Co-stimulatory members of the TNFR family: keys to effective T-cell immunity?

4-1BBL has a Possible Role in Mediating Castration-Resistant Conversion of Prostate Cancer via Up-Regulation of Androgen Receptor

4-1BB ligand (4-1BBL) was a transmembrane glycoprotein belonging to the tumor necrosis factor family. It was expressed on activated T lymphocytes and function as a co-stimulatory molecule via cross-linking with 4-1BB (a.k.a, CD137). In addition to its role in immune regulation, 4-1BBL transmitted signals into the cells on which it was expressed (reverse signaling). 4-1BBL represented a promising target for enhancing antitumor immune responses. Recent studies indicated that 4-1BBL also expressed in non-immune cells and possessed different functions in various types of cells. Here, we reported that 4-1BBL didn't express in normal prostate tissues and benign prostatic hyperplasia tissues, but it expressed in prostate cancer (PCa) tissues at moderate level. Expression of 4-1BBL was up-regulated during the transition from PCa to castration resistant prostate cancer (CRPC). Increasing expression of 4-1BBL not only promoted expression of androgen receptor (AR), but also augmented proliferation and invasion ability of prostate cancer cells in androgen deprivation environment. These results were further verified by xenograft tumor experiments. Meanwhile, inhibiting AR signal pathway by chemical antagonist was able to significantly reduce 4-1BBL mediated proliferation and invasion of PCa cells. These novel findings indicated that 4-1BBL might mediate prostate cancer progression to castration-resistant prostate cancer via enhancing expression and function of AR.

Crystal structure and activation mechanism of DR3 death domain

Death receptor 3 (DR3) (a.k.a. tumor necrosis factor receptor superfamily 25) plays a key role in the immune system by activating nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway. Here we present the crystal structures of human and mouse DR3 intracellular death domain (DD) at 2.7 and 2.5 Å resolutions, respectively. The mouse DR3 DD adopts a classical six-helix bundle structure while human DR3 DD displays an extended fold. Though there is one-amino-acid difference in the linker between maltose-binding protein (MBP) tag and DR3 DD, according to our self-interaction analysis, the hydrophobic interface discovered in MBP-hDR3 DD crystal structure is responsible for both hDR3 DD and mDR3 DD homotypic interaction. Furthermore, our biochemical analysis indicates that the sequence variation between human and mouse DR3 DD does not affect its structure and function. Small-angle X-ray scattering analysis shows the averaged solution structures of both human and mouse MBP-DR3 DD are the combination of different conformations with different proportion. Through switching to the open conformation, DR3 DD could improve the interaction with downstream element TNFR-associated death domain (TRADD). Here we propose an activation-dependent structural rearrangement model: the DD region is folded as the six-helix bundles in the resting state, while upon extracellular ligand engagement, it switches to the open conformation, which facilitates its self-association and the recruitment of TRADD. Our results provide detailed insights into the architecture of DR3 DD and the molecular mechanism of activation. DATABASES: All refined structure coordinates as well as the corresponding structure factors have been deposited in the PDB under the accession codes 5YGS, 5YEV, 5YGP, 5ZNY, 5ZNZ.

Markers of Immune Activation and Inflammation, and Non-Hodgkin Lymphoma: A Meta-Analysis of Prospective Studies

Background

Chronic inflammation and immune activation are reported to play a key role in the etiology of non-Hodgkin lymphoma (NHL). We conducted a meta-analysis on the associations between prediagnosis circulating levels of immune stimulatory markers, interleukin 6 (IL-6), IL-10, tumor necrosis factor α (TNF-α), CXCL13, soluble CD23 (sCD23), sCD27, sCD30, and the risk of NHL.

Methods

Relevant studies were identified from PubMed, EMBASE, and Web of Science up to January 1, 2017. We calculated summary odds ratio (OR) estimates for the association between one natural log increase in concentration of each biomarker and NHL using random-effects models for NHL as a composite outcome and for several histological subtypes of NHL.

Results

Seventeen nested case control studies were included. Elevated levels of several biomarkers were more strongly associated with increased odds of NHL: TNF-α, OR = 1.18 (95% confidence interval [CI] = 1.04 to 1.34); CXCL13, OR = 1.47 (95% CI = 1.03 to 2.08); sCD23, OR = 1.57 (95% CI = 1.21 to 2.05); sCD27, OR = 2.18 (95% CI = 1.20 to 3.98); sCD30, OR = 1.65 (95% CI = 1.22 to 2.22). In stratified analyses, IL-6, TNF-α, sCD27, and sCD30 were more strongly associated with NHL in HIV-infected individuals compared to HIV-uninfected individuals. Between-study heterogeneity was observed across multiple biomarkers for overall NHL and by subtypes.

Conclusion

This meta-analysis provides evidence that elevated circulating levels of TNF-α, CXCL13, sCD23, sCD27, and sCD30 are consistently associated with an increased risk of NHL, suggesting the potential utility of these biomarkers in population risk stratification and prediction.

Delivery technologies for cancer immunotherapy

Immunotherapy has become a powerful clinical strategy for treating cancer. The number of immunotherapy drug approvals has been increasing, with numerous treatments in clinical and preclinical development. However, a key challenge in the broad implementation of immunotherapies for cancer remains the controlled modulation of the immune system, as these therapeutics have serious adverse effects including autoimmunity and nonspecific inflammation. Understanding how to increase the response rates to various classes of immunotherapy is key to improving efficacy and controlling these adverse effects. Advanced biomaterials and drug delivery systems, such as nanoparticles and the use of T cells to deliver therapies, could effectively harness immunotherapies and improve their potency while reducing toxic side effects. Here, we discuss these research advances, as well as the opportunities and challenges for integrating delivery technologies into cancer immunotherapy, and we critically analyse the outlook for these emerging areas.

rs1234313 and rs45454293 are risk factors of cerebral arterial thrombosis, large artery atherosclerosis, and carotid plaque in the Han Chinese population: a case-control study

Background

Ischemic stroke is a leading cause of mortality and morbidity worldwide. Stenosis or blockage of an artery from atherosclerosis can cause insufficient cerebral blood supply, which leads to ischemic stroke. It has been reported that the polymorphisms of TNFSF4 (tumor necrosis factor super family member 4) are associated with multiple autoimmune diseases. However, it is still unclear whether TNFSF4 gene polymorphisms are associated with ischemic stroke in the Han Chinese population. Here we analyzed the association between TNFSF4 single nucleotide polymorphisms (SNPs) and cerebral arterial thrombosis in the Han Chinese population.

Method

We consecutively recruited 481 patients with cerebral arterial thrombosis and 538 healthy controls. Neck ultrasonography and magnetic resonance imaging (MRI) were used to evaluate large artery atherosclerosis (LAA) and small vessel disease (SVD), as well as the thickness and calcification of carotid artery. DNA was purified from the peripheral blood samples. TNFSF4 SNPs, rs1234313 and rs45454293, were genotyped using PCR.

Results

rs1234313 SNP had a significant correlation with the LAA and SVD subtypes in allelic (G vs A), dominate (GG/GA vs AA) and genotypic (GA vs AA; GG vs AA) models, as well as with the calcification of carotid plaque in dominant (GG/GA vs AA, p = 0.022) and genotypic (GA vs AA, p = 0.01) models. rs45454293 SNP had a significant correlation with the LAA and SVD subtypes in allelic (G vs A) and genotypic models, as well as with the thick carotid plaque in allelic (G vs A, p = 0.01) model.

Conclusion

TNFSF4 SNPs, rs1234313 and rs45454293, are associated with the risk of specific subtypes of cerebral arterial thrombosis in the Han Chinese population.

