti-B7-H4 mAb. RESULTS: When compared to early-stage lung adenocarcinoma, MPA possessed higher level of nuclei membranous B7-H4 and lower cytoplasmic B7-H4 expression. Also, nuclei membranous B7-H4 expression was found to be positively correlated to Ki-67 expression, and indicated a possible poor prognosis of MPA. In mouse MPE model, intra-pleurally injection of anti-B7-H4 mAb effectively suppressed MPE formation. CONCLUSIONS: Taken together, our data was in support of the significance of B7-H4 expression in MPA, which also suggest it warrants further exploration for potential immunotherapy of MPE.

PD-L1 induced by IFN-γ from tumor-associated macrophages via the JAK/STAT3 and PI3K/AKT signaling pathways promoted progression of lung cancer.

BACKGROUND: Interferon-γ (IFN-γ) is conventionally regarded as an inflammatory cytokine that has a pivotal role in anti-infection and tumor immune surveillance. It has been used clinically to treat a variety of malignancies. However, increased evidence has suggested IFN-γ can act to induce tumor progression. The role of IFN-γ in regulating antitumor immunity appears to be complex and paradoxical. The mechanism underlying the dual aspects of IFN-γ function in antitumor immunity is not clear. METHODS: (1) Lung cancer cells (A549 cells) were cultured with pleural effusion or supernatant of tumor-associated macrophages (TAMs supernatant), and the expression levels of PD-L1 were detected by flow cytometer. The invasion capacity was measured in vitro using trans-well migration assays. (2) Pleural effusion mononuclear cells (PEMC) were separated by Ficoll Hypaque gradient. The expression of interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, and INF-γ in the tumor-associated macrophages was analyzed by flow cytometry. (3) A549 cells were stimulated with IL-6, IL-10, TNF-α, or IFN-γ and then the expression levels were detected by flow cytometry. (4) The expression levels of phospho-ERK (p-ERK), phospho-AKT (p-AKT), and phospho-Sat3 (p-Stat3) were analyzed with Western blot after stimulation with IFN-γ. (5) Cotreatment of the A549 cells with MAPK/ERK-specific inhibitor PD98059, PI3K/AKT-specific inhibitor LY294002, or JAK/STAT3-specific inhibitor AG490, respectively, blocked IFN-γ-induced PD-L1 expression, and then PD-L1 expression was detected by flow cytometry. RESULTS: We demonstrated that TAMs could induce the expression of PD-L1 by the secretion of IFN-γ through the Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signaling pathway and the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway in A549 cells. Furthermore, the signal pathway blockers LY294002 or AG490 could block the induced expression of PD-L1 by IFN-γ. CONCLUSIONS: IFN-γ was not always successful as an antitumor agent. It also can promote tumor cells to evade immune surveillance. Researchers should be cautious in using IFN-γ as a therapeutic agent for cancer treatment.

The increase of circulating PD-L1-expressing CD68(+) macrophage in ovarian cancer.

Tumor-associated macrophages (TAMs) have been characterized as a critical population of immunosuppressive cells in a variety of tumor types. PD-L1 (also termed B7-H1) has been described to exert co-inhibitory and immune regulatory functions. Here, in ovarian cancer, PD-L1 is selectively overexpressed on some TAM compared that of benign ovarian disease. When expanding the data in peripheral blood, the proportion of PD-L1(+)CD68(+) cell among CD68(+) cells and the intensity of PD-L1 staining on CD68(+) cell in healthy group were similar to that observed in ovarian cyst group; instead, these two measures were significantly higher in ovarian cancer group, thereafter related to TNM stage. Interestingly, intracellular levels of IL-10, IL-6, TNF-α, and IFN-γ in PD-L1(+)CD68(+) macrophage were higher than those in PD-L1(-)CD68(+) macrophage, especially IL-6 expression. Based on the PD-L1 receptor PD-1 expression on tumor-infiltrating cytotoxic cells, our data supported that expression of PD-L1 on TAM promoted apoptosis of T cells via interaction with PD-1 on CD8(+)T cells. Taken together, these results suggested that PD-L1-expressing macrophage represents a novel suppressor cell population in ovarian cancer, which contributes immune escape of ovarian cancer.

Induced expression of B7-H3 on the lung cancer cells and macrophages suppresses T-cell mediating anti-tumor immune response.

