Chemotactic Cytokines Research Articles

Melatonin and TGF-β-Mediated Release of Extracellular Vesicles.

The immune system, unlike other systems, must be flexible and able to "adapt" to fully cope with lurking dangers. The transition from intracorporeal balance to homeostasis disruption is associated with activation of inflammatory signaling pathways, which causes modulation of the immunology response. Chemotactic cytokines, signaling molecules, and extracellular vesicles act as critical mediators of inflammation and participate in intercellular communication, conditioning the immune system's proper response. Among the well-known cytokines allowing for the development and proper functioning of the immune system by mediating cell survival and cell-death-inducing signaling, the tumor necrosis factor α (TNF-α) and transforming growth factor β (TGF-β) are noteworthy. The high bloodstream concentration of those pleiotropic cytokines can be characterized by anti- and pro-inflammatory activity, considering the powerful anti-inflammatory and anti-oxidative stress capabilities of TGF-β known from the literature. Together with the chemokines, the immune system response is also influenced by biologically active chemicals, such as melatonin. The enhanced cellular communication shows the relationship between the TGF-β signaling pathway and the extracellular vesicles (EVs) secreted under the influence of melatonin. This review outlines the findings on melatonin activity on TGF-β-dependent inflammatory response regulation in cell-to-cell communication leading to secretion of the different EV populations.

Abstract 5874: HSF1 downregulation of CCL5 reduces CD8 T cell trafficking in breast cancer

Abstract Breast cancer is the leading cause of cancer related deaths in women. The presence of cytotoxic immune cells, specifically CD8+ T cells, in breast tumors is associated with better patient outcomes. Our goal is to understand mechanisms that regulate the infiltration of CD8+ T cells. This will in turn, improve the treatment and enhance patient overall survival. Utilizing a novel HSF1 activity gene signature, we observed that HSF1 activity was negatively associated with the presence of CD8+ T cells in breast cancer patients. Both CIBERSORT analysis of TCGA data as well as direct assessment of patient primary specimens demonstrated that patient tumors with high HSF1 activity had lower numbers of CD8+ T cells. To functionally test this relationship, HSF1 was knocked down in 4T1 breast cancer cells and grown orthotopically in BALB/c mice. Tumors with HSF1 knockdown showed lower tumor volumes and increased CD8+ T cell infiltration. We subjected the control and knockdown tumors to single- cell RNA sequencing analysis and found increased immune cell presence specifically CD8+ T cell presence in knockdown tumors. We further tested the effect of CD8+ T cells on the growth of HSF1 knockdown tumors by depleting CD8+ T cells in BALB/c mice. HSF1 knockdown tumors were significantly larger with CD8+ T cell depletion suggesting a functional role for HSF1 to inhibit CD8+ T cell infiltration and protect the tumor from immune-mediated killing. To investigate the mechanism by which HSF1 affects CD8+ T cells, we investigated whether HSF1 affects chemotactic cytokines. We found that loss of HSF1 significantly increased secretion of CCL5, a known chemoattractant for CD8+ T cells. Loss of HSF1 also increased mRNA levels of CCL5, suggesting a transcriptional effect on CCL5. To test the importance of CCL5 in the phenotype of HSF1 knockdown, a transwell migration assay was performed wherein T cells from BALB/c mice were placed in the upper chamber of a transwell chamber and the lower chamber contained conditioned medium from 4T1 cells with knockdown of HSF1 with or without knockdown of CCL5. The lower chamber was subjected to flow cytometry for CD3/CD8 to identify CD8+ T cells and we observed that loss of HSF1 increased migration of CD8+ T cells and this was ablated with additional loss of CCL5. These results suggest CCL5 is a significant mediator for the recruitment of CD8+ T cells when HSF1 is lost in cancer cells. We propose the model whereby high HSF1 activity in breast cancer cells suppresses expression and secretion of the chemo-attractant cytokine CCL5 that ultimately leads to a decrease in CD8+ T cells in breast tumors microenvironment. Citation Format: Curteisha LeeAnn Jacobs, Sakhi Shah, Wen-Cheng Lu, Richard Carpenter, Haimanti Ray, Xin Lu, Sha Cao. HSF1 downregulation of CCL5 reduces CD8 T cell trafficking in breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5874.

The Regulation of Neutrophil Migration in Patients with Sepsis: The Complexity of the Molecular Mechanisms and Their Modulation in Sepsis and the Heterogeneity of Sepsis Patients.

