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Atehortua L, Sean Davidson W, Chougnet CA. Interactions Between HDL and CD4+ T Cells: A Novel Understanding of HDL Anti-Inflammatory Properties. Arterioscler Thromb Vasc Biol 2024; 44:1191-1201. [PMID: 38660807 PMCID: PMC11111342 DOI: 10.1161/atvbaha.124.320851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Several studies in animal models and human cohorts have recently suggested that HDLs (high-density lipoproteins) not only modulate innate immune responses but also adaptative immune responses, particularly CD4+ T cells. CD4+ T cells are central effectors and regulators of the adaptive immune system, and any alterations in their homeostasis contribute to the pathogenesis of cardiovascular diseases, autoimmunity, and inflammatory diseases. In this review, we focus on how HDLs and their components affect CD4+ T-cell homeostasis by modulating cholesterol efflux, immune synapsis, proliferation, differentiation, oxidative stress, and apoptosis. While the effects of apoB-containing lipoproteins on T cells have been relatively well established, this review focuses specifically on new connections between HDL and CD4+ T cells. We present a model where HDL may modulate T cells through both direct and indirect mechanisms.
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Affiliation(s)
- Laura Atehortua
- Division of Immunobiology, Cincinnati Children’s Hospital Research Foundation, University of Cincinnati College of Medicine, Cincinnati, OH
| | - W. Sean Davidson
- Division of Experimental Pathology, Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH
| | - Claire A. Chougnet
- Division of Immunobiology, Cincinnati Children’s Hospital Research Foundation, University of Cincinnati College of Medicine, Cincinnati, OH
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2
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Lin CC, Geng JH, Wu PY, Huang JC, Hu HM, Chen SC, Kuo CH. Sex difference in the associations among risk factors with gastroesophageal reflux disease in a large Taiwanese population study. BMC Gastroenterol 2024; 24:165. [PMID: 38750425 PMCID: PMC11095001 DOI: 10.1186/s12876-024-03254-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/02/2024] [Indexed: 05/19/2024] Open
Abstract
BACKGROUND Gastroesophageal reflux disease (GERD) is a common global health issue. Previous studies have revealed a higher prevalence of GERD in females than in males, however few studies have investigated sex differences in the risk factors associated with GERD. Therefore, the aim of this population-based study was to examine sex differences in the risk factors for GERD in a large cohort of over 120,000 Taiwanese participants. METHODS We enrolled 121,583 participants (male: 43,698; female: 77,885; mean age 49.9 ± 11.0 years) from the Taiwan Biobank. The presence of GERD was ascertained using self-reported questionnaires. Sex differences in the risk factors associated with GERD were examined using multivariable logistic regression analysis. RESULTS The overall prevalence of GERD was 13.7%, including 13.0% in the male participants and 14.1% in the female participants (p < 0.001). Multivariable analysis showed that older age, hypertension, smoking history, alcohol history, low fasting glucose, and low uric acid were significantly associated with GERD in the male participants. In the female participants, older age, diabetes, hypertension, smoking history, alcohol history, low systolic blood pressure, low fasting glucose, high hemoglobin, high total cholesterol, low high-density lipoprotein cholesterol (HDL-C), low low-density lipoprotein cholesterol, and low uric acid were significantly associated with GERD. Significant interactions were found between sex and age (p < 0.001), diabetes (p < 0.001), smoking history (p < 0.001), fasting glucose (p = 0.002), triglycerides (p = 0.001), HDL-C (p = 0.001), and estimated glomerular filtration rate (p = 0.002) on GERD. CONCLUSIONS Our results showed a higher prevalence of GERD among females compared to males. Furthermore, sex differences were identified in the risk factors associated with GERD, and older age, diabetes, smoking history, and low HDL-C were more closely related to GERD in females than in males.
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Affiliation(s)
- Chien-Chieh Lin
- Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
- Department of Internal Medicine, Division of Gastroenterology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Jiun-Hung Geng
- Department of Urology, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 812, Taiwan
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Pei-Yu Wu
- Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, 482, Shan-Ming Rd., Siaogang Dist., Kaohsiung, 812, Taiwan R.O.C
- Department of Internal Medicine, Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan, Republic of China
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Jiun-Chi Huang
- Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, 482, Shan-Ming Rd., Siaogang Dist., Kaohsiung, 812, Taiwan R.O.C
- Department of Internal Medicine, Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan, Republic of China
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Huang-Ming Hu
- Department of Internal Medicine, Division of Gastroenterology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Szu-Chia Chen
- Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, 482, Shan-Ming Rd., Siaogang Dist., Kaohsiung, 812, Taiwan R.O.C..
- Department of Internal Medicine, Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan, Republic of China.
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan.
| | - Chao-Hung Kuo
- Department of Internal Medicine, Division of Gastroenterology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan.
- Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, 482, Shan-Ming Rd., Siaogang Dist., Kaohsiung, 812, Taiwan R.O.C..
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan.
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Platzer R, Hellmeier J, Göhring J, Perez ID, Schatzlmaier P, Bodner C, Focke‐Tejkl M, Schütz GJ, Sevcsik E, Stockinger H, Brameshuber M, Huppa JB. Monomeric agonist peptide/MHCII complexes activate T-cells in an autonomous fashion. EMBO Rep 2023; 24:e57842. [PMID: 37768718 PMCID: PMC10626418 DOI: 10.15252/embr.202357842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/04/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Molecular crowding of agonist peptide/MHC class II complexes (pMHCIIs) with structurally similar, yet per se non-stimulatory endogenous pMHCIIs is postulated to sensitize T-cells for the recognition of single antigens on the surface of dendritic cells and B-cells. When testing this premise with the use of advanced live cell microscopy, we observe pMHCIIs as monomeric, randomly distributed entities diffusing rapidly after entering the APC surface. Synaptic TCR engagement of highly abundant endogenous pMHCIIs is low or non-existent and affects neither TCR engagement of rare agonist pMHCII in early and advanced synapses nor agonist-induced TCR-proximal signaling. Our findings highlight the capacity of single freely diffusing agonist pMHCIIs to elicit the full T-cell response in an autonomous and peptide-specific fashion with consequences for adaptive immunity and immunotherapeutic approaches.
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Affiliation(s)
- René Platzer
- Center for Pathophysiology, Infectiology, Immunology, Institute for Hygiene and Applied ImmunologyMedical University of ViennaViennaAustria
| | - Joschka Hellmeier
- TU Wien, Institute of Applied PhysicsViennaAustria
- Present address:
Max Planck Institute of Biochemistry, Molecular Imaging and BionanotechnologyMartinsriedGermany
| | - Janett Göhring
- Center for Pathophysiology, Infectiology, Immunology, Institute for Hygiene and Applied ImmunologyMedical University of ViennaViennaAustria
| | - Iago Doel Perez
- Center for Pathophysiology, Infectiology, Immunology, Institute for Hygiene and Applied ImmunologyMedical University of ViennaViennaAustria
- Present address:
Takeda Manufacturing Austria AGViennaAustria
| | - Philipp Schatzlmaier
- Center for Pathophysiology, Infectiology, Immunology, Institute for Hygiene and Applied ImmunologyMedical University of ViennaViennaAustria
| | - Clara Bodner
- TU Wien, Institute of Applied PhysicsViennaAustria
| | - Margarete Focke‐Tejkl
- Center for Pathophysiology, Infectiology, Immunology, Institute for Pathophysiology and Allergy ResearchMedical University of ViennaViennaAustria
| | | | - Eva Sevcsik
- TU Wien, Institute of Applied PhysicsViennaAustria
| | - Hannes Stockinger
- Center for Pathophysiology, Infectiology, Immunology, Institute for Hygiene and Applied ImmunologyMedical University of ViennaViennaAustria
| | | | - Johannes B Huppa
- Center for Pathophysiology, Infectiology, Immunology, Institute for Hygiene and Applied ImmunologyMedical University of ViennaViennaAustria
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Abstract
Dendritic cells (DCs) are innate immune cells that detect and process environmental signals and communicate them with T cells to bridge innate and adaptive immunity. Immune signals and microenvironmental cues shape the function of DC subsets in different contexts, which is associated with reprogramming of cellular metabolic pathways. In addition to integrating these extracellular cues to meet bioenergetic and biosynthetic demands, cellular metabolism interplays with immune signaling to shape DC-dependent immune responses. Emerging evidence indicates that lipid metabolism serves as a key regulator of DC responses. Here, we summarize the roles of fatty acid and cholesterol metabolism, as well as selective metabolites, in orchestrating the functions of DCs. Specifically, we highlight how different lipid metabolic programs, including de novo fatty acid synthesis, fatty acid β oxidation, lipid storage, and cholesterol efflux, influence DC function in different contexts. Further, we discuss how dysregulation of lipid metabolism shapes DC intracellular signaling and contributes to the impaired DC function in the tumor microenvironment. Finally, we conclude with a discussion on key future directions for the regulation of DC biology by lipid metabolism. Insights into the connections between lipid metabolism and DC functional specialization may facilitate the development of new therapeutic strategies for human diseases.