Macrophages are the prominent components of solid tumors and have complex dual functions in their interaction with cancer cells. Strong evidence suggests that TAM is a part of inflammatory circuits that promote tumor progression. B7-homologue 3 (B7-H3), a recently identified homologue of B7.1/2 (CD80/86), has been described to exert co-stimulatory and immune regulatory functions. Here, we showed that a fraction of macrophages in tumor stroma expressed surface B7-H3 molecule. Normal macrophages, which did not express B7-H3, would be induced expressing B7-H3 molecule when culturing with tumor cell. Although a lung cancer cell line constitutively expressed B7-H3 mRNA and protein in plasma, primary tumor cell isolated from the transplanted lung carcinoma model expressed B7-H3 on the surface. Interestingly, in transplanted lung carcinoma model, the expression of membrane-bound B7-H3 in tumor cells was increased as prolonging of tumor transformation. In support, IL-10 released from TAM could stimulate cancer cell expression of membrane bound B7-H3. Furthermore, Lung cancer and TAM-related B7-H3 was identified as a strong inhibitor of T-cell effect and influenced the outcome of T cell immune response. In conclusion, TAM-tumor cell interaction-induced membrane-bound B7-H3 represents a novel immune escape mechanism which links the pro-inflammatory response to immune tolerance in the tumor milieu.

CD40 signal regulates CXCR4 mediating ovarian carcinoma cell migration: implications for extrapelvic metastastic factors.

Ovarian carcinomas are highly invasive, especially in the peritoneal cavity. SDF-1α and its receptor, CXCR4, play a crucial role in migration of cancer cells. Here, SDF-1α directed HO8910 cell migration, but not SKOV3 cells. After being educated to express CXCR4 in vivo or by treating with sCD40L, SDF-1α reexhibited the ability of directing SKOV3 cell migration, which could be antagonized by CXCR4-neutralizing antibody. Furthermore, concomitant expression of CXCR4/CD40 in ovarian carcinoma tissues had stronger correlation with pelvic metastasis than did each alone. It is suggest that SDF-1α acts through CXCR4 to induce ovarian cancer cell migration, which could be facilitated by CD40 activation. Simultaneously examining the expression of CXCR4 and CD40 will provide valuable diagnosis of pelvic metastasis for ovarian carcinomas.

[Preliminary study of breast cancer magnetic resonance targeting diagnosis basing on magnetic nanoparticles in vitro].

OBJECTIVE: To develop a magnetic nanoparticles based magnetic resonance (MR) probe targeting CD40 mutant in the imaging of breast cancer cells in vitro. METHODS: For preparing an immunologically competent probe, monoclonal antibody was conjugated with ultrasmall superparamagnetic iron oxide (USPIO) particles basing on chemical cross-linking method.Its bioactivity was analyzed with flow cytometry, confocal microscopy and Prussian blue staining. The probe's cell MR imaging in vitro was conducted on breast cancer cells (M231) high expressing CD40 mutant. The signal data from different groups were collected and analyzed with one-way variance and least significant difference-t test. RESULTS: The molecular probe carrying nanoparticles and CD40 mutant antibody was constructed and separated successfully. The probe had similar magnetic property compared with original USPIO particles.It could recognize CD40 mutant on breast cancer cells (M231) with high specificity. MR cell imaging in vitro shows that T2 and T2(*) obviously shortened after probe binding with M231 cells and T2 weighted imaging become darker than control groups, the time of T2 is 5H6-USPIO (51.66 ± 5.31) , 5C11-USPIO (92.89 ± 4.72), USPIO (64.56 ± 3.85) ms. The T2 and T2(*) relaxation time of experiment group was shorter than control groups with statistical significance (P < 0.01) . CONCLUSION: MR molecular probe targeting CD40 mutant may bind with breast cancer cells (M231) to provide further in vivo animal MR imaging. And CD40 mutant is expected to provide a new target for MR molecular imaging of breast cancer.

No observable influence of COVID-19 inactivated vaccines on pregnancy and birth outcomes in the first trimester of gestation.