The detailed distribution of T cell subpopulations in immune-stable renal allograft recipients: a single center study

Background

Most renal allograft recipients reach a stable immune state (neither rejection nor infection) after transplantation. However, the detailed distribution of overall T lymphocyte subsets in the peripheral blood of these immune-stable renal transplant recipients remains unclear. We aim to identify differences between this stable immune state and a healthy immune state.

Methods

In total, 103 recipients underwent renal transplantation from 2012 to 2016 and received regular follow-up in our clinic. A total of 88 of these 103 recipients were enrolled in our study according to the inclusion and exclusion criteria. A total of 47 patients were 1 year post-transplantation, and 41 were 5 years post-transplantation. In addition, 41 healthy volunteers were recruited from our physical examination clinic. Detailed T cell subpopulations from the peripheral blood were assessed via flow cytometry. The parental frequency of each subset was calculated and compared among the diverse groups.

Results

The demographics and baseline characteristics of every group were analyzed. The frequency of total T cells (CD3+) was decreased in the renal allograft recipients. No difference in the variation of the CD4+, CD8+, and activated (HLA-DR+) T cell subsets was noted among the diverse groups. Regarding T cell receptor (TCR) markers, significant reductions were found in the proportion of γδ T cells and their Vδ2 subset in the renal allograft recipients. The proportions of both CD4+ and CD8+ programmed cell death protein (PD) 1+ T cell subsets were increased in the renal allograft recipients. The CD27+CD28+ T cell proportions in both the CD4+ and CD8+ populations were significantly decreased in the allograft recipients, but the opposite results were found for both CD4+ and CD8+ CD27-CD28- T cells. An increased percentage of CD4+ effector memory T cells and a declined fraction of CD8+ central memory T cells were found in the renal allograft recipients.

Conclusion

Limited differences in general T cell subsets (CD4+, CD8+, and HLA-DR+) were noted. However, obvious differences between renal allograft recipients and healthy volunteers were identified with TCR, PD1, costimulatory molecules, and memory T cell markers.

A DNA Vaccine Encoding SA-4-1BBL Fused to HPV-16 E7 Antigen Has Prophylactic and Therapeutic Efficacy in a Cervical Cancer Mouse Model

The SA-4-1BBL, an oligomeric novel form of the natural ligand for the 4-1BB co-stimulatory receptor of the tumor necrosis factor (TNF) superfamily, as a recombinant protein has potent pleiotropic effects on cells of innate, adaptive, and regulatory immunity with demonstrated therapeutic efficacy in several tumor models. However, the production of soluble form of SA-4-1BBL protein and quality control is time and resource intensive and face various issues pertinent to clinical development of biologics. The present study sought to take advantage of the simplicity and translatability of DNA-based vaccines for the production and delivery of SA-4-1BBL for cancer immune prevention and therapy. A chimeric HPV-16 E7 DNA vaccine (SP-SA-E7-4-1BBL) was constructed that contains the signal peptide (SP) of calreticulin (CRT), streptavidin (SA) domain of SA-4-1BBL, HPV-16 E7 double mutant gene, and the extracellular domain of mouse 4-1BBL. Immunization by gene gun with SP-SA-E7-4-1BBL induced greater prophylactic as well as therapeutic effects in C57BL/6 mice against TC-1 tumor model compared with immunization with E7wt, SP-SA-4-1BBL or reference-positive control CRT-E7wt. The therapeutic efficacy of the DNA vaccine was associated with increased frequency of E7-specific T cells producing interferon (IFN)-γ. Overall, our data suggest that this DNA-based vaccine strategy might represent a translational approach because it provides a simpler and versatile alternative to a subunit vaccine based on SA-4-1BBL and E7 proteins.

Diagnostic performance in active TB of QFT-Plus assay and co-expression of CD25/CD134 in response to new antigens of Mycobacterium tuberculosis

The new QuantiFERON-TB Gold Plus employs modified peptides optimized to elicit an IFNγ response from CD8⁺ cytotoxic T lymphocytes in addition to CD4⁺ T cells. With a view to improve the difficult identification of TB cases, we assessed the combination of two specific immunological markers comprising IFNγ secretion and T cells co-expression of CD25 and CD134 in response to Mycobacterium tuberculosis-specific antigens. A total of 34 subjects with suspected TB and 10 age-matched HD were prospectively enrolled. Assessing the performance of QFT-Plus in terms of the TB1 and TB2 results, we found that in TB patients, the quantitative IFNγ value in TB2 was similar to that in TB1, and we did not find any differences irrespective of the disease (pulmonary or extra-pulmonary). The flow cytometric CD25/CD134 assay, allowed a more accurate differentiation between M. tuberculosis-infected and uninfected patients, with a better combination of sensitivity and specificity, especially by evaluation of CD4⁺ T-cell subset. All individuals with negative QFT-Plus results displayed a positive CD25/CD134 response. Overall, a positive correlation was found between T cells co-expressing CD25/CD134 and IFNγ levels in response to both QFT-Plus TB antigen tubes, as well as between the QFT-Plus TB1 and TB2 tubes. We demonstrated that both TB1 and TB2 induce a higher expression of CD25⁺CD134⁺ markers on CD4⁺ T cells among infected TB subjects, compared to the lower degree of CD8⁺ T cells, mainly induced to TB2 stimulation. We suggest that a combined use of classic QFT-Plus and specific CD25/CD134 response may be a useful means in the diagnostic workup for active TB.

Features and roles of T helper 9 cells and interleukin 9 in immunological diseases

T helper 9 (T_H9) cells are considered as newly classified helper T cells that have an important role in the regulation of immune responses. Since these cells preferentially produce IL-9, these cells are termed T_H9 cells. Recently, the role of T_H9 and its signature cytokine (IL-9) has been investigated in a wide range of diseases, including autoimmunity, allergy, infections, cancer and immunodeficiency. Herein, we review the most recent data concerning T_H9 cells and IL-9 as well as their roles in disease. These insights suggest that T_H9 cells are a future target for therapeutic intervention.

Increased accumulation of CD30 ligand-positive mast cells associates with eosinophilic inflammation in nasal polyps

OBJECTIVE

Activation of mast cells associates with eosinophilic inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP). The disease-specific mast cell-triggering mechanisms apart from immunoglobulin E are poorly understood in CRSwNP. CD30L/CD30 are members of the tumor necrosis factor/receptor superfamily and display immune modulatory function on mast cells. The aim of this study was to explore the expression and function of CD30 and CD30L in CRSwNP.

METHODS

The mRNA expression of CD30 and CD30L was analyzed by real-time polymerase chain reaction. The cellular expression of CD30L was determined by immunofluorescence staining. The soluble CD30 levels in nasal tissues were detected by enzyme-linked immunosorbent assay. HMC-1 cells, a human mast cell line, were cultured and stimulated with CD30.

RESULTS

Compared with control tissues, CD30 mRNA expression levels were increased in eosinophilic polyps, and soluble CD30 protein levels were upregulated in both eosinophilic and noneosinophilic polyps with a greater increase in eosinophilic type. CD30 was expressed by T cells and B cells in nasal polyps. The CD30L mRNA expression levels and the number of CD30L⁺ cells and CD30L⁺ tryptase⁺ mast cells were increased in eosinophilic polyps but not in noneosinophilic polyps as compared with control tissues. Mast cells accounted for 60% of CD30L⁺ cells in eosinophilic polyps. CD30 induced HMC-1 cells to produce interleukin (IL)-4 and IL-13 without degranulation. Mast cells expressed IL-4 and IL-13 in eosinophilic polyps. The number of CD30L⁺ tryptase⁺ mast cells was positively correlated with the number of eosinophils and total inflammatory cells in eosinophilic polyps.