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Affiliation(s)
- Zhiyuan You
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Hongbo Chi
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
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Yin J, Xu J, Chen C, Ma X, Zhu H, Xie L, Wang B, Shao Y, Zhao Y, Wei Y, Hu A, Zheng Z, Yu C, Fu J, Zheng L. HECT, UBA and WWE domain containing 1 represses cholesterol efflux during CD4 + T cell activation in Sjögren's syndrome. Front Pharmacol 2023; 14:1191692. [PMID: 37435494 PMCID: PMC10330700 DOI: 10.3389/fphar.2023.1191692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 06/05/2023] [Indexed: 07/13/2023] Open
Abstract
Introduction: Sjögren's syndrome (SS) is a chronic autoimmune disorder characterized by exocrine gland dysfunction, leading to loss of salivary function. Histological analysis of salivary glands from SS patients reveals a high infiltration of immune cells, particularly activated CD4+ T cells. Thus, interventions targeting abnormal activation of CD4+ T cells may provide promising therapeutic strategies for SS. Here, we demonstrate that Hect, uba, and wwe domain containing 1 (HUWE1), a member of the eukaryotic Hect E3 ubiquitin ligase family, plays a critical role in CD4+ T-cell activation and SS pathophysiology. Methods: In the context of HUWE1 inhibition, we investigated the impact of the HUWE1 inhibitor BI8626 and sh-Huwe1 on CD4+ T cells in mice, focusing on the assessment of activation levels, proliferation capacity, and cholesterol abundance. Furthermore, we examined the therapeutic potential of BI8626 in NOD/ShiLtj mice and evaluated its efficacy as a treatment strategy. Results: Inhibition of HUWE1 reduces ABCA1 ubiquitination and promotes cholesterol efflux, decreasing intracellular cholesterol and reducing the expression of phosphorylated ZAP-70, CD25, and other activation markers, culminating in the suppressed proliferation of CD4+ T cells. Moreover, pharmacological inhibition of HUWE1 significantly reduces CD4+ T-cell infiltration in the submandibular glands and improves salivary flow rate in NOD/ShiLtj mice. Conclusion: These findings suggest that HUWE1 may regulate CD4+ T-cell activation and SS development by modulating ABCA1-mediated cholesterol efflux and presents a promising target for SS treatment.
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Affiliation(s)
- Junhao Yin
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Jiabao Xu
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Changyu Chen
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Xinyi Ma
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Hanyi Zhu
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Lisong Xie
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Baoli Wang
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Yanxiong Shao
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Yijie Zhao
- Department of Oral and Maxillofacial Surgery, Shanghai Stomatological Hospital, Fudan University, Shanghai, China
| | - Yu Wei
- Department of Oral and Maxillofacial Surgery, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, School and Hospital of Stomatology, Tongji University, Shanghai, China
| | - Anni Hu
- Department of Oral and Maxillofacial Surgery, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, School and Hospital of Stomatology, Tongji University, Shanghai, China
| | - Zhanglong Zheng
- Department of Oral and Maxillofacial Surgery, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, School and Hospital of Stomatology, Tongji University, Shanghai, China
| | - Chuangqi Yu
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Jiayao Fu
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
| | - Lingyan Zheng
- Department of Oral Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology and National Clinical Research Center for Oral Disease, Shanghai, China
- Shanghai Key Laboratory of Stomatology, Shanghai, China
- Shanghai Institute of Stomatology, Shanghai, China
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Rosa JB, Nassman KY, Sagasti A. Sensory axons induce epithelial lipid microdomain remodeling and determine the distribution of junctions in the epidermis. Mol Biol Cell 2023; 34:ar5. [PMID: 36322392 PMCID: PMC9816649 DOI: 10.1091/mbc.e22-09-0396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/21/2022] [Accepted: 10/25/2022] [Indexed: 12/23/2022] Open
Abstract
Epithelial cell properties are determined by the polarized distribution of membrane lipids, the cytoskeleton, and adhesive junctions. Epithelia are often profusely innervated, but little work has addressed how neurites affect epithelial organization. We previously found that basal keratinocytes in the zebrafish epidermis enclose axons in ensheathment channels sealed by autotypic junctions. Here we characterized how axons remodel cell membranes, the cytoskeleton, and junctions in basal keratinocytes. At the apical surface of basal keratinocytes, axons organized lipid microdomains quantitatively enriched in reporters for PI(4,5)P2 and liquid-ordered (Lo) membranes. Lipid microdomains supported the formation of cadherin-enriched, F-actin protrusions, which wrapped around axons, likely initiating ensheathment. In the absence of axons, cadherin-enriched microdomains formed on basal cells but did not organize into contiguous domains. Instead, these isolated domains formed heterotypic junctions with periderm cells, a distinct epithelial cell type. Thus, axon endings dramatically remodel polarized epithelial components and regulate epidermal adhesion.
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Affiliation(s)
- Jeffrey B. Rosa
- Department of Molecular, Cell and Developmental Biology and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - Khaled Y. Nassman
- Department of Molecular, Cell and Developmental Biology and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - Alvaro Sagasti
- Department of Molecular, Cell and Developmental Biology and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095
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Zhao H, Yu Y, Wang Y, Zhao L, Yang A, Hu Y, Pan Z, Wang Z, Yang J, Han Q, Tian Z, Zhang J. Cholesterol accumulation on dendritic cells reverses chronic hepatitis B virus infection-induced dysfunction. Cell Mol Immunol 2022; 19:1347-1360. [PMID: 36369367 PMCID: PMC9708651 DOI: 10.1038/s41423-022-00939-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 09/11/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
Chronic hepatitis B (CHB) infection remains a serious public health problem worldwide; however, the relationship between cholesterol levels and CHB remains unclear. We isolated peripheral blood mononuclear cells from healthy blood donors and CHB patients to analyze free cholesterol levels, lipid raft formation, and cholesterol metabolism-related pathways. Hepatitis B virus (HBV)-carrier mice were generated and used to confirm changes in cholesterol metabolism and cell-surface lipid raft formation in dendritic cells (DCs) in the context of CHB. Additionally, HBV-carrier mice were immunized with a recombinant HBV vaccine (rHBVvac) combined with lipophilic statins and evaluated for vaccine efficacy against HBV. Serum samples were analyzed for HBsAg, anti-HBs, and alanine aminotransferase levels, and liver samples were evaluated for HBV DNA and RNA and HBcAg. CHB reduced free cholesterol levels and suppressed lipid raft formation on DCs in patients with CHB and HBV-carrier mice, whereas administration of lipophilic statins promoted free cholesterol accumulation and restored lipid rafts on DCs accompanied by an enhanced antigen-presentation ability in vitro and in vivo. Cholesterol accumulation on DCs improved the rHBVvac-mediated elimination of serum HBV DNA and intrahepatic HBV DNA, HBV RNA, and HBcAg and promoted the rHBVvac-mediated generation and polyfunctionality of HBV-specific CD11ahi CD8αlo cells, induction of the development of memory responses against HBV reinfection, and seroconversion from HBsAg to anti-HBs. The results demonstrated the important role of cholesterol levels in DC dysfunction during CHB, suggesting that strategies to increase cholesterol accumulation on DCs might enhance therapeutic vaccine efficacy against HBV and support development toward clinical CHB treatment.
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Affiliation(s)
- Huajun Zhao
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Yating Yu
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Yucan Wang
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Lianhui Zhao
- Department of Gastroenterology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China
| | - Ailu Yang
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Yifei Hu
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Zhaoyi Pan
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Zixuan Wang
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Jiarui Yang
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Qiuju Han
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China
| | - Zhigang Tian
- School of Life Sciences, University of Science and Technology of China, Hefei, 230000, China
| | - Jian Zhang
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China.
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Selvaraj MS, Paruchuri K, Haidermota S, Bernardo R, Rich SS, Peloso GM, Natarajan P. Genome-wide discovery for diabetes-dependent triglycerides-associated loci. PLoS One 2022; 17:e0275934. [PMID: 36269708 PMCID: PMC9586367 DOI: 10.1371/journal.pone.0275934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/26/2022] [Indexed: 11/29/2022] Open
Abstract
PURPOSE We aimed to discover loci associated with triglyceride (TG) levels in the context of type 2 diabetes (T2D). We conducted a genome-wide association study (GWAS) in 424,120 genotyped participants of the UK Biobank (UKB) with T2D status and TG levels. METHODS We stratified the cohort based on T2D status and conducted association analyses of TG levels for genetic variants with minor allele count (MAC) at least 20 in each stratum. Effect differences of genetic variants by T2D status were determined by Cochran's Q-test and we validated the significantly associated variants in the Mass General Brigham Biobank (MGBB). RESULTS Among 21,176 T2D and 402,944 non-T2D samples from UKB, stratified GWAS identified 19 and 315 genomic risk loci significantly associated with TG levels, respectively. Only chr6p21.32 exhibited genome-wide significant heterogeneity (I2 = 98.4%; pheterogeneity = 2.1x10-15), with log(TG) effect estimates of -0.066 (95%CI: -0.082, -0.050) and 0.002 (95%CI: -0.002, 0.006) for T2D and non-T2D, respectively. The lead variant rs9274619:A (allele frequency 0.095) is located 2Kb upstream of the HLA-DQB1 gene, between HLA-DQB1 and HLA-DQA2 genes. We replicated this finding among 25,137 participants (6,951 T2D cases) of MGBB (pheterogeneity = 9.5x10-3). Phenome-wide interaction association analyses showed that the lead variant was strongly associated with a concomitant diagnosis of type 1 diabetes (T1D) as well as diabetes-associated complications. CONCLUSION In conclusion, we identified an intergenic variant near HLA-DQB1/DQA2 significantly associates with decreased triglycerides only among those with T2D and highlights an immune overlap with T1D.
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Affiliation(s)
- Margaret Sunitha Selvaraj
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, United States of America
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, United States of America
- Department of Medicine, Harvard Medical School, Boston, MA, United States of America
| | - Kaavya Paruchuri
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, United States of America
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, United States of America
| | - Sara Haidermota
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, United States of America
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, United States of America
| | - Rachel Bernardo
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, United States of America
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, United States of America
| | - Stephen S. Rich
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, United States of America
| | - Gina M. Peloso
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, United States of America
- * E-mail: (PN); (GMP)
| | - Pradeep Natarajan
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, United States of America
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, United States of America
- Department of Medicine, Harvard Medical School, Boston, MA, United States of America
- * E-mail: (PN); (GMP)
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9
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Grao-Cruces E, Lopez-Enriquez S, Martin ME, Montserrat-de la Paz S. High-density lipoproteins and immune response: A review. Int J Biol Macromol 2022; 195:117-123. [PMID: 34896462 DOI: 10.1016/j.ijbiomac.2021.12.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 01/04/2023]
Abstract
High-density lipoproteins (HDLs) are heterogeneous lipoproteins that modify their composition and functionality depending on physiological or pathological conditions. The main roles of HDL are cholesterol efflux, and anti-inflammatory and antioxidant functions. These functions can be compromised under pathological conditions. HDLs play a role in the immune system as anti-inflammatory molecules but when inflammation occurs, HDLs change their composition and carry pro-inflammatory cargo. Hence, many molecular intermediates that influence inflammatory microenvironments and cell signaling pathways can modulate HDLs structural modification and function. This review provides a comprehensive assessment of the importance of HDL composition and anti-inflammatory function in the onset and progression of atherosclerotic cardiovascular diseases. On the other hand, immune cell activation during progression of atheroma plaque formation can be influenced by HDLs through HDL-derived cholesterol depletion from lipid rafts and through HDL interaction with HDL receptors expressed on T and B lymphocytes. Cholesterol efflux is mediated by HDL receptors located in lipid rafts in peripheral cells, which undergo membrane structural modifications, and interferes with subsequent molecules interactions or intracellular signaling cascades. Regarding antigen-presentation cells such as macrophages or dendritic cells, HDL function may then modulate lymphocytes activation in immune response. Our review also contributes to the understanding of the effects exerted by HDLs in signal transduction associated to our immune cell population during chronic diseases progression.