BACKGROUND: While studies have demonstrated that certain COVID-19 vaccines administered during pregnancy did not affect neonatal or maternal outcomes significantly, the safety of inactivated SARS-CoV-2 vaccines in China, given during the first trimester, remains to be fully elucidated. METHOD: A retrospective cohort study was conducted involving female participants who gave birth from January to October 2021. The study compared pregnancy, delivery, and neonatal outcomes between subjects who received one or two doses of the inactivated COVID-19 vaccines during their first trimester and unvaccinated control subjects. RESULTS: A total of 2658 pregnant women was recruited. Among them, 2358 (88.7%) reported ongoing pregnancies; 326 (13.8%) of these were vaccinated. Additionally, 277 (10.4%) experienced spontaneous miscarriages between 6 to 20 gestational weeks; 40 (14.4%) of these were vaccinated, yielding an odds ratio of 0.67-1.36 (95% confidence interval) for COVID-19 vaccination. The comparison of neonatal complications, including an Apgar score less than 7, preterm birth, low birth weight, and newborn respiratory complications, between unvaccinated and vaccinated participants revealed no statistical significance. CONCLUSION: The administration of COVID-19 inactivated vaccines during the first trimester of pregnancy is not associated with adverse pregnancy or neonatal outcomes, providing a substantial ground for pertinent health education.

Combining local cryoablation with PD-L1 blockade synergistically eradicates established murine lung cancer by modulating mitochondrial in PD-1+CD8+ T cell.

Immune checkpoint blockade (ICB) has shown improvement in overall survival for lung cancer in clinical trials. However, monotherapies have limited efficacy in improving outcomes and benefit only a subset of patients. Combination therapies targeting multiple pathways can augment an immune response to improve survival further. Here, we demonstrate that combinatorial anti-PD-L1/cryoablation therapy generated a synergistic antitumor activity in the established lung cancer model. Importantly, it was observed that this favorable antitumor immune response comes predominantly from the PD-1+CD8+ T cells generated after the combination therapy, referred as improvement of IFN-γ production and mitochondrial metabolism, which resembled highly functional effectors CD8+ T cells. Notably, the cellular levels of mitochondrial reactive oxygen and mitochondria mass excessively coincided with alteration of IFN-γ secretion in PD-1+CD8+T cell subset. So far, anti-PD-L1/cryoablation therapy selectively derived the improvement of depolarized mitochondria in PD-1+CD8+T cell subset, subsequently rebuild the anti-tumor function of the exhausted CD8+ T cells. Collectively, there is considerable interest in anti-PD-L1 plus cryoablation combination therapy for patients with lung cancer, and defining the underlying mechanisms of the observed synergy.

Imbalance of Circulating Monocyte Subsets in Subjects with Newly Emerged and Recurrent Hospital-Acquired Pneumonia.

OBJECTIVE: Hospital-acquired pneumonia (HAP) is one of the most common diseases in the intensive care unit, where the development of disease is closely related with the host immune response. Monocytes play an important role in both innate and adaptive immune system. We aimed to investigate the changes of circulating monocyte subsets in subjects with HAP to explore its value in monitoring HAP. METHODS: In total, 60 HAP patients and 18 healthy individuals were enrolled in this study. Human monocyte subsets are classified into 3 groups: nonclassical (NC), intermediate (ITM), and classical (CL). Also, programmed death ligand 1 (PD-L1) expression on circulating monocyte subsets was measured by flow cytometry. RESULTS: Data showed that the ratio of NC, ITM, and CL among monocytes was comparable between HAP patients and healthy controls (P > .05). There was a remarkable imbalance of NC and CL in newly emerged HAP compared to healthy controls (P < .05), subsequently reaching normalization in recurrent HAP (P > .05). Furthermore, although PD-L1 was seemly constitutively expressed by NC, ITM, and CL groups regardless of disease status, it was noted that PD-L1 was dominantly expressed in the CL group (P < .05). CONCLUSION: Given distinct PD-L1 expression, a shift of CL/NC in newly emerged HAP would constitute an inhibitory anti-pathogen immune response. Normalization of circulating monocyte subsets on recurrence of HAP might be the consequence of immune memory of bacterial infection.

Analysis of CD8+CD28- T-suppressor cells in gastric cancer patients.

