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Molyer B, Kumar A, Angel JB. SMAC Mimetics as Therapeutic Agents in HIV Infection. Front Immunol 2021; 12:780400. [PMID: 34899741 PMCID: PMC8660680 DOI: 10.3389/fimmu.2021.780400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/03/2021] [Indexed: 11/16/2022] Open
Abstract
Although combination antiretroviral therapy is extremely effective in lowering HIV RNA to undetectable levels in the blood, HIV persists in latently infected CD4+ T-cells and persistently infected macrophages. In latently/persistently infected cells, HIV proteins have shown to affect the expression of proteins involved in the apoptosis pathway, notably the inhibitors of apoptosis proteins (IAPs), and thereby influence cell survival. IAPs, which are inhibited by endogenous second mitochondrial-derived activators of caspases (SMAC), can serve as targets for SMAC mimetics, synthetic compounds capable of inducing apoptosis. There is increasing evidence that SMAC mimetics can be used to reverse HIV latency and/or kill cells that are latently/persistently infected with HIV. Here, we review the current state of knowledge of SMAC mimetics as an approach to eliminate HIV infected cells and discuss the potential future use of SMAC mimetics as part of an HIV cure strategy.
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Affiliation(s)
- Bengisu Molyer
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Ashok Kumar
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Apoptosis Research Center of Children's Hospital of Eastern Ontario, Department of Microbiology and Immunology, University of Ottawa, Ottawa, Canada
| | - Jonathan B Angel
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Division of Infectious Diseases, Ottawa Hospital, Ottawa, ON, Canada
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Caballero RE, Dong SXM, Gajanayaka N, Ali H, Cassol E, Cameron WD, Korneluk R, Tremblay MJ, Angel JB, Kumar A. Role of RIPK1 in SMAC mimetics-induced apoptosis in primary human HIV-infected macrophages. Sci Rep 2021; 11:22901. [PMID: 34824340 PMCID: PMC8617210 DOI: 10.1038/s41598-021-02146-w] [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: 07/15/2021] [Accepted: 11/09/2021] [Indexed: 11/09/2022] Open
Abstract
Macrophages serve as viral reservoirs due to their resistance to apoptosis and HIV-cytopathic effects. We have previously shown that inhibitor of apoptosis proteins (IAPs) confer resistance to HIV-Vpr-induced apoptosis in normal macrophages. Herein, we show that second mitochondrial activator of caspases (SMAC) mimetics (SM) induce apoptosis of monocyte-derived macrophages (MDMs) infected in vitro with a R5-tropic laboratory strain expressing heat stable antigen, chronically infected U1 cells, and ex-vivo derived MDMs from HIV-infected individuals. To understand the mechanism governing SM-induced cell death, we show that SM-induced cell death of primary HIV-infected macrophages was independent of the acquisition of M1 phenotype following HIV infection of macrophages. Instead, SM-induced cell death was found to be mediated by IAPs as downregulation of IAPs by siRNAs induced cell death of HIV-infected macrophages. Moreover, HIV infection caused receptor interacting protein kinase-1 (RIPK1) degradation which in concert with IAP1/2 downregulation following SM treatment may result in apoptosis of macrophages. Altogether, our results show that SM selectively induce apoptosis in primary human macrophages infected in vitro with HIV possibly through RIPK1. Moreover, modulation of the IAP pathways may be a potential strategy for selective killing of HIV-infected macrophages in vivo.
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Affiliation(s)
- Ramon Edwin Caballero
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada. .,Division of Virology, Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Research Building 2, University of Ottawa, Ottawa, ON, K1H 8L1, Canada.
| | - Simon Xin Min Dong
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Niranjala Gajanayaka
- Division of Virology, Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Research Building 2, University of Ottawa, Ottawa, ON, K1H 8L1, Canada
| | - Hamza Ali
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Division of Virology, Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Research Building 2, University of Ottawa, Ottawa, ON, K1H 8L1, Canada
| | - Edana Cassol
- Department of Health Sciences, Carleton University, Ottawa, ON, Canada
| | - William D Cameron
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Division of Infectious Diseases, The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Robert Korneluk
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Division of Virology, Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Research Building 2, University of Ottawa, Ottawa, ON, K1H 8L1, Canada
| | - Michel J Tremblay
- Centre de recherche du CHU de Québec-Université Laval, Université Laval, Québec City, QC, Canada
| | - Jonathan B Angel
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Division of Infectious Diseases, The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Ashok Kumar
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada. .,Division of Virology, Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Research Building 2, University of Ottawa, Ottawa, ON, K1H 8L1, Canada. .,Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.
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