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Affiliation(s)
- Elena Grao-Cruces
- Department of Medical Biochemistry, Molecular Biology, and Immunology, School of Medicine, University of Seville, Av. Sanchez Pizjuan s/n, 41009 Seville, Spain
| | - Soledad Lopez-Enriquez
- Department of Medical Biochemistry, Molecular Biology, and Immunology, School of Medicine, University of Seville, Av. Sanchez Pizjuan s/n, 41009 Seville, Spain
| | - Maria E Martin
- Department of Cell Biology, Faculty of Biology, University of Seville, Av. Reina Mercedes s/n, 41012 Seville, Spain
| | - Sergio Montserrat-de la Paz
- Department of Medical Biochemistry, Molecular Biology, and Immunology, School of Medicine, University of Seville, Av. Sanchez Pizjuan s/n, 41009 Seville, Spain.
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10
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Wilson KR, Jenika D, Blum AB, Macri C, Xu B, Liu H, Schriek P, Schienstock D, Francis L, Makota FV, Ishido S, Mueller SN, Lahoud MH, Caminschi I, Edgington-Mitchell LE, Villadangos JA, Mintern JD. MHC Class II Ubiquitination Regulates Dendritic Cell Function and Immunity. THE JOURNAL OF IMMUNOLOGY 2021; 207:2255-2264. [PMID: 34599081 DOI: 10.4049/jimmunol.2001426] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 08/17/2021] [Indexed: 11/19/2022]
Abstract
MHC class II (MHC II) Ag presentation by dendritic cells (DCs) is critical for CD4+ T cell immunity. Cell surface levels of MHC II loaded with peptide is controlled by ubiquitination. In this study, we have examined how MHC II ubiquitination impacts immunity using MHC IIKRKI/KI mice expressing mutant MHC II molecules that are unable to be ubiquitinated. Numbers of conventional DC (cDC) 1, cDC2 and plasmacytoid DCs were significantly reduced in MHC IIKRKI/KI spleen, with the remaining MHC IIKRKI/KI DCs expressing an altered surface phenotype. Whereas Ag uptake, endosomal pH, and cathepsin protease activity were unaltered, MHC IIKRKI/KI cDC1 produced increased inflammatory cytokines and possessed defects in Ag proteolysis. Immunization of MHC IIKRKI/KI mice identified impairments in MHC II and MHC class I presentation of soluble, cell-associated and/or DC-targeted OVA via mAb specific for DC surface receptor Clec9A (anti-Clec9A-OVA mAb). Reduced T cell responses and impaired CTL killing was observed in MHC IIKRKI/KI mice following immunization with cell-associated and anti-Clec9A-OVA. Immunization of MHC IIKRKI/KI mice failed to elicit follicular Th cell responses and generated barely detectable Ab to anti-Clec9A mAb-targeted Ag. In summary, MHC II ubiquitination in DCs impacts the homeostasis, phenotype, cytokine production, and Ag proteolysis by DCs with consequences for Ag presentation and T cell and Ab-mediated immunity.
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Affiliation(s)
- Kayla R Wilson
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Devi Jenika
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Annabelle B Blum
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Christophe Macri
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Bangyan Xu
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Haiyin Liu
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Patrick Schriek
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Dominik Schienstock
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, Victoria, Australia
| | - Lauren Francis
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - F Victor Makota
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Satoshi Ishido
- Department of Microbiology, Hyogo College of Medicine, Nishinomiya, Japan
| | - Scott N Mueller
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, Victoria, Australia
| | - Mireille H Lahoud
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Irina Caminschi
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, Victoria, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Laura E Edgington-Mitchell
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia.,Department of Oral and Maxillofacial Surgery, New York University College of Dentistry, Bluestone Center for Clinical Research, New York, NY; and.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jose A Villadangos
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia; .,Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, Victoria, Australia
| | - Justine D Mintern
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia;
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11
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Höper T, Siewert K, Dumit VI, von Bergen M, Schubert K, Haase A. The Contact Allergen NiSO 4 Triggers a Distinct Molecular Response in Primary Human Dendritic Cells Compared to Bacterial LPS. Front Immunol 2021; 12:644700. [PMID: 33777040 PMCID: PMC7991087 DOI: 10.3389/fimmu.2021.644700] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/19/2021] [Indexed: 12/30/2022] Open
Abstract
Dendritic cells (DC) play a central role in the pathogenesis of allergic contact dermatitis (ACD), the most prevalent form of immunotoxicity in humans. However, knowledge on allergy-induced DC maturation is still limited and proteomic studies, allowing to unravel molecular effects of allergens, remain scarce. Therefore, we conducted a global proteomic analysis of human monocyte-derived dendritic cells (MoDC) treated with NiSO4, the most prominent cause of ACD and compared proteomic alterations induced by NiSO4 to the bacterial trigger lipopolysaccharide (LPS). Both substances possess a similar toll-like receptor (TLR) 4 binding capacity, allowing to identify allergy-specific effects compared to bacterial activation. MoDCs treated for 24 h with 2.5 μg/ml LPS displayed a robust immunological response, characterized by upregulation of DC activation markers, secretion of pro-inflammatory cytokines and stimulation of T cell proliferation. Similar immunological reactions were observed after treatment with 400 μM NiSO4 but less pronounced. Both substances triggered TLR4 and triggering receptor expressed on myeloid cells (TREM) 1 signaling. However, NiSO4 also activated hypoxic and apoptotic pathways, which might have overshadowed initial signaling. Moreover, our proteomic data support the importance of nuclear factor erythroid 2-related factor 2 (Nrf2) as a key player in sensitization since many Nrf2 targets genes were strongly upregulated on protein and gene level selectively after treatment with NiSO4. Strikingly, NiSO4 stimulation induced cellular cholesterol depletion which was counteracted by the induction of genes and proteins relevant for cholesterol biosynthesis. Our proteomic study allowed for the first time to better characterize some of the fundamental differences between NiSO4 and LPS-triggered activation of MoDCs, providing an essential contribution to the molecular understanding of contact allergy.
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Affiliation(s)
- Tessa Höper
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Katherina Siewert
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Verónica I. Dumit
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Martin von Bergen
- Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
- Institute of Biochemistry, Leipzig University, Leipzig, Germany
| | - Kristin Schubert
- Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Andrea Haase
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
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12
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Kim HJ, Bandola-Simon J, Ishido S, Wong NW, Koparde VN, Cam M, Roche PA. Ubiquitination of MHC Class II by March-I Regulates Dendritic Cell Fitness. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 206:494-504. [PMID: 33318291 PMCID: PMC9169697 DOI: 10.4049/jimmunol.2000975] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/16/2020] [Indexed: 11/19/2022]
Abstract
The expression and turnover of Ag-specific peptide-MHC class II (pMHC-II) on the surface of dendritic cells (DCs) is essential for their ability to efficiently activate CD4 T cells. Ubiquitination of pMHC-II by the E3 ubiquitin ligase March-I regulates surface expression and survival of pMHC-II in DCs. We now show that despite their high levels of surface pMHC-II, MHC class II (MHC-II) ubiquitination-deficient mouse DCs are functionally defective; they are poor stimulators of naive CD4 T cells and secrete IL-12 in response to LPS stimulation poorly. MHC-II ubiquitination-mutant DC defects are cell intrinsic, and single-cell RNA sequencing demonstrates that these DCs have an altered gene expression signature as compared with wild-type DCs. Curiously, these functional and gene transcription defects are reversed by activating the DCs with LPS. These results show that dysregulation of MHC-II turnover suppresses DC development and function.
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Affiliation(s)
- Hei Jung Kim
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Joanna Bandola-Simon
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Satoshi Ishido
- Department of Microbiology, Hyogo College of Medicine, Nishinomiya 663-8501, Japan
| | - Nathan W Wong
- Center for Cancer Research Collaborative Bioinformatics Resource, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; and
- Advanced Biomedical Computational Sciences, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Vishal N Koparde
- Center for Cancer Research Collaborative Bioinformatics Resource, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; and
- Advanced Biomedical Computational Sciences, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Maggie Cam
- Center for Cancer Research Collaborative Bioinformatics Resource, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Paul A Roche
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892;
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13
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Teng X, Brown J, Choi SC, Li W, Morel L. Metabolic determinants of lupus pathogenesis. Immunol Rev 2020; 295:167-186. [PMID: 32162304 DOI: 10.1111/imr.12847] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 12/12/2022]
Abstract
The metabolism of healthy murine and more recently human immune cells has been investigated with an increasing amount of details. These studies have revealed the challenges presented by immune cells to respond rapidly to a wide variety of triggers by adjusting the amount, type, and utilization of the nutrients they import. A concept has emerged that cellular metabolic programs regulate the size of the immune response and the plasticity of its effector functions. This has generated a lot of enthusiasm with the prediction that cellular metabolism could be manipulated to either enhance or limit an immune response. In support of this hypothesis, studies in animal models as well as human subjects have shown that the dysregulation of the immune system in autoimmune diseases is associated with a skewing of the immunometabolic programs. These studies have been mostly conducted on autoimmune CD4+ T cells, with the metabolism of other immune cells in autoimmune settings still being understudied. Here we discuss systemic metabolism as well as cellular immunometabolism as novel tools to decipher fundamental mechanisms of autoimmunity. We review the contribution of each major metabolic pathway to autoimmune diseases, with a focus on systemic lupus erythematosus (SLE), with the relevant translational opportunities, existing or predicted from results obtained with healthy immune cells. Finally, we review how targeting metabolic programs may present novel therapeutic venues.
