The Journal of Immunology最新文献

{"title":"Identification and function of a C3 hiIL-33 +fibroblast population in the lungs","authors":"Aishwarya Atakkatan, N. Gour, Aishwarya Magesh, H. Yong, S. Lajoie","doi":"10.4049/jimmunol.210.supp.176.09","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.176.09","url":null,"abstract":"\u0000 Complement component C3 is known to be predominantly expressed by epithelial and immune cells, however, we have found that fibroblasts are a primary source of C3 in murine and human lungs. Specifically, C3 is majorly expressed in adventitial fibroblasts. Moreover, we found that C3 hifibroblasts are characterized by the expression of IL-33. Further, C3 and IL-33 are not only markers of a novel subset of pulmonary adventitial fibroblasts but form a functional axis where C3 drives the expression of IL-33. As compared to other adventitial fibroblasts, this C3 hiIL-33 +subset is enriched for matrix genes, especially type I collagen (COL1A1). These cells require a functional C3− IL-33 axis to maintain their matrix identity. Impairing C3 not only reduces their ability to make collagen but guides them towards a lipofibroblast program characterized by lower collagen content and higher lipid accumulation. As we and others have published that C3 is a key driver of allergic airway inflammation, we wanted to understand how exposure to allergen affected C3 hiIL-33 +fibroblasts. Using a murine model of airway allergy, we observed a significant increase in the C3 hiIL33 +fibroblast population in lung samples from house dust mite (HDM)-treated mice compared to the PBS control group. Recently, IL-33 +fibroblasts were found to support ILC2 recruitment during helminth infection. As we have found C3 is critical to maintain IL-33 in these cells, we aim to understand if C3 hiIL-33 +fibroblasts participate in allergy by mediating cellular crosstalk with ILC2s and T cells during type 2 immune responses.\u0000 Supported by grants from NIH R01AI27644 and the Johns Hopkins Catalyst Award to Dr. Stephane Lajoie.","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73256381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RGC-32 facilitates reactive astrocytosis by modulating the expression of axonal guidance molecules","authors":"H. Rus, A. Tatomir, Jacob Cuevas, Vinh Phu Nguyen, C. Cudrici, T. Badea, V. Rus","doi":"10.4049/jimmunol.210.supp.63.14","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.63.14","url":null,"abstract":"Response Gene to Complement (RGC)-32 modulates TGF-β-induced extracellular matrix secretion and the ability of astrocytes to undergo reactive changes in vivo during experimental autoimmune encephalomyelitis (EAE). However, the molecular pathways underlying these effects are still not well understood. In this study, we investigated how lack of RGC-32 affects the transcriptomic profile and the expression of axonal guidance molecules (AGM) in astrocytes during EAE. We performed next-generation RNA sequencing on brain neonatal astrocytes isolated from wild type (WT) and RGC-32 knock-out (KO) mice, either unstimulated or stimulated with TGF-β. Results were then validated by using Real-Time PCR. Spinal cords from WT and RGC-32 KO mice with EAE (at days 0 and 14) were stained by immunohistochemistry for the astrocyte marker GFAP, AGM, and for nuclear factor IA (NFIA), a gliogenic factor and transcriptional regulator of AGM. Lack of RGC-32 had a significant impact on the transcriptomic programs normally associated with brain development whose re-expression is usually seen in reactive astrocytes. Connectivity analysis revealed that genes coding for AGM were particularly affected. We found lower transcript levels of ephrin receptor A type 7 (Epha7), plexin A1 and Slit guidance ligand 2 in RGC-32 KO astrocytes. Moreover, our results showed that NFIA and EPHA7 are expressed by astrocytes during EAE. We found a lower number of astrocytes expressing EPHA7 and NFIA in RGC-32 KO mice with acute EAE when compared with WT mice. These results suggest that RGC-32 might facilitate reactive astrogliosis during acute EAE through regulating the expression of AGM and NFIA. Veterans Administration Merit Award I01BX001458 (to HR)","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75363206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Akkermansia muciniphilaacts synergistically with Btk-deficiency to prevent Type 1 Diabetes","authors":"Sonam Verma, Lucy S. Cohen, I. Olin, P. Kendall","doi":"10.4049/jimmunol.210.supp.227.12","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.227.12","url":null,"abstract":"\u0000 