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Kachlany SC, Vega BA. Therapeutic Applications of Aggregatibacter actinomycetemcomitans Leukotoxin. Pathogens 2024; 13:354. [PMID: 38787206 PMCID: PMC11123898 DOI: 10.3390/pathogens13050354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative oral bacterium that has been primarily studied for its role in causing periodontal disease. The bacterium has also been implicated in several systemic diseases such as endocarditis and soft tissue abscesses. Leukotoxin (LtxA) is perhaps the best studied protein virulence factor from A. actinomycetemcomitans. The protein can rapidly destroy white blood cells (WBCs), helping the bacterium to subvert the host immune system. The functional receptor for LtxA is lymphocyte function associated antigen-1 (LFA-1), which is expressed exclusively on the surfaces of WBCs. Bacterial expression and secretion of the protein are highly regulated and controlled by a number of genetic and environmental factors. The mechanism of LtxA action on WBCs varies depending on the type of cell that is being killed, and the protein has been shown to activate numerous cell death pathways in susceptible cells. In addition to serving as an important virulence factor for the bacterium, because of its exquisite specificity and rapid activity, LtxA is also being investigated as a therapeutic agent that may be used to treat diseases such as hematological malignancies and autoimmune/inflammatory diseases. It is our hope that this review will inspire an increased intensity of research related to LtxA and its effect on Aggressive Periodontitis, the disease that led to its initial discovery.
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Affiliation(s)
- Scott C. Kachlany
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
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Zhao F, Zhang C, Li G, Zheng H, Gu L, Zhou H, Xiao Y, Wang Z, Yu J, Hu Y, Zeng F, Wang X, Zhao Q, Hu J, Yue C, Zhou P, Huang N, Hao Y, Wu W, Cui K, Li W, Li J. A role for whey acidic protein four-disulfide-core 12 (WFDC12) in the pathogenesis and development of psoriasis disease. Front Immunol 2022; 13:873720. [PMID: 36148224 PMCID: PMC9485559 DOI: 10.3389/fimmu.2022.873720] [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: 03/02/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Whey acidic protein four-disulfide core domain protein 12 (WFDC12) has been implicated in the pathogenesis of psoriasis but the specific molecular mechanism is not clearly defined. In this study, we found the expression of WFDC12 protein closely correlated with psoriasis. WFDC12 in keratinocyte might increase infiltration of Langerhans cells (LCs) and monocyte-derived dendritic cells (moDDCs), up-regulating the co-stimulation molecular CD40/CD86. Th1 cells in lymph nodes were higher in K14-WFDC12 transgenic psoiasis-like mice. Meanwhile, the mRNA of IL-12 and IFN-γ in the lesion skin was significantly increased in transgenic mice. Moreover, we found that the expression of the proteins that participated in the retinoic acid–related pathway and immune signaling pathway was more changed in the lesion skin of K14-WFDC12 transgenic psoriasis-like mice. Collectively, the results implied that WFDC12 might affect the activation of the retinoic acid signaling pathway and regulate the infiltration of DC cells in the skin lesions and lymph nodes, thereby inducing Th1 cells differentiation and increasing the secretion of IFN-γ to exacerbate psoriasis in mice.
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Affiliation(s)
- Fulei Zhao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Chen Zhang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Guolin Li
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Huaping Zheng
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Linna Gu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Hong Zhou
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Yuanyuan Xiao
- Department of Obstetrics and Gynecology, West China Second Hospital of Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
| | - Zhen Wang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Jiadong Yu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Yawen Hu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Fanlian Zeng
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Xiaoyan Wang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Qixiang Zhao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Jing Hu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Chengcheng Yue
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Pei Zhou
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Nongyu Huang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Yan Hao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Wenling Wu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Kaijun Cui
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, China
| | - Wei Li
- Department of Dermatology, Rare Diseases Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jiong Li
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
- *Correspondence: Jiong Li,
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Prince DJ, Patel D, Kachlany SC. Leukotoxin (LtxA/Leukothera) induces ATP expulsion via pannexin-1 channels and subsequent cell death in malignant lymphocytes. Sci Rep 2021; 11:18086. [PMID: 34508147 PMCID: PMC8433231 DOI: 10.1038/s41598-021-97545-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/26/2021] [Indexed: 11/09/2022] Open
Abstract
Leukotoxin (LtxA) (Trade name, Leukothera) is a protein that is secreted from the oral bacterium Aggregatibacter actinomycetemcomitans, which targets and kills activated white blood cells (WBCs) by binding to lymphocyte function associated antigen-1 (LFA-1). Interaction between LtxA and Jurkat T-cells results in cell death and is characterized by increased intracellular Ca2+, activation of caspases, clustering of LtxA and LFA-1 within lipid rafts, and involvement of the Fas death receptor. Here, we show that LtxA can kill malignant lymphocytes via apoptotic and necrotic forms of cell death. We show that LtxA causes activation of caspases and PARP, cleavage of pannexin-1 (Panx1) channels, and expulsion of ATP, ultimately leading to cell death via apoptosis and necrosis. CRISPR-Cas9 mediated knockout (K/O) of Panx1 in Jurkat cells prevented ATP expulsion and resulted in resistance to LtxA for both apoptotic and necrotic forms of death. Resistance to necrosis could only be overcome when supplementing LtxA with endogenous ATP (bzATP). The combination of LtxA and bzATP promoted only necrosis, as no Panx1 K/O cells stained positive for phosphatidylserine (PS) exposure following the combined treatment. Inhibition of LtxA/bzATP-induced necrosis was possible when pretreating Jurkat cells with oATP, a P2X7R antagonist. Similarly, blockage of P2X7Rs with oATP prevented the intracellular mobilization of Ca2+, an important early step in LtxA induced cell death. We show that LtxA is able to kill malignant lymphocytes through an apoptotic death pathway which is potentially linked to a Panx1/P2X7R mediated necrotic form of death. Thus, inhibition of ATP release appears to significantly delay the onset of LtxA induced apoptosis while completely disabling the necrotic death pathway in T-lymphocytes, demonstrating the crucial role of ATP release in LtxA-mediated cell death.
