Interferon gamma in the pathogenesis of hypertension - recent insights

PURPOSE OF REVIEW

The mounting body of evidence underscores the pivotal role of interferon gamma (IFNγ) in the pathogenesis of hypertension, prompting exploration of the mechanisms by which this cytokine fosters a pro-inflammatory immune milieu, subsequently exacerbating hypertension. In this review, we delve into recent preclinical and clinical studies from the past two years to elucidate how IFNγ participates in the progression of hypertension.

RECENT FINDINGS

IFNγ promotes renal CD8 + T cell accumulation by upregulating tubular PDL1 and MHC-I, intensifying cell-to-cell interaction. Intriguingly, a nucleotide polymorphism in LNK, predisposing towards hypertension, correlates with augmented T cell IFNγ production. Additionally, anti-IFNγ treatment exhibits protective effects against T cell-mediated inflammation during angiotensin II infusion or transverse aortic constriction. Moreover, knockout of the mineralocorticoid receptor in T cells protects against cardiac dysfunction induced by myocardial infarction, correlating with reduced IFNγ and IL-6, decreased macrophage recruitment, and attenuated fibrosis. Interestingly, increased IFNγ production correlates with elevated blood pressure, impacting individuals with type 2 diabetes, nondiabetics, and obese hypertensive patients.

SUMMARY

These revelations spotlight IFNγ as the critical mediator bridging the initial phase of blood pressure elevation with the sustained and exacerbated pathology. Consequently, blocking IFNγ signaling emerges as a promising therapeutic target to improve the management of this 'silent killer.'

Fecal Microbiota Transplantation Alleviates Allergic Rhinitis via CD4+ T Cell Modulation Through Gut Microbiota Restoration

Allergic rhinitis (AR) is an allergic condition of the upper respiratory tract with a complex pathogenesis, including epithelial barrier disruption, immune regulation, and gut microbiota, which is not yet fully understood. Gut microbiota is closely linked to allergic diseases, including AR. Fecal microbiota transplantation (FMT) has recently been recognized as a potentially effective therapy for allergic diseases. However, the efficacy and mechanism of action of FMT in AR remain unknown. Herein, we aimed to observe the implications of gut microbiota on epithelial barrier function and T cell homeostasis, as well as the effect of FMT in AR, using the ovalbumin (OVA)-induced AR mice. The intestinal microbiota of recipient mice was cleared using an antibiotic cocktail; thereafter, FMT was performed. Subsequently, the nasal symptom scores and histopathological features of colon and nasal mucosa tissues of mice were monitored, and serum OVA-sIgE and cytokines of IL-4, IFNγ, IL-17A, and IL-10 cytokine concentrations were examined. Thereafter, tight junction protein and CD4+ T cell-related transcription factor and cytokine expressions were observed in the colon and nasal mucosa, and changes in the expression of PI3K/AKT/mTOR and NFκB signaling pathway were detected by WB assay in each group. Fecal DNA was extracted from the four mice groups for high-throughput 16S rRNA sequencing. FMT ameliorated nasal symptoms and reduced nasal mucosal inflammation in AR mice. Moreover, according to 16S rRNA sequencing, FMT restored the disordered gut microbiota in AR mice. Following FMT, ZO-1 and claudin-1 and Th1/Th2/Th17-related transcription factor and cytokine expressions were upregulated, whereas Treg cell-related Foxp3 and IL-10 expressions were downregulated. Mechanistic studies have revealed that FMT also inhibited PI3K/AKT/mTOR and NF-κB pathway protein phosphorylation in AR mouse tissues. FMT alleviates allergic inflammation in AR by repairing the epithelial barrier and modulating CD4+ T cell balance and exerts anti-inflammatory effects through the PI3K/AKT/mTOR and NF-κB signaling pathways. Moreover, gut microbiota disorders are involved in AR pathogenesis. Disturbed gut microbiota causes an altered immune-inflammatory state in mice and increases susceptibility to AR. This study suggested the regulatory role of the gut-nose axis in the pathogenesis of AR is an emerging field, which provides novel directions and ideas for the treatment of AR.

Illuminating T cell-dendritic cell interactions in vivo by FlAsHing antigens

Delineating the complex network of interactions between antigen-specific T cells and antigen presenting cells (APCs) is crucial for effective precision therapies against cancer, chronic infections, and autoimmunity. However, the existing arsenal for examining antigen-specific T cell interactions is restricted to a select few antigen-T cell receptor pairs, with limited in situ utility. This lack of versatility is largely due to the disruptive effects of reagents on the immune synapse, which hinder real-time monitoring of antigen-specific interactions. To address this limitation, we have developed a novel and versatile immune monitoring strategy by adding a short cysteine-rich tag to antigenic peptides that emits fluorescence upon binding to thiol-reactive biarsenical hairpin compounds. Our findings demonstrate the specificity and durability of the novel antigen-targeting probes during dynamic immune monitoring in vitro and in vivo. This strategy opens new avenues for biological validation of T-cell receptors with newly identified epitopes by revealing the behavior of previously unrecognized antigen-receptor pairs, expanding our understanding of T cell responses.

A dynamic atlas of immunocyte migration from the gut

Dysbiosis in the gut microbiota affects several systemic diseases, possibly by driving the migration of perturbed intestinal immunocytes to extraintestinal tissues. Combining Kaede photoconvertible mice and single-cell genomics, we generated a detailed map of migratory trajectories from the colon, at baseline, and in several models of intestinal and extraintestinal inflammation. All lineages emigrated from the colon in an S1P-dependent manner. B lymphocytes represented the largest contingent, with the unexpected circulation of nonexperienced follicular B cells, which carried a gut-imprinted transcriptomic signature. T cell emigration included distinct groups of RORγ+ and IEL-like CD160+ subsets. Gut inflammation curtailed emigration, except for dendritic cells disseminating to lymph nodes. Colon-emigrating cells distributed differentially to distinct sites of extraintestinal models of inflammation (psoriasis-like skin, arthritic synovium, and tumors). Thus, specific cellular trails originating in the gut and influenced by microbiota may shape peripheral immunity in varied ways.

A T cell-targeted multi-antigen vaccine generates robust cellular and humoral immunity against SARS-CoV-2 infection

SARS-CoV-2, the etiological agent behind the coronavirus disease 2019 (COVID-19) pandemic, has continued to mutate and create new variants with increased resistance against the WHO-approved spike-based vaccines. With a significant portion of the worldwide population still unvaccinated and with waning immunity against newly emerging variants, there is a pressing need to develop novel vaccines that provide broader and longer-lasting protection. To generate broader protective immunity against COVID-19, we developed our second-generation vaccinia virus-based COVID-19 vaccine, TOH-VAC-2, encoded with modified versions of the spike (S) and nucleocapsid (N) proteins as well as a unique poly-epitope antigen that contains immunodominant T cell epitopes from seven different SARS-CoV-2 proteins. We show that the poly-epitope antigen restimulates T cells from the PBMCs of individuals formerly infected with SARS-CoV-2. In mice, TOH-VAC-2 vaccination produces high titers of S- and N-specific antibodies and generates robust T cell immunity against S, N, and poly-epitope antigens. The immunity generated from TOH-VAC-2 is also capable of protecting mice from heterologous challenge with recombinant VSV viruses that express the same SARS-CoV-2 antigens. Altogether, these findings demonstrate the effectiveness of our versatile vaccine platform as an alternative or complementary approach to current vaccines.

Exploring Immune Modulatory Effects of Cyclotide-Enriched Viola tricolor Preparations

Viola tricolor is a medicinal plant with documented application as an anti-inflammatory herb. The standard of care for the treatment of inflammatory bowel disease is immunosuppressive therapeutics or biologics, which often have undesired effects. We explored V. tricolor herbal preparations that are rich in an emerging class of phytochemicals with drug-like properties, so-called cyclotides. As an alternative to existing inflammatory bowel disease medications, cyclotides have immunomodulatory properties, and their intrinsic stability allows for application in the gastrointestinal tract, for instance, via oral administration. We optimized the isolation procedure to improve the yield of cyclotides and compared the cellular effects of violet-derived organic solvent-extracts, aqueous preparations, and an isolated cyclotide from this plant on primary human T lymphocytes and macrophages, i.e., cells that are crucial for the initiation and progression of inflammatory bowel disease. The hot water herbal decoctions have a stronger immunosuppressive activity towards proliferation, interferon-γ, and interleukin-21 secretion of primary human T cells than a DCM/MeOH cyclotide-enriched extract, and the isolated cyclotide kalata S appears as one of the active components responsible for the observed effects. This effect was increased by a longer boiling duration. In contrast, the DCM/MeOH cyclotide-enriched extract was more effective in reducing the levels of cytokines interleukin-6, interleukin-12, interleukin-23, tumor necrosis factor-α, and C - X-C motif chemokine ligand 10, secreted by human monocyte-derived macrophages. Defined cyclotide preparations of V. tricolor have promising pharmacological effects in modulating immune cell responses at the cytokine levels. This is important towards understanding the role of cyclotide-containing herbal drug preparations for future applications in immune disorders, such as inflammatory bowel disease.