Btk-deficiency eliminates autoreactive B cells, but not normal ones, and protects against Type 1 diabetes (T1D). Surprisingly, we recently found that rederivation of Btk−/−/NOD mice into a cleaner, “barrier” facility resulted in loss of disease protection. This suggests that T1D protection is microbiome dependent in Btk−/−mice. Akkermansia muciniphila(A. muciniphila)was found to be increased in Btk−/−/NOD mice that were protected against disease compared to WT and Btk−/−/NOD that were not protected. A. muciniphilahas previously been associated with disease protection in humans and mice under some conditions, although causality and mechanisms are unknown. We previously showed that Btk-deficient K/BxN mice have reduced intestinal IgA, and therefore hypothesized that A. muciniphilaescapes suboptimal IgA-coating in Btk−/−/NOD and works synergistically with the loss of autoreactive B cells to protect against T1D. Germ-free female WT NOD and Btk−/−/NOD were gavaged with A. muciniphilaat 3–4 weeks. Mice were tested weekly for diabetes to 30 weeks of age. Additional mice were treated in parallel and euthanized at 9–10 weeks to examine the effects on mucosal immunity and autoimmune attack on pancreatic islets. Monocolonization of Btk−/−/NOD with A. muciniphilaprotected significantly against T1D compared to monocolonized WT NOD. CD19 +GL7 +staining of Peyer’s patches showed small germinal centers in Btk−/−/NOD compared to WT NOD. Thus, A. muciniphilaprotects against T1D in Btk−/−/NOD but not WT NOD, indicating a synergistic effect. Altogether, the data show that Btkplays a previously unrecognized role in the maintenance of gut health that can have downstream effects on T1D outcomes.\u0000 National Institutes of Health Grants R01-DK-084246I Veteran’s Affairs I01-BX-002882 Washington University School of Medicine","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"173 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75515433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anti-HER2 cell specific doxorubicin delivery using synthetic bacterial spores for resistant ovarian cancer treatment.","authors":"D. D’Atri, M. Kong, M. Bilotta, K. Tanner, David Fitzgerald, Kumaran S. Ramamurthi","doi":"10.4049/jimmunol.210.supp.245.01","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.245.01","url":null,"abstract":"\u0000 Delivery of cancer therapeutics to non-specific sites decreases treatment efficacy while increasing toxicity. In ovarian cancer, overexpression of the cell surface marker HER2, which several therapeutics target, relates to poor prognosis. SSHELs are synthetic spore-like particles wherein the spore’s cell surface is partially reconstituted around 1 μm-diameter silica beads. Via a unique cysteine engineered protein, the surface of SSHELs may be covalently decorated to display HER2 (SSHELs αHER2). SKOV3 and SKBR3 cells’ targeting by SSHELs αHER2was evaluated by flow cytometry and confocal microscopy. SSHELs αHER2specifically bound to target cells and were internalized proportionally to their concentration. Subsequently, SSHELs were successfully loaded with doxorubicin (Dox-SSHELs αHER2). Dox-SSHELs αHER2capabilities to kill tumor cells was evaluated by flow cytometry and caspase assay. HER2 negative cells were used as a control. Dox-SSHELs αHER2’s efficacy was tested in vivo using athymic nude mice injected with SKOV3 ovarian cancer cells and then treated for up to 40 days. Dox-SSHELs αHER2can reduce SKOV3 tumor growth up to 75% when compared to the free drug. Further, when compared to liposomal doxorubicin (Doxil TM) Dox-SSHELs αHER2showed similar efficacy in reducing tumor growth, but without any of the typical side effects correlated with Doxil TMinjections. With a facile, reproducible manufacturing process that allows for straightforward targeting towards specific cell types, and lower overall toxicity, we suggest that SSHELs may represent a versatile strategy opening new research avenues for targeted drug delivery treatment or immune system stimulation through vaccination.","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75525074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gene-dose-dependent roles of DEFA1A3in the neutralization of uropathogenic Escherichia coli","authors":"Jorge J Canas, A. Schwaderer, D. Hains","doi":"10.4049/jimmunol.210.supp.71.15","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.71.15","url":null,"abstract":"\u0000 Genetic polymorphisms of the human genome provide information about disease susceptibility and autoimmunity. Genetic