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The molecular mechanisms responsible for the high immunosuppressive capacity of [CD4.sup.+] Tregs in tumors are not well known. High-dimensional single-cell profiling of T cells from chemotherapy-naive individuals with non-small-cell lung cancer identified the transcription factor IRF4 as specifically expressed by a subset of intratumoral [CD4.sup.+] effector Tregs with superior suppressive activity. In contrast to the [IRF4.sup.-] counterparts, [IRF4.sup.+] Tregs expressed a vast array of suppressive molecules, and their presence correlated with multiple exhausted subpopulations of T cells. Integration of transcriptomic and epigenomic data revealed that IRF4, either alone or in combination with its partner BATF, directly controlled a molecular program responsible for immunosuppression in tumors. Accordingly, deletion of Irf4 exclusively in Tregs resulted in delayed tumor growth in mice while the abundance of IRF4+ Tregs correlated with poor prognosis in patients with multiple human cancers. Thus, a common mechanism underlies immunosuppression in the tumor microenvironment irrespective of the tumor type., Introduction Despite recent clinical breakthroughs in adoptive T cell transfer approaches and checkpoint blockade in treating hematopoietic and solid tumors, suppression of the antitumor immune response in the tumor microenvironment [...]

Background: Cardiovascular sequelae may occur in patients recovered from coronavirus disease 2019 (COVID‐19). Recent studies have detected a considerable incidence of subclinical myocardial dysfunction—assessed with speckle‐tracking echocardiography—and of long‐COVID symptoms in these patients. This study aimed to define the long‐term prognostic role of subclinical myocardial dysfunction and long‐COVID condition in patients recovered from COVID‐19 pneumonia. Methods: We prospectively followed up 110 patients hospitalized at our institution due to COVID‐19 pneumonia in April 2020 and then recovered from SARS‐CoV‐2 infection. A 7‐month clinical and echocardiographic evaluation was performed, followed by a 21‐month clinical follow‐up. The primary outcome was major adverse cardiovascular events (MACE), a composite of myocardial infarction, stroke, heart failure hospitalization, and all‐cause mortality. Results: A subclinical myocardial dysfunction—defined as an impairment of left ventricular global longitudinal strain (≥−18%)—was identified at a 7‐month follow‐up in 37 patients (34%), was associated with an increased risk of long‐term MACE with a good discriminative power (area under the curve:.73) and resulted in a strong independent predictor of extended MACE in multivariate regression analyses. Long‐COVID condition was not associated with a worse long‐term prognosis, instead. Conclusions: In patients recovered from COVID‐19 pneumonia, a subclinical myocardial dysfunction is present in one‐third of the whole population at 7‐month follow‐up and is associated with a higher risk of MACE at long‐term follow‐up. Speckle‐tracking echocardiography is a promising tool to optimize the risk‐stratification in patients recovered from COVID‐19 pneumonia, while the definition of a long‐COVID condition has no prognostic relevance. [ABSTRACT FROM AUTHOR]

Background and Aims Invariant natural killer T [iNKT] cells perform pleiotropic functions in different tissues by secreting a vast array of pro-inflammatory and cytotoxic molecules. However, the presence and function of human intestinal iNKT cells capable of secreting immunomodulatory molecules such as IL-10 has never been reported so far. Here we describe for the first time the presence of IL10-producing iNKT cells [NKT10 cells] in the intestinal lamina propria of healthy individuals and of Crohn's disease [CD] patients. Methods Frequency and phenotype of NKT10 cells were analysed ex vivo from intestinal specimens of Crohn's disease [ n = 17] and controls [ n = 7]. Stable CD-derived intestinal NKT10 cell lines were used to perform in vitro suppression assays and co-cultures with patient-derived mucosa-associated microbiota. Experimental colitis models were performed by adoptive cell transfer of splenic naïve CD4+ T cells in the presence or absence of IL10-sufficient or -deficient iNKT cells. In vivo induction of NKT10 cells was performed by administration of short chain fatty acids [SCFA] by oral gavage. Results Patient-derived intestinal NKT10 cells demonstrated suppressive capabilities towards pathogenic CD4+ T cells. The presence of increased proportions of mucosal NKT10 cells associated with better clinical outcomes in CD patients. Moreover, an intestinal microbial community enriched in SCFA-producing bacteria sustained the production of IL10 by iNKT cells. Finally, IL10-deficient iNKT cells failed to control the pathogenic activity of adoptively transferred CD4+ T cells in an experimental colitis model. Conclusions These results describe an unprecedentd IL10-mediated immunoregulatory role of intestinal iNKT cells in controlling the pathogenic functions of mucosal T helper subsets and in maintaining the intestinal immune homeostasis. [ABSTRACT FROM AUTHOR]

