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Bristow CL. Lipoproteins in Negative Feedback with Alpha-1 Antitrypsin. Methods Mol Biol 2024; 2750:167-174. [PMID: 38108976 DOI: 10.1007/978-1-0716-3605-3_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Alpha-1 antitrypsin deficiency patients (AATD) have lower risk of myocardial infarction, a cardiovascular disease that is related to increased remnant cholesterol levels, but not to low-density lipoprotein (LDL) levels. However, when AAT is knocked out in mice (AAT-KO), inflammatory-related, cholesterol metabolism-related, and lipid metabolism-related gene expression in mouse liver was increased, and these data support previous evidence from clinic patients and from a small clinical trial that AAT is in negative feedback regulation with LDL. Herein is a brief summary to examine the roles of AAT in these overlapping pathways.
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Affiliation(s)
- Cynthia L Bristow
- Alpha-1 Biologics, Long Island High Technology Incubator, Stony Brook University, Stony Brook, NY, USA.
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Sun R, Xu Z, Zhu C, Chen T, Muñoz LE, Dai L, Zhao Y. Alpha-1 antitrypsin in autoimmune diseases: Roles and therapeutic prospects. Int Immunopharmacol 2022; 110:109001. [PMID: 35803133 DOI: 10.1016/j.intimp.2022.109001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 02/05/2023]
Abstract
Alpha-1 antitrypsin (A1AT) is a protease inhibitor in the serum. Its primary function is to inhibit the activity of a series of proteases, including proteinase 3, neutrophil elastase, metalloproteases, and cysteine-aspartate proteases. In addition, A1AT also has anti-inflammatory, anti-apoptotic, anti-oxidative stress, anti-viral, and anti-bacterial activities and plays essential roles in the regulation of tissue repair and lymphocyte differentiation and activation. The overactivation of the immune system characterizes the pathogenesis of autoimmune diseases. A1AT treatment shows beneficial effects on patients and animal models with autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. This review summarizes the functions and therapeutic prospects of A1AT in autoimmune diseases.
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Affiliation(s)
- Rui Sun
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, China; Clinical Institute of Inflammation and Immunology (CIII), Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zhiqiang Xu
- Department of Rheumatology and Immunology, National Clinical Research Center for Geriatrics and Department of General Practice, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Chenxi Zhu
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, China; Clinical Institute of Inflammation and Immunology (CIII), Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Tao Chen
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, China; Clinical Institute of Inflammation and Immunology (CIII), Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Luis E Muñoz
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Lunzhi Dai
- Department of Rheumatology and Immunology, National Clinical Research Center for Geriatrics and Department of General Practice, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
| | - Yi Zhao
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, China; Clinical Institute of Inflammation and Immunology (CIII), Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
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Bristow CL, Reeves MAB, Winston R. Alphataxin, a Small-Molecule Drug That Elevates Tumor-Infiltrating CD4 + T Cells, in Combination With Anti-PD-1 Therapy, Suppresses Murine Renal Cancer and Metastasis. Front Oncol 2021; 11:739080. [PMID: 34900690 PMCID: PMC8656697 DOI: 10.3389/fonc.2021.739080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/02/2021] [Indexed: 11/13/2022] Open
Abstract
By promoting the cytotoxic function of CD8+ T cells, immune checkpoint inhibitor therapy, e.g. programmed cell death protein-1 (PD-1), effectively inhibits tumor growth in renal cell carcinoma. Yet, as many as 87% of cancer patients do not respond to immune checkpoint therapy. Importantly, cytotoxic CD8+ T cell function crucially relies on CD4+ T helper cell cytokines, in particular, tumor necrosis factor beta (TNFβ) and its CD8+ T cell receptor (TNFR2) in the opposing manner as immune checkpoints and their receptors. Remarkably, despite advances in immunotherapy, there are no pharmaceutical treatments that increase circulating CD4+ T cell counts. Nor has there been much attention given to tumor-infiltrating CD4+ T cells. Using data from a clinical trial (NCT01731691), we discovered that the protein alpha-1 proteinase inhibitor (α1PI, alpha-1 antitrypsin) regulates the number of circulating CD4+ T cells. The orally available small-molecule drug Alphataxin acts as a surrogate for α1PI in this pathway. We aimed to examine how Alphataxin affected tumor growth in a murine model of renal cell carcinoma. Alphataxin, in combination with anti-PD-1 antibody, significantly elevated the ratio of circulating and tumor-infiltrating CD4+ T cells. In one study, following orthotopic implantation of syngeneic renal adenocarcinoma cells, combination treatment resulted in 100% regression of tumor growth. Moreover, in mice implanted orthotopically with one log more tumor cells, doubling Alphataxin dose in combination treatment led to 100% regression in one-third of mice and 81% suppression of tumor growth in the remaining two-thirds of mice. Lung metastasis was present in monotherapy, but significantly reduced in combination-treated mice. Orally available Alphataxin, the first and only drug developed to increase CD4+ T cells, in combination with anti-PD-1, is a powerful therapeutic method that provides long-term remission in renal cell carcinoma and potentially other T cell-responsive cancers by increasing the number of CD4+ tumor-infiltrating T cells.