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Affiliation(s)
- Xiangyu Teng
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Josephine Brown
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Seung-Chul Choi
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Wei Li
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Laurence Morel
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
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14
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Teng X, Li W, Cornaby C, Morel L. Immune cell metabolism in autoimmunity. Clin Exp Immunol 2019; 197:181-192. [PMID: 30770544 DOI: 10.1111/cei.13277] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2019] [Indexed: 12/13/2022] Open
Abstract
Immune metabolism is a rapidly moving field. While most of the research has been conducted to define the metabolism of healthy immune cells in the mouse, it is recognized that the overactive immune system that drives autoimmune diseases presents metabolic abnormalities that provide therapeutic opportunities, as well as a means to understand the fundamental mechanisms of autoimmune activation more clearly. Here, we review recent publications that have reported how the major metabolic pathways are affected in autoimmune diseases, with a focus on rheumatic diseases.
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Affiliation(s)
- X Teng
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - W Li
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - C Cornaby
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - L Morel
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
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15
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Pyrshev KA, Yesylevskyy SO, Demchenko AP. Double-exponential kinetics of binding and redistribution of the fluorescent dyes in cell membranes witness for the existence of lipid microdomains. Biochem Biophys Res Commun 2019; 508:1139-1144. [PMID: 30554653 DOI: 10.1016/j.bbrc.2018.12.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 12/06/2018] [Indexed: 11/26/2022]
Abstract
New technique of detecting lateral heterogeneity of the plasma membrane of living cells by means of membrane-binding fluorescent dyes is proposed. The kinetics of dye incorporation into the membrane or its lateral diffusion inside the membrane is measured and decomposed into exponential components by means of the Maximum Entropy Method. Two distinct exponential components are obtained consistently in all cases for several fluorescent dyes, two different cell lines and in different types of experiments including spectroscopy, flow cytometry and fluorescence recovery after photobleaching. These components are attributed to the liquid-ordered and disordered phases in the plasma membrane of studied cells in their dynamic equilibrium.
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Affiliation(s)
- Kyrylo A Pyrshev
- Laboratory of Nanobiotechnologies, O.V. Palladin Institute of Biochemistry of the NAS of Ukraine, Leontovicha Str. 9, Kyiv, 01030, Ukraine; Department of Physics of Biological Systems, Institute of Physics of the National Academy of Sciences of Ukraine, Nauky Ave. 46, Kyiv, 03028, Ukraine.
| | - Semen O Yesylevskyy
- Department of Physics of Biological Systems, Institute of Physics of the National Academy of Sciences of Ukraine, Nauky Ave. 46, Kyiv, 03028, Ukraine; Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France
| | - Alexander P Demchenko
- Laboratory of Nanobiotechnologies, O.V. Palladin Institute of Biochemistry of the NAS of Ukraine, Leontovicha Str. 9, Kyiv, 01030, Ukraine
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16
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Dixon AM, Roy S. Role of membrane environment and membrane-spanning protein regions in assembly and function of the Class II Major Histocompatibility complex. Hum Immunol 2019; 80:5-14. [PMID: 30102939 DOI: 10.1016/j.humimm.2018.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/19/2018] [Accepted: 07/09/2018] [Indexed: 10/28/2022]
Abstract
Class II Major Histocompatibility complex (MHC-II) is a polymorphic heterodimer that binds antigen-derived peptides and presents them on the surface of antigen presenting cells. This mechanism of antigen presentation leads to recognition by CD4 T-cells and T-cell activation, making it a critical element of adaptive immune response. For this reason, the structural determinants of MHC-II function have been of great interest for the past 30 years, resulting in a robust structural understanding of the extracellular regions of the complex. However, the membrane-localized regions have also been strongly implicated in protein-protein and protein-lipid interactions that facilitate Class II assembly, transport and function, and it is these regions that are the focus of this review. Here we describe studies that reveal the strong and selective interactions between the transmembrane domains of the MHC α, and invariant chains which, when altered, have broad reaching impacts on antigen presentation and Class II function. We also summarize work that clearly demonstrates the link between membrane lipid composition (particularly the presence of cholesterol) and MHC-II conformation, subsequent peptide binding, and downstream T-cell activation. We have integrated these studies into a comprehensive view of Class II transmembrane domain biology.
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Affiliation(s)
- Ann M Dixon
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
| | - Syamal Roy
- National Institute of Pharmaceutical Education and Research-Kolkata, 4 Raja SC, Mullick Road, Kolkata 700032, India
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17
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Myeloid apolipoprotein E controls dendritic cell antigen presentation and T cell activation. Nat Commun 2018; 9:3083. [PMID: 30082772 PMCID: PMC6079066 DOI: 10.1038/s41467-018-05322-1] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 06/24/2018] [Indexed: 01/06/2023] Open
Abstract
Cholesterol homeostasis has a pivotal function in regulating immune cells. Here we show that apolipoprotein E (apoE) deficiency leads to the accumulation of cholesterol in the cell membrane of dendritic cells (DC), resulting in enhanced MHC-II-dependent antigen presentation and CD4+ T-cell activation. Results from WT and apoE KO bone marrow chimera suggest that apoE from cells of hematopoietic origin has immunomodulatory functions, regardless of the onset of hypercholesterolemia. Humans expressing apoE4 isoform (ε4/3–ε4/4) have increased circulating levels of activated T cells compared to those expressing WT apoE3 (ε3/3) or apoE2 isoform (ε2/3–ε2/2). This increase is caused by enhanced antigen-presentation by apoE4-expressing DCs, and is reversed when these DCs are incubated with serum containing WT apoE3. In summary, our study identifies myeloid-produced apoE as a key physiological modulator of DC antigen presentation function, paving the way for further explorations of apoE as a tool to improve the management of immune diseases. Cholesterol homeostasis can modulate immunity via multiple pathways. Here the authors show that apolipoprotein E, an important regulator of cholesterol, produced by myeloid cells can regulate T cell activation by controlling the antigen presentation activity of dendritic cells in both humans and mice.
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18
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Oh J, Perry JSA, Pua H, Irgens-Möller N, Ishido S, Hsieh CS, Shin JS. MARCH1 protects the lipid raft and tetraspanin web from MHCII proteotoxicity in dendritic cells. J Cell Biol 2018; 217:1395-1410. [PMID: 29371232 PMCID: PMC5881489 DOI: 10.1083/jcb.201611141] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 10/25/2017] [Accepted: 01/08/2018] [Indexed: 12/12/2022] Open
Abstract
Dendritic cells (DCs) produce major histocompatibility complex II (MHCII) in large amounts to function as professional antigen presenting cells. Paradoxically, DCs also ubiquitinate and degrade MHCII in a constitutive manner. Mice deficient in the MHCII-ubiquitinating enzyme membrane-anchored RING-CH1, or the ubiquitin-acceptor lysine of MHCII, exhibit a substantial reduction in the number of regulatory T (Treg) cells, but the underlying mechanism was unclear. Here we report that ubiquitin-dependent MHCII turnover is critical to maintain homeostasis of lipid rafts and the tetraspanin web in DCs. Lack of MHCII ubiquitination results in the accumulation of excessive quantities of MHCII in the plasma membrane, and the resulting disruption to lipid rafts and the tetraspanin web leads to significant impairment in the ability of DCs to engage and activate thymocytes for Treg cell differentiation. Thus, ubiquitin-dependent MHCII turnover represents a novel quality-control mechanism by which DCs maintain homeostasis of membrane domains that support DC's Treg cell-selecting function.
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Affiliation(s)
- Jaehak Oh
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA.,Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA
| | - Justin S A Perry
- Department of Pathology, University of California, San Francisco, San Francisco, CA
| | - Heather Pua
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA.,Department of Pathology, University of California, San Francisco, San Francisco, CA
| | - Nicole Irgens-Möller
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA.,Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA
| | - Satoshi Ishido
- Department of Microbiology, Hyogo College of Medicine 1-1, Mukogawa-cho, Nishinomiya, Japan
| | - Chyi-Song Hsieh
- Department of Internal Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO
| | - Jeoung-Sook Shin
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA .,Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA
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19
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Afridi S, Hoessli DC, Hameed MW. Mechanistic understanding and significance of small peptides interaction with MHC class II molecules for therapeutic applications. Immunol Rev 2017; 272:151-68. [PMID: 27319349 DOI: 10.1111/imr.12435] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Major histocompatibility complex (MHC) class II molecules are expressed by antigen-presenting cells and stimulate CD4(+) T cells, which initiate humoral immune responses. Over the past decade, interest has developed to therapeutically impact the peptides to be exposed to CD4(+) T cells. Structurally diverse small molecules have been discovered that act on the endogenous peptide exchanger HLA-DM by different mechanisms. Exogenously delivered peptides are highly susceptible to proteolytic cleavage in vivo; however, it is only when successfully incorporated into stable MHC II-peptide complexes that these peptides can induce an immune response. Many of the small molecules so far discovered have highlighted the molecular interactions mediating the formation of MHC II-peptide complexes. As potential drugs, these small molecules open new therapeutic approaches to modulate MHC II antigen presentation pathways and influence the quality and specificity of immune responses. This review briefly introduces how CD4(+) T cells recognize antigen when displayed by MHC class II molecules, as well as MHC class II-peptide-loading pathways, structural basis of peptide binding and stabilization of the peptide-MHC complexes. We discuss the concept of MHC-loading enhancers, how they could modulate immune responses and how these molecules have been identified. Finally, we suggest mechanisms whereby MHC-loading enhancers could act upon MHC class II molecules.