CONCLUSION

CD30/CD30L-mediated mast cell activation may promote the eosinophilic inflammation in CRSwNP.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:E110-E117, 2019.

Circulating sCD27 and sCD30 in pre-diagnostic samples collected fifteen years apart and future non-Hodgkin lymphoma risk

Elevated serum sCD27 and sCD30 from a single banked sample have been associated with future non-Hodgkin lymphoma risk (NHL); however, the etiologic relevance of this finding is unclear. To address this question, we conducted a case-control study (235 cases, 235 controls) nested within the CLUE-I and CLUE-II cohorts, which enrolled participants in 1974 and 1989 respectively in Washington County, Maryland. Our study features a subset of 102 cases and 102 controls with two banked pre-diagnostic samples each, collected 15 years apart. In analyses involving an individual sample per subject, both sCD27 and sCD30 were associated with NHL diagnosed up to 20 years later. In analyses involving repeated samples, cases were significantly more likely than controls to have higher analyte levels in the CLUE-II vs. CLUE-I sample for sCD27 (p = 0.006) but not sCD30 (p = 0.16). In joint analyses of dichotomized analyte levels in both samples, the strongest NHL association observed for sCD27 was for having below-median levels in CLUE-I and above-median levels in CLUE-II [odds ratio (OR) 3.6, 95% confidence interval (CI) 1.4-9.2 vs. below-median levels in both). In joint analyses for sCD30, the strongest NHL association was observed for having above-median levels in both samples (OR 1.7, 95% CI 0.8-3.7), particularly for cases diagnosed >10 years after the CLUE-II sample (OR 2.4, 95% CI 0.9-6.7). Our findings suggest that sCD27 is a disease marker for NHL and add to the weight of evidence that elevated circulating sCD30 is a marker of increased NHL susceptibility.

The Role of Co-Stimulatory Molecules in Chagas Disease

Chagas disease, caused by Trypanosoma cruzi, is a potentially life-threatening tropical disease endemic to Latin American countries that affects approximately 8 million people. In the chronic phase of the disease, individuals are classified as belonging to the indeterminate clinical form or to the cardiac and/or digestive forms when clinical symptoms are apparent. The relationship between monocytes and lymphocytes may be an important point to help clarify the complexity that surrounds the clinical symptoms of the chronic phase of Chagas disease. The co-stimulatory signals are essential to determining the magnitude of T cell response to the antigen. The signals are known to determine the regulation of subsequent adaptive immune response. However, little is known about the expression and function of these molecules in Chagas disease. Therefore, this review aims to discuss the possible role of main pathways of co-stimulatory molecule-receptor interactions in this pathology that could be crucial to understand the disease dynamics.

Understanding how combinatorial targeting of TLRs and TNFR family costimulatory members promote enhanced T cell responses

INTRODUCTION

Due to the ability of pathogen-associated molecular patters and tumor necrosis factor receptor (TNFR) family costimulatory agonists to boost T cell responses, studies have combined Toll-like receptor (TLR) ligands with TNFR family costimulatory receptor agonists to induce impressive and long-lasting T cell responses. Although some studies have determined how these combinatorial vaccines promote enhanced T cell responses, much remains unknown about the mechanism used by these combinations to promote synergistic T cell responses - especially in settings of infectious diseases or cancer.

AREAS COVERED

In this review, we look in detail at the signaling pathways induced by combinatorial targeting of TLR and TNFR family costimulatory members that help them promote synergistic T cell responses. Understanding this can greatly aid the development of novel vaccine regimens that promote cellular immune responses, which is essential for treating certain infectious diseases and cancer.

EXPERT OPINION

Vaccines against some infectious diseases as well as therapeutic cancer vaccines require cellular immunity. Therefore, we evaluate here how signaling pathways induced by TLR ligand and costimulatory agonist combinations promote enhanced T cell responses during immunization with model antigens, viral pathogens, or tumor antigens. Once pathways that drive these combinatorial vaccines to boost T cell activation are identified, they can be incorporated in vaccines designed to target pathogens or cancer.

Duokines: a novel class of dual-acting co-stimulatory molecules acting in cis or trans

Co-stimulatory signals induced by ligands of the tumor necrosis factor superfamily (TNFSF) play a central role in T cell activation and have emerged as a promising strategy in cancer immunotherapy. Here, we established a novel class of bifunctional co-stimulatory fusion proteins with the aim to boost T cell activation at the level of T cell – antigen-presenting cell (APC) interaction. These novel dual-acting cytokine fusion proteins were created by connecting two different homotrimeric TNFSF ligands to form homotrimeric bifunctional molecules (Duokines) or by connecting single-chain derivatives of two different homotrimeric TNFSF with a single, flexible linker (single-chain Duokines, scDuokines). By linking the TNFSF ligands 4-1BBL, OX40L and CD27L in all possible combinations, cis-acting Duokines were generated that act on the same or adjacent T cells, while combining CD40L with 4-1BBL, OX40L and CD27L resulted in trans-acting Duokines acting simultaneously on APCs and T cells. In vitro, co-stimulation of T cells was seen for cis- and trans-acting Duokines and scDuokines in an antigen-independent as well as antigen-specific setting. Trans-acting molecules furthermore activated B cells, which represent a subclass of APCs. In a pilot experiment using the syngeneic B16-FAP mouse tumor model scDuokines displayed antitumoral activity in vivo in combination with a primary T cell-activating bispecific antibody, evident from reduced number of lung metastasis compared to the antibody-only treated group. Our data show that the bifunctional, co-stimulatory duokines are capable to enhance T cell-mediated anti-tumor immune responses, suggesting that they can serve as a new class of immuno-stimulatory molecules for use in cancer immunotherapy strategies.

Changes in T cell effector functions over an 8-year period with TNF antagonists in patients with chronic inflammatory rheumatic diseases

The aim of the study was to clarify the effect of long-term anti-TNF therapy on T cell function in patients with rheumatologic immune-mediated inflammatory diseases (IMID). The production of IFNγ by T cells was evaluated at baseline and after 1, 2, 4, and 8 years of anti-TNF agents by means of a QuantiFERON-TB Gold In-Tube assay. The T cell proliferation and surface co-expression of CD25/CD134 in response to phytohaemagglutinin together with the in vitro impact of anti-TNF therapy on the functional capacity of T cells were evaluated after 8 years from the onset of the biological treatment. Age-matched healthy donors were enrolled as controls. The quantitative mitogen-induced IFNγ responses significantly increased with respect to baseline at each time point, apart from the determination after 4 years. We found an increased expression of CD25/CD134 in CD4⁺ compared to CD8⁺ T cells both in patients and controls. The in vitro addition of anti-TNF agents induced a significant decrease of both the IFNγ response and of CD25/CD134, whereas no effect on the intensity of the proliferative response was observed. Our data provide a biological basis for the reassuring issues on the safety of long-term anti-TNF treatment in patients with IMID.