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Affiliation(s)
- Cynthia L Bristow
- Alpha-1 Biologics, Long Island High Technology Incubator, Stony Brook University, Stony Brook, NY, United States.,Institute for Human Genetics and Biochemistry, Vesenaz, Switzerland
| | - Mary Ann B Reeves
- Alpha-1 Biologics, Long Island High Technology Incubator, Stony Brook University, Stony Brook, NY, United States.,The University of Queensland, Medicine, Brisbane, QLD, Australia
| | - Ronald Winston
- Alpha-1 Biologics, Long Island High Technology Incubator, Stony Brook University, Stony Brook, NY, United States.,Institute for Human Genetics and Biochemistry, Vesenaz, Switzerland
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Bristow CL, Winston R. Alphataxin, an Orally Available Small Molecule, Decreases LDL Levels in Mice as a Surrogate for the LDL-Lowering Activity of Alpha-1 Antitrypsin in Humans. Front Pharmacol 2021; 12:695971. [PMID: 34177602 PMCID: PMC8220083 DOI: 10.3389/fphar.2021.695971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 05/24/2021] [Indexed: 11/13/2022] Open
Abstract
The abundant blood protein α1-proteinase inhibitor (α1PI, Αlpha-1, α1-antitrypsin, SerpinA1) is known to bind to the active site of granule-associated human leukocyte elastase (HLE-G). Less well known is that binding of α1PI to cell surface HLE (HLE-CS) induces lymphocyte locomotion mediated by members of the low density lipoprotein receptor family (LDL-RFMs) thereby facilitating low density lipoprotein (LDL) clearance. LDL and α1PI were previously shown to be in negative feedback regulation during transport and clearance of lipoproteins. Further examination herein of the influence of α1PI in lipoprotein regulation using data from a small randomized, double-blind clinical trial shows that treatment of HIV-1-infected individuals with α1PI plasma products lowered apolipoprotein and lipoprotein levels including LDL. Although promising, plasma-purified α1PI is limited in quantity and not a feasible treatment for the vast number of people who need treatment for lowering LDL levels. We sought to develop orally available small molecules to act as surrogates for α1PI. Small molecule β-lactams are highly characterized for their binding to the active site of HLE-G including crystallographic studies at 1.84 Å. Using high throughput screening (HLE-G inhibition, HLE-CS-induced cellular locomotion), we show here that a panel of β-lactams, including the LDL-lowering drug ezetimibe, have the capacity to act as surrogates for α1PI by binding to HLE-G and HLE-CS. Because β-lactams are antibiotics that also have the capacity to promote evolution of antibiotic resistant bacteria, we modified the β-lactam Alphataxin to prevent antibiotic activity. We demonstrate using the diet-induced obesity (DIO) mouse model that Alphataxin, a penam, is as effective in lowering LDL levels as FDA-approved ezetimibe, a monobactam. Non-antibiotic β-lactams provide a promising new therapeutic class of small molecules for lowering LDL levels.
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Affiliation(s)
- Cynthia L Bristow
- Alpha-1 Biologics, Long Island High Technology Incubator, Stony Brook University, Stony Brook, NY, United States.,Institute for Human Genetics and Biochemistry, Vesenaz, Switzerland
| | - Ronald Winston
- Alpha-1 Biologics, Long Island High Technology Incubator, Stony Brook University, Stony Brook, NY, United States.,Institute for Human Genetics and Biochemistry, Vesenaz, Switzerland
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Is α1-Antitrypsin Important for Murine Thymocyte Development? Trends Immunol 2021; 42:178-180. [PMID: 33518416 DOI: 10.1016/j.it.2021.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 01/08/2021] [Indexed: 11/21/2022]
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