Aim Loss of immunosuppressive response supports inflammation during atherosclerosis. We tested whether adoptive cell therapy (ACT) with Tregulatory cells (Tregs), engineered to selectively migrate in the atherosclerotic plaque, would dampen the immune-inflammatory response in the arterial wall in animal models of familial hypercholesterolaemia (FH). Methods and results FH patients presented a decreased Treg suppressive function associated to an increased inflammatory burden. A similar phenotype was observed in Ldlr −/− mice accompanied by a selective increased expression of the chemokine CX3CL1 in the aorta but not in other districts (lymph nodes, spleen, and liver). Treg overexpressing CX3CR1 were thus generated (CX3CR1+-Tregs) to drive Tregs selectively to the plaque. CX3CR1+-Tregs were injected (i.v.) in Ldlr −/− fed high-cholesterol diet (western type diet, WTD) for 8 weeks. CX3CR1+-Tregs were detected in the aorta, but not in other tissues, of Ldlr −/− mice 24 h after ACT, corroborating the efficacy of this approach. After 4 additional weeks of WTD, ACT with CX3CR1+-Tregs resulted in reduced plaque progression and lipid deposition, ameliorated plaque stability by increasing collagen and smooth muscle cells content, while decreasing the number of pro-inflammatory macrophages. Shotgun proteomics of the aorta showed a metabolic rewiring in CX3CR1+-Tregs treated Ldlr −/− mice compared to controls that was associated with the improvement of inflammation-resolving pathways and disease progression. Conclusion ACT with vasculotropic Tregs appears as a promising strategy to selectively target immune activation in the atherosclerotic plaque. [ABSTRACT FROM AUTHOR]

Keywords: Editorials; CD8-positive T-lymphocytes; chemokines; immune checkpoint inhibitors; immunotherapy; myocarditis EN Editorials CD8-positive T-lymphocytes chemokines immune checkpoint inhibitors immunotherapy myocarditis 336 338 3 07/25/22 20220726 NES 220726 Immune checkpoint inhibitor (ICI) therapy for tumors is a life-saving treatment, yet occasionally patients experience ICI-induced myocarditis, an immune-mediated adverse reaction that is frequently lethal. ICI myocarditis is an urgent clinical problem, both for the patients experiencing the cardiac symptoms, and for the oncological patients, as well, whose access to novel ICIs may be experiencing delays linked to slower drug development that has to keep ICI myocarditis in mind. [Extracted from the article]