Increased Soluble CD137 Levels and CD4+ T-Cell-Associated Expression of CD137 in Acute Atherothrombotic Stroke

As a proinflammatory cytokine, CD137 (4‐1BB, TNFRSF9) is present in membrane‐bound and soluble forms. Increased expression of CD137 was recently found in T cells in human atherosclerotic plaques. However, the exact role of CD137 in ischemic stroke is not clear. In this study we analyzed the protein levels of soluble CD137 (sCD137) and the expression of CD137 on CD4+ T cells in the peripheral blood of patients with acute atherothrombotic stroke by using the cytometry beads array (CBA) and flow cytometry. Within 24 hours of onset, the stroke patients showed elevated levels of sCD137 (2.7 pg/ml) and CD137 expression on CD4+ T cells (4.9 ± 3.2%) compared with normal controls (1.1 pg/ml, P < 0.01; 1.3 ± 1.0%, P < 0.01). Alterations in CD137 expression may enhance ischemia‐induced inflammatory responses via bidirectional signaling and, consequently, aggravate brain injury in early stages of this disorder.

Research progress of follicular cytotoxic T cells in HIV infection

Recently, a new type of CD8+ T-cell subset, namely, the chemokine (C-X-C motif) receptor 5 (CXCR5+) cluster of differentiation (CD8+) T-cell subset (also called the follicular cytotoxic T-cell (TFC) subgroup), has been discovered around B-cell follicles. The discovery has aroused widespread interest. However, the processes and mechanisms of TFCs taking part in the immune response of the germinal center and their specific roles must still be clearly identified. This article reviews domestic and foreign studies on factors regulating the phenotype, physiological functions, maturity, and differentiation of TFCs and roles and clinical significance of these cells in HIV infection. This review has shown good application prospects for TFCs. The author believes that further studies on TFCs can provide another tool for cytotherapy to control or cure chronic viral infections or tumors.

Human CD134 (OX40) expressed on T cells plays a key role for human herpesvirus 6B replication after allogeneic hematopoietic stem cell transplantation

BACKGROUND

CD134 (OX40), which is a cellular receptor for human herpesvirus-6B (HHV-6B) and expresses on activated T cells, may play a key role for HHV-6B replication after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

OBJECTIVES

Therefore, we examined the CD134 expression on T cells and HHV-6B replication after allo-HSCT, and analyzed the correlation between them.

STUDY DESIGN

Twenty-three patients after allo-HSCT were enrolled. The percentages of CD134-positive cells within the CD4⁺ and CD8⁺ cell populations were measured by flow cytometry, and the viral copy number of HHV-6B was simultaneously quantified by real-time PCR. The correlation between CD134 and HHV-6B viral load was then statistically analyzed.

RESULTS

HHV-6B reactivation occurred in 11 of 23 patients (47.8%). CD134 expression was seen on T cells and was coincident with the time of peak viral load. The percentage of CD134-positive cells decreased significantly when HHV-6B DNA disappeared (p = .005 in CD4⁺ T cells, p = .02 in CD8⁺ T cells). In the 4 patients who underwent umbilical cord blood transplantation (UCBT), the viral load varied with the percentage of CD134-positive cells. In the comparison between the HHV-6B reactivation group and non-reactivation group, maximum percentages of CD134-positive cells among CD4⁺ T cells in reactivation group were significantly higher than those in non-reactivation group (p = .04).

CONCLUSIONS

This is the first study to show that a correlation of CD134 expression on T cells with HHV-6B replication after allo-HSCT, especially in UCBT. The results possibly indicate that CD134 on T cells plays a key role for HHV-6B replication after allo-HSCT.

Features of Effective T Cell-Inducing Vaccines against Chronic Viral Infections

For many years, the focus of prophylactic vaccines was to elicit neutralizing antibodies, but it has become increasingly evident that T cell-mediated immunity plays a central role in controlling persistent viral infections such as with human immunodeficiency virus, cytomegalovirus, and hepatitis C virus. Currently, various promising prophylactic vaccines, capable of inducing substantial vaccine-specific T cell responses, are investigated in preclinical and clinical studies. There is compelling evidence that protection by T cells is related to the magnitude and breadth of the T cell response, the type and homing properties of the memory T cell subsets, and their cytokine polyfunctionality and metabolic fitness. In this review, we evaluated these key factors that determine the qualitative and quantitative properties of CD4+ and CD8+ T cell responses in the context of chronic viral disease and prophylactic vaccine development. Elucidation of the mechanisms underlying T cell-mediated protection against chronic viral pathogens will facilitate the development of more potent, durable and safe prophylactic T cell-based vaccines.

Withaferin A Associated Differential Regulation of Inflammatory Cytokines

A role of inflammation-associated cytokines/chemokines has been implicated in a wide variety of human diseases. Here, we investigated the regulation of inflammatory cytokines released by monocyte-derived THP-1 cells following treatment with the dietary agent withaferin A (WFA). Membrane-based cytokine array profiling of the culture supernatant from adenosine triphosphate-stimulated WFA-treated THP-1 cells showed differential regulation of multiple cytokines/chemokines. A selected group of cytokines/chemokines [interleukin-1 beta (IL-1β), CCL2/MCP-1, granulocyte-macrophage colony stimulating factor, PDGF-AA, PTX3, cystatin-3, relaxin-2, TNFRSF8/CD30, and ACRP30] was validated at the transcription level using qPCR. In silico analysis for transcriptional binding factors revealed the presence of nuclear factor-kappa B (NF-κB) in a group of downregulated cytokine gene promoters. WFA treatment of THP-1 cells blocks the nuclear translocation of NF-kB and corresponds with the reduced levels of cytokine secretion. To further understand the differential expression of cytokines/chemokines, we showed that WFA alters the nigericin-induced co-localization of NLRP3 and ASC proteins, thereby inhibiting caspase-1 activation, which is responsible for the cleavage and maturation of pro-inflammatory cytokines IL-1β and IL-18. These data suggest that dietary agent WFA concurrently targets NF-κB and the inflammasome complex, leading to inhibition of IL-1β and IL-18, respectively, in addition to differential expression of multiple cytokines/chemokines. Taken together, these results provide a rationale for using WFA to further explore the anti-inflammatory mechanism of cytokines/chemokines associated with inflammatory diseases.

Expression of LLT1 and its receptor CD161 in lung cancer is associated with better clinical outcome

Co-stimulatory and inhibitory receptors expressed by immune cells in the tumor microenvironment modulate the immune response and cancer progression. Their expression and regulation are still not fully characterized and a better understanding of these mechanisms is needed to improve current immunotherapies. Our previous work has identified a novel ligand/receptor pair, LLT1/CD161, that modulates immune responses. Here, we extensively characterize its expression in non-small cell lung cancer (NSCLC). We show that LLT1 expression is restricted to germinal center (GC) B cells within tertiary lymphoid structures (TLS), representing a new hallmark of the presence of active TLS in the tumor microenvironment. CD161-expressing immune cells are found at the vicinity of these structures, with a global enrichment of NSCLC tumors in CD161+ CD4+ and CD8+ T cells as compared to normal distant lung and peripheral blood. CD161+ CD4+ T cells are more activated and produce Th1-cytokines at a higher frequency than their matched CD161-negative counterparts. Interestingly, CD161+ CD4+ T cells highly express OX40 co-stimulatory receptor, less frequently 4-1BB, and display an activated but not completely exhausted PD-1-positive Tim-3-negative phenotype. Finally, a meta-analysis revealed a positive association of CLEC2D (coding for LLT1) and KLRB1 (coding for CD161) gene expression with favorable outcome in NSCLC, independently of the size of T and B cell infiltrates. These data are consistent with a positive impact of LLT1/CD161 on NSCLC patient survival, and make CD161-expressing CD4+ T cells ideal candidates for efficient anti-tumor recall responses.