A Rare and Isolated Presentation of Primary Cutaneous Anaplastic Large Cell Lymphoma on the Breast

Primary cutaneous anaplastic large-cell lymphoma (PC-ALCL) is a subtype of non-Hodgkin lymphoma belonging to the CD30+ spectrum of lymphoproliferative disorders. It constitutes the second most prevalent category within cutaneous T-cell lymphomas (CTCL), encompassing approximately 25% of cases. This disorder is characterized by its exclusive cutaneous involvement and favorable overall prognosis. Patients typically present with reddish-brown nodules, which may evolve into ulcers. Although some cases experience regression, complete resolution is uncommon. While most lesions manifest on the extremities, followed by the head and neck, the breast region may rarely be affected by PC-ALCL. Distinctions between anaplastic lymphoma kinase (ALK)-positive and ALK-negative subtypes have been documented in breast presentations, often associated with breast implants. In this context, we present an isolated PC-ALCL instance in a 26-year-old woman with no history of breast implants.

The role of interferon in the thymus

Interferons (IFNs) are a family of proteins that are generated in response to viral infection and induce an antiviral response in many cell types. The COVID-19 pandemic revealed that patients with inborn errors of type-I IFN immunity were more prone to severe infections, but also found that many patients with severe COVID-19 had anti-IFN autoantibodies that led to acquired defects in type-I IFN immunity. These findings revealed the previously unappreciated finding that central immune tolerance to IFN is essential to immune health. Further evidence has also highlighted the importance of IFN within the thymus and its impact on T-cell development. This review will highlight what is known of IFN's role in T-cell development, T-cell central tolerance, and the impact of IFN on the thymus.

Circulating Blood Lymphocytes and Acute Pancreatitis Severity: A Systematic Review

Acute pancreatitis is an acute inflammatory process of the pancreas with high prevalence and varying degrees of severity that can be potentially life-threatening. Much is still unknown about which mechanisms determine the course and severity of acute pancreatitis. The primary objective of this review is to identify the potential association between circulating lymphocytes and the severity of acute pancreatitis. A systematic search was performed in Medline, Web of Science, Cochrane Central Register of Controlled Trials and ClinicalTrails.gov. The authors independently did the selection process as well as data extraction that was recorded into a flow diagram following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). Our initial search identified 27,783 studies which were narrowed down to 13 by applying strict inclusion and exclusion algorithms. The consistent findings across the studies indicated that peripheral blood lymphocytes are related to acute pancreatitis severity.

CD4 Effector TCR Avidity for Peptide on APC Determines the Level of Memory Generated

Initial TCR affinity for peptide Ag is known to impact the generation of memory; however, its contributions later, when effectors must again recognize Ag at 5-8 d postinfection to become memory, is unclear. We examined whether the effector TCR affinity for peptide at this "effector checkpoint" dictates the extent of memory and degree of protection against rechallenge. We made an influenza A virus nucleoprotein (NP)-specific TCR transgenic mouse strain, FluNP, and generated NP-peptide variants that are presented by MHC class II to bind to the FluNP TCR over a broad range of avidity. To evaluate the impact of avidity in vivo, we primed naive donor FluNP in influenza A virus-infected host mice, purified donor effectors at the checkpoint, and cotransferred them with the range of peptides pulsed on activated APCs into second uninfected hosts. Higher-avidity peptides yielded higher numbers of FluNP memory cells in spleen and most dramatically in lung and draining lymph nodes and induced better protection against lethal influenza infection. Avidity determined memory cell number, not cytokine profile, and already impacted donor cell number within several days of transfer. We previously found that autocrine IL-2 production at the checkpoint prevents default effector apoptosis and supports memory formation. Here, we find that peptide avidity determines the level of IL-2 produced by these effectors and that IL-2Rα expression by the APCs enhances memory formation, suggesting that transpresentation of IL-2 by APCs further amplifies IL-2 availability. Secondary memory generation was also avidity dependent. We propose that this regulatory pathway selects CD4 effectors of highest affinity to progress to memory.

T cell-Mediated Development of Stromal Fibroblasts with an Immune-Enhancing Chemokine Profile

Stromal fibroblasts reside in inflammatory tissues that are characterized by either immune suppression or activation. Whether and how fibroblasts adapt to these contrasting microenvironments remains unknown. Cancer-associated fibroblasts (CAF) mediate immune quiescence by producing the chemokine CXCL12, which coats cancer cells to suppress T-cell infiltration. We examined whether CAFs can also adopt an immune-promoting chemokine profile. Single-cell RNA sequencing of CAFs from mouse pancreatic adenocarcinomas identified a subpopulation of CAFs with decreased expression of Cxcl12 and increased expression of the T cell-attracting chemokine Cxcl9 in association with T-cell infiltration. TNFα and IFNγ containing conditioned media from activated CD8+ T cells converted stromal fibroblasts from a CXCL12+/CXCL9- immune-suppressive phenotype into a CXCL12-/CXCL9+ immune-activating phenotype. Recombinant IFNγ and TNFα acted together to augment CXCL9 expression, whereas TNFα alone suppressed CXCL12 expression. This coordinated chemokine switch led to increased T-cell infiltration in an in vitro chemotaxis assay. Our study demonstrates that CAFs have a phenotypic plasticity that allows their adaptation to contrasting immune tissue microenvironments.

A Novel Cell-based Luciferase Reporter Platform for the Development and Characterization of T-Cell Redirecting Therapies and Vaccine Development

T-cell immunotherapies are promising strategies to generate T-cell responses towards tumor-derived or pathogen-derived antigens. Adoptive transfer of T cells genetically modified to express antigen receptor transgenes has shown promise for the treatment of cancer. However, the development of T-cell redirecting therapies relies on the use of primary immune cells and is hampered by the lack of easy-to-use model systems and sensitive readouts to facilitate candidate screening and development. Particularly, testing T-cell receptor (TCR)-specific responses in primary T cells and immortalized T cells is confounded by the presence of endogenous TCR expression which results in mixed alpha/beta TCR pairings and compresses assay readouts. Herein, we describe the development of a novel cell-based TCR knockout (TCR-KO) reporter assay platform for the development and characterization of T-cell redirecting therapies. CRISPR/Cas9 was used to knockout the endogenous TCR chains in Jurkat cells stably expressing a human interleukin-2 promoter-driven luciferase reporter gene to measure TCR signaling. Reintroduction of a transgenic TCR into the TCR-KO reporter cells results in robust antigen-specific reporter activation compared with parental reporter cells. The further development of CD4/CD8 double-positive and double-negative versions enabled low-avidity and high-avidity TCR screening with or without major histocompatibility complex bias. Furthermore, stable TCR-expressing reporter cells generated from TCR-KO reporter cells exhibit sufficient sensitivity to probe in vitro T-cell immunogenicity of protein and nucleic acid-based vaccines. Therefore, our data demonstrated that TCR-KO reporter cells can be a useful tool for the discovery, characterization, and deployment of T-cell immunotherapy.

Eradication of Heterogeneous Tumors by T Cells Targeted with Combination Bispecific Chemically Self-assembled Nanorings

Cancer stem-like cells (CSCs) are often the root cause of refractive relapse due to their inherent resistance to most therapies and ability to rapidly self-propagate. Recently, the antigen CD133 has been identified as a CSC marker on several cancer types and αCD133 therapies have shown selective targeting against CSCs with minimal off-target toxicity. Theoretically, by selectively eliminating CSCs, the sensitivity to bulk tumor-targeting therapies should be enhanced. Previously, our laboratory has developed bispecific chemically self-assembled nanorings (CSANs) that successfully induced T-cell eradication of EpCAM-positive (EpCAM+) tumors. We reasoned that targeting both CSCs [CD133-positive (CD133+)] and the bulk tumor (EpCAM+) simultaneously using our CSAN platform should produce a synergistic effect. We evaluated αCD133/αCD3 CSANs as both a single agent and in combination with αEpCAM/αCD3 CSANs to treat triple-negative breast cancer (TNBC) cells, which express a subpopulation of CD133+ cancer stem cells and EpCAM+ bulk tumor cells. Furthermore, an orthotopic breast cancer model validated the ability of αCD133 and αEpCAM targeting to combine synergistically in the elimination of TNBC MDA-MB-231 cells. Complete tumor eradication only occurred when EpCAM and CD133 were targeted simultaneously and lead to full remission in 80% of the test mice. Importantly, the depletion and enrichment of CD133 TNBCs highlighted the role of CD133+ cancer cells in regulating tumor growth and progression. Collectively, our results demonstrate that dual targeting with bispecific CSANs can be effective against heterogenous tumor cell populations and that elimination of primary and CD133+ CSCs may be necessary for eradication of at least a subset of TNBC.

Systemic Administration of Acazicolcept, a Dual CD28 and Inducible T cell Costimulator Inhibitor, Ameliorates Experimental Autoimmune Uveitis

Purpose

Combined inhibition of CD28 and inducible T cell costimulator (ICOS) pathways with acazicolcept (ALPN-101) represents a potential new treatment for uveitis. Here, we evaluate preclinical efficacy using experimental autoimmune uveitis (EAU) in Lewis rats.

Methods

Efficacy was tested in 57 Lewis rats treated with either systemic (subcutaneous) or local (intravitreal) administration of acazicolcept and compared to treatment with a matched Fc-only control or corticosteroid. Impact of treatment on uveitis was assessed using clinical scoring, optical coherence tomography (OCT), and histology. Ocular effector T cell populations were determined using flow cytometry, and multiplex ELISA used to measure aqueous cytokine concentrations.

