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Duffy FJ, Hertoghs N, Du Y, Neal ML, Oyong D, McDermott S, Minkah N, Carnes J, Schwedhelm KV, McElrath MJ, De Rosa SC, Newell E, Aitchison JD, Stuart K. Longitudinal immune profiling after radiation-attenuated sporozoite vaccination reveals coordinated immune processes correlated with malaria protection. Front Immunol 2022; 13:1042741. [PMID: 36591224 PMCID: PMC9798120 DOI: 10.3389/fimmu.2022.1042741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
Background Identifying immune processes required for liver-stage sterilizing immunity to malaria remains an open problem. The IMRAS trial comprised 5x immunizations with radiation-attenuated sporozoites resulting in 55% protection from subsequent challenge. Methods To identify correlates of vaccination and protection, we performed detailed systems immunology longitudinal profiling of the entire trial time course including whole blood transcriptomics, detailed PBMC cell phenotyping and serum antigen array profiling of 11 IMRAS radiation-attenuated sporozoite (RAS) vaccinees at up to 21 timepoints each. Results RAS vaccination induced serum antibody responses to CSP, TRAP, and AMA1 in all vaccinees. We observed large numbers of differentially expressed genes associated with vaccination response and protection, with distinctly differing transcriptome responses elicited after each immunization. These included inflammatory and proliferative responses, as well as increased abundance of monocyte and DC subsets after each immunization. Increases in Vδ2 γδ; T cells and MAIT cells were observed in response to immunization over the course of study, and CD1c+ CD40+ DC abundance was significantly associated with protection. Interferon responses strongly differed between protected and non-protected individuals with high interferon responses after the 1st immunization, but not the 2nd-5th. Blood transcriptional interferon responses were correlated with abundances of different circulating classical and non-classical monocyte populations. Conclusions This study has revealed multiple coordinated immunological processes induced by vaccination and associated with protection. Our work represents the most detailed immunological profiling of a RAS vaccine trial performed to date and will guide the design and interpretation of future malaria vaccine trials.
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Affiliation(s)
- Fergal J. Duffy
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States,*Correspondence: Fergal J. Duffy, ; Ken Stuart,
| | - Nina Hertoghs
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States
| | - Ying Du
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States
| | - Maxwell L. Neal
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States
| | - Damian Oyong
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States
| | - Suzanne McDermott
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States
| | - Nana Minkah
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States
| | - Jason Carnes
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States
| | - Katharine V. Schwedhelm
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, United States
| | - M. Juliana McElrath
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, United States
| | - Stephen C. De Rosa
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, United States
| | - Evan Newell
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, United States
| | - John D. Aitchison
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States
| | - Ken Stuart
- Center for Global Infectious Disease Research, Seattle Children’s Hospital, Seattle, WA, United States,*Correspondence: Fergal J. Duffy, ; Ken Stuart,
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2
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Chauhan R, Awasthi V, Thakur RS, Pande V, Chattopadhyay D, Das J. CD4 +ICOS +Foxp3 +: a sub-population of regulatory T cells contribute to malaria pathogenesis. Malar J 2022; 21:32. [PMID: 35109868 PMCID: PMC8812217 DOI: 10.1186/s12936-022-04055-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 01/19/2022] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Regulatory T cells are known to play a key role to counter balance the protective immune response and immune mediated pathology. However, the role of naturally occurring regulatory cells CD4+CD25+Foxp3+ in malaria infection during the disease pathogenesis is controversial. Beside this, ICOS molecule has been shown to be involved in the development and function of regulatory T cell enhance IL-10 production. Therefore, possible involvement of the ICOS dependent regulatory CD4+ICOS+Foxp3+ T cells in resistance/susceptibility during malaria parasite is explored in this study. METHODS 5 × 105 red blood cells infected with non-lethal and lethal parasites were inoculated in female Balb/c mice by intra-peritoneal injection. Infected or uninfected mice were sacrificed at early (3rd day post infection) and later stage (10th day post infection) of infection. Harvested cells were analysed by using flow cytometer and serum cytokine by Bioplex assay. RESULTS Thin blood films show that percentages of parasitaemia increases with disease progression in infections with the lethal malaria parasite and mice eventually die by day 14th post-infection. Whereas in case of non-lethal malaria parasite, parasitaemia goes down by 7th day post infection and gets cleared within 13th day. The number of CD4+ ICOS+ T cells increases in lethal infection with disease progression. Surprisingly, in non-lethal parasite, ICOS expression decreases after day 7th post infection as parasitaemia goes down. The frequency of CD4+ICOS+FoxP3+ Tregs was significantly higher in lethal parasitic infection as compared to the non-lethal parasite. The level of IL-12 cytokine was remarkably higher in non-lethal infection compared to the lethal infection. In contrast, the level of IL-10 cytokines was higher in lethal parasite infection compared to the non-lethal parasite. CONCLUSION Taken together, these data suggest that lethal parasite induce immunosuppressive environment, protecting from host immune responses and help the parasite to survive whereas non-lethal parasite leads to low frequencies of Treg cells seldom impede immune response that allow the parasite to get self-resolved.