Crystal structure of murine 4-1BB and its interaction with 4-1BBL support a role for galectin-9 in 4-1BB signaling

4-1BB (CD137) is a TNF receptor superfamily (TNFRSF) member that is thought to undergo receptor trimerization upon binding to its trimeric TNF superfamily ligand (4-1BBL) to stimulate immune responses. 4-1BB also can bind to the tandem repeat-type lectin galectin-9 (Gal-9), and signaling through mouse (m)4-1BB is reduced in galectin-9 (Gal-9)-deficient mice, suggesting a pivotal role of Gal-9 in m4-1BB activation. Here, using sulfur-SAD phasing, we determined the crystal structure of m4-1BB to 2.2-Å resolution. We found that similar to other TNFRSFs, m4-1BB has four cysteine-rich domains (CRDs). However, the organization of CRD1 and the orientation of CRD3 and CRD4 with respect to CRD2 in the m4-1BB structure distinctly differed from those of other TNFRSFs. Moreover, we mapped two Asn residues within CRD4 that are N-linked glycosylated and mediate m4-1BB binding to Gal-9. Kinetics studies of m4-1BB disclosed a very tight nanomolar binding affinity to m4-1BBL with an unexpectedly strong avidity effect. Both N- and C-terminal domains of Gal-9 bound m4-1BB, but with lower affinity compared with m4-1BBL. Although the TNF homology domain (THD) of human (h)4-1BBL forms non-covalent trimers, we found that m4-1BBL formed a covalent dimer via 2 cysteines absent in h4-1BBL. As multimerization and clustering is a prerequisite for TNFR intracellular signaling, and as m4-1BBL can only recruit two m4-1BB monomers, we hypothesize that m4-1BBL and Gal-9 act together to aid aggregation of m4-1BB monomers to efficiently initiate m4-1BB signaling.

S100A4 blockage alleviates agonistic anti-CD137 antibody-induced liver pathology without disruption of antitumor immunity

Liver-related autoimmune toxicities triggered by agonistic anti-CD137 antibodies have greatly limited their use in clinical applications. Here, we found that anti-CD137 monoclonal antibody (mAb) treatment in mice induced the infiltration of a large number of S100A4⁺ macrophages into the liver. Depletion of these cells or deficiency of S100A4 decreased inflammatory cytokine profiles and drastically reduced the number of liver pathogenic CD8⁺ T cells. Mechanistically, soluble S100A4 directly activated the Akt pathway and specifically prolonged CD8⁺ T cell survival. Interestingly, one S100A4 neutralizing mAb selectively alleviated liver abnormalities but did not affect the antitumor immunity induced by anti-CD137 mAb therapy. Thus, our study presents a novel molecular link to the liver pathology induced by an immune stimulatory antibody and proposes that combinational immunotherapies targeting those pathways could potentially elicit optimal antitumor immunity with minimal side effects.

Co-expression of CD40L with CD70 or OX40L increases B-cell viability and antitumor efficacy

Activated B-cells are a promising alternative source of antigen-presenting cells. They can generally be obtained in sufficient numbers for clinical use, but in most instances produce weak immune responses and therapeutic effects that are suboptimal for use in therapeutic cancer vaccines. To improve the immunogenic potency and therapeutic efficacy of B-cell-based vaccines, ex vivo-activated B-cells were transduced with recombinant lentiviruses in order to express additional costimulatory ligands—CD40L, CD70, OX40L, or 4-1BBL—either individually or in pairs (CD70/CD40L, OX40L/CD40L, or 4-1BBL/CD40L). We observed that the expression of CD40L molecules on B-cells was crucial for T-cell priming and activation. Administration of B-cells co-expressing CD40L with the other costimulatory ligands provided substantial antigen-specific CD8 T-cell responses capable of provoking in vivo proliferation and potent cytolytic activities. Notably, expression of CD40L augmented B-cell viability by inhibiting apoptosis through upregulated expression of the anti-apoptotic molecules BCL2, Bcl-xL and Bax. B-cells co-expressing CD40L with CD70, OX40L, or 4-1BBL induced potent therapeutic antitumor effects in a B16 melanoma model. Moreover, the combination of genetically-modified B-cell vaccines with programmed cell death-1 blockade potentiated the therapeutic efficacy. These results suggest that B-cells endowed with additional costimulatory ligands enable the design of effective vaccination strategies against cancer.

Co-stimulatory molecules in and beyond co-stimulation – tipping the balance in atherosclerosis?

A plethora of basic laboratory and clinical studies has uncovered the chronic inflammatory nature of atherosclerosis. The adaptive immune system with its front-runner, the T cell, drives the atherogenic process at all stages. T cell function is dependent on and controlled by a variety of either co-stimulatory or co-inhibitory signals. In addition, many of these proteins enfold T cell-independent pro-atherogenic functions on a variety of cell types. Accordingly they represent potential targets for immune- modulatory and/or anti-inflammatory therapy of atherosclerosis. This review focuses on the diverse role of co-stimulatory molecules of the B7 and tumour necrosis factor (TNF)-superfamily and their downstream signalling effectors in atherosclerosis. In particular, the contribution of CD28/CD80/CD86/CTLA4, ICOS/ICOSL, PD-1/PDL-1/2, TRAF, CD40/CD154, OX40/OX40L, CD137/CD137L, CD70/CD27, GITR/GITRL, and LIGHT to arterial disease is reviewed. Finally, the potential for a therapeutic exploitation of these molecules in the treatment of atherosclerosis is discussed.

Deubiquitinases A20 and CYLD modulate costimulatory signaling via CD137 (4-1BB)

TRAF2 dependent K63-polyubiquitinations have been recently shown to connect CD137 (4-1BB) stimulation to NF-κB activation. In a search of deubiquitinase enzymes (DUBs) that could regulate such a signaling route, A20 and CYLD were found to coimmunoprecipitate with CD137 and TRAF2 complexes. Indeed, overexpression of A20 or CYLD downregulated CD137-elicited ubiquitination of TRAF2 and TAK1 upon stimulation with agonist monoclonal antibodies. Moreover, overexpression of A20 or CYLD downregulated CD137-induced NF-κB activation in cultured cells and in gene-transferred hepatocytes in vivo, while silencing these deubiquitinases enhanced CD137 costimulation of primary human CD8 T cells. Therefore A20 and CYLD directly downregulate the signaling from a T and NK-cell costimulatory receptor under exploitation for cancer immunotherapy in clinical trials.

Potential Diagnostic and Therapeutic Applications of Oligonucleotide Aptamers in Breast Cancer

Breast cancer is one of the most common causes of cancer related deaths in women. Currently, with the development of early detection, increased social awareness and kinds of treatment options, survival rate has improved in nearly every type of breast cancer patients. However, about one third patients still have increased chances of recurrence within five years and the five-year relative survival rate in patients with metastasis is less than 30%. Breast cancer contains multiple subtypes. Each subtype could cause distinct clinical outcomes and systemic interventions. Thereby, new targeted therapies are of particular importance to solve this major clinical problem. Aptamers, often termed “chemical antibodies”, are functionally similar to antibodies and have demonstrated their superiority of recognizing target with high selectivity, affinity and stability. With these intrinsic properties, aptamers have been widely studied in cancer biology and some are in clinical trials. In this review, we will firstly discuss about the global impacts and mechanisms of breast cancer, then briefly highlight applications of aptamers that have been developed for breast cancer and finally summarize various challenges in clinical translation of aptamers.

Clinical and immunological responses after CD30-specific chimeric antigen receptor-redirected lymphocytes

BACKGROUND

Targeting CD30 with monoclonal antibodies in Hodgkin lymphoma (HL) and anaplastic large cell lymphoma (ALCL) has had profound clinical success. However, adverse events, mainly mediated by the toxin component of the conjugated antibodies, cause treatment discontinuation in many patients. Targeting CD30 with T cells expressing a CD30-specific chimeric antigen receptor (CAR) may reduce the side effects and augment antitumor activity.