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Affiliation(s)
- Saifullah Afridi
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Daniel C Hoessli
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Muhammad Waqar Hameed
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
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20
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Regulation of Adaptive Immunity in Health and Disease by Cholesterol Metabolism. Curr Allergy Asthma Rep 2015; 15:48. [PMID: 26149587 DOI: 10.1007/s11882-015-0548-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Four decades ago, it was observed that stimulation of T cells induces rapid changes in cellular cholesterol that are required before proliferation can commence. Investigators returning to this phenomenon have finally revealed its molecular underpinnings. Cholesterol trafficking and its dysregulation are now also recognized to strongly influence dendritic cell function, T cell polarization, and antibody responses. In this review, the state of the literature is reviewed on how cholesterol and its trafficking regulate the cells of the adaptive immune response and in vivo disease phenotypes of dysregulated adaptive immunity, including allergy, asthma, and autoimmune disease. Emerging evidence supporting a potential role for statins and other lipid-targeted therapies in the treatment of these diseases is presented. Just as vascular biologists have embraced immunity in the pathogenesis and treatment of atherosclerosis, so should basic and clinical immunologists in allergy, pulmonology, and other disciplines seek to encompass a basic understanding of lipid science.
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21
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Nassef Kadry Naguib Roufaiel M, Wells JW, Steptoe RJ. Impaired T-Cell Function in B-Cell Lymphoma: A Direct Consequence of Events at the Immunological Synapse? Front Immunol 2015; 6:258. [PMID: 26082776 PMCID: PMC4451642 DOI: 10.3389/fimmu.2015.00258] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/11/2015] [Indexed: 12/21/2022] Open
Abstract
Tumors can escape immune destruction through the development of antigen loss variants and loss of antigen processing/presentation pathways, thereby rendering them invisible to T cells. Alternatively, mechanisms of peripheral T-cell tolerance that would normally be important for protection from the development of autoimmunity may also be co-opted to (i) generate an immuno-inhibitory tumor environment, (ii) promote development of regulatory cell populations, or (iii) cell-intrinsically inactivate tumor-specific T cells. Emerging evidence suggests that T-cell function is impaired in hematological malignancies, which may manifest from cognate interactions between T cells and the tumor. The immunological synapse forms the cognate T-cell and antigen-presenting cell interaction and is the site where key signalling events, including those delivered by co-inhibitory receptors, that determine the fate of T cells occur. Here, we review evidence that events at the immune synapse between T cells and malignant B cells and alterations in immune synapse function may contribute to loss of T-cell function in B-cell malignancies.
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Affiliation(s)
- Marian Nassef Kadry Naguib Roufaiel
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute , Brisbane, QLD , Australia
| | - James W Wells
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute , Brisbane, QLD , Australia
| | - Raymond J Steptoe
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute , Brisbane, QLD , Australia
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22
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Schieffer D, Naware S, Bakun W, Bamezai AK. Lipid raft-based membrane order is important for antigen-specific clonal expansion of CD4(+) T lymphocytes. BMC Immunol 2014; 15:58. [PMID: 25494999 PMCID: PMC4270042 DOI: 10.1186/s12865-014-0058-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 11/24/2014] [Indexed: 11/24/2022] Open
Abstract
Background Lipid rafts are cholesterol and saturated lipid-rich, nanometer sized membrane domains that are hypothesized to play an important role in compartmentalization and spatiotemporal regulation of cellular signaling. Lipid rafts contribute to the plasma membrane order and to its spatial asymmetry, as well. The raft nanodomains on the surface of CD4+ T lymphocytes coalesce during their interaction with antigen presenting cells (APCs). Sensing of foreign antigen by the antigen receptor on CD4+ T cells occurs during these cell-cell interactions. In response to foreign antigen the CD4+ T cells proliferate, allowing the expansion of few antigen-specific primary CD4+ T cell clones. Proliferating CD4+ T cells specialize in their function by undergoing differentiation into appropriate effectors tailored to mount an effective adaptive immune response against the invading pathogen. Results To investigate the role of lipid raft-based membrane order in the clonal expansion phase of primary CD4+ T cells, we have disrupted membrane order by incorporating an oxysterol, 7-ketocholesterol (7-KC), into the plasma membrane of primary CD4+ T cells expressing a T cell receptor specific to chicken ovalbumin323–339 peptide sequence and tested their antigen-specific response. We report that 7-KC, at concentrations that disrupt lipid rafts, significantly diminish the c-Ovalbumin323–339 peptide-specific clonal expansion of primary CD4+ T cells. Conclusions Our findings suggest that lipid raft-based membrane order is important for clonal expansion of CD4+ T cells in response to a model peptide. Electronic supplementary material The online version of this article (doi:10.1186/s12865-014-0058-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniel Schieffer
- Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA. .,Current Address: DeNovix Inc, Wilmington, DE, 19808, USA.
| | - Sanya Naware
- Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA. .,Current Address: M.D. Program, Drexel University, 3141 Chestnut Street, Philadelphia, PA, 19104, USA.
| | - Walter Bakun
- Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA.
| | - Anil K Bamezai
- Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA.
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Anderson HA, Roche PA. MHC class II association with lipid rafts on the antigen presenting cell surface. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:775-80. [PMID: 25261705 DOI: 10.1016/j.bbamcr.2014.09.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/16/2014] [Accepted: 09/17/2014] [Indexed: 12/29/2022]
Abstract
MHC class II (MHC-II) molecules function by binding peptides derived from either self or foreign proteins and expressing these peptides on the surface of antigen presenting cells (APCs) for recognition by CD4 T cells. MHC-II is known to exist on clusters on the surface of APCs, and a variety of biochemical and functional studies have suggested that these clusters represent lipid raft microdomain-associated MHC-II. This review will summarize data exploring the biosynthesis of raft-associated MHC-II and the role that lipid raft association plays in regulating T cell activation by APCs. This article is part of a Special Issue entitled: Nanoscale membrane organisation and signalling.
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Affiliation(s)
- Howard A Anderson
- Division of Therapeutic Proteins, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Paul A Roche
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Dixon AM, Drake L, Hughes KT, Sargent E, Hunt D, Harton JA, Drake JR. Differential transmembrane domain GXXXG motif pairing impacts major histocompatibility complex (MHC) class II structure. J Biol Chem 2014; 289:11695-11703. [PMID: 24619409 DOI: 10.1074/jbc.m113.516997] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Major histocompatibility complex (MHC) class II molecules exhibit conformational heterogeneity, which influences their ability to stimulate CD4 T cells and drive immune responses. Previous studies suggest a role for the transmembrane domain of the class II αβ heterodimer in determining molecular structure and function. Our previous studies identified an MHC class II conformer that is marked by the Ia.2 epitope. These Ia.2(+) class II conformers are lipid raft-associated and able to drive both tyrosine kinase signaling and efficient antigen presentation to CD4 T cells. Here, we establish that the Ia.2(+) I-A(k) conformer is formed early in the class II biosynthetic pathway and that differential pairing of highly conserved transmembrane domain GXXXG dimerization motifs is responsible for formation of Ia.2(+) versus Ia.2(-) I-A(k) class II conformers and controlling lipid raft partitioning. These findings provide a molecular explanation for the formation of two distinct MHC class II conformers that differ in their inherent ability to signal and drive robust T cell activation, providing new insight into the role of MHC class II in regulating antigen-presenting cell-T cell interactions critical to the initiation and control of multiple aspects of the immune response.
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Affiliation(s)
- Ann M Dixon
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Lisa Drake
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208
| | - Kelly T Hughes
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208
| | - Elizabeth Sargent
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208
| | - Danielle Hunt
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208
| | - Jonathan A Harton
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208
| | - James R Drake
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208.
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CD1d favors MHC neighborhood, GM1 ganglioside proximity and low detergent sensitive membrane regions on the surface of B lymphocytes. Biochim Biophys Acta Gen Subj 2014. [DOI: 10.1016/j.bbagen.2013.10.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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26
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Ferez M, Castro M, Alarcon B, van Santen HM. Cognate peptide-MHC complexes are expressed as tightly apposed nanoclusters in virus-infected cells to allow TCR crosslinking. THE JOURNAL OF IMMUNOLOGY 2013; 192:52-8. [PMID: 24307729 DOI: 10.4049/jimmunol.1301224] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Antigenic T cell stimulation requires interaction between the TCR of the T cell and cognate peptide-MHC molecules presented by the APC. Although studies with TCR-specific Abs and soluble peptide-MHC ligands have shown that the TCR needs to be crosslinked by two or more ligands to induce T cell stimulation, it is not understood how several MHC molecules loaded with the cognate antigenic peptide can produce crosslinking under physiological conditions. We show at the molecular level that large clusters of cognate peptide-MHC are formed at the surface of murine professional and nonprofessional APCs upon virus infection and that these clusters impinge on the stimulatory capacity of the APC. These clusters are formed by tight apposition of cognate peptide-MHC complexes in a configuration that is compatible with simultaneous engagement of two or more TCRs. This suggests that physiological expression of Ag allows formation of multivalent ligands for the TCR that permit TCR crosslinking and T cell activation.
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Affiliation(s)
- María Ferez
- Departamento de Biología Celular e Inmunología, Centro Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas/Universidad Autónoma de Madrid, 28049 Cantoblanco, Spain
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27
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Bosch B, Heipertz EL, Drake JR, Roche PA. Major histocompatibility complex (MHC) class II-peptide complexes arrive at the plasma membrane in cholesterol-rich microclusters. J Biol Chem 2013; 288:13236-42. [PMID: 23532855 DOI: 10.1074/jbc.m112.442640] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Antigen-specific CD4 T cells are activated by small numbers of antigenic peptide-MHC class II (pMHC-II) complexes on dendritic cells (DCs). RESULTS Newly generated pMHC-II complexes are present in small clusters on the DC surface. CONCLUSION pMHC-II clusters permit efficient T cell activation. SIGNIFICANCE The appearance of clustered pMHC-II reveals the organization of the T cell antigen receptor ligand on the DC surface. Dendritic cells (DCs) function by stimulating naive antigen-specific CD4 T cells to proliferate and secrete a variety of immunomodulatory factors. The ability to activate naive T cells comes from the capacity of DCs to internalize, degrade, and express peptide fragments of antigenic proteins on their surface bound to MHC class II molecules (MHC-II). Although DCs express tens of thousands of distinct MHC-II, very small amounts of specific peptide-MHC-II complexes are required to interact with and activate T cells. We now show that stimulatory MHC-II I-A(k)-HEL(46-61) complexes that move from intracellular antigen-processing compartments to the plasma membrane are not randomly distributed on the DC surface. Confocal immunofluorescence microscopy and quantitative immunoelectron microscopy reveal that the majority of newly generated MHC-II I-A(k)-HEL(46-61) complexes are expressed in sub-100-nm microclusters on the DC membrane. These microclusters are stabilized in cholesterol-containing microdomains, and cholesterol depletion inhibits the stability of these clusters as well as the ability of the DCs to function as antigen-presenting cells. These results demonstrate that specific cohorts of peptide-MHC-II complexes expressed on the DC surface are present in cholesterol-dependent microclusters and that cluster integrity is important for antigen-specific naive CD4 T cell activation by DCs.