Results

When compared to Fc control treatment, systemic acazicolcept led to statistically significant decreases in clinical score (P < 0.01), histologic score (P < 0.05), and number of ocular CD45+ cells (P < 0.01). Number of ocular CD4+ and CD8+ T cells expressing IL-17A+ and IFNγ+ were also decreased with statistical significance (P < 0.01). Similar results were achieved with corticosteroids. Intravitreal acazicolcept decreased inflammation scores when compared to untreated fellow eyes and to Fc control treated eyes, although not statistically significant. Systemic toxicity, measured by weight loss, occurred in the corticosteroid-treated, but not in the acazicolcept-treated animals.

Conclusions

Systemic treatment with acazicolcept statistically significantly suppressed EAU. Acazicolcept was well-tolerated without the weight loss associated with corticosteroids. Acazicolcept may be an effective alternative to corticosteroids for use in treating autoimmune uveitis. Additional studies are needed to clarify the optimal dose and route for use in humans.

Translational Relevance

We show that T cell costimulatory blockade could be an effective mechanism for treating uveitis.

Extracellular CIRP Induces Novel Nectin-2+ (CD112+) Neutrophils to Promote Th1 Differentiation in Sepsis

Neutrophil heterogeneity represents different subtypes, states, phenotypes, and functionality of neutrophils implicated in sepsis pathobiology. Extracellular cold-inducible RNA-binding protein (eCIRP) is a damage-associated molecular pattern that promotes inflammation and alters neutrophil phenotype and function through TLR4. Nectin-2 or CD112 is an Ig-like superfamily member. CD112 serves as the ligand for DNAM-1 (CD226), which induces Th1 differentiation in naive CD4+ T cells. Th1 cells produce IFN-γ to fuel inflammation. CD112 is expressed mainly on APCs, but its expression in neutrophils is unknown. We hypothesize that eCIRP induces CD112 expression in neutrophils, promoting Th1 differentiation in sepsis. Incubation of neutrophils with recombinant murine (rm)CIRP significantly increased the gene and protein expression of CD112 in neutrophils. Anti-TLR4 Ab-treated neutrophils significantly decreased CD112+ neutrophils compared with controls upon rmCIRP stimulation. After 4 h of rmCIRP injection in mice, CD112+ neutrophils were significantly increased in the blood and spleen. At 20 h after cecal ligation and puncture-induced sepsis, CD112+ neutrophils were also significantly increased. Blood and splenic CD112+ neutrophils in septic CIRP-/- mice were much lower than in septic wild-type mice. Coculture of naive CD4 T cells with rmCIRP-treated (CD112+) neutrophils significantly increased IFN-γ-producing Th1 cells compared with coculture with PBS-treated neutrophils. CD112 Ab significantly attenuated Th1 differentiation induced by rmCIRP-treated neutrophils. Thus, eCIRP increases CD112 expression in neutrophils via TLR4 to promote Th1 differentiation in sepsis. Targeting eCIRP may attenuate sepsis by reducing Th1-promoting CD112+ neutrophils.

Brief Report: Intracellular Cystatin B Levels Are Altered in HIV-Infected Participants With Respect to Neurocognitive Status and Antiretroviral Therapy

ABSTRACT

With advances in HIV treatment, people with HIV (PWH) are living longer but experience aging-related comorbidities, including cognitive deficits, at higher rates than the general population. Previous studies have shown alterations in lysosomal proteins in blood from PWH with severe dementia. However, these markers have not been evaluated in PWH with milder neurocognitive impairment. We sought to determine whether levels of the lysosomal cysteine protease cathepsin B (CatB) and its endogenous inhibitor cystatin B (CysB) were altered in PWH with neurocognitive impairment and whether antiretroviral therapy (ART) further influenced these levels. Peripheral blood mononuclear cells were obtained from the tenofovir arm of a multicenter clinical trial in which ART-naive, HIV+ participants received treatment for 48 weeks (ACTG A5303, NCT01400412). PWH were divided by neurocognitive status (eg, with or without neurocognitive impairment) before ART initiation. Intracellular levels of CatB and CysB were measured in T cells and monocytes by means of flow cytometry. Levels of CysB were significantly decreased in both CD4 + T cells and CD8 + T cells after 48 weeks of ART in HIV+ participants without neurocognitive impairment but not in participants with neurocognitive impairment. Levels of CysB were increased in CD14 + monocytes from the participants with neurocognitive impairment after ART. Levels of CysB and CatB positively correlated regardless of HIV, neurocognitive status, or exposure to ART. These findings suggest that CysB has the potential to provide mechanistic insight into HIV-associated neurocognitive disorders or provide a molecular target for systemic monitoring or treatment of neurocognitive impairment in the context of ART and should be investigated further.

Stress-Mediated Attenuation of Translation Undermines T-cell Activity in Cancer

Protein synthesis supports robust immune responses. Nutrient competition and global cell stressors in the tumor microenvironment (TME) may impact protein translation in T cells and antitumor immunity. Using human and mouse tumors, we demonstrated here that protein translation in T cells is repressed in solid tumors. Reduced glucose availability to T cells in the TME led to activation of the unfolded protein response (UPR) element eIF2α (eukaryotic translation initiation factor 2 alpha). Genetic mouse models revealed that translation attenuation mediated by activated p-eIF2α undermines the ability of T cells to suppress tumor growth. Reprograming T-cell metabolism was able to alleviate p-eIF2α accumulation and translational attenuation in the TME, allowing for sustained protein translation. Metabolic and pharmacological approaches showed that proteasome activity mitigates induction of p-eIF2α to support optimal antitumor T-cell function, protecting from translation attenuation and enabling prolonged cytokine synthesis in solid tumors. Together, these data identify a new therapeutic avenue to fuel the efficacy of tumor immunotherapy.

SIGNIFICANCE

Proteasome function is a necessary cellular component for endowing T cells with tumor killing capacity by mitigating translation attenuation resulting from the unfolded protein response induced by stress in the tumor microenvironment.

Manipulating Metabolic Alterations and Its Consequence to Unleash the Potential of Antitumor Immunotherapy

Cellular metabolic reprogramming driven by oncogenic mutations is considered as a hallmark in the development of malignant cells, and has been a focus of increased investigation over the past decade. A common theme emerging from these metabolic alterations is that tumor cells can acquire necessary nutrients from a nutrient-limited microenvironment and utilize them to sustain growth and unrestrained cellular division. However, this significant metabolic flexibility and the hostile microenvironment caused by the insufficient vascular exchange, depletion of nutrients, hypoxia, and accumulation of waste products, can inhibit the metabolism and immune activity of tumor-infiltrating lymphocytes and impose barriers to effective antitumor immunotherapies. In this Perspective, we review the classical alterations in tumorigenesis-associated metabolic reprogramming and examine the functional contribution of these aberrant metabolisms to the establishment and maintenance of an immunosuppressive microenvironment. Furthermore, we explore the possible approaches to targeting these metabolic pathways to achieve anti-tumor immunotherapy, as well as some hypothetical or ongoing combination therapeutic strategies that could, to a certain extent, biologically rationalize and broaden the utility of immune checkpoint inhibitors. Ultimately, we elucidate some dietary modifications that can limit tumor-specific nutritional requirements and maximize the cytotoxicity of other antineoplastic drugs.

Intramuscular administration of autologous total immunoglobulin G induces immunomodulatory effects on T cells in healthy human subjects: An open-labeled prospective single-arm trial

BACKGROUND

We hypothesized that intramuscular administration of autologous total immunoglobulin G (IgG) could induce an immunomodulatory effect in human subjects. In our previous studies, we showed that intramuscular administration of autologous total IgG could induce significant clinical improvements and increases of the serum levels of interleukin-10 (IL-10) and interferon-gamma (IFN-γ) in patients with atopic dermatitis.

OBJECTIVE

To investigate the mechanism of immunomodulation induced by intramuscular administration of autologous total IgG, we evaluated changes in T cells before and after intramuscular administrations of autologous total IgG in this study.

METHODS

Thirteen healthy adults received 8 intramuscular injections of 50 mg autologous total IgG for 4 weeks (from week 0 to week 4). The percentages of IL-10- or IFN-γ-producing peripheral blood T cells, as well as serum levels of IL-10, IFN-γ, and immunoglobulins, were measured at baseline (week 0) and at weeks 4, 8, and 12.

RESULTS

The percentage of IL-10-producing CD4+ T cells was significantly increased at weeks 8 and 12 compared to baseline (P < .05), while the percentage of IFN-γ-producing CD3+ T cells was significantly increased at week 12 compared to baseline (P < .05). There were no significant differences in the serum levels of IL-10, IFN-γ, and immunoglobulins before and after intramuscular administration of autologous total IgG (P > .05). No serious adverse events were observed.

CONCLUSION

Intramuscular administration of autologous total IgG induced immunomodulatory effects on T cells in healthy human subjects. This simple intervention could be a safe, effective, and economical T cell immunomodulation method for human subjects (NCT03695757).

Impaired Lymphocyte Responses in Pediatric Sepsis Vary by Pathogen Type and are Associated with Features of Immunometabolic Dysregulation

BACKGROUND

Sepsis is the leading cause of death in hospitalized children worldwide. Despite its hypothesized immune-mediated mechanism, targeted immunotherapy for sepsis is not available for clinical use.