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Affiliation(s)
- Derek J Prince
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, 07103, USA
| | | | - Scott C Kachlany
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, 07103, USA.
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Cho JH, Kang JY, Kim S, Baek HR, Kim J, Jang KS, Kim JW. Skin protein-derived peptide-conjugated vesicular nanocargos for selected skin cell targeting and consequent activation. J Mater Chem B 2021; 9:4956-4962. [PMID: 34109337 DOI: 10.1039/d1tb00935d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Several studies have reported that a drug nanocarrier conjugated with ligands having cell binding ability improves drug delivery performance, but multiple cell-targeting and the resultant activation in designated cells has not been investigated yet. This study reports a skin cell multi-targeting vesicular nanocargo system. We selectively conjugated several skin protein-derived cell-targeting peptides (CTPs), including KTTKS, NAP-amide, and Lam332, to amphiphilic polymer-reinforced lipid nanovesicles (PLNVs) to specifically target fibroblasts, melanocytes, and keratinocytes, respectively, through effective association with the corresponding cell membrane receptors. We then showed that CTP-conjugated PLNVs specifically bind to the designated skin cells, even in a mixture of different types of skin cells, eventually leading to skin cell multi-targeting and consequent activation. These results highlight that this CTP-conjugated PLNV system has significant potential for developing an intelligent cellular drug delivery technology for dermatological applications.
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Affiliation(s)
- Jung Hyeon Cho
- School of Chemical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
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Vega BA, Belinka BA, Kachlany SC. Aggregatibacter actinomycetemcomitans Leukotoxin (LtxA; Leukothera ®): Mechanisms of Action and Therapeutic Applications. Toxins (Basel) 2019; 11:toxins11090489. [PMID: 31454891 PMCID: PMC6784247 DOI: 10.3390/toxins11090489] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 12/18/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is an oral pathogen that produces the RTX toxin, leukotoxin (LtxA; Leukothera®). A. actinomycetemcomitans is strongly associated with the development of localized aggressive periodontitis. LtxA acts as a virulence factor for A. actinomycetemcomitans to subvert the host immune response by binding to the β2 integrin lymphocyte function-associated antigen-1 (LFA-1; CD11a/CD18) on white blood cells (WBCs), causing cell death. In this paper, we reviewed the state of knowledge on LtxA interaction with WBCs and the subsequent mechanisms of induced cell death. Finally, we touched on the potential therapeutic applications of LtxA (trade name Leukothera®) toxin therapy for the treatment of hematological malignancies and immune-mediated diseases.
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Affiliation(s)
- Brian A Vega
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
- Actinobac Biomed, Inc., Princeton, NJ 08540, USA
| | | | - Scott C Kachlany
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, USA.
- Actinobac Biomed, Inc., Princeton, NJ 08540, USA.
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Aggregatibacter actinomycetemcomitans Leukotoxin (LtxA) Requires Death Receptor Fas, in Addition to LFA-1, To Trigger Cell Death in T Lymphocytes. Infect Immun 2019; 87:IAI.00309-19. [PMID: 31109948 DOI: 10.1128/iai.00309-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 05/10/2019] [Indexed: 11/20/2022] Open
Abstract
Leukotoxin (LtxA) (trade name, Leukothera) is a protein secreted by the oral bacterium Aggregatibacter actinomycetemcomitans A. actinomycetemcomitans is an oral pathogen strongly associated with development of localized aggressive periodontitis. LtxA acts as a virulence factor for A. actinomycetemcomitans by binding to the β2 integrin lymphocyte function-associated antigen-1 (LFA-1; CD11a/CD18) on white blood cells (WBCs) and causing cell death. In addition, because of its specificity for malignant and activated WBCs, LtxA is being investigated as a therapeutic agent for treatment of hematological malignancies and autoimmune diseases. Here, we report the successful generation and characterization of Jurkat T lymphocytes with deletions in CD18, CD11a, and Fas that were engineered using CRISPR/Cas9 gene editing. Using these clones, we demonstrate the specificity of LtxA for cells expressing LFA-1. We also demonstrate the requirement of the cell death receptor Fas for LtxA-mediated cell death in T lymphocytes. We show that LFA-1 and Fas are early events in the LtxA-mediated cell death cascade as caspase activation and mitochondrial perturbation do not occur in the absence of either receptor. To our knowledge, LtxA is the first molecule, other than FasL, known to require the Fas death receptor to initiate cell death. Knowledge of the mechanism of cell death induced by LtxA will facilitate the understanding of LtxA as a bacterial virulence factor and development of it as a potential therapeutic agent.