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Common causes include gram-negative and gram-positive bacteria as well as fungi. Neutrophils are among the first cells to arrive at an infection site where they function as important effector cells of the innate immune system and as regulators of the host immune response. The regulation of neutrophil migration is therefore important both for the infection-directed host response and for the development of organ dysfunctions in sepsis. Downregulation of CXCR4/CXCL12 stimulates neutrophil migration from the bone marrow. This is followed by transmigration/extravasation across the endothelial cell barrier at the infection site; this process is directed by adhesion molecules and various chemotactic gradients created by chemotactic cytokines, lipid mediators, bacterial peptides, and peptides from damaged cells. These mechanisms of neutrophil migration are modulated by sepsis, leading to reduced neutrophil migration and even reversed migration that contributes to distant organ failure. The sepsis-induced modulation seems to differ between neutrophil subsets. Furthermore, sepsis patients should be regarded as heterogeneous because neutrophil migration will possibly be further modulated by the infecting microorganisms, antimicrobial treatment, patient age/frailty/sex, other diseases (e.g., hematological malignancies and stem cell transplantation), and the metabolic status. The present review describes molecular mechanisms involved in the regulation of neutrophil migration; how these mechanisms are altered during sepsis; and how bacteria/fungi, antimicrobial treatment, and aging/frailty/comorbidity influence the regulation of neutrophil migration.

Mirtazapine, an atypical antidepressant, mitigates lung fibrosis by suppressing NLPR3 inflammasome and fibrosis-related mediators in endotracheal bleomycin rat model

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible lung disease with a poor prognosis. There is currently no definitive cure for IPF. The present study establishes a platform for the development of a novel therapeutic approach for the treatment of PF using the atypical antidepressant, mirtazapine. In the endotracheal bleomycin rat model, mirtazapine interfered with the activation of NLRP3 inflammasome via downregulating the NLRP3 on the gene and protein expression levels. Accordingly, the downstream mediators IL-1β and IL-18 were repressed. Such observation is potentially a direct result of the reported improvement in oxidative stress. Additionally, mirtazapine corrected the bleomycin-induced disparities in the levels of the fibrogenic mediators TGF-β, PDGF-BB, and TIMP-1, in consequence, the lung content of hydroxyproline and the expression of α-SMA were reduced. Besides, mirtazapine curbed the ICAM-1 and the chemotactic cytokines MCP-1 and CXCL4. This protective property of mirtazapine resulted in improving the BALF total and differential cell counts, diminishing LDH activity, and reducing the BALF total protein. Moreover, the inflammation and fibrosis scores were accordingly lower. To conclude, we reveal for the first time the efficacy of mirtazapine as a potential treatment for PF. The combination of social isolation, sleep problems, breathing difficulties, and fear of death can lead to psychological distress and depression in patients with IPF. Hence, mirtazapine is a promising treatment option that may improve the prognosis for IPF patients due to its antifibrotic effects, as well as its ability to alleviate depressive episodes.

Serum CXCL5 Detects Early Hepatocellular Carcinoma and Indicates Tumor Progression

Chemokines or chemotactic cytokines play a pivotal role in the immune pathogenesis of liver cirrhosis and hepatocellular carcinoma (HCC). Nevertheless, comprehensive cytokine profiling data across different etiologies of liver diseases are lacking. Chemokines might serve as diagnostic and prognostic biomarkers. In our study, we analyzed serum concentrations of 12 inflammation-related chemokines in a cohort of patients (n = 222) with cirrhosis of different etiologies and/or HCC. We compared 97 patients with cirrhosis and treatment-naïve HCC to the chemokine profile of 125 patients with cirrhosis but confirmed absence of HCC. Nine out of twelve chemokines were significantly elevated in sera of cirrhotic patients with HCC compared to HCC-free cirrhosis controls (CCL2, CCL11, CCL17, CCL20, CXCL1, CXCL5, CXCL9, CXCL10, CXCL11). Among those, CXCL5, CXCL9, CXCL10, and CXCL11 were significantly elevated in patients with early HCC according to the Barcelona Clinic Liver Cancer (BCLC) stages 0/A compared to cirrhotic controls without HCC. In patients with HCC, CXCL5 serum levels were associated with tumor progression, and levels of CCL20 and CXCL8 with macrovascular invasion. Importantly, our study identified CXCL5, CXCL9, and CXCL10 as universal HCC markers, independent from underlying etiology of cirrhosis. In conclusion, regardless of the underlying liver disease, patients with cirrhosis share an HCC-specific chemokine profile. CXCL5 may serve as a diagnostic biomarker in cirrhotic patients for early HCC detection as well as for tumor progression.