OBJECTIVE

To determine the association between longitudinal cytometric, proteomic, bioenergetic, and metabolomic markers of immunometabolic dysregulation and pathogen type in pediatric sepsis.

METHODS

Serial peripheral blood mononuclear cell (PBMC) samples were obtained from 14 sepsis patients (34 total samples) and 7 control patients for this observational study. Flow cytometry was used to define immunophenotype, including T cell subset frequency and activation state, and assess intracellular cytokine production. Global immune dysfunction was assessed by tumor necrosis factor-α (TNF-α) production capacity and monocyte human leukocyte antigen DR (HLA-DR) expression. Mitochondrial function was assessed by bulk respirometry. Plasma cytokine levels were determined via Luminex assay. Metabolites were measured by liquid chromatography-mass spectrometry. Results were compared by timepoint and pathogen type.

RESULTS

Sepsis patients were older (15.9 years vs. 10.4 years, P = 0.02) and had higher illness severity by PRISM-III (12.0 vs. 2.0, P < 0.001) compared to controls; demographics were otherwise similar, though control patients were predominately male. Compared to controls, sepsis patients at timepoint 1 demonstrated lower monocyte HLA-DR expression (75% vs. 92%, P = 0.02), loss of peripheral of non-naïve CD4+ T cells (62.4% vs. 77.6%, P = 0.04), and reduced PBMC mitochondrial spare residual capacity (SRC; 4.0 pmol/s/106 cells vs. 8.4 pmol/s/106 cells, P = 0.01). At sepsis onset, immunoparalysis (defined as TNF-α production capacity < 200 pg/mL) was present in 39% of sepsis patients and not identified among controls. Metabolomic findings in sepsis patients were most pronounced at sepsis onset and included elevated uridine and 2-dehydrogluconate and depleted citrulline. Loss of peripheral non-naïve CD4+ T cells was associated with immune dysfunction and reduced cytokine production despite increased T cell activation. CD4+ T cell differentiation and corresponding pro- and anti-inflammatory cytokines varied by pathogen.

CONCLUSION

Pediatric sepsis patients exhibit a complex, dynamic physiologic state characterized by impaired T cell function and immunometabolic dysregulation which varies by pathogen type.

Carbon Monoxide Activates PERK-Regulated Autophagy to Induce Immunometabolic Reprogramming and Boost Antitumor T-cell Function

Mitochondria and endoplasmic reticulum (ER) share structural and functional networks and activate well-orchestrated signaling processes to shape cells' fate and function. While persistent ER stress (ERS) response leads to mitochondrial collapse, moderate ERS promotes mitochondrial function. Strategies to boost antitumor T-cell function by targeting ER-mitochondria cross-talk have not yet been exploited. Here, we used carbon monoxide (CO), a short-lived gaseous molecule, to test whether engaging moderate ERS conditions can improve mitochondrial and antitumor functions in T cells. In melanoma antigen-specific T cells, CO-induced transient activation of ERS sensor protein kinase R-like endoplasmic reticulum kinase (PERK) significantly increased antitumor T-cell function. Furthermore, CO-induced PERK activation temporarily halted protein translation and induced protective autophagy, including mitophagy. The use of LC3-GFP enabled differentiation between the cells that prepare themselves to undergo active autophagy (LC3-GFPpos) and those that fail to enter the process (LC3-GFPneg). LC3-GFPpos T cells showed strong antitumor potential, whereas LC3-GFPneg cells exhibited a T regulatory-like phenotype, harbored dysfunctional mitochondria, and accumulated abnormal metabolite content. These anomalous ratios of metabolites rendered the cells with a hypermethylated state and distinct epigenetic profile, limiting their antitumor activity. Overall, this study shows that ERS-activated autophagy pathways modify the mitochondrial function and epigenetically reprogram T cells toward a superior antitumor phenotype to achieve robust tumor control.

SIGNIFICANCE

Transient activation of ER stress with carbon monoxide drives mitochondrial biogenesis and protective autophagy that elicits superior antitumor T-cell function, revealing an approach to improving adoptive cell efficacy therapy.

Noninvasive Imaging of CD4+ T Cells in Humanized Mice

Antibody-based PET (immunoPET) with radiotracers that recognize specific cells of the immune system provides an opportunity to monitor immune cell trafficking at the organismal scale. We previously reported the visualization of human CD8+ T cells, including CD8+ tumor-infiltrating lymphocytes (TIL), in mice using a humanized CD8-targeted minibody. Given the important role of CD4+ T cells in adaptive immune responses of health and disease including infections, tumors, and autoimmunity, we explored immunoPET using an anti-human-CD4 minibody. We assessed the ability of [64Cu]Cu-NOTA-IAB41 to bind to various CD4+ T-cell subsets in vitro. We also determined the effect of the CD4-targeted minibody on CD4+ T-cell abundance, proliferation, and activation state in vitro. We subsequently evaluated the ability of the radiotracer to visualize CD4+ T cells in T-cell rich organs and orthotopic brain tumors in vivo. For the latter, we injected the [64Cu]Cu-NOTA-IAB41 radiotracer into humanized mice that harbored intracranial patient-derived glioblastoma (GBM) xenografts and performed in vivo PET, ex vivo autoradiography, and anti-CD4 IHC on serial brain sections. [64Cu]Cu-NOTA-IAB41 specifically detects human CD4+ T cells without impacting their abundance, proliferation, and activation. In humanized mice, [64Cu]Cu-NOTA-IAB41 can visualize various peripheral tissues in addition to orthotopically implanted GBM tumors. [64Cu]Cu-NOTA-IAB41 is able to visualize human CD4+ T cells in humanized mice and can provide noninvasive quantification of CD4+ T-cell distribution on the organismal scale.

Fecal Microbial Transplant in Individuals With Immune-Mediated Dry Eye

PURPOSE

To evaluate the safety of the Fecal Microbial Transplant for Sjogren Syndrome (FMT) trial in individuals with immune-mediated dry eye (DE).

DESIGN

Open-label, nonrandomized clinical trial.

METHODS

The study population included 10 individuals with DE symptoms and signs meeting criteria for Sjögren or positive early Sjögren markers. Procedures were 2 FMTs from a single healthy donor delivered via enema, 1 week apart. The primary outcome measure was safety. In addition, gut microbiome profiles, DE metrics, and T-cell profiles in blood were examined at baseline before FMT, and at 1 week, 1 month, and 3 months after FMT.

RESULTS

The mean age of the population was 60.4 years; 30% were male; 50% were white; and 50% were Hispanic. At baseline, all subjects had significantly different gut microbiome profiles from the donor, including higher mean diversity indices. Subjects had a decreased abundance of genera Faecalibacterium, Prevotella, and Ruminococcus and an increased abundance of genera Alistipes, Streptococcus, and Blautia compared to the donor. Effector and regulatory T-cell profiles were positively correlated with each other and with DE symptom severity (T helper 1 cells [Th₁]; r = .76; P = .01; Th₁₇: r = 0.83; P = .003; CD25: r = 0.66; P = .04; FoxP3: r = 0.68; P = .03). No adverse events were noted with FMT. After FMT, gut microbiome profiles in 8 subjects moved closer to the donor's profile. As a group, gut microbiome profiles at all follow-up time points were more similar to the original recipients' than the donor's microbiome; however, certain phyla, classes, and genera operational taxonomic unit (OTU) numbers remained closer to the donor vs recipients' baseline profiles out to 3 months. Five individuals subjectively reported improved dry eye symptoms 3 months after FMT.

CONCLUSIONS

FMT was safely performed in individuals with immune-mediated DE, with certain bacterial profiles resembling the donor out to 3 months after FMT. One-half the subjects reported improved DE symptoms. The most effective FMT administration method has yet to be determined.

A mouse model for the study of anti-tumor T cell responses in Kras-driven lung adenocarcinoma

Kras-driven lung adenocarcinoma (LUAD) is the most common lung cancer. A significant fraction of patients with Kras-driven LUAD respond to immunotherapy, but mechanistic studies of immune responses against LUAD have been limited because of a lack of immunotherapy-responsive models. We report the development of the immunogenic KP × NINJA (inversion inducible joined neoantigen) (KP-NINJA) LUAD model. This model allows temporal uncoupling of antigen and tumor induction, which allows one to wait until after infection-induced inflammation has subsided to induce neoantigen expression by tumors. Neoantigen expression is restricted to EPCAM+ cells in the lung and expression of neoantigen was more consistent between tumors than when neoantigens were encoded on lentiviruses. Moreover, tumors were infiltrated by tumor-specific CD8 T cells. Finally, LUAD cell lines derived from KP-NINJA mice were immunogenic and responded to immune checkpoint therapy (anti-PD1 and anti-CTLA4), providing means for future studies into the immunobiology of therapeutic responses in LUAD.