Host anti-tumor immune responses can be attenuated by suppressor T cells of the phenotype CD8(+)CD28(-) (T(s) cells). In the present study, we investigated the presence of CD8(+)CD28(-) (T(s) cells) in the peripheral blood compartment of gastric cancer (GC) patients. Flow cytometry was used to detect the population of CD8(+)CD28(-) T(s) cells present in peripheral blood in therapy naïve patients with gastric cancer (n = 26), postoperative chemotherapy naïve gastric cancer patients (n = 23), and healthy controls (n = 27). Meanwhile, the clinical data of gastric cancer patients were analyzed. A significant difference in the percentage of T(s) cells was observed when comparing peripheral blood samples from cancer patients to healthy volunteers (27.08 ± 1.60% versus 10.86 ± 0.75%). In the patient group, the percentage of CD8(+)CD28(-) cells among lymphocytes was higher in patients with LN metastasis than those without LN metastasis. The percentage of CD8(+)CD28(-) cells was also related to tumor infiltration and size, but not with the degree of differentiation of cancer cells. Moreover, the percentage of CD8(+)CD28(-) cells was higher in preoperative gastric cancer patients (26.24 ± 1.78%) than in those of postoperation patients (15.79 ± 1.11%). These findings may reflect the possibility of tumor-induced immunosuppression, and they should be complemented with further studies.

The interaction between the soluble programmed death ligand-1 (sPD-L1) and PD-1+ regulator B cells mediates immunosuppression in triple-negative breast cancer.

Accumulating evidence suggests that regulatory B cells (Bregs) play important roles in inhibiting the immune response in tumors. Programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) are important molecules that maintain the balance of the immune response and immune tolerance. This study aims to evaluate the soluble form of PD-L1 and its function in inducing the differentiation of B lymphocytes, investigate the relationship between soluble PD-L1 (sPD-L1) and B-cell subsets, and explore the antitumor activity of T lymphocytes after PD-L1 blockade in coculture systems. In an effort to explore the role of sPD-L1 in human breast cancer etiology, we examined the levels of sPD-L1 and interleukin-10 (IL-10) in the serum of breast tumor patients and the proportions of B cells, PD-1+ B cells, Bregs, and PD-1+ Bregs in the peripheral blood of patients with breast tumors and assessed their relationship among sPD-L1, IL-10, and B-cell subsets. The levels of sPD-L1 and IL-10 in serum were found to be significantly higher in invasive breast cancer (IBCa) patients than in breast fibroadenoma (FIBma) patients. Meanwhile, the proportions and absolute numbers of Bregs and PD-1+ Bregs in the peripheral blood of IBCa patients were significantly higher than those of FIBma patients. Notably, they were the highest in triple-negative breast cancer (TNBC) among other subtypes of IBCa. Positive correlations of sPD-L1 and IL-10, IL-10 and PD-1+ Bregs, and also sPD-L1 and PD-1+ Bregs were observed in IBCa. We further demonstrated that sPD-L1 could induce Breg differentiation, IL-10 secretion, and IL-10 mRNA expression in a dose-dependent manner in vitro. Finally, the induction of regulatory T cells (Tregs) by Bregs was further shown to suppress the antitumor response and that PD-L1 blockade therapies could promote the apoptosis of tumor cells. Together, these results indicated that sPD-L1 could mediate the differentiation of Bregs, expand CD4+ Tregs and weaken the antitumor activity of CD4+ T cells. PD-L1/PD-1 blockade therapies might be a powerful therapeutic strategy for IBCa patients, particularly for TNBC patients with high level of PD-1+ Bregs.

Overexpression of B7-H4 in tumor infiltrated dendritic cells.

DCs infiltrated tumors appears to be phenotypically and functionally defective. B7-H4 was highlighted for its inhibitory role in T cell responses. In this study, we showed that B7-H4 was moderately expressed in imDCs, and up-regulated by IL-10, and TNF-α could counteract the up-regulatory effects of IL-10 on expression of B7-H4 in DCs in vitro. Furthermore, tumor infiltrated DCs expressed B7-H4 at high levels. Blockade of B7-H4 expressed in DCs highly resulted in enhanced T cell proliferation and IFN-γ production significantly. Otherwise, the high level of IL-10 and TNF-α was both detected in the tumor, which suggested that TNF-α can not antagonize the effects of IL-10 on expression of B7-H4 in DCs in vivo. These data indicate that tumor environment may condition local DCs to become dysfunctional in the phenotype, and that the high expression of B7-H4 may contribute to the tumor infiltrated DCs to mediate immune invasion.

IL36 Cooperates With Anti-CTLA-4 mAbs to Facilitate Antitumor Immune Responses.