Tissue CD14+CD8+ T cells reprogrammed by myeloid cells and modulated by LPS.

The liver is bathed in bacterial products, including lipopolysaccharide transported from the intestinal portal vasculature, but maintains a state of tolerance that is exploited by persistent pathogens and tumours1-4. The cellular basis mediating this tolerance, yet allowing a switch to immunity or immunopathology, needs to be better understood for successful immunotherapy of liver diseases. Here we show that a variable proportion of CD8+ T cells compartmentalized in the human liver co-stain for CD14 and other prototypic myeloid membrane proteins and are enriched in close proximity to CD14high myeloid cells in hepatic zone 2. CD14+CD8+ T cells preferentially accumulate within the donor pool in liver allografts, among hepatic virus-specific and tumour-infiltrating responses, and in cirrhotic ascites. CD14+CD8+ T cells exhibit increased turnover, activation and constitutive immunomodulatory features with high homeostatic IL-10 and IL-2 production ex vivo, and enhanced antiviral/anti-tumour effector function after TCR engagement. This CD14+CD8+ T cell profile can be recapitulated by the acquisition of membrane proteins-including the lipopolysaccharide receptor complex-from mononuclear phagocytes, resulting in augmented tumour killing by TCR-redirected T cells in vitro. CD14+CD8+ T cells express integrins and chemokine receptors that favour interactions with the local stroma, which can promote their induction through CXCL12. Lipopolysaccharide can also increase the frequency of CD14+CD8+ T cells in vitro and in vivo, and skew their function towards the production of chemotactic and regenerative cytokines. Thus, bacterial products in the gut-liver axis and tissue stromal factors can tune liver immunity by driving myeloid instruction of CD8+ T cells with immunomodulatory ability.

Chemokines and chemokine receptors in Behçet's disease.

Behçet's disease (BD), a chronic vascular inflammatory disease, is characterized by the symptoms of ocular lesions, recurrent genital and oral ulcers, skin symptoms and arthritis in addition to neurological, intestinal and vascular involvement. The pathogenesis of BD is poorly understood, and there are no effective laboratory markers for the diagnosis of BD. In addition, BD is presently incurable. Chemokines, a family of small secreted chemotactic cytokines, interact with chemokine receptors and mediate the migration, localization and cellular interactions of inflammatory cells. Several studies have suggested that chemokines and their receptors play an important role in the occurrence and development of BD and that these chemokines along with their receptors can be utilized as biomarkers and therapeutic targets. In the present review, chemokines and chemokine receptors involved in BD and their potential application in diagnosis and therapy have been discussed.

Abstract C035: ACKR1 expression in stromal cells regulates immune infiltration in triple negative breast cancer

Abstract Triple-negative breast cancer (TNBC), a highly aggressive and metastatic subtype of breast cancer, lacks expression of the estrogen and progesterone receptors and amplification of HER2 and comprises 15-20% of all breast cancer. Incidence and mortality of TNBC are higher in Black Americans than in other racial/ethnic groups. Conversely, Black patients are underrepresented in clinical breast cancer drug trials, limiting our understanding of differential treatment responses. Leukocyte infiltration is a key modulator of TNBC outcome, and Black patients show immunological differences that may contribute to differential outcomes in TNBC. About 60-80% of Black Americans are homozygous for a polymorphism in the Atypical Chemokine Receptor 1 (ACKR1) promoter region that causes loss of ACKR1 expression on red blood cells, also known as the “Duffy-null” serotype. ACKR1 is expressed on tumor cells, red blood cells, and endothelial cells, and can act as a chemokine sink or chemokine concentrator, depending on the context. Whole-tumor RNA analysis shows that overall loss of ACKR1 expression in TNBC tumors correlates strongly with decreased survival, but it is unclear which ACKR1-expressing cell type(s) contribute to this effect. Under inflammatory conditions, ACKR1 expression in endothelial cells localizes chemotactic cytokines at the endothelial junction, and loss of endothelial ACKR1 blocks the ability of leukocytes to extravasate through the endothelial barrier into surrounding tissues. We hypothesized that loss of endothelial/stromal ACKR1 reduces immune infiltration and activation in TNBC and racial/ethnic differences in ACKR1 expression may contribute to health disparities. To determine the role of ACKR1 in tumor immune infiltration, we chose a syngeneic immunocompetent mouse model to incorporate species-matched stromal-tumor interactions. We orthotopically inoculated E0771.LMB cells, a C57BL6/J syngeneic TNBC cell line, into ACKR1null and ACKR1het female mice. Tumor growth was measured triweekly, and tumor mass was measured at the 28-day endpoint. To measure immune infiltration, we fluorescently stained representative tumor cryosections with CD45 to detect all classes of infiltrating hematopoietic cells involved in immune response. There was no significant difference in tumor volume and mass among the ACKR1null and ACKR1het controls. Tumors implanted in ACKR1het controls showed broadly infiltrated leukocytes clusters, while tumors in ACKR1nullhosts showed sparse and infrequent leukocyte infiltration. Conclusion: Stromal ACKR1 does not have a strong effect on primary tumor growth. Loss of stromal ACKR1 reduces infiltration of leukocytes into the tumor microenvironment even when ACKR1 is not manipulated in the tumor cells, suggesting that ACKR1 in endothelial or other stromal cells regulates immune response in TNBC. Impact: Understanding the immunogenic functions of ACKR1 allelic variation will elucidate mechanisms of racially distinct therapeutic response in TNBC, enhance precision oncology, and promote cancer health equity. Citation Format: Chinwe Obianuju Ewenighi-Amankwah, Tanner Roach, Joseph Dufraine, Naiche Adler, Jan Kitajewski. ACKR1 expression in stromal cells regulates immune infiltration in triple negative breast cancer [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C035.