Background: Chronic low-grade inflammation and alterations in innate and adaptive immunity were reported in Type 2 diabetes (T2D). Here, we investigated the abundance and activation of T cells in the bone marrow (BM) of patients with T2D. We then verified the human data in a murine model and tested if the activation of T cells can be rescued by treating mice with abatacept, an immunomodulatory drug employed for the treatment of rheumatoid arthritis. Clinical evidence indicated abatacept can slow the decline in beta-cell function. Methods: A cohort of 24 patients (12 with T2D) undergoing hip replacement surgery was enrolled in the study. Flow cytometry and cytokine analyses were performed on BM leftovers from surgery. We next compared the immune profile of db/db and control wt/db mice. In an additional study, db/db mice were randomized to receive abatacept or vehicle for 4 weeks, with endpoints being immune cell profile, indices of insulin sensitivity, and heart performance. Results: Patients with T2D showed increased frequencies of BM CD4+ (2.8-fold, p = 0.001) and CD8+ T cells (1.8-fold, p = 0.01), with the upregulation of the activation marker CD69 and the homing receptor CCR7 in CD4+ (1.64-fold, p = 0.003 and 2.27-fold, p = 0.01, respectively) and CD8+ fractions (1.79-fold, p = 0.05 and 1.69-fold, p = 0.02, respectively). These differences were confirmed in a multivariable regression model. CCL19 (CCR7 receptor ligand) and CXCL10/11 (CXCR3 receptor ligands), implicated in T-cell migration and activation, were the most differentially modulated chemokines. Studies in mice confirmed the activation of adaptive immunity in T2D. Abatacept reduced the activation of T cells and the levels of proinflammatory cytokines and improved cardiac function but not insulin sensitivity. Conclusions: Results provide proof-of-concept evidence for the activation of BM adaptive immunity in T2D. In mice, treatment with abatacept dampens the activation of adaptive immunity and protects from cardiac damage. [ABSTRACT FROM AUTHOR]

Objective: Risk stratification is crucial to optimise treatment strategies in patients with COVID-19. We aimed to evaluate the impact on mortality of an early assessment of cardiac biomarkers in patients with COVID-19.Methods: Humanitas Clinical and Research Hospital (Rozzano-Milan, Lombardy, Italy) is a tertiary centre that has been converted to the management of COVID-19. Patients with confirmed COVID-19 were entered in a dedicated database for cohort observational analyses. Outcomes were stratified according to elevated levels (ie, above the upper level of normal) of high-sensitivity cardiac troponin I (hs-TnI), B-type natriuretic peptide (BNP) or both measured within 24 hours after hospital admission. The primary outcome was all-cause mortality.Results: A total of 397 consecutive patients with COVID-19 were included up to 1 April 2020. At the time of hospital admission, 208 patients (52.4%) had normal values for cardiac biomarkers, 90 (22.7%) had elevated both hs-TnI and BNP, 59 (14.9%) had elevated only BNP and 40 (10.1%) had elevated only hs-TnI. The rate of mortality was higher in patients with elevated hs-TnI (22.5%, OR 4.35, 95% CI 1.72 to 11.04), BNP (33.9%, OR 7.37, 95% CI 3.53 to 16.75) or both (55.6%, OR 18.75, 95% CI 9.32 to 37.71) as compared with those without elevated cardiac biomarkers (6.25%). A multivariate analysis identified concomitant elevation of both hs-TnI and BNP as a strong independent predictor of all-cause mortality (OR 3.24, 95% CI 1.06 to 9.93).Conclusions: An early detection of elevated hs-TnI and BNP predicts mortality in patients with COVID-19. Cardiac biomarkers should be systematically assessed in patients with COVID-19 at the time of hospital admission in order to optimise risk stratification. [ABSTRACT FROM AUTHOR]

The evolution of the full range of functions of regulatory T cells (Treg) coincides with the evolution of mammalian pregnancy. Accordingly, Treg function has been shown to be crucial for maternal-fetal tolerance and implantation. As reproduction is a key point of selective pressure, mammalian pregnancy may represent an evolutionary driver for the development of Treg. Yet beyond the chronological boundaries of mammalian pregnancy, several key physiological and pathological events are being gradually uncovered as involving the immunomodulating functions of Treg cells. These include autoimmunity, age-related inflammation in males and in post-menopausal females, but also oncological and cardiovascular diseases. The latter two sets of diseases collectively compose the main causes of mortality world-wide. Emerging data point to Treg-modulable effects in these diseases, in a departure from the relatively narrower perceived role of Treg as master regulators of autoimmunity. Yet recent evidence also suggests that changes in intestinal microbiota can affect the above pathological conditions. This is likely due to the finding that, whilst the presence and maintenance of intestinal microbiota requires active immune tolerance, mediated by Treg, the existence of microbiota per se profoundly affects the polarization, stability, and balance of pro- and anti-inflammatory T cell populations, including Treg and induced Treg cells. The study of these "novel," but possibly highly relevant from an ontogenesis perspective, facets of Treg function may hold great potential for our understanding of the mechanisms underlying human disease. [ABSTRACT FROM AUTHOR]