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Affiliation(s)
- Berta Bosch
- Experimental Immunology Branch, NCI, National Institutes of Health, Bethesda, MD 20892, USA
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28
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High-density lipoproteins and the immune system. J Lipids 2013; 2013:684903. [PMID: 23431458 PMCID: PMC3572698 DOI: 10.1155/2013/684903] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 12/28/2012] [Accepted: 12/31/2012] [Indexed: 12/16/2022] Open
Abstract
High-density lipoprotein (HDL) plays a major role in vasodilation and in the reduction of low-density lipoprotein (LDL) oxidation, inflammation, apoptosis, thrombosis, and infection; however, HDL is now less functional in these roles under certain conditions. This paper focuses on HDL, its anti-inflammation behavior, and the mechanisms by which HDL interacts with components of the innate and adaptive immune systems. Genome-wide association studies (GWAS) and proteomic studies have elucidated important molecules involved in the interaction between HDL and the immune system. An understanding of these mechanisms is expected to be useful for the prevention and treatment of chronic inflammation due to metabolic syndrome, atherosclerosis, or various autoimmune diseases.
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29
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High density lipoproteins and atherosclerosis: emerging aspects. J Geriatr Cardiol 2013; 9:401-7. [PMID: 23341845 PMCID: PMC3545258 DOI: 10.3724/sp.j.1263.2011.12282] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 06/04/2012] [Accepted: 10/22/2012] [Indexed: 12/27/2022] Open
Abstract
High density lipoproteins (HDL) promote the efflux of excess cholesterol from peripheral tissues to the liver for excretion. This ability is responsible for the most relevant anti-atherogenic effect of HDL. The ability of HDL to promote cholesterol efflux results also in the modulation of a series of responses in the immune cells involved in atherosclerosis, including monocyte-macrophages, B and T lymphocytes. Furthermore, during inflammation, the composition of this class of lipoproteins varies to a large extent, thus promoting the formation of dysfunctional HDL. The aim of this review is to discuss the emerging role of HDL in modulating the activity of immune cells and immune-inflammatory mediators during atherogenesis.
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30
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Abstract
Using an elaborately evolved language of cytokines and chemokines as well as cell-cell interactions, the different components of the immune system communicate with each other and orchestrate a response (or wind one down). Immunological synapses are a key feature of the system in the ways in which they can facilitate and direct these responses. Studies analyzing the structure of an immune synapse as it forms between two cells have provided insight into how the stability and kinetics of this interaction ultimately affect the sensitivity, potency, and magnitude of a given response. Furthermore, we have gained an appreciation of how the immunological synapse provides directionality and contextual cues for downstream signaling and cellular decision-making. In this review, we discuss how using a variety of techniques, developed over the last decade, have allowed us to visualize and quantify key aspects of the dynamic synaptic interface and have furthered our understanding of their function. We describe some of the many characteristics of the immunological synapse that make it a vital part of intercellular communication and some of the questions that remain to be answered.
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Affiliation(s)
- Jianming Xie
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Cristina M. Tato
- Institute for Immunity, Transplantation and Infection, Stanford University School of Medicine, Stanford, CA, USA
| | - Mark M. Davis
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
- Institute for Immunity, Transplantation and Infection, Stanford University School of Medicine, Stanford, CA, USA
- The Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
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31
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Encounter with antigen-specific primed CD4 T cells promotes MHC class II degradation in dendritic cells. Proc Natl Acad Sci U S A 2012; 109:19380-5. [PMID: 23129633 DOI: 10.1073/pnas.1213868109] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Major histocompatibility complex class II molecules (MHC-II) on antigen presenting cells (APCs) engage the TCR on antigen-specific CD4 T cells, thereby providing the specificity required for T cell priming and the induction of an effective immune response. In this study, we have asked whether antigen-loaded dendritic cells (DCs) that have been in contact with antigen-specific CD4 T cells retain the ability to stimulate additional naïve T cells. We show that encounter with antigen-specific primed CD4 T cells induces the degradation of surface MHC-II in antigen-loaded DCs and inhibits the ability of these DCs to stimulate additional naïve CD4 T cells. Cross-linking with MHC-II mAb as a surrogate for T-cell engagement also inhibits APC function and induces MHC-II degradation by promoting the clustering of MHC-II present in lipid raft membrane microdomains, a process that leads to MHC-II endocytosis and degradation in lysosomes. Encounter of DCs with antigen-specific primed T cells or engagement of MHC-II with antibodies promotes the degradation of both immunologically relevant and irrelevant MHC-II molecules. These data demonstrate that engagement of MHC-II on DCs after encounter with antigen-specific primed CD4 T cells promotes the down-regulation of cell surface MHC-II in DCs, thereby attenuating additional activation of naïve CD4 T cells by these APCs.
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32
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Chen F, Meng F, Pan L, Xu F, Liu X, Yu W. Boosting immune response with the invariant chain segments via association with non-peptide binding region of major histocompatibility complex class II molecules. BMC Immunol 2012; 13:55. [PMID: 23016601 PMCID: PMC3517428 DOI: 10.1186/1471-2172-13-55] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 09/17/2012] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Based on binding of invariant chain (Ii) to major histocompatibility complex (MHC) class II molecules to form complexes, Ii-segment hybrids, Ii-key structure linking an epitope, or Ii class II-associated invariant chain peptide (CLIP) replaced with an epitope were used to increase immune response. It is currently unknown whether the Ii-segment cytosolic and transmembrane domains bind to the MHC non-peptide binding region (PBR) and consequently influence immune response. To investigate the potential role of Ii-segments in the immune response via MHC II/peptide complexes, a few hybrids containing Ii-segments and a multiepitope (F306) from Newcastle disease virus fusion protein (F) were constructed, and their binding effects on MHC II molecules and specific antibody production were compared using confocal microscopy, immunoprecipitation, western blotting and animal experiments. RESULTS One of the Ii-segment/F306 hybrids, containing ND (Asn-Asp) outside the F306 in the Ii-key structure (Ii-key/F306/ND), neither co-localized with MHC II molecules on plasma membrane nor bound to MHC II molecules to form complexes. However, stimulation of mice with the structure produced 4-fold higher antibody titers compared with F306 alone. The two other Ii-segment/F306 hybrids, in which the transmembrane and cytosolic domains of Ii were linked to this structure (Cyt/TM/Ii-key/F306/ND), partially co-localized on plasma membrane with MHC class II molecules and weakly bound MHC II molecules to form complexes. They induced mice to produce approximately 9-fold higher antibody titers compared with F306 alone. Furthermore, an Ii/F306 hybrid (F306 substituting CLIP) co-localized well with MHC II molecules on the membrane to form complexes, although it increased antibody titer about 3-fold relative to F306 alone. CONCLUSIONS These results suggest that Ii-segments improve specific immune response by binding to the non-PBR on MHC class II molecules and enabling membrane co-localization with MHC II molecules, resulting in the formation of relatively stable MHC II/peptide complexes on the plasma membrane, and signal transduction.
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Affiliation(s)
- Fangfang Chen
- Key Laboratory of Zoonoses of Anhui Province, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
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RAFTsomes containing epitope-MHC-II complexes mediated CD4+ T cell activation and antigen-specific immune responses. Pharm Res 2012; 30:60-9. [PMID: 22878683 DOI: 10.1007/s11095-012-0849-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 07/31/2012] [Indexed: 12/13/2022]
Abstract
PURPOSE To develop a liposome formulation incorporating antigen-presenting cells (APCs) membrane microdomains with enriched epitope/MHC complexes to evaluate the activities of these liposomes (RAFTsomes) to activate T cells and prime immune responses. METHODS We isolated membrane microdomain structures that contained the epitope/MHC complexes from ovalbumin (OVA) primed dendritic cells (DCs), and reconstituted them on liposomes surface by detergent dialysis. The resulted RAFTsomes were purified by density gradient centrifugation. Their T cell activation functions were evaluated by IL-2 secreting and proliferation assays in vitro. In vivo immune responses and the protective effect against OVA expressing EG.7 tumor challenge were also examined. RESULTS Membrane microdomains containing enriched epitope/MHC complexes can be reconstituted into liposomes with defined size and composition. The integrity and activities of these complexes after reconstitution were confirmed by in vitro T cell assays. OVA epitope loaded RAFTsomes injected in vivo resulted in high anti-OVA IgG production (predominantly IgG1). The immunized mice were protected from EG.7 tumor cell inoculation challenge. CONCLUSIONS Based on these findings, we propose that RAFTsomes can be prepared with unique properties that may be used as an antigen delivery system for immunotherapeutic applications.