Clinical and biochemical characteristics of people experiencing post-coronavirus disease 2019-related symptoms: A prospective follow-up investigation.

Post-acute coronavirus disease 2019 (COVID-19) syndrome, also known as long COVID, is a prolonged illness after the acute phase of COVID-19. Hospitalized patients were known to have persisting symptoms of fatigue, headache, dyspnea, and anosmia. There is a need to describe the characteristics of individuals with post-COVID-19 symptoms in comparison to the baseline characteristics. To investigate the clinical and biochemical characteristics of people who recovered from COVID-19 after 6 months of discharge from the hospital. This was a prospective follow-up investigation of hospitalized and discharged COVID-19 patients. Adult patients admitted to King Saud University Medical City, Riyadh, Saudi Arabia, with laboratory-confirmed COVID-19 and discharged were recruited. The baseline demographic information, comorbidities, vital signs and symptoms, laboratory parameters, COVID-19 therapy, and outcomes were collected from the medical records. Blood samples were collected for cytokines estimation. A detailed interview about signs and symptoms was undertaken during the follow-up. Half of the followed-up people reported experiencing at least one of the COVID-19-related symptoms. The mean blood pressure was found higher in follow-up. People with the symptoms were characterized by low lymphocyte count, lower serum calcium levels, and hyperglycemia compared to people without any post-COVID-19 symptoms. Cytokines IL-8, VEGF, and MCP-1 were higher in people with the most frequent symptoms. People with post-COVID-19 symptoms were characterized by lower lymphocyte count, lower serum calcium levels, and hyperglycemia compared to people without symptoms. Individuals with the most frequent post-COVID-19 symptoms had higher baseline pro-inflammatory, chemotactic, and angiogenic cytokines.

The role of CXCR3 and its ligands in cancer.

Chemokines are a class of small cytokines or signaling proteins that are secreted by cells. Owing to their ability to induce directional chemotaxis of nearby responding cells, they are called chemotactic cytokines. Chemokines and chemokine receptors have now been shown to influence many cellular functions, including survival, adhesion, invasion, and proliferation, and regulate chemokine levels. Most malignant tumors express one or more chemokine receptors. The CXC subgroup of chemokine receptors, CXCR3, is mainly expressed on the surface of activated T cells, B cells, and natural killer cells, and plays an essential role in infection, autoimmune diseases, and tumor immunity by binding to specific receptors on target cell membranes to induce targeted migration and immune responses. It is vital to treat infections, autoimmune diseases, and tumors. CXCR3 and its ligands, CXCL9, CXCL10, and CXCL11, are closely associated with the development and progression of many tumors. With the elucidation of its mechanism of action, CXCR3 is expected to become a new indicator for evaluating the prognosis of patients with tumors and a new target for clinical tumor immunotherapy. This article reviews the significance and mechanism of action of the chemokine receptor CXCR3 and its specific ligands in tumor development.