Abstract: Heart failure (HF), the final stage of pathological cardiac hypertrophy, is a major cause of hospitalization and mortality. The role of inflammation in the pathogenesis of HF has been extensively studied, with great emphasis on proinflammatory cytokines. Yet, clinical trials targeting these cytokines failed to become a credible therapeutic strategy for HF. More recent studies are increasingly highlighting an active role for T cells in the progression of HF pathology. As a result, a number of novel immunotherapy strategies are emerging for the treatment of HF and other cardiovascular diseases, via the targeting of adaptive immunity. Here we provide an overview of the background, details, and expected outcomes of these attempts. [ABSTRACT FROM AUTHOR]

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The Warts, Hypogammaglobulinemia, Infections, Myelokathexis (WHIM) syndrome is an immunodeficiency caused by mutations in chemokine receptor CXCR4. WHIM patient adaptive immunity defects remain largely unexplained. We have previously shown that WHIM-mutant T cells form unstable immunological synapses, affecting T cell activation. Here, we show that, in WHIM patients and WHIM CXCR4 knock-in mice, B cells are more apoptosis prone. Intriguingly, WHIM-mutant B cells were also characterized by spontaneous activation. Searching for a mechanistic explanation for these observations, we uncovered a novel costimulatory effect of CXCL12, the CXCR4 ligand, on WHIM-mutant but not wild-type B cells. The WHIM CXCR4-mediated costimulation led to increased B-cell activation, possibly involving mTOR, albeit without concurrently promoting survival. A reduction in antigenic load during immunization in the mouse was able to circumvent the adaptive immunity defects. These results suggest that WHIM-mutant CXCR4 may lead to spontaneous aberrant B-cell activation, via CXCL12-mediated costimulation, impairing B-cell survival and thus possibly contributing to the WHIM syndrome defects in adaptive immunity. [ABSTRACT FROM AUTHOR]

Several studies support the role of Western-style diet (WD) in inflammatory bowel disease (IBD). Toll-like receptors/NOD-like receptors (TLRs/NLRs) are important to maintain a healthy epithelium as well as inducing inflammation. Given that dietary factors influence IBD development, that epithelial dysfunction is thought to be involved in initiating intestinal inflammation and that TLR-NLR are involved in maintenance of the functionality of intestinal epithelium as well as in regulating inflammation, we decided to examine the role of TLR signals in the triggering events that lead to alteration of the small intestinal epithelium associated to consumption of WD. C57BL/6J mice deficient for TLR2, 4, 9, or NOD2 and wild-type (WT) were fed a WD or a standard diet for 3 months. The effects of WD on small intestinal samples were evaluated by histological and immunohistochemical analysis. After 3 months, WD modifies the morphology and the organization of the small intestine in TLR9 KO mice compared with WT mice and the others TLRs. The most interesting change involved the expression of proliferative and differentiation markers of WNT signaling, Ki67 and FzD5. Mice deficient in TLR2, 4, and NOD2 have a significant reduction in the proliferative cell numbers but do not show any signs of histological alterations. Our results suggest that TLR9 is an important protective factor in intestinal epithelial homeostasis and provide new insights into an unrecognized role of TLR9 signaling in the small intestinal mucosa dysfunction associated with WD. [ABSTRACT FROM AUTHOR]