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Jönsson F, Gurniak CB, Fleischer B, Kirfel G, Witke W. Immunological responses and actin dynamics in macrophages are controlled by N-cofilin but are independent from ADF. PLoS One 2012; 7:e36034. [PMID: 22558315 PMCID: PMC3338623 DOI: 10.1371/journal.pone.0036034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 03/28/2012] [Indexed: 11/19/2022] Open
Abstract
Dynamic changes in the actin cytoskeleton are essential for immune cell function and a number of immune deficiencies have been linked to mutations, which disturb the actin cytoskeleton. In macrophages and dendritic cells, actin remodelling is critical for motility, phagocytosis and antigen presentation, however the actin binding proteins, which control antigen presentation have been poorly characterized. Here we dissect the specific roles of the family of ADF/cofilin F-actin depolymerizing factors in macrophages and in local immune responses. Macrophage migration, cell polarization and antigen presentation to T-cells require n-cofilin mediated F-actin remodelling. Using a conditional mouse model, we show that n-cofilin also controls MHC class II-dependent antigen presentation. Other cellular processes such as phagocytosis and antigen processing were found to be independent of n-cofilin. Our data identify n-cofilin as a novel regulator of antigen presentation, while ADF on the other hand is dispensable for macrophage motility and antigen presentation.
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Affiliation(s)
- Friederike Jönsson
- Department of Immunology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
- Département d'Immunologie, Unité d'Allergologie Moléculaire et Cellulaire, Institut Pasteur, Inserm U.760, Paris, France
| | - Christine B. Gurniak
- Institute of Genetics, Cell Motility Unit, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Bernhard Fleischer
- Department of Immunology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Gregor Kirfel
- Institute for Cell Biology, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Walter Witke
- Institute of Genetics, Cell Motility Unit, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
- * E-mail:
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35
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Epstein-Barr virus latent membrane protein 2A exacerbates experimental autoimmune encephalomyelitis and enhances antigen presentation function. Sci Rep 2012; 2:353. [PMID: 22616025 PMCID: PMC3354779 DOI: 10.1038/srep00353] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Accepted: 03/13/2012] [Indexed: 11/30/2022] Open
Abstract
Multiple sclerosis (MS) is an inflammatory, autoimmune disease of the central nervous system. The cause of MS is still unknown but epidemiological and immunological studies have implicated Epstein-Barr virus (EBV), which infects B cells, as a possible etiological agent involved in disease. Of particular interest is EBV latent membrane protein 2A (LMP2A) because previous studies have demonstrated that LMP2A enhances the expansion and differentiation of B cells upon antigen stimulation, revealing a potential contribution of this protein in autoimmunity. Since B cells are thought to contribute to MS, we examined the role of LMP2A in the animal model experimental autoimmune encephalomyelitis (EAE). In this model, transgenic mice in which B cells express LMP2A show increased severity and incidence of disease. This difference was not due to lymphocyte recruitment into the CNS or differences in T cell activation, rather, we show that LMP2A enhances antigen presentation function.
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36
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The AC8 IgG3 monoclonal anti-cholesterol antibody modulates uptake and presentation of antigens for T cell activation. Immunol Lett 2012; 143:106-15. [DOI: 10.1016/j.imlet.2012.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 01/13/2012] [Accepted: 01/16/2012] [Indexed: 01/07/2023]
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Analysis of detergent-free lipid rafts isolated from CD4+ T cell line: interaction with antigen presenting cells promotes coalescing of lipid rafts. Cell Commun Signal 2011; 9:31. [PMID: 22151974 PMCID: PMC3283486 DOI: 10.1186/1478-811x-9-31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 12/08/2011] [Indexed: 11/19/2022] Open
Abstract
Background Lipid rafts present on the plasma membrane play an important role in spatiotemporal regulation of cell signaling. Physical and chemical characterization of lipid raft size and assessment of their composition before, and after cell stimulation will aid in developing a clear understanding of their regulatory role in cell signaling. We have used visual and biochemical methods and approaches for examining individual and lipid raft sub-populations isolated from a mouse CD4+ T cell line in the absence of detergents. Results Detergent-free rafts were analyzed before and after their interaction with antigen presenting cells. We provide evidence that the average diameter of lipid rafts isolated from un-stimulated T cells, in the absence of detergents, is less than 100 nm. Lipid rafts on CD4+ T cell membranes coalesce to form larger structures, after interacting with antigen presenting cells even in the absence of a foreign antigen. Conclusions Findings presented here indicate that lipid raft coalescence occurs during cellular interactions prior to sensing a foreign antigen.
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Abstract
PURPOSE OF REVIEW HDLs possess several physiological activities that may explain their antiatherosclerotic properties. Among them, the most relevant is the ability of HDL to promote the efflux of excess cholesterol from peripheral tissues to the liver for excretion. RECENT FINDINGS The ability of HDL to promote cholesterol efflux results also in the modulation of a series of responses in the immune cells involved in atherosclerosis, including monocyte-macrophages, B and T lymphocytes. HDL also acts as a reservoir for a number of biologically active substances that may impact the immune system, and as the HDL composition varies to a large extent during inflammation. SUMMARY The understanding of how these interactions take place and how biologically active substances can be delivered to relevant targets during atherogenesis is of great interest and may provide a better understanding for the role of HDL in atherogenesis.
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Affiliation(s)
- Giuseppe D Norata
- Department of Pharmacological Sciences, Università degli Studi di Milano, Centro SISA per lo Studio dell'Aterosclerosi, Ospedale Bassini, Cinisello Balsamo, Milan, Italy
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Duchez S, Rodrigues M, Bertrand F, Valitutti S. Reciprocal Polarization of T and B Cells at the Immunological Synapse. THE JOURNAL OF IMMUNOLOGY 2011; 187:4571-80. [DOI: 10.4049/jimmunol.1100600] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Emerging role of high density lipoproteins as a player in the immune system. Atherosclerosis 2011; 220:11-21. [PMID: 21783193 DOI: 10.1016/j.atherosclerosis.2011.06.045] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 06/08/2011] [Accepted: 06/24/2011] [Indexed: 11/23/2022]
Abstract
High density lipoproteins (HDL) possess a number of physiological activities. The most studied and, perhaps, better understood is the ability of HDL to promote excess cholesterol efflux from peripheral tissues and transport to the liver for excretion, a mechanism believed to confer protection against atherosclerotic cardiovascular disease. The ability of HDL to modulate cholesterol bioavailability in the lipid rafts, membrane microdomains enriched in glycosphingolipids and cholesterol, is evolutionary conserved and affects the properties of cells involved in the innate and adaptive immune response, tuning inflammatory response and antigen presentation functions in macrophages as well as B and T cell activation. Also sphingosine-1 phosphate (S1P), a major active sphingolipid carried by HDL, is of relevance in the pathogenesis of several immuno-inflammatory disorders through the modulation of macrophage and lymphocyte functions. Furthermore, HDL influence the humoral innate immunity by modulating the activation of the complement system and the expression of pentraxin 3 (PTX3). Finally, in humans, HDL levels and functions are altered in several immune-mediated disorders, such as rheumatoid arthritis, systemic lupus eritematosus, Crohn's disease and multiple sclerosis as well as during inflammatory responses. Altogether these observations suggest that the effects of HDL in immunity could be related, to either the ability of HDL to modulate cholesterol content in immune cell lipid rafts and to their role as reservoir for several biologically active substances that may impact the immune system.
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41
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Kaplan A, Kotzer S, Almeida CR, Kohen R, Halpert G, Salmon-Divon M, Köhler K, Höglund P, Davis DM, Mehr R. Simulations of the NK cell immune synapse reveal that activation thresholds can be established by inhibitory receptors acting locally. THE JOURNAL OF IMMUNOLOGY 2011; 187:760-73. [PMID: 21690326 DOI: 10.4049/jimmunol.1002208] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
NK cell activation is regulated by a balance between activating and inhibitory signals. To address the question of how these signals are spatially integrated, we created a computer simulation of activating and inhibitory NK cell immunological synapse (NKIS) assembly, implementing either a "quantity-based" inhibition model or a "distance-based" inhibition model. The simulations mimicked the observed molecule distributions in inhibitory and activating NKIS and yielded several new insights. First, the total signal is highly influenced by activating complex dissociation rates but not by adhesion and inhibitory complex dissociation rates. Second, concerted motion of receptors in clusters significantly accelerates NKIS maturation. Third, when the potential of a cis interaction between Ly49 receptors and MHC class I on murine NK cells was added to the model, the integrated signal as a function of receptor and ligand numbers was only slightly increased, at least up to the level of 50% cis-bound Ly49 receptors reached in the model. Fourth, and perhaps most importantly, the integrated signal behavior obtained when using the distance-based inhibition signal model was closer to the experimentally observed behavior, with an inhibition radius of the order 3-10 molecules. Microscopy to visualize Vav activation in NK cells on micropatterned surfaces of activating and inhibitory strips revealed that Vav is only locally activated where activating receptors are ligated within a single NK cell contact. Taken together, these data are consistent with a model in which inhibitory receptors act locally; that is, that every bound inhibitory receptor acts on activating receptors within a certain radius around it.
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Affiliation(s)
- Asya Kaplan
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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De Temmerman ML, Rejman J, Demeester J, Irvine DJ, Gander B, De Smedt SC. Particulate vaccines: on the quest for optimal delivery and immune response. Drug Discov Today 2011; 16:569-82. [PMID: 21570475 DOI: 10.1016/j.drudis.2011.04.006] [Citation(s) in RCA: 216] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 02/10/2011] [Accepted: 04/20/2011] [Indexed: 12/22/2022]
Abstract
Subunit vaccines offer a safer alternative to traditional organism-based vaccines, but their immunogenicity is impaired. This hurdle might be overcome by the use of micro- and nanodelivery systems carrying the antigen(s). This review discusses the rationale for the use of particulate vaccines and provides an overview of antigen-delivery vehicles currently under investigation. It further highlights the cellular uptake, antigen processing and the presentation by antigen-presenting cells because these processes are partially governed by particle characteristics and eventually determine the immunological outcome. Finally, we address the attractive concept of concomitant delivery of antigens and immunopotentiators. The condensed knowledge could be an asset for rationally designing antigen-delivery vehicles to obtain safe and efficacious vaccines.