METHODS

We conducted a phase I dose escalation study in which 9 patients with relapsed/refractory HL or ALCL were infused with autologous T cells that were gene-modified with a retroviral vector to express the CD30-specific CAR (CD30.CAR-Ts) encoding the CD28 costimulatory endodomain. Three dose levels, from 0.2 × 108 to 2 × 108 CD30.CAR-Ts/m2, were infused without a conditioning regimen. All other therapy for malignancy was discontinued at least 4 weeks before CD30.CAR-T infusion. Seven patients had previously experienced disease progression while being treated with brentuximab.

RESULTS

No toxicities attributable to CD30.CAR-Ts were observed. Of 7 patients with relapsed HL, 1 entered complete response (CR) lasting more than 2.5 years after the second infusion of CD30.CAR-Ts, 1 remained in continued CR for almost 2 years, and 3 had transient stable disease. Of 2 patients with ALCL, 1 had a CR that persisted 9 months after the fourth infusion of CD30.CAR-Ts. CD30.CAR-T expansion in peripheral blood peaked 1 week after infusion, and CD30.CAR-Ts remained detectable for over 6 weeks. Although CD30 may also be expressed by normal activated T cells, no patients developed impaired virus-specific immunity.

CONCLUSION

CD30.CAR-Ts are safe and can lead to clinical responses in patients with HL and ALCL, indicating that further assessment of this therapy is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01316146.

FUNDING

National Cancer Institute (3P50CA126752, R01CA131027 and P30CA125123), National Heart, Lung, and Blood Institute (R01HL114564), and Leukemia and Lymphoma Society (LLSTR 6227-08).

Tumor microenvironment changes leading to resistance of immune checkpoint inhibitors in metastatic melanoma and strategies to overcome resistance

Immunotherapy with checkpoint inhibitors targeting CTLA-4 and/or PD-1 receptors independent of the BRAF mutational status and targeted therapy with BRAF and MEK inhibitors in BRAF V600 mutated patients have taken the forefront of advanced melanoma treatment. The main advantage of immunotherapy is its ability to provide durable responses in a subset of patients. However, significant proportions of patients either do not respond or have progression after initial response to immunotherapies. Multiple changes in the tumor microenvironment, such as down regulation of immune checkpoint ligands by tumor, alteration in interferon signaling, and activation of alternate immune suppressive pathways, have been identified as possible reasons for failure of immune checkpoint therapy. Here, we review the resistance mechanisms adopted by cancer cells to checkpoint inhibitor therapy and targeted therapy. In addition, we focus on the available and emerging evidence on tumor microenvironment modulation by BRAF/MEK inhibitor therapy and its role in improving responses to checkpoint inhibitor therapy.

The promise of 4-1BB (CD137) mediated immunomodulation and immunotherapy for viral diseases

The T-cell surface receptor, 4-1BB (CD137), has been of increasing interest to immunologists as a co-stimulatory immune checkpoint molecule over the last two decades. Ligation of 4-1BB can activate signals in CD8+ T cells and NK cells, resulting in increased proinflammatory cytokine secretion, cytolytic function and antibody-dependent cell-mediated cytotoxicity. Targeting 4-1BB, using a 4-1BB ligand (4-1BBL) or agonistic monoclonal antibodies, has delivered a new strategy to fight against cancer, autoimmune diseases and viral infections. In this review, different aspects of 4-1BB mediated antiviral responses, the mechanistic basis of such responses and future directions are discussed.

Human CD6 Down-Modulation following T-Cell Activation Compromises Lymphocyte Survival and Proliferative Responses

Available evidence indicates that the CD6 lymphocyte surface receptor is involved in T-cell developmental and activation processes, by facilitating cell-to-cell adhesive contacts with antigen-presenting cells and likely modulating T-cell receptor (TCR) signaling. Here, we show that in vitro activation of human T cells under different TCR-ligation conditions leads to surface downregulation of CD6 expression. This phenomenon was (i) concomitant to increased levels of soluble CD6 (sCD6) in culture supernatants, (ii) partially reverted by protease inhibitors, (iii) not associated to CD6 mRNA down-regulation, and (iv) reversible by stimulus removal. CD6 down-modulation inversely correlated with the upregulation of CD25 in both FoxP3⁻ (T_act) and FoxP3⁺ (T_reg) T-cell subsets. Furthermore, ex vivo analysis of peripheral CD4⁺ and CD8⁺ T cells with activated (CD25⁺) or effector memory (effector memory T cell, CD45RA⁻CCR7⁻) phenotype present lower CD6 levels than their naïve or central memory (central memory T cell, CD45RA⁻CCR7⁺) counterparts. CD6^lo/− T cells resulting from in vitro T-cell activation show higher apoptosis and lower proliferation levels than CD6^hi T cells, supporting the relevance of CD6 in the induction of proper T-cell proliferative responses and resistance to apoptosis. Accordingly, CD6 transfectants also showed higher viability when exposed to TCR-independent apoptosis-inducing conditions in comparison with untransfected cells. Taken together, these results provide insight into the origin of sCD6 and the previously reported circulating CD6-negative T-cell subset in humans, as well as into the functional consequences of CD6 down-modulation on ongoing T-cell responses, which includes sensitization to apoptotic events and attenuation of T-cell proliferative responses.

Cytokines and metabolic factors regulate tumoricidal T-cell function during cancer immunotherapy

Recent advances in cancer biology and genetics have fostered precision therapies targeting tumor-specific attributes. Immune-based therapies that elicit cytolytic T cells (CTL) specific for tumor antigens can provide therapeutic benefit to cancer patients, however, cure rates are typically low. This largely results from immunosuppressive mechanisms operating within the tumor microenvironment, many of which inflict metabolic stresses upon CTL. Conversely, immunotherapies can mitigate specific metabolic stressors. For instance, dual costimulation immunotherapy with CD134 (OX40) plus CD137 (4-1BB) agonists appears to mediate tumor control in part by engaging cytokine networks that enable infiltrating CTL to compete for limiting supplies of glucose. Future efforts combining modalities that endow CTL with complimentary metabolic advantages should improve therapeutic efficacies.

TWEAK mediates inflammation in experimental atopic dermatitis and psoriasis

Atopic dermatitis (AD) and psoriasis are driven by alternate type 2 and type 17 immune responses, but some proteins might be critical to both diseases. Here we show that a deficiency of the TNF superfamily molecule TWEAK (TNFSF12) in mice results in defective maintenance of AD-specific T helper type 2 (Th2) and psoriasis-specific Th17 cells in the skin, and impaired expression of disease-characteristic chemokines and cytokines, such as CCL17 and TSLP in AD, and CCL20 and IL-19 in psoriasis. The TWEAK receptor, Fn14, is upregulated in keratinocytes and dermal fibroblasts, and TWEAK induces these cytokines and chemokines alone and in synergy with the signature T helper cytokines of either disease, IL-13 and IL-17. Furthermore, subcutaneous injection of recombinant TWEAK into naive mice induces cutaneous inflammation with histological and molecular signs of both diseases. TWEAK is therefore a critical contributor to skin inflammation and a possible therapeutic target in AD and psoriasis.