Phosphatidylinositol 4,5-biphosphate (PIP2) is critical for T lymphocyte activation serving as a substrate for the generation of second messengers and the remodeling of actin cytoskeleton necessary for the clustering of lipid rafts, TCR, and costimulatory receptors toward the T:APC interface. Spatiotemporal analysis of PIP2 synthesis in T lymphocytes suggested that distinct isoforms of the main PIP2-generating enzyme, phosphatidylinositol 4-phosphate 5-kinase (PIP5K), play a differential role on the basis of their distinct localization. In this study, we analyze the contribution of PIP5Kβ to T cell activation and show that CD28 induces the recruitment of PIP5Kβ to the immunological synapse, where it regulates filamin A and lipid raft accumulation, as well as T cell activation, in a nonredundant manner. Finally, we found that Vav1 and the C-terminal 83 aa of PIP5Kβ are pivotal for the PIP5Kβ regulatory functions in response to CD28 stimulation. [ABSTRACT FROM AUTHOR]

The primary event for initiating adaptive immune responses is the encounter between T lymphocytes and antigen presenting cells (APCs) in the T cell area of secondary lymphoid organs and the formation of highly organized intercellular junctions referred to as immune synapses (IS). In vivo live-cell imaging of APC-T cell interactions combined to functional studies unveiled that T cell fate is dictated, in large part, by the stability of the initial contact. Immune cell interaction is equally important during delivery of T cell help to B cells and for the killing of target cells by cytotoxic T cells and NK cells. The critical role of contact dynamics and synapse stability on the immune response is well illustrated by human immune deficiencies in which disease pathogenesis is linked to altered adhesion or defective cross-talk between the synaptic partners. The Wiskott-Aldrich syndrome (WAS) is a severe primary immunodeficiency caused by mutations in the Wiskott-Aldrich syndrome protein (WASp), a scaffold that promotes actin polymerization and links TCR stimulation to T cell activation. Absence or mutations in WASp affects intercellular APC-T cell communications by interfering with multiple mechanisms on both sides of the IS. The warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is caused by mutations in CXCR4, a chemokine receptor that in mutant form leads to impairment of APC-T cell interactions. Present evidences suggest that other recently characterized primary immune deficiencies caused by mutation in genes linked to actin cytoskeletal reorganization, such as WIP and DOCK8, may also depend on altered synapse stability. Here, we will discuss in details the mechanisms of disturbed APC-T cell interactions in WAS and WHIM. Moreover, we will summarize the evidence pointing to a compromised conjugate formation in WIP, DOCK8, and X-linked lymphoproliferative syndrome. [ABSTRACT FROM AUTHOR]

Regulatory T cells play an essential role in preventing fetal rejection by the maternal immune system. Here we show that, based on the expression of CCR5, regulatory T cells can be divided into a highly suppressive CCR5+ and a far less suppressive CCRS- sub-population, suggesting that the former represent the effector arm of regulatory T cells. Although regulatory T ceils from CCR5-/- gene deletion mutants still suppress, they are less effective mediators of maternal-fetal tolerance. The accumulation of CCR5+ regulatory T cells at this site appears to be enhanced by alloantigen. This finding is in stark contrast to the systemic expansion of regulatory T cells during pregnancy, which appears to be alloantigen-independent. The fact that CCR5+ regulatory T cells preferentially accumulate in the gravid uterus and that expression of CCR5 on regulatory T cells can be induced by activation lead us to propose that CCR5 is responsible for the accumulation of those regulatory T cells that have been activated by paternal antigens. [ABSTRACT FROM AUTHOR]