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Abdullahi M, Olotu FA, Soliman ME. Solving the riddle: Unraveling the mechanisms of blocking the binding of leukotoxin by therapeutic antagonists in periodontal diseases. J Cell Biochem 2018; 119:9364-9379. [PMID: 30129224 DOI: 10.1002/jcb.27254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/21/2018] [Indexed: 12/12/2022]
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacteria that has gained wide recognition for its causative role in the development of various immune diseases, which includes localized aggressive periodontitis. Its ability to evade host defense mechanisms is mediated by the secretion of leukotoxin (LtxA), which induces death of white blood cells (leukocytes) by specific binding to their surface-expressed leukocyte function-associated receptor (LFA-1) in its active state. Therapeutic compounds that interfere with this pathogenic process and abrogate A. actinomycetemcomitans virulence have been reported in literature. These include doxycycline, and more recently phytochemical compounds such as hamamelitanin, resveratrol, naringin, and quercetin. However, the question remains how do they work? Therefore, with the aid of computational tools, we explore the molecular mechanisms by which they possibly elicit their therapeutic functions. Molecular mechanics Poisson/Boltzmann surface area analyses revealed that these compounds bind favorably to active LFA-1 with high affinity and considerable stability, indicative of their ability to occupy the LtxA binding site (LBS) and prevent LtxA binding. The conformational transition of open LFA-1 to its closed state further describe the mechanistic activity of these compounds. In addition to notable reductions in structural mobility and flexibility, the burial of surface-exposed interactive side chains at the LBS was observed, an occurrence that could alter the complementary binding of LtxA. It is also important to mention that these occurrences were induced more prominently by the phytochemicals. We believe that these findings will enhance the scope of drug design and discovery for potent LtxA antagonists with improved activities and therapeutic efficacies in the treatment of virulent A. actinomycetemcomitans diseases.
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Affiliation(s)
- Maryam Abdullahi
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Fisayo A Olotu
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Mahmoud E Soliman
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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Chamcheu JC, Siddiqui IA, Adhami VM, Esnault S, Bharali DJ, Babatunde AS, Adame S, Massey RJ, Wood GS, Longley BJ, Mousa SA, Mukhtar H. Chitosan-based nanoformulated (-)-epigallocatechin-3-gallate (EGCG) modulates human keratinocyte-induced responses and alleviates imiquimod-induced murine psoriasiform dermatitis. Int J Nanomedicine 2018; 13:4189-4206. [PMID: 30057446 PMCID: PMC6059258 DOI: 10.2147/ijn.s165966] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Background Psoriasis is a chronic and currently incurable inflammatory skin disease characterized by hyperproliferation, aberrant differentiation, and inflammation, leading to disrupted skin barrier function. The use of natural agents that can abrogate these effects could be useful for the treatment of psoriasis. Earlier studies have shown that treatment of keratinocytes and mouse skin with the green tea polyphenol (−)-epigallocatechin-3-gallate (EGCG) mitigated inflammation and increased the expression of caspase-14 while promoting epidermal differentiation and cornification. However, bioavailability issues have restricted the development of EGCG for the treatment of psoriasis. Materials and methods To overcome these limitations, we employed a chitosan-based polymeric nanoparticle formulation of EGCG (CHI-EGCG-NPs, hereafter termed nanoEGCG) suitable for topical delivery for treating psoriasis. We investigated and compared the efficacy of nanoEGCG versus native or free EGCG in vitro and in an in vivo imiquimod (IMQ)-induced murine psoriasis-like dermatitis model. The in vivo relevance and efficacy of nanoEGCG formulation (48 µg/mouse) were assessed in an IMQ-induced mouse psoriasis-like skin lesion model compared to free EGCG (1 mg/mouse). Results Like free EGCG, nanoEGCG treatment induced differentiation, and decreased proliferation and inflammatory responses in cultured keratinocytes, but with a 4-fold dose advantage. Topically applied nanoEGCG elicited a significant (p<0.01) amelioration of psoriasiform pathological markers in IMQ-induced mouse skin lesions, including reductions in ear and skin thickness, erythema and scales, proliferation (Ki-67), infiltratory immune cells (mast cells, neutrophils, macrophages, and CD4+ T cells), and angiogenesis (CD31). We also observed increases in the protein expression of caspase-14, early (keratin-10) and late (filaggrin and loricrin) markers of differentiation, and the activator protein-1 factor (JunB). Importantly, a significant modulation of several psoriasis-related inflammatory cytokines and chemokines was observed compared to the high dose of free EGCG (p<0.05). Taken together, topically applied nanoEGCG displayed a >20-fold dose advantage over free EGCG. Conclusion Based on these observations, our nanoEGCG formulation represents a promising drug-delivery strategy for treating psoriasis and possibly other inflammatory skin diseases.