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Affiliation(s)
- Rubika Chauhan
- Parasite-Host Biology, National Institute of Malaria Research, Sector-8, Dwarka, New Delhi, 110077, India
| | - Vikky Awasthi
- Parasite-Host Biology, National Institute of Malaria Research, Sector-8, Dwarka, New Delhi, 110077, India
| | - Reva Sharan Thakur
- Parasite-Host Biology, National Institute of Malaria Research, Sector-8, Dwarka, New Delhi, 110077, India
| | - Veena Pande
- Biotechnology Department, Kumaun University, Nainital, India
| | - Debprasad Chattopadhyay
- ICMR Virus Unit, ID and BG Hospital, Kolkata, 700010, India.,ICMR-National Institute of Traditional Medicine (NITM), Belagavi, 590010, India
| | - Jyoti Das
- Parasite-Host Biology, National Institute of Malaria Research, Sector-8, Dwarka, New Delhi, 110077, India.
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3
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Cai C, Hu Z, Yu X. Accelerator or Brake: Immune Regulators in Malaria. Front Cell Infect Microbiol 2020; 10:610121. [PMID: 33363057 PMCID: PMC7758250 DOI: 10.3389/fcimb.2020.610121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022] Open
Abstract
Malaria is a life-threatening infectious disease, affecting over 250 million individuals worldwide each year, eradicating malaria has been one of the greatest challenges to public health for a century. Growing resistance to anti-parasitic therapies and lack of effective vaccines are major contributing factors in controlling this disease. However, the incomplete understanding of parasite interactions with host anti-malaria immunity hinders vaccine development efforts to date. Recent studies have been unveiling the complexity of immune responses and regulators against Plasmodium infection. Here, we summarize our current understanding of host immune responses against Plasmodium-derived components infection and mainly focus on the various regulatory mechanisms mediated by recent identified immune regulators orchestrating anti-malaria immunity.
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Affiliation(s)
- Chunmei Cai
- Research Center for High Altitude Medicine, School of Medical, Qinghai University, Xining, China
- Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province, Qinghai University, Xining, China
| | - Zhiqiang Hu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiao Yu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Lab of Single Cell Technology and Application, Southern Medical University, Guangzhou, China
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4
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Sun Y, Cheng Y. STING or Sting: cGAS-STING-Mediated Immune Response to Protozoan Parasites. Trends Parasitol 2020; 36:773-784. [PMID: 32736985 DOI: 10.1016/j.pt.2020.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/18/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023]
Abstract
Emerging evidence suggests that the DNA-sensing pathway plays a crucial role in innate immunity against multiple diseases, especially infectious diseases. Cyclic GMP-AMP synthase (cGAS), as a DNA sensor, and stimulator of interferon (IFN) genes (STING), as an adaptor protein, are the central components that link DNA sensing to immunologic functions - including, but not limited to, the type I IFN response. Recently, a series of studies have revealed that genomic DNA from protozoan parasites triggers the cGAS-STING pathway, and these studies identified the positive and negative regulators that modulate the signaling in parasite infection. Here, we summarize current understanding of the critical functions and potential applications of the cGAS-STING axis in parasitic diseases, specifically those caused by malaria parasites.
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Affiliation(s)
- Yifan Sun
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi 214122, Jiangsu, People's Republic of China
| | - Yang Cheng
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi 214122, Jiangsu, People's Republic of China.