variations involving the innate immune system have the potential to improve the effectiveness of diagnosis and treatment of urinary tract infections in children and adults. DNA copy number variations (CNVs) of DEFA1A3, which encodes for antimicrobial peptides α-defensin 1–3, have been associated with recurrent UTI risk in children with vesicoureteral reflux (VUR). α-Defensins 1–3 are pleiotropic antimicrobial peptides with bactericidal and immunomodulatory properties. Due to the absence of a gene ortholog in mice, traditional murine models to study the effect of DEFA1A3CNVs are lacking. Our objective is to explore the gene-dosage pleiotropic effects of the DEFA1A3locus by utilizing a UTI-challenged transgenic mouse model expressing variable copies of the human gene. To model murine UTIs, uropathogenic E. coli(UPEC) pyelonephritis strain (CFT073) or vehicle volume was injected transurethrally into DEFA4/4, DEFA4/0, and DEFA0/0mice. Urinary tract organs were analyzed for quantifiable bacterial growth, immune cell frequencies, and antimicrobial response gene expression array. Kidney bacterial clearance effects are proportional to gene-dosage; gradually decreasing colonization in mice between DEFA4/4(71%), DEFA4/0(57%), and DEFA0/0(43%) genotypes. The kidney immune cells displayed differential mRNA expression of pro-inflammatory genes Il1βand Il6genes as well as phagocytic genes Rac1and Lyz2between the infected mice genotypes. Our findings support pleiotropic gene-dosage protective roles of the human DEFA1A3gene in a murine model of UTI-induced pyelonephritis.\u0000 Supported by the grants from NIH (R01 DK117934 & R01 DK106286 )","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"193 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75534398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mass cytometry analysis of mouse nonclassical monocyte heterogeneity in breast tumors","authors":"Gabriel Valentín-Guillama, F. Alkan, H. Alkan, A. Alimadadi, H. Korkaya, C. Hedrick","doi":"10.4049/jimmunol.210.supp.84.08","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.84.08","url":null,"abstract":"\u0000 Monocytes have emerged as important regulators of cancer progression. Our previous studies demonstrated the importance of nonclassical Ly6C lomonocytes in regulating cancer metastasis in mouse models. Here, we aimed to study monocyte heterogeneity in two different breast cancer tumors in mice using either 4T1 or EMT6 cells. 4T1 tumors exhibit an increased ability to metastasize in the lung in a BALB/c mouse breast cancer model compared to the less aggressive EMT6 tumor model. We evaluated 35 surface markers of tumor-infiltrated monocytes and dendritic cells in tumors isolated from each model using CyTOF mass cytometry. Analysis of monocytes and dendritic cells in the tumors using the Seurat package and the FlowSom algorithm identified 12 cell subsets. Significant differences were discovered between the two tumor types in frequencies of four of 12 identified subsets. However, only one of these subsets, a nonclassical monocyte subset, was higher in the less metastatic EMT6 tumors. This subset was 5-fold higher in EMT6 tumors versus more aggressive 4T1 tumors. This Ly6C lononclassical monocyte subset showed high expression of CD169 and CX3CR1, CD86 and CD80. These differentially expressed markers suggest a functional importance in this subset in migration to the tumor and antigen presentation, both of which are anti-tumoral functions. Ongoing studies are aimed towards understanding the role of this non-classical monocyte population in regulating breast cancer metastasis.\u0000 This work was supported by NIH R01 CA202987, and P01 HL136275","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75552720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding the structural and cellular composition of the tumor microenvironment in multiple human cancers using Imaging Mass Cytometry","authors":"T. Pfister, Liang Lim, S. Ouladan, Nick Zabinyakov, Qanber Raza, Christina Loh","doi":"10.4049/jimmunol.210.supp.249.02","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.249.02","url":null,"abstract":"\u0000 High-plex imaging techniques such as Imaging Mass Cytometry™ (IMC™) have become key tools in understanding and decoding the spatial complexity of the tumor microenvironment (TME). The TME contains tumor-infiltrating lymphocytes that have been associated with positive therapeutic outcomes. IMC enables detailed assessment of cell phenotype and function using 40-plus markers simultaneously at subcellular resolution on a single slide without spectral overlap or background autofluorescence.