EXTH-58. UNRAVELING THE MECHANISMS UNDERLYING THE THERAPEUTIC EFFICACY OF TIM-3 BLOCKADE IN DIPGS

Abstract Diffuse intrinsic pontine glioma (DIPG) is an aggressive brain tumor and the leading cause of pediatric death caused by cancer. Despite great strides in the understanding of this disease, the survival is still dismal. One of the objectives of our lab is to modulate the tumor microenvironment (TME) towards a proinflammatory phenotype to render these tumors amenable to immunotherapy. TIM-3 is a member of the TIM-family of immunoregulatory proteins expressed on multiple immune cell types, including T-cells, NK, myeloid populations, and microglia, regulating adaptive and innate immunity. In silico assessment of TIM-3 expression in DIPG mRNA and single-cell datasets showed a robust expression of this gene in tumor cells and microglia uncovering this molecule as a potential target in DIPGs. In vivo studies showed that TIM-3 blockade with an antibody significantly increased the overall survival of two DIPG immunocompetent orthotopic models, led to long-term survivors (50%), and showed immune resident memory. TIM-3 inhibition resulted in a significant increase in the number and proliferative state of microglia, NK, and CD8+ cells and higher levels of IFNγ, GrzB and TNFα corresponding to NK and T-cell activate phenotypes. Interestingly, there was a decrease in the Treg population, which causes an increase in the pro-inflammatory CD8/Treg ratio. Chemokine studies demonstrated an augmentation of CCL5, CCL2 chemotactic cytokines, and CXCL10/IL-1β/IFN-γ pro-inflammatory axis in the tumor microenvironment of treated-mice. Additionally, DCs, CD4+, and CD8+ cells were increased in treated draining lymph nodes and of functional significance, expressed higher amounts of pro-inflammatory cytokines than in control mice. Interestingly, the depletion of the different immune populations did not completely abrogate the treatment efficacy indicating a residual although significant TIM-3 effect in the tumor. In conclusion, these data uncover TIM-3 as a potential target for the treatment of DIPG and its potential as an immune regulator of DIPG TME.

Physiology of chemokines in the cancer microenvironment.

Chemokines are chemotactic cytokines whose canonical functions govern movement of receptor-expressing cells along chemical gradients. Chemokines are a physiological system that is finely tuned by ligand and receptor expression, ligand or receptor oligomerization, redundancy, expression of atypical receptors, and non-GPCR binding partners that cumulatively influence discrete pharmacological signaling responses and cellular functions. In cancer, chemokines play paradoxical roles in both the directed emigration of metastatic, receptor-expressing cancer cells out of the tumor as well as immigration of tumor-infiltrating immune cells that culminate in a tumor-unique immune microenvironment. In the age of precision oncology, strategies to effectively harness the power of immunotherapy requires consideration of chemokine gradients within the unique spatial topography and temporal influences with heterogeneous tumors. In this article, we review current literature on the diversity of chemokine ligands and their cellular receptors that detect and process chemotactic gradients and illustrate how differences between ligand recognition and receptor activation influence the signaling machinery that drives cellular movement into and out of the tumor microenvironment. Facets of chemokine physiology across discrete cancer immune phenotypes are contrasted to existing chemokine-centered therapies in cancer.

KDM6A Loss Recruits Tumor-Associated Neutrophils and Promotes Neutrophil Extracellular Trap Formation in Pancreatic Cancer.

KDM6A loss in pancreatic cancer cells alters the immune microenvironment by increasing CXCL1 secretion and neutrophil recruitment, providing a rationale for targeting the CXCL1-CXCR2 signaling axis in tumors with low KDM6A.

Microarray analysis reveals the potential molecular mechanism of Lp299v in stable coronary atherosclerotic disease

A growing body of evidence has confirmed that inflammatory mechanisms are involved in the formation and treatment of coronary atherosclerotic disease (CAD). An increase in circulatory levels of inflammatory cytokines has been found in patients with CAD, while the molecular mechanisms of inflammation still remain elusive. This study was designed to identify differentially expressed genes (DEGs), and to explore the molecular mechanism and hub genes that are involved in the effects of Lactobacillus plantarum 299v (Lp299v) supplementation. Microarray dataset (GSE156357) was downloaded from the Gene Expression Omnibus (GEO) database. The DEGs were identified by the R software. Then, the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses and construction of protein–protein interaction (PPI) network were performed by DAVID, STRING, and Cytoscape software. In daily alcohol user (DAU) group, 7,541 DEGs were identified, including 206 up-regulated and 7,335 down-regulated DEGs. In non-daily alcohol user (non-DAU) group, 2,799 DEGs were identified (2,491 up-regulated and 308 down-regulated DEGs). The GO enrichment analysis revealed that miosis was up-regulated and immune response was down-regulated. The KEGG enrichment analysis showed that Lp299v supplementation reduced the levels of chemotactic cytokines, and weakened immune response. Proteins of G protein-coupled receptor, inflammatory response, regulation of cell proliferation and apoptosis-related proteins were found in the PPI network. The hub genes were associated with G protein-coupled receptor, inflammatory response, and cell proliferation and apoptosis. The weighted gene co-expression network analysis (WGCNA) enriched the DEGs in 4 modules. This study indicated the expressions of chemokine receptors and regulation of immune response in the Lp299v supplementation. Meanwhile, it was supposed that chemokine receptors may have a cellular effect.