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Affiliation(s)
- Jean Christopher Chamcheu
- Department of Dermatology, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA, .,School of Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA, USA,
| | - Imtiaz A Siddiqui
- Department of Dermatology, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA,
| | - Vaqar M Adhami
- Department of Dermatology, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA,
| | - Stephane Esnault
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, The University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Dhruba J Bharali
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Albany, NY, USA
| | - Abiola S Babatunde
- Department of Dermatology, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA, .,Department of Hematology, University of Ilorin, Ilorin, Nigeria
| | - Stephanie Adame
- Department of Dermatology, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA,
| | - Randall J Massey
- Electron Microscope Facility, Medical School Research Support Programs, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA
| | - Gary S Wood
- Department of Dermatology, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA,
| | - B Jack Longley
- Department of Dermatology, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA,
| | - Shaker A Mousa
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Albany, NY, USA
| | - Hasan Mukhtar
- Department of Dermatology, School of Medicine and Public Health, The University of Wisconsin-Madison, Madison, WI, USA,
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Kachlany SC. Mechanisms of LtxA (Leukotoxin), a Potent New Anti-Inflammatory Agent for the Treatment of Alopecia Areata. J Investig Dermatol Symp Proc 2016; 17:19-22. [PMID: 26551939 DOI: 10.1038/jidsymp.2015.34] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alopecia areata is an autoimmune condition where activated, pro-inflammatory white blood cells (WBCs) attack the hair follicles, resulting in hair loss. Migration of these activated WBCs from the blood stream and into the follicle tissue requires interaction between the integrin, lymphocyte function-associated antigen-1 (LFA-1) on WBCs, and ICAM-1 on vascular endothelial cells. High levels of active LFA-1 are uniquely expressed on WBCs that are involved in autoimmune and inflammatory conditions. The natural biologic agent LtxA (Leukothera) preferentially targets and depletes disease activated and malignant WBCs by binding to active LFA-1. The experimental drug has demonstrated significant therapeutic efficacy against autoimmune/inflammatory conditions such as psoriasis and allergic asthma in mouse models for these diseases. In addition, when injected into rodents, rhesus macaques, and dogs, LtxA was demonstrated to be physiologically active, biologically specific, and extremely well-tolerated. LFA-1 is an attractive target for therapy because it is only normally present on WBCs and has been shown to be activated and overexpressed on WBCs that are responsible for autoimmune/inflammatory conditions.
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Affiliation(s)
- Scott C Kachlany
- Department of Oral Biology, Rutgers University School of Dental Medicine, Newark, New Jersey, USA.,Actinobac Biomed, Inc., Kendall Park, New Jersey, USA
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Stenderup K, Rosada C, Shanebeck K, Brady W, Van Brunt MP, King G, Marelli M, Slagle P, Xu H, Nairn NW, Johnson J, Wang AA, Li G, Thornton KC, Dam TN, Grabstein KH. AZ17: a new bispecific drug targeting IL-6 and IL-23 with potential clinical use—improves psoriasis in a human xenograft transplantation model. Protein Eng Des Sel 2015; 28:467-80. [DOI: 10.1093/protein/gzv034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 07/10/2015] [Indexed: 12/20/2022] Open
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Sharma N, Craig AWB. Editorial: leukocyte-targeting toxins as therapeutics in allergic asthma. J Leukoc Biol 2015; 97:435-6. [PMID: 25733374 DOI: 10.1189/jlb.3ce1014-462r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Namit Sharma
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Andrew W B Craig
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
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12
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DiFranco KM, Johnson-Farley N, Bertino JR, Elson D, Vega BA, Belinka BA, Kachlany SC. LFA-1-targeting Leukotoxin (LtxA; Leukothera®) causes lymphoma tumor regression in a humanized mouse model and requires caspase-8 and Fas to kill malignant lymphocytes. Leuk Res 2015; 39:649-56. [PMID: 25850729 DOI: 10.1016/j.leukres.2015.03.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/07/2015] [Accepted: 03/16/2015] [Indexed: 12/12/2022]
Abstract
Leukotoxin (LtxA) is a protein secreted from the oral bacterium Aggregatibacter actinomycetemcomitans. LtxA binds to the β2 integrin lymphocyte-associated function antigen-1 (LFA-1) on human white blood cells (WBCs), resulting in cell death. LtxA is currently under investigation as a novel therapy (Leukothera(®)) for treating hematologic malignancies and autoimmune diseases. We show here that LtxA has potent in vivo anti-lymphoma activity in mice. LtxA caused complete regression of B-cell tumors and promoted long-term survival of mice. The mechanism of LtxA-mediated killing of malignant lymphocytes was further examined. We found that LtxA kills malignant lymphocytes by a novel mechanism requiring the death receptor Fas and caspase-8, but not Fas ligand (FasL) or caspase-9. We also determined that LFA-1 and Fas are closely associated on the cell surface and this proximity of LFA-1 and Fas could explain how signaling through an integrin can lead to cell death. In addition to LFA-1, this work reveals a second surface protein, Fas, that is critical for LtxA-mediated cell death. Knowledge of the mechanism of cell death induced by LtxA will facilitate the development and understanding of this potent experimental therapeutic agent.