\u0000 We customized the Maxpar® Human Immuno-Oncology IMC Panel Kit using antibodies from the Standard BioTools™ catalog to create panels for tissue-based immuno-oncology research. Data acquisition was performed using a Hyperion™ Imaging System. Cell segmentation was facilitated using an IMC Cell Segmentation Kit. A pixel classification approach and CellProfiler™ were applied for single-cell segmentation. HistoCAT™ was used for single-cell analysis to visualize protein expression in various cancer types via PhenoGraph clustering and t-SNE maps.\u0000 Our custom panels were applied to normal and cancer human tissue microarrays to phenotype and analyze cell populations in these tissues. We classified the activation state of immune cells, epithelial-to-mesenchymal transition (EMT) progression, and composition of the extracellular matrix. In-depth single-cell analysis quantitatively evaluated the cellular makeup and immune cell component in the TME of cancer tissues. This work demonstrates the capability of IMC to identify subcellular localization of cellular and structural markers, including quantitative and spatial identification of multiple immune parameters in the TME, in tumor microarrays of cancer subject samples.","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"133 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75703191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innate and adaptive mechanisms induced by BCG immunotherapy in melanoma murine model","authors":"N. M. G. D. de Queiroz, Vinícius Martins Borges, Christiane Vieira Alves Caldeira, F. V. Marinho, S. Oliveira","doi":"10.4049/jimmunol.210.supp.245.12","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.245.12","url":null,"abstract":"\u0000 BCG (Bacillus Calmette-Guérin) vaccine has been proposed in clinical trials for the treatment of melanoma since 1970, however its mechanism of action still not fully understood. The purpose of this study was to investigate the immune mechanisms involved in the BCG immunotherapy against melanoma. We first characterized the immunological profile of the mouse melanoma B16–F10 cell line compared to BMDMs (bone marrow-derived macrophages) infected with BCG or stimulated with agonists for different innate immune pathways. B16–F10 were only capable to respond after poly I:C and dsDNA90 stimulus inducing CXCL10 and IFN-β, but no response against BCG infection. Moreover, we evaluated BCG intratumoral treatment in a B16–F10 subcutaneous mouse tumor model in C57BL/6 wild type (WT) and several knockout mice (MyD88 −/−, TLR3 −/−, TLR4 −/−, TLR7 −/−, TLR3/7/9 −/−, cGAS −/−, STING −/−, IFNAR −/−, Caspase 1 −/−, Caspase 11 −/−and IL-1R −/−). BCG dramatically reduces melanoma in all the mice strains, except for MyD88 −/−, suggesting a role played by this adaptor molecule related to the innate immune response. In order to investigate the adaptive immunity, we evaluate BCG treatment in IFNγ −/−and Rag −/−, which demonstrated the importance of lymphocytes for tumor regression. The experiments using B16–F10 infected with BCG and co-cultured with spleen cells or BMDMs from WT or MyD88 −/−mice demonstrated that MyD88 is essential for inflammatory cytokines production. MyD88 is also important to regulate the recruitment of immune cells in the tumor microenvironment. Our data suggests that BCG immunotherapy in melanoma depends on MyD88-related innate immune pathway and adaptive response for an efficient tumor control.\u0000 This study was funded by Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPQ (152478/2022-1) and Fundação de Amparo à Pesquisa do Estado de Minas Gerais - FAPEMIG (5.18/2022).","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74235228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"VEGFR1 blockade reduces Mycobacterium tuberculosis-induced pathology in immunocompromised mice","authors":"Melinda Herbath, Thanthrige Thiunuwan Priyathilaka, Z. Fabry, M. Sandor","doi":"10.4049/jimmunol.210.supp.80.02","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.80.02","url":null,"abstract":"\u0000 Mycobacterium tuberculosis (Mtb) is a major public health concern that caused 1.6 million deaths in 2021. New treatments are needed, especially in immunocompromised individuals, such as patients with HIV coinfection, who are severely impacted by the disease.