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Affiliation(s)
- Marie-Luce De Temmerman
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Ghent, Belgium
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Busman-Sahay K, Sargent E, Harton JA, Drake JR. The Ia.2 epitope defines a subset of lipid raft-resident MHC class II molecules crucial to effective antigen presentation. THE JOURNAL OF IMMUNOLOGY 2011; 186:6710-7. [PMID: 21543648 DOI: 10.4049/jimmunol.1100336] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Previous work established that binding of the 11-5.2 anti-I-A(k) mAb, which recognizes the Ia.2 epitope on I-A(k) class II molecules, elicits MHC class II signaling, whereas binding of two other anti-I-A(k) mAbs that recognize the Ia.17 epitope fail to elicit signaling. Using a biochemical approach, we establish that the Ia.2 epitope recognized by the widely used 11-5.2 mAb defines a subset of cell surface I-A(k) molecules predominantly found within membrane lipid rafts. Functional studies demonstrate that the Ia.2-bearing subset of I-A(k) class II molecules is critically necessary for effective B cell-T cell interactions, especially at low Ag doses, a finding consistent with published studies on the role of raft-resident class II molecules in CD4 T cell activation. Interestingly, B cells expressing recombinant I-A(k) class II molecules possessing a β-chain-tethered hen egg lysosome peptide lack the Ia.2 epitope and fail to partition into lipid rafts. Moreover, cells expressing Ia.2(-) tethered peptide-class II molecules are severely impaired in their ability to present both tethered peptide or peptide derived from exogenous Ag to CD4 T cells. These results establish the Ia.2 epitope as defining a lipid raft-resident MHC class II conformer vital to the initiation of MHC class II-restricted B cell-T cell interactions.
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Affiliation(s)
- Kathleen Busman-Sahay
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA
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Kumar S, Naqvi RA, Khanna N, Rao DN. Disruption of HLA-DR raft, deregulations of Lck-ZAP-70-Cbl-b cross-talk and miR181a towards T cell hyporesponsiveness in leprosy. Mol Immunol 2011; 48:1178-90. [PMID: 21453975 DOI: 10.1016/j.molimm.2011.02.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 02/24/2011] [Accepted: 02/25/2011] [Indexed: 11/27/2022]
Abstract
Leprosy, a chronic human disease, results from infection of Mycobacterium leprae. Defective CMI and T cell hyporesponsiveness are the major hallmark of M. leprae pathogenesis. The present study demonstrates immunological-deregulations that eventually lead to T cell anergy/hyporesponsiveness in M. lepare infection. We firstly, evaluated the membrane fluidity and antigen-presenting-lipid-raft (HLA-DR) on macrophages of leprosy patients using fluorescence anisotropy and confocal microscopy, respectively. Increased membrane fluidity and raft-out localizations of over-expressed HLA-DR towards BL/LL pole are pinpointed as major defects, may be leading to defective antigen presentation in leprosy. Furthermore, altered expression and localization of Lck, ZAP-70, etc. and their deregulated cross talks with negative regulators (CD45, Cbl-b and SHP2) turned out to be the major putative reason(s) leading to T cell hyporesponsiveness in leprosy. Deregulations of Lck-ZAP-70 cross-talk in T cells were found to be associated with cholesterol-dependent-dismantling of HLA-DR rafts in macrophages in leprosy progression. Increased molecular interactions between Cbl-b and Lck/ZAP-70 and their subsequent degradation via ubiquitinization pathway, as result of high expression of Cbl-b, were turned out to be one of the principal underlying reason leading to T cell anergy in leprosy patients. Interestingly, overexpression of SHP2 due to gradual losses of miR181a and subsequent dephosphorylation of imperative T cell signaling molecules were emerged out as another important reason associated with prevailing T cell hyporesponsiveness during leprosy progression. Thus, this study for the first time pinpointed overexpression of Cbl-b and expressional losses of miR-181 as important hallmarks of progression of leprosy.
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Affiliation(s)
- Sudhir Kumar
- Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
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Karmakar S, Paul J, De T. Leishmania donovani glycosphingolipid facilitates antigen presentation by inducing relocation of CD1d into lipid rafts in infected macrophages. Eur J Immunol 2011; 41:1376-87. [DOI: 10.1002/eji.201040981] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 12/29/2010] [Accepted: 01/31/2011] [Indexed: 01/13/2023]
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Role of TLR4 in ethanol effects on innate and adaptive immune responses in peritoneal macrophages. Immunol Cell Biol 2011; 89:716-27. [DOI: 10.1038/icb.2010.163] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Khandelwal S, Roche PA. Distinct MHC class II molecules are associated on the dendritic cell surface in cholesterol-dependent membrane microdomains. J Biol Chem 2010; 285:35303-10. [PMID: 20833718 DOI: 10.1074/jbc.m110.147793] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Very small amounts of MHC class II-peptide complexes expressed on the surface of antigen-presenting cells (APCs) are capable of stimulating antigen-specific CD4 T cells. There is intense interest to elucidate the molecular mechanisms by which these small amounts of MHC-II can cluster, cross-link T cell receptors, and promote T cell proliferation. We now demonstrate that a significant fraction of the total pool of MHC-II molecules on the surface of dendritic cells is physically associated in macromolecular aggregates. These MHC-II/MHC-II interactions have been probed by co-immunoprecipitation analysis of the MHC-II I-A molecule with the related I-E molecule. These molecular associations are maintained in gentle detergents but are disrupted in harsh detergents such as Triton X-100. MHC-II I-A/I-E interactions are disrupted when plasma membrane cholesterol is extracted using methyl β-cyclodextrin, suggesting that lipid raft microdomains are important mediators of these MHC-II interactions. Although it has been proposed that tetraspanin proteins regulate molecular clustering, aggregation, and co-immunoprecipitation in APCs, genetic deletion of the tetraspanin family members CD9 or CD81 had no effect on MHC-II I-A/I-E binding. These data demonstrate that the presence of distinct forms of MHC-II with plasma membrane lipid rafts is required for MHC-II aggregation in APCs and provides a molecular mechanism allowing dendritic cells expressing small amounts of MHC-II-peptide complexes to cross-link and stimulate CD4 T cells.
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Affiliation(s)
- Sanjay Khandelwal
- Experimental Immunology Branch, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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Yi L, Rosales T, Rose JJ, Chowdhury B, Chaudhury B, Knutson JR, Venkatesan S. HIV-1 Nef binds a subpopulation of MHC-I throughout its trafficking itinerary and down-regulates MHC-I by perturbing both anterograde and retrograde trafficking. J Biol Chem 2010; 285:30884-905. [PMID: 20622010 DOI: 10.1074/jbc.m110.135947] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The HIV protein Nef is thought to mediate immune evasion and promote viral persistence in part by down-regulating major histocompatibility complex class I protein (MHC-I or HLA-I) from the cell surface. Two different models have been proposed to explain this phenomenon as follows: 1) stimulation of MHC-I retrograde trafficking from and aberrant recycling to the plasma membrane, and 2) inhibition of anterograde trafficking of newly synthesized HLA-I from the endoplasmic reticulum to the plasma membrane. We show here that Nef simultaneously uses both mechanisms to down-regulate HLA-I in peripheral blood mononuclear cells or HeLa cells. Consistent with this, we found by using fluorescence correlation spectroscopy that a third of diffusing HLA-I at the endoplasmic reticulum, Golgi/trans-Golgi network, and the plasma membrane (PM) was associated with Nef. The binding of Nef was similarly avid for native HLA-I and recombinant HLA-I A2 at the PM. Nef binding to HLA-I at the PM was sensitive to specific inhibition of endocytosis. It was also attenuated by cyclodextrin disruption of PM lipid micro-domain architecture, a change that also retarded lateral diffusion and induced large clusters of HLA-I. In all, our data support a model for Nef down-regulation of HLA-I that involves both major trafficking itineraries and persistent protein-protein interactions throughout the cell.
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Affiliation(s)
- Ling Yi
- Molecular and Cell Biology Unit, Laboratory of Molecular Immunology, NIAID, Laboratory of Molecular Biophysics, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, USA
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Wang SH, Yuan SG, Peng DQ, Zhao SP. High-density lipoprotein affects antigen presentation by interfering with lipid raft: a promising anti-atherogenic strategy. Clin Exp Immunol 2010; 160:137-42. [PMID: 20059478 DOI: 10.1111/j.1365-2249.2009.04068.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Atherosclerosis is a chronic inflammatory disease. Immunomodulation of atherosclerosis emerges as a promising approach to prevention and treatment of this widely prevalent disease. The function of high-density lipoprotein (HDL) to promote reverse cholesterol transport may explain the ability of its protection against atherosclerosis. Findings that HDL and apolipoprotein A-I (apoA-I) inhibited the ability of antigen presenting cells (APCs) to stimulate T cells might be attributed to lipid raft, a cholesterol-rich microdomain exhibiting functional properties depending largely upon its lipid composition. Thus, modulating cholesterol in lipid raft may provide a promising anti-atherogenic strategy.
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Affiliation(s)
- S-H Wang
- Department of Cardiology, the Second Xiangya Hospital of Central South University, Changsha, Hunan, China
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Knorr R, Karacsonyi C, Lindner R. Endocytosis of MHC molecules by distinct membrane rafts. J Cell Sci 2009; 122:1584-94. [PMID: 19383725 DOI: 10.1242/jcs.039727] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In B-lymphocytes, endocytosis of MHC I and MHC II molecules is important for the cross-priming and presentation of labile antigens, respectively. Here, we report that MHC I and MHC II were internalized by separate endocytic carriers that lacked transferrin receptor. Cholera toxin B was co-internalized with MHC II, but not with MHC I, suggesting that the CLIC/GEEC pathway is involved in the uptake of MHC II. Endocytosis of MHC I and MHC II was inhibited by filipin, but only MHC II showed a strong preference for a membrane raft environment in a co-clustering analysis with G(M)1. By using a novel method for the extraction of detergent-resistant membranes (DRMs), we observed that MHC I and MHC II associate with two distinct types of DRMs. These differ in density, protein content, lipid composition, and ultrastructure. The results of cell surface biotinylation and subsequent DRM isolation show that precursors for both DRMs coexist in the plasma membrane. Moreover, clustering of MHC proteins at the cell surface resulted in shifts of the respective DRMs, revealing proximity-induced changes in the membrane environment. Our results suggest that the preference of MHC I and MHC II for distinct membrane rafts directs them to different cellular entry points.
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Affiliation(s)
- Ruth Knorr
- Department of Cell Biology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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