Antitumor efficacy of CRISPR/Cas9-engineered ICP6 mutant herpes simplex viruses in a mouse xenograft model for lung adenocarcinoma.

Oncolytic viruses (OVs), including oncolytic herpes simplex viruses (oHSVs), are promising therapeutics against cancer. Here, we report two ICP6-mutated HSVs (type I) generated by CRISPR/Cas9, rHSV1/∆RR (with ICP6 ribonucleotide reductase [RR]domain deleted) and rHSV1/∆ICP6 (with a complete deletion of ICP6), exhibiting potent antitumor efficacy against lung adenocarcinoma. Both the mutants showed strong cytotoxicity in vitro, comparable with the control viruses expressing intact ICP6, but in relatively lower titers. Moreover, these mutant viruses exhibited preferential killing ability against lung tumor cells rather than normal lung fibroblast cells. Further, unlike the control HSV-1 causing severe illness or death in the mouse model, the ICP6-mutated viruses did not induce significant pathogenicity but instead effectively reduced tumor burden in vivo and led to 100% survival of the animals, indicating notable antitumor activity and attenuated virulence. In addition, rHSV1/∆RR seemed to have even better antitumor efficacy than rHSV1/∆ICP6, albeit no statistical significance in inhibition of tumor volume. Histopathologically, rHSV1/∆RR induced massive neutrophil infiltration to the tumor microenvironment and consistently, triggered more antitumor immune and neutrophil chemotactic cytokines or higher expression levels of them (indicated by quantitative polymerase chain reaction and transcriptome analyses). These results demonstrate the anti-adenocarcinoma potential of the CRISPR/Cas9-engineered ICP6 mutant HSV1, especially the rHSV1/∆RR, which likely induces stronger innate antitumor immune response. Together, these findings may provide new valuable clues for further development of OV-based therapeutics against lung adenocarcinoma or other types of tumors.

The Chemokines CXC, CC and C in the Pathogenesis of COVID-19 Disease and as Surrogates of Vaccine-Induced Innate and Adaptive Protective Responses.

COVID-19 is one of the progressive viral pandemics that originated from East Asia. COVID-19 or SARS-CoV-2 has been shown to be associated with a chain of physio-pathological mechanisms that are basically immunological in nature. In addition, chemokines have been proposed as a subgroup of chemotactic cytokines with different activities ranging from leukocyte recruitment to injury sites, irritation, and inflammation to angiostasis and angiogenesis. Therefore, researchers have categorized the chemotactic elements into four classes, including CX3C, CXC, CC, and C, based on the location of the cysteine motifs in their structures. Considering the severe cases of COVID-19, the hyperproduction of particular chemokines occurring in lung tissue as well as pro-inflammatory cytokines significantly worsen the disease prognosis. According to the studies conducted in the field documenting the changing expression of CXC and CC chemokines in COVID-19 cases, the CC and CXC chemokines contribute to this pandemic, and their impact could reflect the development of reasonable strategies for COVID-19 management. The CC and the CXC families of chemokines are important in host immunity to viral infections and along with other biomarkers can serve as the surrogates of vaccine-induced innate and adaptive protective responses, facilitating the improvement of vaccine efficacy. Furthermore, the immunogenicity elicited by the chemokine response to adenovirus vector vaccines may constitute the basis of vaccine-induced immune thrombotic thrombocytopaenia.

IL-8 Is Upregulated in the Tissue-Derived EVs of Odontogenic Keratocysts.