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Affiliation(s)
- Kristina M DiFranco
- From the Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, United States
| | | | - Joseph R Bertino
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, United States
| | - David Elson
- From the Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, United States
| | - Brian A Vega
- From the Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, United States
| | | | - Scott C Kachlany
- From the Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, United States; Actinobac Biomed, Inc., North Brunswick, NJ 08902, United States.
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Pal HC, Chamcheu JC, Adhami VM, Wood GS, Elmets CA, Mukhtar H, Afaq F. Topical application of delphinidin reduces psoriasiform lesions in the flaky skin mouse model by inducing epidermal differentiation and inhibiting inflammation. Br J Dermatol 2014; 172:354-64. [PMID: 25533330 DOI: 10.1111/bjd.13513] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2014] [Indexed: 12/14/2022]
Abstract
BACKGROUND Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation and aberrant keratinocyte differentiation. We have shown that treatment of reconstituted human skin with delphinidin, an anthocyanidin, present in pigmented fruits and vegetables, increased the expression and processing of caspase-14, which is involved in cornification. Delphinidin also increases the expression of epidermal differentiation marker proteins. OBJECTIVES To determine whether topical application of delphinidin can modulate pathological markers of psoriasiform lesions in flaky skin mice and if this is associated with increased epidermal differentiation and a reduction in proliferation and inflammation. METHODS Five-week-old female homozygous flaky skin mice (fsn/fsn) were treated topically with delphinidin (0·5 mg cm(-2) and 1 mg cm(-2) skin areas, respectively), five times a week, up to 14 weeks of age. RESULTS Treatment of flaky skin mice with delphinidin resulted in a reduction in (i) pathological markers of psoriasiform lesions; (ii) infiltration of inflammatory cells; and (iii) mRNA and protein expression of inflammatory cytokines. Delphinidin treatment also increased the expression and processing of caspase-14, and expression of filaggrin, loricrin, keratin-1 and keratin-10. Furthermore, there was a decrease in the expression of markers for cell proliferation (proliferating cell nuclear antigen and keratin-14) and modulation of tight junction proteins (occludin and claudin-1). In addition, delphinidin treatment increased the expression of activator protein-1 transcription factor proteins (JunB, JunD, Fra1 and Fra2). CONCLUSIONS Delphinidin could be a promising agent for treatment of psoriasis and other hyperproliferative skin disorders.
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Affiliation(s)
- H C Pal
- Department of Dermatology, University of Alabama at Birmingham, 1670 University Blvd, Birmingham, 35294, AL, U.S.A
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Mitroulis I, Alexaki VI, Kourtzelis I, Ziogas A, Hajishengallis G, Chavakis T. Leukocyte integrins: role in leukocyte recruitment and as therapeutic targets in inflammatory disease. Pharmacol Ther 2014; 147:123-135. [PMID: 25448040 DOI: 10.1016/j.pharmthera.2014.11.008] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 11/06/2014] [Indexed: 02/06/2023]
Abstract
Infection or sterile inflammation triggers site-specific attraction of leukocytes. Leukocyte recruitment is a process comprising several steps orchestrated by adhesion molecules, chemokines, cytokines and endogenous regulatory molecules. Distinct adhesive interactions between endothelial cells and leukocytes and signaling mechanisms contribute to the temporal and spatial fine-tuning of the leukocyte adhesion cascade. Central players in the leukocyte adhesion cascade include the leukocyte adhesion receptors of the β2-integrin family, such as the αLβ2 and αMβ2 integrins, or of the β1-integrin family, such as the α4β1-integrin. Given the central involvement of leukocyte recruitment in different inflammatory and autoimmune diseases, the leukocyte adhesion cascade in general, and leukocyte integrins in particular, represent key therapeutic targets. In this context, the present review focuses on the role of leukocyte integrins in the leukocyte adhesion cascade. Experimental evidence that has implicated leukocyte integrins as targets in animal models of inflammatory disorders, such as experimental autoimmune encephalomyelitis, psoriasis, inflammatory bone loss and inflammatory bowel disease as well as preclinical and clinical therapeutic applications of antibodies that target leukocyte integrins in various inflammatory disorders are presented. Finally, we review recent findings on endogenous inhibitors that modify leukocyte integrin function, which could emerge as promising therapeutic targets.