Despite the great impact on long-term survival of some cancer patients, the immune checkpoint blockade (ICB) therapy is limited by its low response rates for most cancers. There is a pressing need for novel combination immunotherapies that overcome the resistance to current ICB therapies. Cytokines play a pivotal role in tumor immunotherapy by helping initiating and driving antitumor immune responses. Here, we demonstrated that, besides conventional CD4+ and CD8+ T cells, IL36 surprisingly increased the number of tumor-infiltrating regulatory T (Treg) cells in vivo and enhanced proliferation of Tregs in vitro. Administration of CTLA-4 monoclonal antibodies (mAbs) strongly enhanced IL36-stimulated antitumor activities through depletion of Tregs. In addition, a cancer gene therapy using the IL36-loaded nanoparticles in combination with CTLA-4 mAbs additively reduced lung metastasis of breast tumor cells. We further showed that the combined therapy of CTLA-4 mAbs and IL36 led to an increase in proliferation and IFN-γ production by CD4+ and CD8+ T cells when compared to single therapy with CTLA-4 mAbs or IL36. Collectively, our findings demonstrated a new combination therapy that could improve the clinical response to ICB immunotherapy for cancer.

4-1BB Agonism Combined With PD-L1 Blockade Increases the Number of Tissue-Resident CD8+ T Cells and Facilitates Tumor Abrogation.

Although the milestone discovery of immune checkpoint blockade (ICB) has been translated into clinical practice, only a fraction of patients can benefit from it with durable responses and subsequent long-term survival. Here, we tested the anti-tumor effect of combining PD-L1 blockade with 4-1BB costimulation in 3LL and 4T1.2 murine tumor models. Dual treatment induced further tumor regression and enhanced survival in tumor-bearing mice more so than PD-L1 and 4-1BB mAb alone. It was demonstrated that dual anti-PD-L1/anti-4-1BB immunotherapy increased the number of intratumoral CD103+CD8+ T cells and altered their distribution. Phenotypically, CD103+CD8+ T cells expressed a higher level of 4-1BB and PD-1 than their CD103- counterparts. Administration of PD-L1 mAb and 4-1BB mAb further increased the cytolytic capacity of CD103+CD8+ T cells. In vivo, CD103-CD8+ T cells could differentiate into CD103+CD8+ progeny cells. In a human setting, more CD8+ T cells differentiated into CD103+CD8+ T cells in the peripheral tumor region of lung cancer tissues than in the central tumor region. Collectively, infiltrated CD103+CD8+ T cells served as a potential effector T cell population. Combining 4-1BB agonism with PD-L1 blockade could increase tumor-infiltrated CD103+CD8+T cells, thereby facilitating tumor regression.

Optimal Guaranteed Cost Sliding Mode Control for Constrained-Input Nonlinear Systems With Matched and Unmatched Disturbances.

Based on integral sliding mode and approximate dynamic programming (ADP) theory, a novel optimal guaranteed cost sliding mode control is designed for constrained-input nonlinear systems with matched and unmatched disturbances. When the system moves on the sliding surface, the optimal guaranteed cost control problem of sliding mode dynamics is transformed into the optimal control problem of a reformulated auxiliary system with a modified cost function. The ADP algorithm based on single critic neural network (NN) is applied to obtain the approximate optimal control law for the auxiliary system. Lyapunov techniques are used to demonstrate the convergence of the NN weight errors. In addition, the derived approximate optimal control is verified to guarantee the sliding mode dynamics system to be stable in the sense of uniform ultimate boundedness. Some simulation results are presented to verify the feasibility of the proposed control scheme.

Expression of programmed-death receptor ligands 1 and 2 may contribute to the poor stimulatory potential of murine immature dendritic cells.

Recent data have revealed that Ag presentation by immature dendritic cells (imDCs) plays a role in establishing and maintaining T-cell tolerance, but the mechanism remains unclear. PD-L1 and PD-L2, ligands for programmed-death receptor 1 (PD-1), members of the expanding B7 family, were highlighted for their inhibitory role in T-cell responses. Here, we show that blockade of PD-1 ligands on imDCs resulted in enhanced T-cell proliferation, which is perhaps due to the enhancement of IL-2 production from DC-stimulated T cells. PD-1 ligands blockade on mDCs did not show a significant stimulatory effect as markedly as imDCs. The inhibitory effects of PD-1 ligands would be dependent on maturation status of DCs, where attenuated positive costimulatory molecules provided the opportunity for PD-1 ligands to exert their strong capacity. Our data are consistent with the hypothesis that imDCs have an inhibitory bias, and indicate that PD-L1 and PD-L2 contribute to the poor stimulatory capacity of imDCs.