Background Interleukin 8 (IL-8) is a chemotactic cytokine released by various cells including leukocytes, endothelial cells, and epithelial cells. IL-8 has multiple functions in inflammation, tumour invasion, or angiogenesis. Human odontogenic cystic lesions are chronic and frequently inflamed. Tissue-derived extracellular vesicles (Ti-EVs) are widely present in various tissues and could more accurately reflect the characteristics of the primary tissue. However, the involvement of IL-8 in Ti-EVs of human odontogenic lesions is still unclear. This study aimed to explore the expression of IL-8 in Ti-EVs of human odontogenic lesions and the potential roles of Ti-EVs that carried IL-8. Methods Fresh tissue samples of dentigerous cyst (DC, n = 5) and odontogenic keratocyst (OKC, n = 5) were collected for Ti-EVs isolation. Ti-EVs were characterised by transmission electron microscopy and nano-flow cytometry analysis. The cytokine profile of Ti-EVs was explored by cytokine antibody array. The IL-8 expression was examined by immunochemical staining in tissue of odontogenic lesions (DC, n =12; OKC, n =28). Antioxidants (N-acetyl-L-cysteine and diphenyleneiodonium) were employed to treat HaCaT cells, and the expression of IL-8 was detected by enzyme-linked immunosorbent assay. The gene expression of MMP9 was explored by quantitative real-time polymerase chain reaction in co-culture system of fibroblasts of OKC with Ti-EVs. Results Compared with DC, the expression of IL-8 in Ti-EVs and fixed tissue specimens of OKC was markedly upregulated. The antioxidants decreased the expression level of IL-8 protein in the supernatant of HaCaT cells. The Ti-EVs treatment (10 μg/ml) of fibroblasts significantly induced the MMP9 mRNA expressions in OKC fibroblasts. Conclusions IL-8 was upregulated in Ti-EVs of OKC and might be involved in the tissue destruction of OKC.

Chemotactic cytokines secreted from Kupffer cells contribute to the sex-dependent susceptibility to non-alcoholic fatty liver diseases in mice

AimsThe global prevalence of non-alcoholic fatty liver disease (NAFLD) has rapidly increased over the last decade due to an elevated occurrence of metabolic syndromes. Importantly, the prevalence and severity of NAFLD is higher in men than in women. Therefore, in the present study we endeavored to identify the mechanistic disparity between male and female mice. Main methodsGlobal gene transcriptomics analysis was done with the high-fat diet (HFD)-induced NAFLD model of male, female, and ovariectomized (OVX) female mice. The expression of CCL2, CXCL2, and CXCL10 in mRNA level and serum protein level was done by qPCR and ELISA each. Immunohistochemistry staining was used to observe hepatic immune cell infiltration. To analyzing portion of immune cells, flow cytometry was done with isolated liver cells from HFD-fed male and female mice. Primary mouse liver cells were isolated from male and female mice for in vitro studies. Key findingsWe identified sex differences in inflammatory chemokines, CCL2, CXCL2, and CXCL10, with the expression of these chemokines enhanced in male and OVX, but not in female, mice after HFD feeding. Resident Kupffer cells (KCs) were identified as the major source of production of CCL2, CXCL2, and CXCL10 in the mouse NAFLD model. Notably, KCs obtained from male mice expressed higher levels of chemokines than those from female mice, indicating that KCs may mediate the sex discrepancy in NAFLD progression. SignificanceOur findings offer new insights into the pathology of sex-specific differences in NAFLD, involving chemokines and KCs.

Abstract 5556: Monotherapy of anti-CXCL16 antibody is a potential therapeutic for macrophage-enriched triple-negative breast cancer by modulating tumor immune microenvironment and glutamine metabolism