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Affiliation(s)
- Ioannis Mitroulis
- Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Vasileia I Alexaki
- Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Ioannis Kourtzelis
- Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Athanassios Ziogas
- Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - George Hajishengallis
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Triantafyllos Chavakis
- Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
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15
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Gupta A, Espinosa V, Galusha LE, Rahimian V, Miro KL, Rivera-Medina A, Kasinathan C, Capitle E, Aguila HA, Kachlany SC. Expression and targeting of lymphocyte function-associated antigen 1 (LFA-1) on white blood cells for treatment of allergic asthma. J Leukoc Biol 2014; 97:439-46. [PMID: 25341726 DOI: 10.1189/jlb.5hi0414-196r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Allergic asthma is a chronic respiratory disease that results from an exaggerated inflammatory response in the airways. Environment stimuli, such as pollen and HDM, cause activation and migration of inflammatory WBCs into the respiratory tract, where they cause lung damage. Migration of these WBCs is dependent on the active configuration of the β2 integrin LFA-1. The experimental therapeutic agent LtxA specifically targets active LFA-1 and causes cell death. We investigated the association between LFA-1 and allergic asthma and hypothesized that targeting LFA-1 with LtxA could be an attractive strategy for treatment of the condition. We examined LFA-1 (CD11a) levels on PBMCs from patients with allergic asthma compared with healthy controls. Patients exhibited a significantly higher percentage of PBMCs expressing LFA-1 than healthy controls. Furthermore, the level of LFA-1 expression on patient PBMCs was greater than on healthy PBMCs. We identified a unique cellular population in patients that consisted of CD4(-) CD11a(hi) cells. We also evaluated LtxA in a HDM extract-induced mouse model for allergic asthma. LtxA caused resolution of disease in mice, as demonstrated by a decrease in BALF WBCs, a reduction in pulmonary inflammation and tissue remodeling, and a decrease in proinflammatory cytokines IL-4, IL-5, IL-9, IL-17F, and IL-23α in lung tissue. LFA-1 may serve as an important marker in allergic asthma, and the elimination of activated WBCs by use of LtxA could be a viable therapeutic strategy for treating patients with this condition.
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Affiliation(s)
- Anukriti Gupta
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Vanessa Espinosa
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Lindsey E Galusha
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Vahid Rahimian
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Katie L Miro
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Amariliz Rivera-Medina
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Chinnaswamy Kasinathan
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Eugenio Capitle
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Helen A Aguila
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
| | - Scott C Kachlany
- *Department of Oral Biology, Rutgers School of Dental Medicine, Newark, New Jersey, USA; Departments of Medicine, Center for Immunity and Inflammation and Division of Allergy and Immunology, and Pediatrics, Rutgers New Jersey Medical School, Newark, New Jersey, USA; and Actinobac Biomed, New Brunswick, New Jersey, USA
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16
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Kaur M, Kachlany SC. Aggregatibacter actinomycetemcomitans leukotoxin (LtxA; Leukothera) induces cofilin dephosphorylation and actin depolymerization during killing of malignant monocytes. MICROBIOLOGY-SGM 2014; 160:2443-2452. [PMID: 25169107 DOI: 10.1099/mic.0.082347-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Leukotoxin (LtxA; Leukothera), a protein toxin secreted by the oral bacterium Aggregatibacter actinomycetemcomitans, specifically kills white blood cells (WBCs). LtxA binds to the receptor known as lymphocyte function associated antigen-1 (LFA-1), a β2 integrin expressed only on the surface of WBCs. LtxA is being studied as a virulence factor that helps A. actinomycetemcomitans evade host defences and as a potential therapeutic agent for the treatment of WBC diseases. LtxA-mediated cell death in monocytes involves both caspases and lysosomes; however, the signalling proteins that regulate and mediate cell death remain largely unknown. We used a 2D-gel proteomics approach to analyse the global protein expression changes that occur in response to LtxA. This approach identified the protein cofilin, which underwent dephosphorylation upon LtxA treatment. Cofilin is a ubiquitous actin-binding protein known to regulate actin dynamics and is regulated by LIM kinase (LIMK)-mediated phosphorylation. LtxA-mediated cofilin dephosphorylation was dependent on LFA-1 and cofilin dephosphorylation did not occur when LFA-1 bound to its natural ligand, ICAM-1. Treatment of cells with an inhibitor of LIMK (LIMKi) also led to cofilin dephosphorylation and enhanced killing by LtxA. This enhanced sensitivity to LtxA coincided with an increase in lysosomal disruption, and an increase in LFA-1 surface expression and clustering. Both LIMKi and LtxA treatment also induced actin depolymerization, which could play a role in trafficking and surface distribution of LFA-1. We propose a model in which LtxA-mediated cofilin dephosphorylation leads to actin depolymerization, LFA-1 overexpression/clustering, and enhanced lysosomal-mediated cell death.