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5
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Innate immunity limits protective adaptive immune responses against pre-erythrocytic malaria parasites. Nat Commun 2019; 10:3950. [PMID: 31477704 PMCID: PMC6718385 DOI: 10.1038/s41467-019-11819-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/06/2019] [Indexed: 02/07/2023] Open
Abstract
Immunization with attenuated whole Plasmodium sporozoites constitutes a promising vaccination strategy. Compared to replication-deficient parasites, immunization with replication-competent parasites confers better protection and also induces a type I IFN (IFN-1) response, but whether this IFN-1 response has beneficial or adverse effects on vaccine-induced adaptive immunity is not known. Here, we show that IFN-1 signaling-deficient mice immunized with replication-competent sporozoites exhibit superior protection against infection. This correlates with superior CD8 T cell memory including reduced expression of the exhaustion markers PD-1 and LAG-3 on these cells and increased numbers of memory CD8 T cells in the liver. Moreover, the adoptive transfer of memory CD8 T cells from the livers of previously immunized IFN-1 signaling-deficient mice confers greater protection against liver stage parasites. However, the detrimental role of IFN-1 signaling is not CD8 T cell intrinsic. Together, our data demonstrate that liver stage-engendered IFN-1 signaling impairs hepatic CD8 T cell memory via a CD8 T cell-extrinsic mechanism. Here, Minkah et al. show that, while immunization with replication-competent Plasmodium parasites can confer sterile protection against infection, it also induces a type I interferon response that adversely affects anti-malaria immunity by affecting numbers of protective hepatic CD8 T cells and CD8 T cell function.
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6
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Othman AS, Franke-Fayard BM, Imai T, van der Gracht ETI, Redeker A, Salman AM, Marin-Mogollon C, Ramesar J, Chevalley-Maurel S, Janse CJ, Arens R, Khan SM. OX40 Stimulation Enhances Protective Immune Responses Induced After Vaccination With Attenuated Malaria Parasites. Front Cell Infect Microbiol 2018; 8:247. [PMID: 30073152 PMCID: PMC6060232 DOI: 10.3389/fcimb.2018.00247] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 06/28/2018] [Indexed: 01/15/2023] Open
Abstract
Protection against a malaria infection can be achieved by immunization with live-attenuated Plasmodium sporozoites and while the precise mechanisms of protection remain unknown, T cell responses are thought to be critical in the elimination of infected liver cells. In cancer immunotherapies, agonistic antibodies that target T cell surface proteins, such as CD27, OX40 (CD134), and 4-1BB (CD137), have been used to enhance T cell function by increasing co-stimulation. In this study, we have analyzed the effect of agonistic OX40 monoclonal antibody treatment on protective immunity induced in mice immunized with genetically attenuated parasites (GAPs). OX40 stimulation enhanced protective immunity after vaccination as shown by an increase in the number of protected mice and delay to blood-stage infection after challenge with wild-type sporozoites. Consistent with the enhanced protective immunity enforced OX40 stimulation resulted in an increased expansion of antigen-experienced effector (CD11ahiCD44hi) CD8+ and CD4+ T cells in the liver and spleen and also increased IFN-γ and TNF producing CD4+ T cells in the liver and spleen. In addition, GAP immunization plus α-OX40 treatment significantly increased sporozoite-specific IgG responses. Thus, we demonstrate that targeting T cell costimulatory receptors can improve sporozoite-based vaccine efficacy.