Abstract CXCL16, as a chemotactic cytokine, has been observed in various human solid cancers. The effects of CXCL16 on tumor behavior is controversial and showed tissue-specific manners. In breast cancers, previous studies have showed that CXCL16 mainly originated from mesenchymal stromal cells or cancer-associated fibroblasts and played pro-tumorigenic roles. CXCL16 is highly expressed in triple-negative breast cancers (TNBC) in TCGA dataset for breast cancer. This study aimed to investigate the therapeutic effects of CXCL16 neutralizing antibody and its mechanisms in TNBC. To establish a xenograft mouse model of TNBC, MDA-MB-231 cells were injected subcutaneously to athymic nude mice, and mice were randomized into anti-CXCL16 and control groups. When measurable tumors were established, anti-CXCL16 neutralizing antibody (CLS-A101, cellus inc.) or control IgG were intravenously injected. Tumor growth was significantly delayed in the anti-CXCL16 group than the control group by 67% for 3 weeks. Flow cytometric analysis showed that macrophages (CD11b+F4/80+ cells) and myeloid derived suppressor cells (MDSC, CD11b+GR1+ cells) were decreased in the anti-CXCL16 group than the control group. Histologic examination showed that anti-CXCL16 antibody significantly reduced tumor vessel formation and decreased macrophage infiltration in both intra- and peri-tumoral area. Collectively, treatment of anti-CXCL16 antibody reduced tumor growth by inhibiting macrophage and MDSC infiltration following reduced tumor angiogenesis. To explore the mechanistic insight into the monotherapy of anti-CXCL16 antibody, we further analyzed the metabolic changes. In human tumor tissues, TNBC harboring high expression of CXCL16 showed significant shift of glutamine metabolism pathway-related genes (upregulation of GLS and downregulation of GLUL, GLUD1, and GLUD2) toward accumulating glutamate. For cellular experiments, CXCL16-enriched cancer/macrophage co-cultured conditioned medium (co-CM) or cancer single-cultured conditioned medium (s-CM) were treated to cancer cells, and glutamine and glutamate levels were measured. In MDA-MB-231 cells, co-CM treatment significantly enhanced glutamate/glutamine ratio and anti-CXCL16 antibody significantly decreased it. Consistently, glutamate measures in tumor lysates from TNBC xenograft were lower in the anti-CXCL16 group than the control group. In conclusion, anti-CXCL16 antibody (CLS-A101) inhibited immune suppressive myeloid cell infiltration followed tumor angiogenesis and glutamate productions in cancer cells. These dual actions on both tumor immune microenvironment and cancer cell metabolism enables anti-CXCL16 antibody to be a potential monotherapy for TNBC. Citation Format: Min Joo Kim, Hyun Jin Sun, Geun-Hyung Kang, Seong Keun Kim, Sun Wook Cho. Monotherapy of anti-CXCL16 antibody is a potential therapeutic for macrophage-enriched triple-negative breast cancer by modulating tumor immune microenvironment and glutamine metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5556.

Abstract 2192: HSF1 downregulation of CCL5 reduces CD8 + T cell trafficking in breast cancer

Abstract Breast cancer is the second leading cause of cancer-related death in women. The presence of cytotoxic immune cells, specifically CD8+ T cells, in breast tumors is associated with better patient outcomes. Understanding the mechanisms that regulate the infiltration of CD8+ T cells into breast tumors could improve the treatment and enhance patient overall survival. Utilizing a novel HSF1 activity gene signature, we observed that HSF1 activity was negatively associated with the presence of CD8+ T cells in breast cancer patients. Both CIBERSORT analysis of TCGA data as well as direct assessment of patient primary specimens demonstrated that patient tumors with high HSF1 activity had lower numbers of CD8+ T cells. To functionally test this relationship, HSF1 was knocked down in 4T1 breast cancer cells and grown orthotopically in BALB/c mice. Tumors with HSF1 knockdown showed lower tumor volumes and increased CD8+ T cell infiltration. We further tested the effect of CD8+ T cells on the growth of HSF1 knockdown tumors by depleting CD8+ T cells in BALB/c mice. HSF1 knockdown tumors were significantly larger with CD8+ T cell depletion suggesting a functional role for HSF1 to inhibit CD8+ T cell infiltration and protect the tumor from immune-mediated killing. To investigate the mechanism by which HSF1 affects CD8+ T cells, we investigated whether HSF1 affects chemotactic cytokines. We found that loss of HSF1 significantly increased secretion of CCL5, a known chemoattractant for CD8+ T cells. Loss of HSF1 also increased mRNA levels of CCL5, suggesting a transcriptional effect on CCL5. To test the importance of CCL5 in the phenotype of HSF1 knockdown, a transwell migration assay was performed wherein T cells from BALB/c mice were placed in the upper chamber of a transwell chamber and the lower chamber contained conditioned medium from 4T1 cells with knockdown of HSF1 with or without knockdown of CCL5. The lower chamber was subjected to flow cytometry for CD3/CD8 to identify CD8+ T cells and we observed that loss of HSF1 increased migration of CD8+ T cells and this was ablated with additional loss of CCL5. These results suggest CCL5 is a significant mediator for the recruitment of CD8+ T cells when HSF1 is lost in cancer cells. We propose the model whereby high HSF1 activity in breast cancer cells suppresses expression and secretion of the chemo-attractant cytokine CCL5 that ultimately leads to a decrease in CD8+ T cells in breast tumors microenvironment. Citation Format: Curteisha LeeAnn Jacobs, Sakhi Shan, Wen-Cheng Lu, Richard Carpenter. HSF1 downregulation of CCL5 reduces CD8 + T cell trafficking in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2192.