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Affiliation(s)
- Manpreet Kaur
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, USA
| | - Scott C Kachlany
- Actinobac Biomed Inc., New Brunswick, NJ, USA.,Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, USA
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17
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Sialic acid residues are essential for cell lysis mediated by leukotoxin from Aggregatibacter actinomycetemcomitans. Infect Immun 2014; 82:2219-28. [PMID: 24643533 DOI: 10.1128/iai.01647-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leukotoxin (LtxA) from Aggregatibacter actinomycetemcomitans is known to target and lyse β2-integrin-expressing cells such as polymorphonuclear leukocytes and macrophages. LtxA is an important virulence factor that facilitates chronic inflammation and is strongly associated with a fast-progressing form of periodontitis caused by the JP2 clone of the bacterium. Here, we show that sialic acid residues are important for LtxA-induced cell lysis, regardless of whether the cell express β2-integrin or not. Clearly, removal of sialic acid groups significantly reduces a β2-integrin-specific LtxA-induced lysis. Moreover, sialic acid presented on alternative proteins, such as, for instance, on erythrocytes that do not express β2-integrin, also makes the cells more sensitive to LtxA. The data also illustrate the importance of the negative charge in order for the sialic acid to associate LtxA with the membrane. Removal of sialic acid is in itself sufficient to significantly reduce the negative charge on the erythrocytes. Moreover, we found that on human erythrocytes there is a positive association between the sensitivity to LtxA and the amount of negative charge caused by sialic acid. Interestingly, these features are not shared by all RTX toxins, since α-hemolysin from Escherichia coli induced cell lysis of both β2-integrin-expressing and nonexpressing cells and this lysis is independent of the presence of sialic acid residues. In conclusion, LtxA not only is cytotoxic to β2-integrin-expressing cells but can potentially initiate cell lysis in all cells that present a sufficient density of sialic acid groups on their plasma membrane.
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18
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Inhibition of LFA-1/ICAM-1-mediated cell adhesion by stilbene derivatives from Rheum undulatum. Arch Pharm Res 2012; 35:1763-70. [DOI: 10.1007/s12272-012-1008-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 07/16/2012] [Accepted: 07/17/2012] [Indexed: 10/27/2022]
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19
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DiFranco KM, Gupta A, Galusha LE, Perez J, Nguyen TVK, Fineza CD, Kachlany SC. Leukotoxin (Leukothera®) targets active leukocyte function antigen-1 (LFA-1) protein and triggers a lysosomal mediated cell death pathway. J Biol Chem 2012; 287:17618-17627. [PMID: 22467872 DOI: 10.1074/jbc.m111.314674] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Leukotoxin (LtxA) is a protein toxin that is secreted from the oral bacterium, Aggregatibacter actinomycetemcomitans. LtxA targets specifically the β(2) integrin, leukocyte function antigen-1 (LFA-1) on white blood cells (WBCs) and causes cell death. LtxA preferentially targets activated WBCs and is being developed as a therapeutic agent for the treatment of WBC diseases such as hematologic malignancies and autoimmune/inflammatory diseases. However, the mechanism by which interaction between LtxA and LFA-1 results in cell death is not well understood. Furthermore, how LtxA preferentially recognizes activated WBCs is not known. We show here that LtxA interacts specifically with LFA-1 in the active (exposed) conformation. In THP-1 monocytes, LtxA caused rapid activation of caspases, but LtxA could overcome the inhibition of caspases and still intoxicate. In contrast, inhibiting the vesicular trafficking pathway or cathepsin D release from the lysosome resulted in significant inhibition of LtxA-mediated cytotoxicity, indicating a more potent, lysosomal mediated cell death pathway. LtxA caused rapid disruption of the lysosomal membrane and release of lysosomal contents into the cytosol. Binding of LtxA to LFA-1 resulted in the internalization of both LtxA and LFA-1, with LtxA localizing specifically to the lysosomal compartment. To our knowledge, LtxA represents the first bacterial toxin shown to localize to the lysosome where it induces rapid cell death.
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Affiliation(s)
- Kristina M DiFranco
- Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103
| | - Anukriti Gupta
- Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103
| | - Lindsey E Galusha
- Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103
| | - Jarelys Perez
- Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103
| | - To-Vy K Nguyen
- Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103
| | - Camille D Fineza
- Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103
| | - Scott C Kachlany
- Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103; Actinobac Biomed, Inc., North Brunswick, New Jersey 08902.
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20
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Norsgaard H, Svensson L, Hagedorn PH, Moller K, Olsen GM, Labuda T. Translating clinical activity and gene expression signatures of etanercept and ciclosporin to the psoriasis xenograft SCID mouse model. Br J Dermatol 2012; 166:649-52. [PMID: 22050597 DOI: 10.1111/j.1365-2133.2011.10713.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND The psoriasis xenograft severe combined immunodeficiency (SCID) mouse model is used in drug discovery to obtain preclinical proof-of-principle of new antipsoriatic drug candidates. Validation of this model by antipsoriatic therapeutic agents in clinical use is important to understand its utility as well as its limitations. The effects of the clinically efficacious antitumour necrosis factor-α biologics have not yet been demonstrated in the psoriasis xenograft SCID mouse model. OBJECTIVES To investigate the effect of etanercept and to explore the time-dependent changes induced by ciclosporin on psoriatic biomarkers at the gene expression level in the psoriasis xenograft SCID mouse model. METHODS Xenografted SCID mice were treated either with etanercept and vehicle for 2 weeks or with ciclosporin and vehicle for 2 and 4 weeks, respectively. Treatment-induced changes in the psoriatic grafts were assessed by gene expression analysis and compared with published clinical microarray data. The grafts were further evaluated by histology and immunohistochemistry. RESULTS Etanercept induced normalization of gene expression, which correlated with a significant reduction in epidermal thickness as well as a decrease in the number of proliferative cells. Anti-inflammatory activity induced by ciclosporin preceded the reduction in epidermal hyperplasia. Comparison of the etanercept- and ciclosporin-induced gene expression signatures with clinical microarray data showed significant correlations. CONCLUSIONS Efficacy of etanercept and ciclosporin could be translated to the psoriasis xenograft SCID mouse model.