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Affiliation(s)
- Ahmad Syibli Othman
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands.,Faculty of Health Sciences, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
| | - Blandine M Franke-Fayard
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Takashi Imai
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Esmé T I van der Gracht
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Anke Redeker
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Ahmed M Salman
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands.,The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Catherin Marin-Mogollon
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Jai Ramesar
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Chris J Janse
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Ramon Arens
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Shahid M Khan
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
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7
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Parmar R, Patel H, Yadav N, Parikh R, Patel K, Mohankrishnan A, Bhurani V, Joshi U, Dalai SK. Infectious Sporozoites of Plasmodium berghei Effectively Activate Liver CD8α + Dendritic Cells. Front Immunol 2018; 9:192. [PMID: 29472929 PMCID: PMC5809440 DOI: 10.3389/fimmu.2018.00192] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 01/23/2018] [Indexed: 11/13/2022] Open
Abstract
Immunization with radiation-attenuated sporozoites (RAS) shown to confer complete sterile protection against Plasmodia liver-stage (LS) infection that lasts about 6 to 9 months in mice. We have found that the intermittent infectious sporozoite challenge to immune mice following RAS vaccination extends the longevity of sterile protection by maintaining CD8+ T cell memory responses to LS infection. It is reported that CD8α+ dendritic cells (DCs) are involved in the induction of LS-specific CD8+ T cells following RAS or genetically attenuated parasite (GAP) vaccination. In this study, we demonstrate that CD8α+ DCs respond differently to infectious sporozoite or RAS inoculation. The higher accumulation and activation of CD8α+ DCs was seen in the liver in response to infectious sporozoite 72 h postinoculation and found to be associated with higher expression of chemokines (CCL-20 and CCL-21) and type I interferon response via toll-like receptor signaling in liver. Moreover, the infectious sporozoites were found to induce qualitative changes in terms of the increased MHCII expression as well as costimulatory molecules including CD40 on the CD8α+ DCs compared to RAS inoculation. We have also found that infectious sporozoite challenge increased CD40L-expressing CD4+ T cells, which could help CD8+ T cells in the liver through "licensing" of the antigen-presenting cells. Our results suggest that infectious sporozoite challenge to prior RAS immunized mice modulates the CD8α+ DCs, which might be shaping the fate of memory CD8+ T cells against Plasmodium LS infection.
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Affiliation(s)
- Rajesh Parmar
- Institute of Science, Nirma University, Ahmedabad, India
| | - Hardik Patel
- Institute of Science, Nirma University, Ahmedabad, India
| | - Naveen Yadav
- Institute of Science, Nirma University, Ahmedabad, India
| | - Ritika Parikh
- Institute of Science, Nirma University, Ahmedabad, India
| | - Khyati Patel
- Institute of Science, Nirma University, Ahmedabad, India
| | | | | | - Urja Joshi
- Institute of Science, Nirma University, Ahmedabad, India
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8
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Feng C, Feng M, Jiao R, Liu D, Jin Y, Zhao X, Xiao R. Effect of Dezocine on IL-12 and IL-10 secretion and lymphocyte activation by culturing dendritic cells from human umbilical cord blood. Eur J Pharmacol 2016; 796:110-114. [PMID: 28017828 DOI: 10.1016/j.ejphar.2016.12.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 12/20/2016] [Accepted: 12/21/2016] [Indexed: 01/06/2023]
Abstract
Dezocine has been generally utilized for pain therapy and auxiliary anesthesia. Although it has some advantages on the prevention of some anesthesia related complications, its effect on immune responses remains unclear. Our study investigated the effects of Dezocine on IL-10 and IL-12 secretion and lymphocytes activation by culturing dendritic cells (DCs), and revealed the underlying mechanism. Mononuclear cells were divided into negative control group (GN), positive control group (GP), experimental group (GD; GD5, D7, D9). DCs morphological structure was performed by microscope and its phenotypes were evaluated by flow cytometry. IL-12 and IL-10 levels were determined by ELISA and lymphocyte proliferation capacity was performed by MTT assay. Results showed that typical morphological characters of DCs were observed in GP and GD. The positive cell percentages of CD83, HLA-DR, CD80, CD86 and CD40 in GD were lower than those in GP, but higher than the GN group (P<0.01). IL-12 level in GD was higher than in GP, however, IL-10 was opposite (P<0.01). The optical density in GD was lower than in GP (P<0.05). There were no dose-dependent relationships correlated with DCs phenotypes, IL-12 and IL-10 secretion and lymphocytes activation (P>0.05). Our conclusion was that Dezocine might play a role in immunity by regulating IL-12 and IL-10 secretion, and affecting lymphocyte activity in process of DCs maturation. Our findings reveal an unexpected immuno-regulatory function of Dezocine in DCs and provide an important insight for investigating the effect of opioid drugs in immunologic responses.