TNF superfamily receptor OX40 triggers invariant NKT cell pyroptosis and liver injury

Tissue-resident immune cells play a key role in local and systemic immune responses. The liver, in particular, hosts a large number of invariant natural killer T (iNKT) cells, which are involved in diverse immune responses. However, the mechanisms that regulate survival and homeostasis of liver iNKT cells are poorly defined. Here we have found that liver iNKT cells constitutively express the costimulatory TNF superfamily receptor OX40 and that OX40 stimulation results in massive pyroptotic death of iNKT cells, characterized by the release of potent proinflammatory cytokines that induce liver injury. This OX40/NKT pyroptosis pathway also plays a key role in concanavalin A-induced murine hepatitis. Mechanistically, we demonstrated that liver iNKT cells express high levels of caspase 1 and that OX40 stimulation activates caspase 1 via TNF receptor-associated factor 6-mediated recruitment of the paracaspase MALT1. We also found that activation of caspase 1 in iNKT cells results in processing of pro-IL-1β to mature IL-1β as well as cleavage of the pyroptotic protein gasdermin D, which generates a membrane pore-forming fragment to produce pyroptotic cell death. Thus, our study has identified OX40 as a death receptor for iNKT cells and uncovered a molecular mechanism of pyroptotic cell death. These findings may have important clinical implications in the development of OX40-directed therapies.

Targeted deletion of Traf2 allows immunosuppression-free islet allograft survival in mice

AIMS/HYPOTHESIS

Administration of anti-CD40 ligand (CD40L) antibodies has been reported to allow long-term islet allograft survival in non-human primates without the need for exogenous immunosuppression. However, the use of anti-CD40L antibodies was associated with thromboembolic complications. Targeting downstream intracellular components shared between CD40 and other TNF family co-stimulatory molecules could bypass these complications. TNF receptor associated factor 2 (TRAF2) integrates multiple TNF receptor family signalling pathways that are critical for T cell activation and may be a central node of alloimmune responses.

METHODS

T cell-specific Traf2-deficient mice (Traf2TKO) were generated to define the role of TRAF2 in CD4⁺ T cell effector responses that mediate islet allograft rejection in vivo. In vitro allograft responses were tested using mixed lymphocyte reactions and analysis of IFN-γ and granzyme B effector molecule expression. T cell function was assessed using anti-CD3/CD28-mediated proliferation and T cell polarisation studies.

RESULTS

Traf2TKO mice exhibited permanent survival of full MHC-mismatched pancreatic islet allografts without exogenous immunosuppression. Traf2TKO CD4⁺ T cells exhibited reduced proliferation, activation and acquisition of effector function following T cell receptor stimulation; however, both Traf2TKO CD4⁺ and CD8⁺ T cells exhibited impaired alloantigen-mediated proliferation and acquisition of effector function. In polarisation studies, Traf2TKO CD4⁺ T cells preferentially converted to a T helper (Th)2 phenotype, but exhibited impaired Th17 differentiation. Without TRAF2, thymocytes exhibited dysregulated TNF-mediated induction of c-Jun N-terminal kinase (JNK) and canonical NFκB pathways. Critically, targeting TRAF2 in T cells did not impair the acute phase of CD8-dependent viral immunity. These data highlight a specific requirement for a TRAF2-NFκB and TRAF2-JNK signalling cascade in T cell activation and effector function in rejecting islet allografts.

CONCLUSION/INTERPRETATION

Targeting TRAF2 may be useful as a therapeutic approach for immunosuppression-free islet allograft survival that avoids the thromboembolic complications associated with the use of anti-CD40L antibodies.

Beyond TNF: TNF superfamily cytokines as targets for the treatment of rheumatic diseases

TNF blockers are highly efficacious at dampening inflammation and reducing symptoms in rheumatic diseases such as rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis, and also in nonrheumatic syndromes such as inflammatory bowel disease. As TNF belongs to a superfamily of 19 structurally related proteins that have both proinflammatory and anti-inflammatory activity, reagents that disrupt the interaction between proinflammatory TNF family cytokines and their receptors, or agonize the anti-inflammatory receptors, are being considered for the treatment of rheumatic diseases. Biologic agents that block B cell activating factor (BAFF) and receptor activator of nuclear factor-κB ligand (RANKL) have been approved for the treatment of systemic lupus erythematosus and osteoporosis, respectively. In this Review, we focus on additional members of the TNF superfamily that could be relevant for the pathogenesis of rheumatic disease, including those that can strongly promote activity of immune cells or increase activity of tissue cells, as well as those that promote death pathways and might limit inflammation. We examine preclinical mouse and human data linking these molecules to the control of damage in the joints, muscle, bone or other tissues, and discuss their potential as targets for future therapy of rheumatic diseases.

T Cell Receptor and Cytokine Signaling Can Function at Different Stages to Establish and Maintain Transcriptional Memory and Enable T Helper Cell Differentiation

Experienced T cells exhibit immunological memory via a rapid recall response, responding to restimulation much faster than naïve T cells. The formation of immunological memory starts during an initial slow response, when naïve T cells become transformed to proliferating T blast cells, and inducible immune response genes are reprogrammed as active chromatin domains. We demonstrated that these active domains are supported by thousands of priming elements which cooperate with inducible transcriptional enhancers to enable efficient responses to stimuli. At the conclusion of this response, a small proportion of these cells return to the quiescent state as long-term memory T cells. We proposed that priming elements can be established in a hit-and-run process dependent on the inducible factor AP-1, but then maintained by the constitutive factors RUNX1 and ETS-1. This priming mechanism may also function to render genes receptive to additional differentiation-inducing factors such as GATA3 and TBX21 that are encountered under polarizing conditions. The proliferation of recently activated T cells and the maintenance of immunological memory in quiescent memory T cells are also dependent on various cytokine signaling pathways upstream of AP-1. We suggest that immunological memory is established by T cell receptor signaling, but maintained by cytokine signaling.

Cryogel-supported stem cell factory for customized sustained release of bispecific antibodies for cancer immunotherapy

Combining stem cells with biomaterial scaffolds provides a promising strategy for the development of drug delivery systems. Here we propose an innovative immunotherapeutic organoid by housing human mesenchymal stromal cells (MSCs), gene-modified for the secretion of an anti-CD33-anti-CD3 bispecific antibody (bsAb), in a small biocompatible star-shaped poly(ethylene glycol)-heparin cryogel scaffold as a transplantable and low invasive therapeutic machinery for the treatment of acute myeloid leukemia (AML). The macroporous biohybrid cryogel platform displays effectiveness in supporting proliferation and survival of bsAb-releasing-MSCs overtime in vitro and in vivo, avoiding cell loss and ensuring a constant release of sustained and detectable levels of bsAb capable of triggering T-cell-mediated anti-tumor responses and a rapid regression of CD33⁺ AML blasts. This therapeutic device results as a promising and safe alternative to the continuous administration of short-lived immunoagents and paves the way for effective bsAb-based therapeutic strategies for future tumor treatments.