Pregnancy constitutes a major challenge to the maternal immune system, as it has to tolerate the persistence of paternal alloantigen. Although localized mechanisms contribute to fetal evasion from immune attack, maternal alloreactive lymphocytes persist. We demonstrate here an alloantigen-independent, systemic expansion of the maternal CD25+ T cell pool during pregnancy and show that this population contains dominant regulatory T cell activity. In addition to their function in suppressing autoimmune responses, maternal regulatory T cells suppressed an aggressive allogeneic response directed against the fetus. Their absence led to a failure of gestation due to immunological rejection of the fetus. [ABSTRACT FROM AUTHOR]

Using gene expression profiling, we show here that activation of B cells and professional antigen-presenting cells (APCs) induces the expression of common chemokines. Among these, CCL4 was the most potent chemoattractant of a CD4+CD25+ T cell population, which is a characteristic phenotype of regulatory T cells. Depletion of either regulatory T cells or CCL4 resulted in a deregulated humoral response, which culminated in the production of autoantibodies. This suggested that the recruitment of regulatory T cells to B cells and APCs by CCL4 plays a central role in the normal initiation of T cell and humoral responses, and failure to do this leads to autoimmune activation. [ABSTRACT FROM AUTHOR]

Simple Summary: Lung cancer is the leading cause of cancer death worldwide. Detecting lung malignancies promptly is essential for any anticancer treatment to reduce mortality and morbidity, especially in high-risk individuals. The use of liquid biopsy to detect circulating biomarkers such as RNA, microRNA, DNA, proteins, autoantibodies in the blood, as well as circulating tumor cells (CTCs), can substantially change the way we manage lung cancer patients by improving disease stratification using intrinsic molecular characteristics, identification of therapeutic targets and monitoring molecular residual disease. Here, we made an update on recent developments in liquid biopsy-based biomarkers for lung cancer early diagnosis, and we propose guidelines for an accurate study design, execution, and data interpretation for biomarker development. Lung cancer burden is increasing, with 2 million deaths/year worldwide. Current limitations in early detection impede lung cancer diagnosis when the disease is still localized and thus more curable by surgery or multimodality treatment. Liquid biopsy is emerging as an important tool for lung cancer early detection and for monitoring therapy response. Here, we reviewed recent advances in liquid biopsy for early diagnosis of lung cancer. We summarized DNA- or RNA-based biomarkers, proteins, autoantibodies circulating in the blood, as well as circulating tumor cells (CTCs), and compared the most promising studies in terms of biomarkers prediction performance. While we observed an overall good performance for the proposed biomarkers, we noticed some critical aspects which may complicate the successful translation of these biomarkers into the clinical setting. We, therefore, proposed a roadmap for successful development of lung cancer biomarkers during the discovery, prioritization, and clinical validation phase. The integration of innovative minimally invasive biomarkers in screening programs is highly demanded to augment lung cancer early detection. [ABSTRACT FROM AUTHOR]

Heart failure (HF) is a leading cause of mortality. Inflammation is implicated in HF, yet clinical trials targeting pro-inflammatory cytokines in HF were unsuccessful, possibly due to redundant functions of individual cytokines. Searching for better cardiac inflammation targets, here we link T cells with HF development in a mouse model of pathological cardiac hypertrophy and in human HF patients. T cell costimulation blockade, through FDA-approved rheumatoid arthritis drug abatacept, leads to highly significant delay in progression and decreased severity of cardiac dysfunction in the mouse HF model. The therapeutic effect occurs via inhibition of activation and cardiac infiltration of T cells and macrophages, leading to reduced cardiomyocyte death. Abatacept treatment also induces production of anti-inflammatory cytokine interleukin-10 (IL-10). IL-10-deficient mice are refractive to treatment, while protection could be rescued by transfer of IL-10-sufficient B cells. These results suggest that T cell costimulation blockade might be therapeutically exploited to treat HF. [ABSTRACT FROM AUTHOR]