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Affiliation(s)
- Chang Feng
- Department of Anesthesiology, The Second Hospital of Shandong University, 247 Bei Yuan Street, Jinan 250033, China
| | - Man Feng
- Department of Pathology, Affiliated Hospital of Shandong Academy of Medical Sciences, Shandong Academy of Medical Sciences, 38 Wu Yingshan Road, Jinan 250031, China
| | - Ran Jiao
- Department of Operation Room, Ophthalmologic Hospital of Shandong Province, 372 Jing Si Road, Jinan 250021, China
| | - Dongyi Liu
- Department of Anesthesiology, The Second Hospital of Shandong University, 247 Bei Yuan Street, Jinan 250033, China
| | - Yanwu Jin
- Department of Anesthesiology, The Second Hospital of Shandong University, 247 Bei Yuan Street, Jinan 250033, China
| | - Xin Zhao
- Department of Anesthesiology, The Second Hospital of Shandong University, 247 Bei Yuan Street, Jinan 250033, China.
| | - Ruixue Xiao
- Department of Pathology, Affiliated Hospital of Shandong Academy of Medical Sciences, Shandong Academy of Medical Sciences, 38 Wu Yingshan Road, Jinan 250031, China
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9
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Increased CD40 Expression Enhances Early STING-Mediated Type I Interferon Response and Host Survival in a Rodent Malaria Model. PLoS Pathog 2016; 12:e1005930. [PMID: 27716849 PMCID: PMC5055354 DOI: 10.1371/journal.ppat.1005930] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 09/12/2016] [Indexed: 01/01/2023] Open
Abstract
Both type I interferon (IFN-I) and CD40 play a significant role in various infectious diseases, including malaria and autoimmune disorders. CD40 is mostly known to function in adaptive immunity, but previous observations of elevated CD40 levels early after malaria infection of mice led us to investigate its roles in innate IFN-I responses and disease control. Using a Plasmodium yoelii nigeriensis N67 and C57BL/6 mouse model, we showed that infected CD40-/- mice had reduced STING and serum IFN-β levels day-2 post infection, higher day-4 parasitemia, and earlier deaths. CD40 could greatly enhance STING-stimulated luciferase signals driven by the IFN-β promoter in vitro, which was mediated by increased STING protein levels. The ability of CD40 to influence STING expression was confirmed in CD40-/- mice after malaria infection. Substitutions at CD40 TRAF binding domains significantly decreased the IFN-β signals and STING protein level, which was likely mediated by changes in STING ubiquitination and degradation. Increased levels of CD40, STING, and ISRE driven luciferase signal in RAW Lucia were observed after phagocytosis of N67-infected red blood cells (iRBCs), stimulation with parasite DNA/RNA, or with selected TLR ligands [LPS, poly(I:C), and Pam3CSK4]. The results suggest stimulation of CD40 expression by parasite materials through TLR signaling pathways, which was further confirmed in bone marrow derived dendritic cells/macrophages (BMDCs/BMDMs) and splenic DCs from CD40-/-, TLR3-/- TLR4-/-, TRIF-/-, and MyD88-/- mice after iRBC stimulation or parasite infection. Our data connect several signaling pathways consisting of phagocytosis of iRBCs, recognition of parasite DNA/RNA (possibly GPI) by TLRs, elevated levels of CD40 and STING proteins, increased IFN-I production, and longer host survival time. This study reveals previously unrecognized CD40 function in innate IFN-I responses and protective pathways in infections with malaria strains that induce a strong IFN-I response, which may provide important information for better understanding and management of malaria.
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10
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Dendritic Cells and Their Multiple Roles during Malaria Infection. J Immunol Res 2016; 2016:2926436. [PMID: 27110574 PMCID: PMC4823477 DOI: 10.1155/2016/2926436] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/06/2016] [Indexed: 12/22/2022] Open
Abstract
Dendritic cells (DCs) play a central role in the initiation of adaptive immune responses, efficiently presenting antigens to T cells. This ability relies on the presence of numerous surface and intracellular receptors capable of sensing microbial components as well as inflammation and on a very efficient machinery for antigen presentation. In this way, DCs sense the presence of a myriad of pathogens, including Plasmodium spp., the causative agent of malaria. Despite many efforts to control this infection, malaria is still responsible for high rates of morbidity and mortality. Different groups have shown that DCs act during Plasmodium infection, and data suggest that the phenotypically distinct DCs subsets are key factors in the regulation of immunity during infection. In this review, we will discuss the importance of DCs for the induction of immunity against the different stages of Plasmodium, the outcomes of DCs activation, and also what is currently known about Plasmodium components that trigger such activation.
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