\u0000 We have recently reported that blocking VEGFR1, a receptor that is present on monocytes and contributes to their recruitment to the sites of infection, limits Mtb-induced pathology in immunocompetent mice of both Mtb-resistant (C57BL/6J) and Mtb-supersusceptible (C3HeB/FeJ) strains (Harding et al., 2019). These results offer a way to reduce lung pathology without impeding host defense. Here, we extend this finding by showing that VEGFR1 blockade has similar effects in immunocompromised (RAG1KO) mice as well, measured by a reduction in the area of inflammation and without a change in bacterial burden. Following treatment with the VEGFR1 blocker SU5416, we have found an elevated ratio and an increase in the absolute number of neutrophil granulocytes in the Mtb-infected lungs in both immunosufficient and immunocompromised mice. Surprisingly however, this did not result in exacerbated pathology as the majority of the recruited neutrophils remained in the lung vasculature.\u0000 Our results indicate that further evaluation of VEGFR1 blockers as an adjunctive treatment to antitubercular drug therapy for immunocompromised populations could be worthwhile.\u0000 Supported by grants from NIH (R01 HL128778 and R01 NS123449)","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74255131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneous Specificities of Nickel Presentation to Nickel Specific CD4 T Cells","authors":"S. Dai, Yan Zhang, Lan Chen, Yang Wang, Wei Li","doi":"10.4049/jimmunol.210.supp.221.31","DOIUrl":"https://doi.org/10.4049/jimmunol.210.supp.221.31","url":null,"abstract":"Sensitization to nickel (Ni2+) is the most common T cell mediated type IV hypersensitivity, although the mechanisms by which Ni2+ alters antigen presentation are not understood. To study how the TCR then recognizes Ni2+ bound to the MHC molecule, we performed paired single cell RNA sequencing of PBMCs from two highly Ni2+ sensitized subjects to orthopedic implants and characterized three Ni2+ specific CD4+ T cell clones. One Ni2+ specific CD4+ T cell is highly restricted to HLA-DR7. But the other highly cross-reactive CD4+ T cell clones was restricted to multiple HLA alleles, including HLA-DR, HLA-DP, and HLA-DQ expressing antigen presenting cells. We identified a HLA-DQ8 restricted Ni2+ dependent mimotope reactive to the highly cross-reactive T cell clone. This mimotope appeared to present Ni2+ ions with the Glu at P2 position, involving βH81. The mutational studies of HLA-DP2 molecule showed that the same T cell recognized the Ni2+ ion bound to a completely different location in the P4-P7 pocket. Ni2+ ion was also can be presented efficiently by HLA-DR53 to the same T cells. mutational and structural study of HLA-DR53 molecules suggested that HLA-DR53 presented Ni2+ in the P4-P7 pocket. This is the first evidence showing that a metal ion can be presented by HLA using the different sites. The metal binding sites are HLA and peptide dependent. The heterogeneous specificities of Ni2+ specific TCRs are determined by different alleles of HLAs together with particular self-peptides.\u0000 Sensitization to nickel (Ni2+) is the most common T cell mediated type IV hypersensitivity, although the mechanisms by which Ni2+ alters antigen presentation are not understood. To study how the TCR then recognizes Ni2+ bound to the MHC molecule, we performed paired single cell RNA sequencing of PBMCs from two highly Ni2+ sensitized subjects to orthopedic implants and characterized three Ni2+ specific CD4+ T cell clones. One Ni2+ specific CD4+ T cell is highly restricted to HLA-DR7. But the other highly cross-reactive CD4+ T cell clones was restricted to multiple HLA alleles, including HLA-DR, HLA-DP, and HLA-DQ expressing antigen presenting cells. We identified a HLA-DQ8 restricted Ni2+ dependent mimotope reactive to the highly cross-reactive T cell clone. This mimotope appeared to present Ni2+ ions with the Glu at P2 position, involving βH81. The mutational studies of HLA-DP2 molecule showed that the same T cell recognized the Ni2+ ion bound to a completely different location in the P4-P7 pocket. Ni2+ ion was also can be presented efficiently by HLA-DR53 to the same T cells. mutational and structural study of HLA-DR53 molecules suggested that HLA-DR53 presented Ni2+ in the P4-P7 pocket. This is the first evidence showing that a metal ion can be presented by HLA using the different sites. The metal binding sites are HLA and peptide dependent. The heterogeneous specificities of Ni2+ specific TCRs are determined by different alleles of HLAs together with particular self-p","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78688791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}