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Affiliation(s)
- H Norsgaard
- Departments of Molecular Biomedicine Disease Pharmacology, LEO Pharma A/S, Industriparken 55, Ballerup, Denmark
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21
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Svensson L, Røpke MA, Norsgaard H. Psoriasis drug discovery: methods for evaluation of potential drug candidates. Expert Opin Drug Discov 2011; 7:49-61. [DOI: 10.1517/17460441.2011.632629] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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22
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Hioe CE, Tuen M, Vasiliver-Shamis G, Alvarez Y, Prins KC, Banerjee S, Nádas A, Cho MW, Dustin ML, Kachlany SC. HIV envelope gp120 activates LFA-1 on CD4 T-lymphocytes and increases cell susceptibility to LFA-1-targeting leukotoxin (LtxA). PLoS One 2011; 6:e23202. [PMID: 21850260 PMCID: PMC3151267 DOI: 10.1371/journal.pone.0023202] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 07/08/2011] [Indexed: 11/18/2022] Open
Abstract
The cellular adhesion molecule LFA-1 and its ICAM-1 ligand play an important role in promoting HIV-1 infectivity and transmission. These molecules are present on the envelope of HIV-1 virions and are integral components of the HIV virological synapse. However, cellular activation is required to convert LFA-1 to the active conformation that has high affinity binding for ICAM-1. This study evaluates whether such activation can be induced by HIV itself. The data show that HIV-1 gp120 was sufficient to trigger LFA-1 activation in fully quiescent naïve CD4 T cells in a CD4-dependent manner, and these CD4 T cells became more susceptible to killing by LtxA, a bacterial leukotoxin that preferentially targets leukocytes expressing high levels of the active LFA-1. Moreover, virus p24-expressing CD4 T cells in the peripheral blood of HIV-infected subjects were found to have higher levels of surface LFA-1, and LtxA treatment led to significant reduction of the viral DNA burden. These results demonstrate for the first time the ability of HIV to directly induce LFA-1 activation on CD4 T cells. Although LFA-1 activation may enhance HIV infectivity and transmission, it also renders the cells more susceptible to an LFA-1-targeting bacterial toxin, which may be harnessed as a novel therapeutic strategy to deplete virus reservoir in HIV-infected individuals.
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Affiliation(s)
- Catarina E Hioe
- Department of Pathology, New York University School of Medicine, and Veterans Affairs New York Harbor Healthcare System, Manhattan Campus, New York, New York, United States of America.
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Gupta A, Le A, Belinka BA, Kachlany SC. In vitro synergism between LFA-1 targeting leukotoxin (Leukothera™) and standard chemotherapeutic agents in leukemia cells. Leuk Res 2011; 35:1498-505. [PMID: 21664691 DOI: 10.1016/j.leukres.2011.05.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 05/06/2011] [Accepted: 05/15/2011] [Indexed: 01/29/2023]
Abstract
Leukotoxin (Leukothera™; LtxA) is a bacterial protein and experimental therapeutic that binds leukocyte function antigen (LFA-1) on white blood cells (WBCs) and induces cell death via apoptosis or necrosis. We previously found that LtxA preferentially targets WBCs with high levels of activated LFA-1, which is characteristic of many leukemias and lymphomas, and showed that LtxA exhibits significant anti-leukemia activity in vivo using the humanized SCID mouse model. In this report, we demonstrate that LtxA induces very rapid (1h) apoptosis in acute monocytic leukemia THP-1 cells characterized by binding of annexin V to cells, loss of mitochondrial membrane potential, depletion of cellular ATP, and fragmentation of chromosomal DNA. We tested the activity of LtxA in combination with the standard chemotherapeutic agents, etoposide, mitoxantrone, daunorubicin, busulfan, and imatinib against several leukemia cell lines, including THP-1, GDM-1, HL-60, and KU-812 cells. LtxA exhibited synergism with all the drugs, and the levels of synergy were dependent on the doses used and cell lines examined. In general, the greatest level of synergy was observed with LtxA and etoposide or imatinib. Combination index (CI) values were less than 0.1 for many of the combinations, indicating very strong synergism. In addition, LtxA alone was cytotoxic to primary cells from newly diagnosed, relapsed, and refractory patients with different hematological malignancies. Thus, LtxA is highly effective at inducing rapid apoptosis both as a single agent and in combination with approved leukemia therapies.
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Affiliation(s)
- Anukriti Gupta
- Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA
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