Expression and clinical significance of inhibitory receptor Leukocyte-associated immunoglobulin-like receptor-1 on peripheral blood T cells of chronic hepatitis B patients: A cross-sectional study

Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an inhibitory receptor that is expressed on the surface of multiple immune cells and plays key roles in immune modulation. In patients with chronic hepatitis B (CHB), T cell number and functions are abnormal and the expression of inhibitory receptors is elevated. However, the expression of LAIR-1 on T cells in patients with CHB is still undetermined.We recruited 320 patients with CHB in different disease phases and 17 healthy donors. Serum biochemical and virological examinations were performed for each participant, and their demographic and clinical data were collected. According to the latest American Association for the Study of Liver Disease guidelines, we categorized the patients into 4 groups: immune active, immune tolerant, inactive CHB, and gray zone. Additionally, we tested the expression of LAIR-1 on T cells and T cell subsets using flow cytometry.We observed a significant decrease in LAIR-1 expression on CD3+ T cells and its two subsets (CD4+ and CD8+ T cells) in patients with CHB. LAIR-1 expression on T cells was the lowest in the immune active group. LAIR-1 expression levels on CD4+ and CD8+ T cells showed a significant negative association with hepatitis B virus (HBV) DNA load and were lower in hepatitis B e antigen (HBeAg)-positive patients than in HBeAg-negative patients (P < .05). In addition, LAIR-1 expression levels on CD3+, CD4+, and CD8+ T cells were all negatively associated with liver inflammation and fibrosis parameters, such as alanine aminotransferase and aspartate aminotransferase levels, FibroScan value, and aspartate aminotransferase-to-platelet ratio index score.LAIR-1 expression levels on T cells were associated with HBV DNA load and liver inflammation and fibrosis parameters, indicating that LAIR-1 may play an important regulatory role in HBV-induced T cell immune pathogenesis and may be a therapeutic target for CHB.

Loss of Optineurin Drives Cancer Immune Evasion via Palmitoylation-Dependent IFNGR1 Lysosomal Sorting and Degradation

Mutations in IFN and MHC signaling genes endow immunotherapy resistance. Patients with colorectal cancer infrequently exhibit IFN and MHC signaling gene mutations and are generally resistant to immunotherapy. In exploring the integrity of IFN and MHC signaling in colorectal cancer, we found that optineurin was a shared node between the two pathways and predicted colorectal cancer patient outcome. Loss of optineurin occurs in early-stage human colorectal cancer. Immunologically, optineurin deficiency was shown to attenuate IFNGR1 and MHC-I expression, impair T-cell immunity, and diminish immunotherapy efficacy in murine cancer models and patients with cancer. Mechanistically, we observed that IFNGR1 was S-palmitoylated on Cys122, and AP3D1 bound with and sorted palmitoylated IFNGR1 to lysosome for degradation. Unexpectedly, optineurin interacted with AP3D1 to prevent palmitoylated IFNGR1 lysosomal sorting and degradation, thereby maintaining IFNγ and MHC-I signaling integrity. Furthermore, pharmacologically targeting IFNGR1 palmitoylation stabilized IFNGR1, augmented tumor immunity, and sensitized checkpoint therapy. Thus, loss of optineurin drives immune evasion and intrinsic immunotherapy resistance in colorectal cancer. SIGNIFICANCE: Loss of optineurin impairs the integrity of both IFNγ and MHC-I signaling pathways via palmitoylation-dependent IFNGR1 lysosomal sorting and degradation, thereby driving immune evasion and intrinsic immunotherapy resistance in colorectal cancer. Our work suggests that pharmacologically targeting IFNGR1 palmitoylation can stabilize IFNGR1, enhance T-cell immunity, and sensitize checkpoint therapy in colorectal cancer.See related commentary by Salvagno and Cubillos-Ruiz, p. 1623.This article is highlighted in the In This Issue feature, p. 1601.

The Complex Integration of T-cell Metabolism and Immunotherapy

Immune oncology approaches of adoptive cell therapy and immune checkpoint blockade aim to activate T cells to eliminate tumors. Normal stimulation of resting T cells induces metabolic reprogramming from catabolic and oxidative metabolism to aerobic glycolysis in effector T cells, and back to oxidative metabolism in long-lived memory cells. These metabolic reprogramming events are now appreciated to be essential aspects of T-cell function and fate. Here, we review these transitions, how they are disrupted by T-cell interactions with tumors and the tumor microenvironment, and how they can inform immune oncology to enhance T-cell function against tumors. SIGNIFICANCE: T-cell metabolism plays a central role in T-cell fate yet is altered in cancer in ways that can suppress antitumor immunity. Here, we discuss challenges and opportunities to stimulate effector T-cell metabolism and improve cancer immunotherapy.

Association of Monocyte Migration Marker CD11b With Pulmonary Function in People Living With HIV

BACKGROUND

Maladaptive immune responses contribute to the pathogenesis of many chronic lung diseases. Here, we tested hypotheses that CD4 and CD8 T-cell and monocyte phenotypes are associated with lung function in people living with HIV and those without HIV.

METHODS

Markers of T cell differentiation, activation, exhaustion and senescence, and markers of monocyte recruitment and migration were quantified in 142 HIV-positive and 73 HIV-negative participants of the Pittsburgh HIV Lung Cohort. All participants underwent lung function testing.

RESULTS

CD4 or CD8 T-cell phenotypes were not associated with measures of lung function in HIV-positive or HIV-negative participants after adjustment for multiple comparisons. In HIV-positive participants, however, the percentage of classical monocytes that were CD11b+ had positive associations at the Bonferroni-adjusted significance threshold of P = 0.05/63 with prebronchodilator and postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio (β = 0.36; P = 0.00003 and β = 0.31; P = 0.0003, respectively). In stratified analyses of n = 87 participants with CD4 ≥ 500 cells/µL, associations of percentage of classical monocytes that were CD11b+ with prebronchodilator and postbronchodilator FEV1/FVC ratio were stronger (β = 0.48 and β = 0.41, for pre- and post-, respectively) than in the entire HIV-positive study population. Significant associations of monocyte phenotypes were not observed in HIV-negative participants after adjustment for multiple comparisons.

CONCLUSIONS

CD11b+ expression on classical monocytes is positively associated with FEV1/FVC ratio in people living with HIV including in those with CD4 T-cell recovery. Given the normal surveillance activity of monocytes, such association suggests this monocyte subset may play a role in preservation of pulmonary function in PLWH.

A Genetic Mouse Model Recapitulates Immune Checkpoint Inhibitor-Associated Myocarditis and Supports a Mechanism-Based Therapeutic Intervention

Immune checkpoint inhibitors (ICI) targeting CTLA4 or PD-1/PD-L1 have transformed cancer therapy but are associated with immune-related adverse events, including myocarditis. Here, we report a robust preclinical mouse model of ICI-associated myocarditis in which monoallelic loss of Ctla4 in the context of complete genetic absence of Pdcd1 leads to premature death in approximately half of mice. Premature death results from myocardial infiltration by T cells and macrophages and severe ECG abnormalities, closely recapitulating the clinical and pathologic hallmarks of ICI-associated myocarditis observed in patients. Using this model, we show that Ctla4 and Pdcd1 functionally interact in a gene dosage-dependent manner, providing a mechanism by which myocarditis arises with increased frequency in the setting of combination ICI therapy. We demonstrate that intervention with CTLA4-Ig (abatacept) is sufficient to ameliorate disease progression and additionally provide a case series of patients in which abatacept mitigates the fulminant course of ICI myocarditis. SIGNIFICANCE: We provide a preclinical model of ICI-associated myocarditis which recapitulates this clinical syndrome. Using this model, we demonstrate that CTLA4 and PD-1 (ICI targets) functionally interact for myocarditis development and that intervention with CTLA4-Ig (abatacept) attenuates myocarditis, providing mechanistic rationale and preclinical support for therapeutic clinical studies.See related commentary by Young and Bluestone, p. 537.This article is highlighted in the In This Issue feature, p. 521.

Characterization of Gene Therapy Associated Uveitis Following Intravitreal Adeno-Associated Virus Injection in Mice

Purpose

To characterize the intraocular immune cell infiltrate induced by intravitreal adeno-associated virus (AAV) gene therapy.

Methods

AAV vectors carrying plasmids expressing green fluorescent protein under the control of PR2.1 were injected intravitreally into AAV naive and AAV primed C57Bl/6 mice. Clinical inflammation was assessed using optical coherence tomography. Intraocular immune cell populations were identified and quantified by flow cytometry on days 1, 7, and 29 after intravitreal injection and compared with sham and fellow eye controls.

Results

Optical coherence tomography inflammation score and total CD45+ cell number were significantly higher in AAV injected eyes compared to uninjected fellow eye and sham injected controls. Clinically apparent inflammation (vitritis on optical coherence tomography) and cellular inflammation (CD45+ cell number) was significantly increased in AAV injected eyes and peaked around day 7. Vitritis resolved by day 29, but cellular inflammation persisted through day 29. On day 1, neutrophils and activated monocytes were the dominant cell populations in all AAV injected eyes. On day 7, eyes of AAV exposed animals had significantly more dendritic cells and T cells than eyes of AAV naive animals. By day 29, CD8- T cells were the dominant CD45+ cell population in AAV injected eyes.

Conclusions

Intravitreal AAV injection in mice generates clinically evident inflammation that is mild and seems to resolve spontaneously. However, the total number of intraocular CD45+ cells, particularly T cells, remain elevated. Both innate and adaptive immune cells respond to intravitreal AAV regardless of prior immune status, but the adaptive response is delayed in AAV naive eyes.