Abstract: Pregnancy frequently has a beneficial effect on the autoimmune disease Rheumatoid Arthritis, ranging from improvement in clinical symptoms to complete remission. Despite decades of study, a mechanistic explanation remains elusive. Here, we demonstrate that an analogous pregnancy-induced remission can be observed in a mouse model of arthritis. We demonstrate that during pregnancy mice are protected from collagen-induced arthritis, but are still capable of launching normal immune responses to influenza infections. We examine the role of regulatory T (TR) cells in this beneficial effect. TR cells are essential for many aspects of immune tolerance, including the suppression of autoimmune responses. Remarkably, transfer of regulatory T cells from pregnant ‘protected’ mice was sufficient to confer protection to non-pregnant mice. These results suggest that regulatory T cells are responsible for the pregnancy-induced amelioration of arthritis. [Copyright &y& Elsevier]

Obesity represents a global health problem. Excessive caloric intake promotes the release of inflammatory mediators by hypertrophic adipocytes and obesity-induced inflammation is now recognized as a risk factor for the development of several diseases, such as cardiovascular diseases, insulin resistance, type-II diabetes, liver steatosis and cancer. Since obesity causes inflammation, we tested the ability of acetylsalicylic acid (ASA), a potent anti-inflammatory drug, in counteracting this inflammatory process and in mitigating obesity-associated health complications. Mice were fed with standard (SD) or high fat diet (HFD) for 3 months and then treated with acetylsalicylic acid for the subsequent two months. We then analyzed the metabolic and inflammatory status of their adipose and liver tissue by histological, molecular and biochemical analysis. Although ASA did not exert any effect on body weight, quantification of adipocyte size revealed that the drug slightly reduced adipocyte hypertrophy, however not sufficient so as to induce weight loss. Most importantly, ASA was able to improve insulin resistance. Gene expression profiles of pro- and anti-inflammatory cytokines as well as the expression of macrophage and lymphocyte markers revealed that HFD led to a marked macrophage accumulation in the adipose tissue and an increase of several pro-inflammatory cytokines, a situation almost completely reverted after ASA administration. In addition, liver steatosis caused by HFD was completely abrogated by ASA treatment. ASA can efficiently ameliorate pathological conditions usually associated with obesity by inhibiting the inflammatory process occurring in the adipose tissue. • Acetylsalicylic acid can counteract the inflammatory process induced by high-fat diet consumption • Acetylsalicylic acid acts on adipose tissue reducing the release of inflammatory cytokines • Acetylsalicylic acid can revert high insulin and glucose levels induced by high-fat diet • Acetylsalicylic acid improves hepatic steatosis by a mechanism not involving the resolution of inflammation in liver [ABSTRACT FROM AUTHOR]

In recent years, tumor Adoptive Cell Therapy (ACT), using administration of ex vivo-enhanced T cells from the cancer patient, has become a promising therapeutic strategy. However, efficient homing of the anti-tumoral T cells to the tumor or metastatic site still remains a substantial hurdle. Yet the tumor site itself attracts both tumor-promoting and anti-tumoral immune cell populations through the secretion of chemokines. We attempted to identify these chemokines in a model of spontaneous metastasis, in order to "hijack" their function by expressing matching chemokine receptors on the cytotoxic T cells used in ACT, thus allowing us to enhance the recruitment of these therapeutic cells. Here we show that this enabled the modified T cells to preferentially home into spontaneous lymph node metastases in the TRAMP model, as well as in an inducible tumor model, E.G7-OVA. Due to the improved homing, the modified CD8+ T cells displayed an enhanced in vivo protective effect, as seen by a significant delay in E.G7-OVA tumor growth. These results offer a proof of principle for the tailored application of chemokine receptor modification as a means of improving T cell homing to the target tumor, thus enhancing ACT efficacy. Surprisingly, we also uncover that the formation of the peri-tumoral fibrotic capsule, which has been shown to impede T cell access to tumor, is partially dependent on host T cell presence. This finding, which would be impossible to observe in immunodeficient model studies, highlights possible conflicting roles that T cells may play in a therapeutic context., Competing Interests: The authors have no conflicts of interest.