Structural insights of homotypic interaction domains in the ligand-receptor signal transduction of tumor necrosis factor (TNF)

Several members of tumor necrosis factor receptor (TNFR) superfamily that these members activate caspase-8 from death-inducing signaling complex (DISC) in TNF ligand-receptor signal transduction have been identified. In the extrinsic pathway, apoptotic signal transduction is induced in death domain (DD) superfamily; it consists of a hexahelical bundle that contains 80 amino acids. The DD superfamily includes about 100 members that belong to four subfamilies: death domain (DD), caspase recruitment domain (CARD), pyrin domain (PYD), and death effector domain (DED). This superfamily contains key building blocks: with these blocks, multimeric complexes are formed through homotypic interactions. Furthermore, each DD-binding event occurs exclusively. The DD superfamily regulates the balance between death and survival of cells. In this study, the structures, functions, and unique features of DD superfamily members are compared with their complexes. By elucidating structural insights of DD superfamily members, we investigate the interaction mechanisms of DD domains; these domains are involved in TNF ligand-receptor signaling. These DD superfamily members play a pivotal role in the development of more specific treatments of cancer. [BMB Reports 2016; 49(3): 159-166]

Aptamers for CD Antigens: From Cell Profiling to Activity Modulation

Nucleic acid-based aptamers are considered to be a promising alternative to antibodies because of their strong and specific binding to diverse targets, fast and inexpensive chemical synthesis, and easy labeling with a fluorescent dye or therapeutic agent. Cluster of differentiation (CD) proteins are among the most popular antigens for aptamers on the cell surface. These anti-CD aptamers could be used in cell biology and biomedicine, from simple cell phenotyping by flow cytometry or fluorescent microscopy to diagnosis and treatment of HIV/AIDS to cancer and immune therapies. The unique feature of aptamers is that they can act simultaneously as an agonist and antagonist of CD receptors depending on a degree of aptamer oligomerization. Aptamers can also deliver small interfering RNA to silence vital genes in CD-positive cells. In this review, we summarize nucleic acid sequences of anti-CD aptamers and their use, which have been validated in multiple studies.

TNF superfamily cytokines in the promotion of Th9 differentiation and immunopathology

The tumor necrosis factor (TNF) receptors and their corresponding cytokine ligands have been implicated in many aspects of the biology of immune functions. TNF receptors have key roles during various stages of T cell homeostasis. Many of them can co-stimulate lymphocyte proliferation and cytokine production. Additionally, several TNF cytokines can regulate T cell differentiation, including promoting Th1, Th2, Th17, and more recently the newly described Th9 subset. Four TNF family cytokines have been identified as regulators for IL-9 production by T cells. OX40L, TL1A, and GITRL can promote Th9 formation but can also divert iTreg into Th9, while 4-1BBL seems to inhibit IL-9 production from iTreg and has not been studied for its ability to promote Th9 generation. Regulation of IL-9 production by TNF family cytokines has repercussions in vivo, including enhancement of anti-tumor immunity and immunopathology in allergic lung and ocular inflammation. Regulating T cell production of IL-9 through blockade or agonism of TNF family cytokine receptors may be a therapeutic strategy for autoimmune and allergic diseases and in tumor.

The Roles of CD137 Signaling in Atherosclerosis

The tumor necrosis factor receptor superfamily (TNFRSF), which includes CD40, LIGHT, and OX40, plays important roles in the initiation and progression of cardiovascular diseases, involving atherosclerosis. CD137, a member of TNFRSF, is a well-known activation-induced T cell co-stimulatory molecule and has been reported to be expressed in human atherosclerotic plaque lesions, and plays pivotal roles in mediating disease processes. In this review, we focus on and summarize recent advances in mouse studies on the involvement of CD137 signaling in the pathogenesis and plaque stability of atherosclerosis, thereby highlighting a valuable therapeutic target in atherosclerosis.

Emerging role of immunotherapy in urothelial carcinoma-Future directions and novel therapies

Tremendous advances in our understanding of the tumor immunology and molecular biology of urothelial carcinoma (UC) have led to the recent approval of immunotherapy as a novel option for patients with UC with advanced disease. Despite the promising data of novel immune checkpoint inhibitors, only a small subset of patients with UC achieves durable remissions. Because an optimal antitumor response requires coordination of multiple immune, tumor, and microenvironment effector cells, novel approaches targeting distinct mechanisms of action likely in combination are needed. In addition, discovery of reliable immune biomarkers, understanding of mechanisms of resistance, and novel clinical trial designs are warranted for maximum benefit of UC immunotherapy.

Changes in peripheral blood lymphocytes in polycythemia vera and essential thrombocythemia patients treated with pegylated-interferon alpha and correlation with JAK2V617F allelic burden

BACKGROUND

Pegylated-interferon alpha (PegINFα) treatment of patients with polycythemia vera (PV) and essential thrombocythemia (ET) has resulted in long-term clinical response, decreased JAK2^V617F allelic burden and restoration of polyclonal hematopoiesis. The mechanisms of the beneficial effects of PegINFα are not clear, but available evidence suggests direct suppression of JAK2-mutated clone, induction of dormant stem cells to proliferation, and augmentation of an immune effect against PV and ET clones.

METHODS

We analyzed the phenotype and frequency of peripheral blood lymphocytes (PBL) from PegINFα treated patients and compared them to patients treated with hydroxyurea (HU). Samples collected at various time points before and during treatment were analyzed using multicolor flow cytometry.

RESULTS

We found that PegINFα increased the frequency of peripheral blood CD4⁺ Foxp3⁺ regulatory T cells (Treg). Highly suppressive Treg, characterized by co-expression of CD39 and HLA-DR, were also increased in PBL from PegINFα treated patients. We observed an augmentation of cycling CD8⁺ T cells, NK cells, and of poorly activated CD38⁺CD8⁺ T cells. Our results also suggest that PegINFα increased the frequency of PD-1⁺ CD4⁺ helper cells and PD-1⁺ CD4⁺ Foxp3⁺ Treg cells. None of these changes were present in HU treated patients. We analyzed the correlation between changes in different T cell populations in the peripheral blood with the changes in JAK2^V617F allelic burden in clonal granulocytes. Augmentation of Ki-67⁺ Treg, HLA-DR⁺ CD39⁺ Treg, Helios⁺ Treg and HLA-DR⁺ CD38⁺ CD8⁺ T cells correlated with an increase in JAK2^V617F allelic burden. We also found a positive correlation between PD-1⁺ Treg and JAK2^V617F allelic burden; however, the number of available patients was small (n = 7).

CONCLUSIONS

We report marked changes in frequencies of PBL subsets after PegINFα treatment, suggesting an immunomodulatory effect by PegINFα. Generation of a more suppressive immune response, as measured by an increase in highly suppressive Treg and poorly activated CD8⁺ T cells, correlated with a poor molecular response. In this study, we have not identified changes in the PBL that would indicate the presence of an effective anti-tumor response.Trial registration NCT01259856, December 7. 2010 and NCT01259817, December 6. 2010, Grant #1P01CA108671-O1A2, July 17. 2006, Sponsor: MPDRC/NIH, NCI-2012-00269, January 12. 2011 and NCI-2012-00268, January 12. 2011.

Forsythoside A Inhibits BVDV Replication via TRAF2-Dependent CD28-4-1BB Signaling in Bovine PBMCs

Bovine viral diarrhea virus (BVDV), the causative agent of bovine viral diarrhea/mucosal disease (BVD/MD), is an important pathogen of cattle and other wild animals throughout the world. BVDV infection typically leads to an impaired immune response in cattle. In the present study, we investigated the effect of Forsythoside A (FTA) on BVDV infection of bovine peripheral blood mononuclear cells (PBMCs). We found that Forsythoside A could not only promote proliferation of PBMCs and T cells activation but also inhibit the replication of BVDV as well as apoptosis induced by BVDV. FTA treatment could counteract the BVDV-induced overproduction of IFN-γ to maintain the immune homeostasis in bovine PBMCs. At same time, FTA can enhance the secretion of IL-2. What's more, BVDV promotes the expression of CD28, 4-1BB and TRAF-2, which can be modulated by FTA. Our data suggest that FTA protects PBMCs from BVDV infection possibly via TRAF2-dependent CD28-4-1BB signaling, which may activate PBMCs in response to BVDV infection. Therefore, this aids in the development of an effective adjuvant for vaccines against BVDV and other specific FTA-based therapies for preventing BVDV infection.