Effect of radiotherapy on T cell and PD-1 / PD-L1 blocking therapy in tumor microenvironment

Cancer is a worldwide problem that threatens human health. Radiotherapy plays an important role in a variety of cancer treatment methods. The administration of radiotherapy can alter the differentiation pathways and functions of T cells, which in turn improves the immune response of T cells. Radiotherapy can also induce up-regulation of PD-L1 expression, which means that it has great potential for enhancing the therapeutic effect of anti-PD-1/PD-L1 inhibitors and reducing the risk of drug resistance toward them. At present, the combination of radiotherapy and anti-PD-1/PD-L1 inhibitors has shown significant therapeutic effects in clinical tumor research. This review focuses on the mechanism of radiotherapy on T cells reported in recent years, as well as related research progress in the application of PD-1/PD-L1 blockers. It will provide a theoretical basis for the rational clinical application of radiotherapy combined with PD-1/PD-L1 inhibitors.

Epigenetic Control of Cdkn2a.Arf Protects Tumor-Infiltrating Lymphocytes from Metabolic Exhaustion

T-cell exhaustion in cancer is linked to poor clinical outcomes, where evidence suggests T-cell metabolic changes precede functional exhaustion. Direct competition between tumor-infiltrating lymphocytes (TIL) and cancer cells for metabolic resources often renders T cells dysfunctional. Environmental stress produces epigenome remodeling events within TIL resulting from loss of the histone methyltransferase EZH2. Here, we report an epigenetic mechanism contributing to the development of metabolic exhaustion in TIL. A multiomics approach revealed a Cdkn2a.Arf-mediated, p53-independent mechanism by which EZH2 inhibition leads to mitochondrial dysfunction and the resultant exhaustion. Reprogramming T cells to express a gain-of-function EZH2 mutant resulted in an enhanced ability of T cells to inhibit tumor growth in vitro and in vivo. Our data suggest that manipulation of T-cell EZH2 within the context of cellular therapies may yield lymphocytes that are able to withstand harsh tumor metabolic environments and collateral pharmacologic insults. SIGNIFICANCE: These findings demonstrate that manipulation of T-cell EZH2 in cellular therapies may yield cellular products able to withstand solid tumor metabolic-deficient environments. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/21/4707/F1.large.jpg.

Arming cytotoxic lymphocytes for cancer immunotherapy by means of the NKG2D/NKG2D-ligand system

INTRODUCTION

The activating NKG2D receptor plays a central role in the immune recognition and elimination of abnormal self-cells by cytotoxic lymphocytes. NKG2D binding to cell stress-inducible ligands (NKG2DL) up-regulated on cancer cells facilitates their immunorecognition. Yet tumor cells utilize various escape mechanisms to avert NKG2D-based immunosurveillance. Hence, therapeutic strategies targeting the potent NKG2D/NKG2DL axis and such immune escape mechanisms become increasingly attractive in cancer therapy.

AREAS COVERED

This perspective provides a brief introduction into the NKG2D/NKG2DL axis and its relevance for cancer immune surveillance. Subsequently, the most advanced therapeutic approaches targeting the NKG2D system are presented focusing on NKG2D-CAR engineered immune cells and antibody-mediated strategies to inhibit NKG2DL shedding by tumors.

EXPERT OPINION

Thus far, NKG2D-CAR engineered lymphocytes represent the most advanced therapeutic approach utilizing the NKG2D system. Similarly to other tumor-targeting CAR approaches, NKG2D-CAR cells demonstrate powerful on-target activity, but may also cause off-tumor toxicities or lose efficacy, if NKG2DL expression by tumors is reduced. However, NKG2D-CAR cells also act on the tumor microenvironment curtailing its immunosuppressive properties, thus providing an independent therapeutic benefit. The potency of tumoricidal NKG2D-expressing lymphocytes can be further boosted by enhancing NKG2DL expression through small molecules and therapeutic antibodies inhibiting tumor-associated shedding of NKG2DL.

Antigen discovery unveils resident memory and migratory cell roles in antifungal resistance

Priming at the site of natural infection typically elicits a protective T cell response against subsequent pathogen encounter. Here, we report the identification of a novel fungal antigen that we harnessed for mucosal vaccination and tetramer generation to test whether we can elicit protective, antigen-specific tissue-resident memory (Trm) CD4+ T cells in the lung parenchyma. In contrast to expectations, CD69+, CXCR3+, CD103- Trm cells failed to protect against a lethal pulmonary fungal infection. Surprisingly, systemic vaccination induced a population of tetramer+ CD4+ T cells enriched within the pulmonary vasculature, and expressing CXCR3 and CX3CR1, that migrated to the lung tissue upon challenge and efficiently protected mice against infection. Mucosal vaccine priming of Trm may not reliably protect against mucosal pathogens.

Differential Effects of Depleting versus Programming Tumor-Associated Macrophages on Engineered T Cells in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy resistant to therapies, including immune-checkpoint blockade. We investigated two distinct strategies to modulate tumor-associated macrophages (TAM) to enhance cellular therapy targeting mesothelin in an autochthonous PDA mouse model. Administration of an antibody to colony-stimulating factor (anti-Csf1R) depleted Ly6Clow protumorigenic TAMs and significantly enhanced endogenous T-cell intratumoral accumulation. Despite increasing the number of endogenous T cells at the tumor site, as previously reported, TAM depletion had only minimal impact on intratumoral accumulation and persistence of T cells engineered to express a murine mesothelin-specific T-cell receptor (TCR). TAM depletion interfered with the antitumor activity of the infused T cells in PDA, evidenced by reduced tumor cell apoptosis. In contrast, TAM programming with agonistic anti-CD40 increased both Ly6Chigh TAMs and the intratumoral accumulation and longevity of TCR-engineered T cells. Anti-CD40 significantly increased the frequency and number of proliferating and granzyme B+ engineered T cells, and increased tumor cell apoptosis. However, anti-CD40 failed to rescue intratumoral engineered T-cell IFNγ production. Thus, although functional modulation, rather than TAM depletion, enhanced the longevity of engineered T cells and increased tumor cell apoptosis, ultimately, anti-CD40 modulation was insufficient to rescue key effector defects in tumor-reactive T cells. This study highlights critical distinctions between how endogenous T cells that evolve in vivo, and engineered T cells with previously acquired effector activity, respond to modifications of the tumor microenvironment.

Suboptimal T-cell Therapy Drives a Tumor Cell Mutator Phenotype That Promotes Escape from First-Line Treatment

Antitumor T-cell responses raised by first-line therapies such as chemotherapy, radiation, tumor cell vaccines, and viroimmunotherapy tend to be weak, both quantitatively (low frequency) and qualitatively (low affinity). We show here that T cells that recognize tumor-associated antigens can directly kill tumor cells if used at high effector-to-target ratios. However, when these tumor-reactive T cells were present at suboptimal ratios, direct T-cell-mediated tumor cell killing was reduced and the ability of tumor cells to evolve away from a coapplied therapy (oncolytic or suicide gene therapy) was promoted. This T-cell-mediated increase in therapeutic resistance was associated with C to T transition mutations that are characteristic of APOBEC3 cytosine deaminase activity and was induced through a TNFα and protein kinase C-dependent pathway. Short hairpin RNA inhibition of endogenous APOBEC3 reduced rates of tumor escape from oncolytic virus or suicide gene therapy to those seen in the absence of antitumor T-cell coculture. Conversely, overexpression of human APOBEC3B in tumor cells enhanced escape from suicide gene therapy and oncolytic virus therapy both in vitro and in vivo Our data suggest that weak affinity or low frequency T-cell responses against tumor antigens may contribute to the ability of tumor cells to evolve away from first-line therapies. We conclude that immunotherapies need to be optimized as early as possible so that, if they do not kill the tumor completely, they do not promote treatment resistance.

Valine 11 and phenylalanine 13 have a greater impact on the T-cell response to citrullinated peptides than the 70-74 shared epitope of the DRB1 molecule in macaques

OBJECTIVES

Various rheumatoid arthritis (RA) HLA-DRB-1 risk haplotypes have been regrouped under the shared epitope (SE) in position 70-74. The presence of Valine in position 11 (Val11) and phenylalanine in position 13 (Phe13) are also associated with RA, but it is impossible to differentiate their role compared with the SE since they are in strong linkage disequilibrium (LD) in humans. Similar to humans, certain macaques express the SE (H6). We analysed the effect of various DRB1 haplotypes on T-cell response to citrullinated peptides (Cit-P) in macaques.

METHODS

Six H6 and six non-H6 macaques were immunized with four Cit-P. T-cell response was assessed using Interferon γ enzyme-linked immunospot.

RESULTS

Animals developed a specific anti-Cit-P T-cell response. Surprisingly, H6 animals had a significantly lower T-cell response than non-H6. In macaques, the 70-74 SE and the Val11 are on separate haplotypes. Presence of Val11 was strongly associated with the anti-Cit-P T-cell response, whatever the 70-74 sequence was. This response was amplified in case of presence of Phe13.

CONCLUSION

The absence of LD between Val11 and SE in macaques allowed us to demonstrate that the most important HLA positions to induce a T-cell response against Cit-P were Val11 and Phe13 and not the 70-74 SE.

Pharmacological Inhibition of CCR2/5 Signaling Prevents and Reverses Alcohol-Induced Liver Damage, Steatosis, and Inflammation in Mice

Kupffer cell and macrophage (MØ) activation contributes to steatosis, inflammation, and fibrosis in alcoholic liver disease (ALD). We found increased frequency of MØ, T cells, and expression of C-C chemokine receptor type 2 (Ccr2) and C-C chemokine receptor type 5 (Ccr5) in the livers of patients with ALD, and increased circulating chemokines, C-C chemokine ligand types 2 (CCL2), and C-C chemokine ligand types 5 (CCL5) in patients with alcoholic hepatitis. We hypothesized that inhibition of CCL2 signaling with the dual CCR2/5 inhibitor, cenicriviroc (CVC), would attenuate ALD. In a mouse model of ALD, liver injury (alanine aminotransferase [ALT]) and steatosis were prevented by CVC whether administered as "prevention" throughout the alcohol feeding or as "treatment" started after the development of ALD. Alcohol-induced increases in early liver fibrosis markers (sirius red, hydroxyproline, and collagen-1) were normalized by both modes of CVC administration. We found that prevention and treatment with CVC reversed alcohol-related increases in liver mRNA and protein expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and CCL2. CVC administration regimens prevented the increase in infiltrating MØ (F4/80^lo CD11b^hi ) and reduced proinflammatory Ly6C^hi MØ in livers of alcohol-fed mice. CVC increased liver T-cell numbers and attenuated Il-2 expression without an effect on CD69⁺ or CD25⁺ T-cell expression. In vitro, CVC inhibited CCL2-induced increases in hepatocyte fatty acid synthase (Fasn) and adipose differentiation-related protein (Adrp), whereas it augmented acyl-coenzyme A oxidase 1 (Acox-1), proliferator-activated receptor gamma co-activator alpha (Pgc1α) and uncoupling protein 2 expression, suggesting mechanisms for attenuated hepatocyte steatosis. We found that CCL2 and CCL5 sensitized hepatocytes to lipopolysaccharide-induced liver injury (TNF-α, ALT, and lactate dehydrogenase release). Alcohol feeding induced apoptosis (poly ADP-ribose polymerase [PARP] and caspase-3 [CASP-3] cleavage) and pyroptosis (gasdermin D [GSDMD] cleavage) in livers, and CVC prevented both of these forms of cell death. Conclusion: Together, our data demonstrate preclinical evidence for CCR2/CCR5 inhibition with CVC as a potent intervention to ameliorate alcohol-induced steatohepatitis and liver damage.

CXCL9 promotes prostate cancer progression through inhibition of cytokines from T cells

Chemokines have been demonstrated to serve an important role in a variety of diseases, particularly in tumor progression. There have been numerous studies that have reported that T cells serve major roles in tumor progression. However, the function of CXC motif chemokine ligand 9 (CXCL9) in prostate cancer remains unknown. The present study aimed to investigate the role of CXCL9 in prostate cancer. A prostate cancer mouse model was generated by treating C57/BL‑6 and B6.Cg‑Selplgtm1Fur/J mice with 3,2'‑dimethyl 4‑aminobiphenyl (DMAB). Hematoxylin and eosin staining detected the histopathological alterations of mouse prostate tissues. Immunohistochemistry (IHC) staining determined cell proliferation of the mice. Flow cytometry was used to detect the alterations of T cells in C57+DMAB or CXCL9+DMAB mice. Immunofluorescence revealed that there was positive expression of interleukin‑6 (IL‑6) and transforming growth factor (TGF)‑β in the mouse tissues. The survival rates of C57+DMAB and CXCL9+DMAB mice was analyzed. The association of CXCL9 expression and clinical stages was also evaluated. Results revealed that prostate cancer pathology and cell proliferation in CXCL9+DMAB mice were significantly greater compared with the C57+DMAB mice. Compared with C57+DMAB mice, the number of T cells in peripheral blood and spleen of CXCL9+DMAB mice was significantly reduced. IHC demonstrated that the expression of IL‑6 and TGF‑β was significantly downregulated in the CXCL9+DMAB mice. The survival rate of CXCL9+DMAB mice was significantly decreased compared with the C57+DMAB mice. In addition, reverse transcription‑quantitative polymerase chain reaction analysis demonstrated that CXCL9 mRNA expression in clinical samples was positively associated with clinical pathological stages of prostate cancer. In conclusion, CXCL9 may promote prostate cancer progression via inhibition of cytokines from T cells.

[Advances in application of Jurkat cell model in research on infectious diseases]

Infectious diseases can be caused by multiple pathogens, which can produce specific immune response in human body. The immune response produced by T cells is cellular immunity, which plays an important role in the anti-infection process of human body, and can participate in immunological protection and cause immunopathology. The outcome of various infectious diseases is closely related to cellular immune function, especially the function of T cells. Jurkat cells belong to the human acute T lymphocyte leukemia cell line. Jurkat cell model can simulate the function T lymphocytes, so it is widely used in the in vitro studies of T cell signal transduction, cytokines, and receptor expression, and can provide reference and guidance for the treatment of various infectious diseases and the research on their pathogenesis. The Jurkat cell model has been widely used in the in vitro studies of viral diseases and atypical pathogens, but parasitic infection studies using the Jurkat cell model are still rare. This article reviews advances in the application of Jurkat cell model in the research on infectious diseases.

A case report of nodal CD4-positive T-cell lymphoproliferative disorder with an indolent course

RATIONALE

Primary nodal CD4-positive T-cell lymophoproliferative disorder with a relatively indolent process is a rare kind of lymphoproliferative disease. Here we report the first case of a 49 year-old man developed indolent nodal CD4-positive T-cell lymophoproliferative disorder. To our knowledge, based on a careful search of PubMed, it is the first case of primary nodal CD4-positive T-cell lymophoproliferative disorder.

PATIENT CONCERNS

A 49-year-old Chinese man presented to our hospital with fever, enlargement of multiple superficial lymphonodes more than 14 years and splenomegaly. Clinical and pathological data were collected under treatment. This case was diagnosed based on histologically characteristic, immunohistochemical staining, and lymphoid clonality testing. On immunohistochemical staining, the abnormal T-cells were CD4 positive and CD8 negative. The lymphoid clonality testing showed positive results. The patient also has enlarged spleen.

DIAGNOSES

The patient was diagnosed with nodal CD4-positive T-cell lymophoproliferative disorder.

INTERVENTIONS

A watch-and-wait stratagem was performed without any chemotherapy or radiation therapy.

OUTCOMES

During 17 years of follow-up, this case presented an indolent course without evidence of systemic dissemination.

LESSONS

This report presents the first case of indolent nodal CD4-positive T-cell lymophoproliferative disorder. In this case, the proliferated T-cell in the paracortex of lymph node showed T-cell receptor gene rearrangement, which indicated a clonal proliferation. There are several kinds of nodal CD4-positive T-cell lymphoma, which have a relatively aggressive course; however, this case has a relatively indolent course.

T-cell Localization, Activation, and Clonal Expansion in Human Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy resistant to most therapies, including immune checkpoint blockade. To elucidate mechanisms of immunotherapy resistance, we assessed immune parameters in resected human PDA. We demonstrate significant interpatient variability in T-cell number, localization, and phenotype. CD8+ T cells, Foxp3+ regulatory T cells, and PD-1+ and PD-L1+ cells were preferentially enriched in tertiary lymphoid structures that were found in most tumors compared with stroma and tumor cell nests. Tumors containing more CD8+ T cells also had increased granulocytes, CD163+ (M2 immunosuppressive phenotype) macrophages, and FOXP3+ regulatory T cells. PD-L1 was rare on tumor cells, but was expressed by CD163+ macrophages and an additional stromal cell subset commonly found clustered together adjacent to tumor epithelium. The majority of tumoral CD8+ T cells did not express molecules suggestive of recent T-cell receptor (TCR) signaling. However, 41BB+PD-1+ T cells were still significantly enriched in tumors compared with circulation. Tumoral CD8+PD-1+ T cells commonly expressed additional inhibitory receptors, yet were mostly T-BEThi and EOMESlo, consistent with a less terminally exhausted state. Analysis of gene expression and rearranged TCR genes by deep sequencing suggested most patients have a limited tumor-reactive T-cell response. Multiplex immunohistochemistry revealed variable T-cell infiltration based on abundance and location, which may result in different mechanisms of immunotherapy resistance. Overall, the data support the need for therapies that either induce endogenous, or provide engineered, tumor-specific T-cell responses, and concurrently relieve suppressive mechanisms operative at the tumor site. Cancer Immunol Res; 5(11); 978-91. ©2017 AACR.

Osthole treatment ameliorates Th2-mediated allergic asthma and exerts immunomodulatory effects on dendritic cell maturation and function

Osthole, an active component of Chinese herbal medicines, reportedly possesses various pharmacological properties and has potential therapeutic applications. This study explored the anti-allergic effects of osthole in asthmatic mice and investigated the immunomodulatory actions of osthole on dendritic cells (DCs) and T cells. Herein, we show that oral administration of osthole to BALB/c mice after ovalbumin (OVA) sensitization ameliorated all of the cardinal features of T helper 2 (Th2)-mediated allergic asthma; namely, the production of OVA-specific immunoglobulin E, airway hyperresponsiveness, airway inflammation and the production of Th2-type cytokines including interleukin (IL)-4, IL-5 and IL-13. Surprisingly, IL-10 production was not inhibited and was even enhanced by osthole treatment. We observed a significant increase in the percentages of IL-10-producing DCs and forkhead box P3-positive regulatory T (Treg) cells in osthole-treated asthmatic mice. Additionally, in vitro analyses revealed that osthole-treated bone-marrow-derived DCs had a partial maturation phenotype, secreting large amounts of IL-10 and low levels of proinflammatory cytokines, such as IL-12, IL-6 and tumor necrosis factor-α, and displaying reduced levels of MHC class II surface molecules. These DCs displayed immunosuppressive capacity by directly inhibiting effector T-cell responses or inducing Treg cells. In addition, osthole directly inhibited the activated CD4+ T-cell proliferation and Th1/Th2-type cytokine production in this system. Collectively, these results suggest that DCs and T cells are potential target cells responsible for the action of osthole against allergic asthma.Cellular &Molecular Immunology advance online publication, 7 August 2017; doi:10.1038/cmi.2017.71.

T-lymphocyte homing: an underappreciated yet critical hurdle for successful cancer immunotherapy

Advances in cancer immunotherapy have offered new hope for patients with metastatic disease. This unfolding success story has been exemplified by a growing arsenal of novel immunotherapeutics, including blocking antibodies targeting immune checkpoint pathways, cancer vaccines, and adoptive cell therapy (ACT). Nonetheless, clinical benefit remains highly variable and patient-specific, in part, because all immunotherapeutic regimens vitally hinge on the capacity of endogenous and/or adoptively transferred T-effector (T_eff) cells, including chimeric antigen receptor (CAR) T cells, to home efficiently into tumor target tissue. Thus, defects intrinsic to the multi-step T-cell homing cascade have become an obvious, though significantly underappreciated contributor to immunotherapy resistance. Conspicuous have been low intralesional frequencies of tumor-infiltrating T-lymphocytes (TILs) below clinically beneficial threshold levels, and peripheral rather than deep lesional TIL infiltration. Therefore, a T_eff cell 'homing deficit' may arguably represent a dominant factor responsible for ineffective immunotherapeutic outcomes, as tumors resistant to immune-targeted killing thrive in such permissive, immune-vacuous microenvironments. Fortunately, emerging data is shedding light into the diverse mechanisms of immune escape by which tumors restrict T_eff cell trafficking and lesional penetrance. In this review, we scrutinize evolving knowledge on the molecular determinants of T_eff cell navigation into tumors. By integrating recently described, though sporadic information of pivotal adhesive and chemokine homing signatures within the tumor microenvironment with better established paradigms of T-cell trafficking under homeostatic or infectious disease scenarios, we seek to refine currently incomplete models of T_eff cell entry into tumor tissue. We further summarize how cancers thwart homing to escape immune-mediated destruction and raise awareness of the potential impact of immune checkpoint blockers on T_eff cell homing. Finally, we speculate on innovative therapeutic opportunities for augmenting T_eff cell homing capabilities to improve immunotherapy-based tumor eradication in cancer patients, with special focus on malignant melanoma.

Systematic Pan-Cancer Analysis Reveals Immune Cell Interactions in the Tumor Microenvironment

With the recent advent of immunotherapy, there is a critical need to understand immune cell interactions in the tumor microenvironment in both pan-cancer and tissue-specific contexts. Multidimensional datasets have enabled systematic approaches to dissect these interactions in large numbers of patients, furthering our understanding of the patient immune response to solid tumors. Using an integrated approach, we inferred the infiltration levels of distinct immune cell subsets in 23 tumor types from The Cancer Genome Atlas. From these quantities, we constructed a coinfiltration network, revealing interactions between cytolytic cells and myeloid cells in the tumor microenvironment. By integrating patient mutation data, we found that while mutation burden was associated with immune infiltration differences between distinct tumor types, additional factors likely explained differences between tumors originating from the same tissue. We concluded this analysis by examining the prognostic value of individual immune cell subsets as well as how coinfiltration of functionally discordant cell types associated with patient survival. In multiple tumor types, we found that the protective effect of CD8+ T cell infiltration was heavily modulated by coinfiltration of macrophages and other myeloid cell types, suggesting the involvement of myeloid-derived suppressor cells in tumor development. Our findings illustrate complex interactions between different immune cell types in the tumor microenvironment and indicate these interactions play meaningful roles in patient survival. These results demonstrate the importance of personalized immune response profiles when studying the factors underlying tumor immunogenicity and immunotherapy response. Cancer Res; 77(6); 1271-82. ©2017 AACR.

The effect of chronic kidney disease on T cell alloimmunity

PURPOSE OF REVIEW

Altered differentiation and activation of T-cell subsets occur in patients with chronic kidney disease (CKD), but the impact on graft rejection and protective immunity during transplantation are not fully understood.

RECENT FINDINGS

Patients with CKD have decreased frequency of naïve T cells, accumulation of activated, terminally differentiated memory cells, and skewed regulatory versus T helper 17 ratio. Naïve and memory T-cell subsets do not appear to improve following kidney transplantation. Retained thymic output is associated with acute rejection, whereas naïve lymphopenia and accumulation of CD8 TEMRA cells correlate with long-term graft dysfunction. CD28 memory cells accumulate during CKD and appear to confer protection against acute rejection under standard immunosuppression and possibly costimulation blockade. T cells bearing CD57 are also increased in patients with CKD and may underlie rejection during costimulation blockade.

SUMMARY

The mechanisms by which CKD alters the differentiation and activation status of T-cell subsets is poorly understood. Further research is also needed to understand which cell populations mediate rejection under various immunosuppressive regimens. To date, there is little use of animal models of organ failure in transplant immunology research. CKD mouse models may help identify novel pathways and targets to better control alloimmunity in posttransplant.

Role of immune cells in pancreatic cancer from bench to clinical application: An updated review

BACKGROUND

Pancreatic cancer (PC) remains difficult to treat, despite the recent advances in various anticancer therapies. Immuno-inflammatory response is considered to be a major risk factor for the development of PC in addition to a combination of genetic background and environmental factors. Although patients with PC exhibit evidence of systemic immune dysfunction, the PC microenvironment is replete with immune cells.

METHODS

We searched PubMed for all relevant English language articles published up to March 2016. They included clinical trials, experimental studies, observational studies, and reviews. Trials enrolled at Clinical trial.gov were also searched.

RESULTS

PC induces an immunosuppressive microenvironment, and intratumoral activation of immunity in PC is attenuated by inhibitory signals that limit immune effector function. Multiple types of immune responses can promote an immunosuppressive microenvironment; key regulators of the host tumor immune response are dendritic cells, natural killer cells, macrophages, myeloid derived suppressor cells, and T cells. The function of these immune cells in PC is also influenced by chemotherapeutic agents and the components in tumor microenvironment such as pancreatic stellate cells. Immunotherapy of PC employs monoclonal antibodies/effector cells generated in vitro or vaccination to stimulate antitumor response. Immune therapy in PC has failed to improve overall survival; however, combination therapies comprising immune checkpoint inhibitors and vaccines have been attempted to increase the response.

CONCLUSION

A number of studies have begun to elucidate the roles of immune cell subtypes and their capacity to function or dysfunction in the tumor microenvironment of PC. It will not be long before immune therapy for PC becomes a clinical reality.

Microfluidic models for adoptive cell-mediated cancer immunotherapies

Current adoptive T cell therapies have shown promising results in clinical trials but need further development as an effective cancer treatment. Here, we discuss how 3D microfluidic tumour models mimicking the tumour microenvironment could help in testing T cell immunotherapies by assessing engineered T cells and identifying combinatorial therapy to improve therapeutic efficacy. We propose that 3D microfluidic systems can be used to screen different patient-specific treatments, thereby reducing the burden of in vivo testing and facilitating the rapid translation of successful T cell cancer immunotherapies to the clinic.

Drugs in early clinical development for Systemic Lupus Erythematosus

INTRODUCTION

While immunosuppressive therapy has positively impacted the prognosis of systemic lupus erythematosus (SLE), many patients still do not respond to traditional therapy. Thus, active SLE disease remains a significant problem. Furthermore, conventional immunosuppressive treatments for SLE are associated a high risk of side effects. These issues call for improvement in our current therapeutic armamentarium.

AREAS COVERED

In this review, the authors highlight the recent developments in therapies for SLE, and present an overview of drugs which are in early clinical development for SLE. There are many new therapeutic approaches being developed, including those focused on B-cell targets, T-cell downregulation, co-stimulatory blockade, anti-cytokine agents, and kinase inhibition, and Toll-like receptor inhibition. They also discuss peptide therapy as a potential method to re-establish immune tolerance, and some of the challenges ahead in developing and testing novel agents for SLE.

EXPERT OPINION

Many novel agents are currently in development for SLE, but this encouraging news is tempered by several disappointments in clinical trials and provides a timely moment to reflect on the future of therapeutic development in SLE. It seems likely that biological heterogeneity between patients is a major contributor to difficulty in drug design in SLE.

Mechanistic insights into the oncolytic activity of vesicular stomatitis virus in cancer immunotherapy

Immunotherapy and oncolytic virotherapy have both shown anticancer efficacy in the clinic as monotherapies but the greatest promise lies in therapies that combine these approaches. Vesicular stomatitis virus is a prominent oncolytic virus with several features that promise synergy between oncolytic virotherapy and immunotherapy. This review will address the cytotoxicity of vesicular stomatitis virus in transformed cells and what this means for antitumor immunity and the virus’ immunogenicity, as well as how it facilitates the breaking of tolerance within the tumor, and finally, we will outline how these features can be incorporated into the rational design of new treatment strategies in combination with immunotherapy.