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Rabacal W, Schweitzer F, Kling HM, Buzzelli L, Rayens E, Norris KA. A therapeutic vaccine strategy to prevent Pneumocystis pneumonia in an immunocompromised host in a non-human primate model of HIV and Pneumocystis co-infection. Front Immunol 2022; 13:1036658. [PMID: 36561749 PMCID: PMC9763597 DOI: 10.3389/fimmu.2022.1036658] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022] Open
Abstract
Introduction Pneumocystis is a ubiquitous fungal pathogen that causes pneumonia (PCP) and pulmonary sequelae in HIV-infected individuals and other immunocompromised populations. With the success of anti-retroviral therapy for HIV-infected individuals the frequency of PCP in that population has decreased, however, PCP remains a significant cause of morbidity and mortality in individuals with hematologic and solid malignancies, and in individuals treated with immunosuppressive therapies for autoimmune diseases, and following bone marrow and solid organ transplantation. Despite the clinical need, there is no approved vaccine to prevent PCP in vulnerable populations. The ultimate goal of the field is to develop an effective vaccine that can overcome immune deficits in at risk populations and induce long-lasting protective immunity to Pneumocystis. Toward this goal, our laboratory has established a model of PCP co-infection in simian immunodeficiency virus (SIV)-infected non-human primates (NHP) and identified a recombinant protein sub-unit vaccine, KEX1, that induces robust anti-Pneumocystis immunity in immune-competent macaques that is durable and prevents PCP following simian immunodeficiency virus (SIV)-induced immunosuppression. Type I, or invariant natural killer T (iNKT) cells have the potential to provide B cell help under conditions of reduced CD4+ T cell help. Methods In the present study, we used the SIV model of HIV infection to address whether therapeutic vaccination with the iNKT cell-activating adjuvant α-galactosylceramide (α-GC) and KEX1 (α-GC+KEX1) can effectively boost anti-Pneumocystis humoral immunity following virus-induced immunosuppression. Results Immunization of antigen-experienced NHPs with α-GC+KEX1 during the early chronic phase of SIV-infection significantly boosted anti-Pneumocystis humoral immunity by increasing memory B cells and antibody titers, and enhanced titer durability during SIV-induced immunosuppression. This therapeutic vaccination strategy boosted anti-Pneumocystis immune responses during SIV-infection and contributed to protection against Pneumocystis co-infection in KEX1-vaccinated macaques. Conclusion These studies present a novel strategy for stimulating durable anti-Pneumocystis humoral immunity in the context of complex, chronic SIV-induced immunosuppression and may be further applied to immunization of other immunosuppressed populations, and toward other common recall antigens.
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Affiliation(s)
- Whitney Rabacal
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia, Athens, GA, United States
| | - Finja Schweitzer
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia, Athens, GA, United States
| | - Heather M. Kling
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Lizabeth Buzzelli
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia, Athens, GA, United States
| | - Emily Rayens
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia, Athens, GA, United States
| | - Karen A. Norris
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia, Athens, GA, United States
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Rayens E, Rabacal W, Willems HME, Kirton GM, Barber JP, Mousa JJ, Celia-Sanchez BN, Momany M, Norris KA. Immunogenicity and protective efficacy of a pan-fungal vaccine in preclinical models of aspergillosis, candidiasis, and pneumocystosis. PNAS NEXUS 2022; 1:pgac248. [PMID: 36712332 PMCID: PMC9802316 DOI: 10.1093/pnasnexus/pgac248] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022]
Abstract
Invasive fungal infections cause over 1.5 million deaths worldwide. Despite increases in fungal infections as well as the numbers of individuals at risk, there are no clinically approved fungal vaccines. We produced a "pan-fungal" peptide, NXT-2, based on a previously identified vaccine candidate and homologous sequences from Pneumocystis, Aspergillus,Candida, and Cryptococcus. We evaluated the immunogenicity and protective capacity of NXT-2 in murine and nonhuman primate models of invasive aspergillosis, systemic candidiasis, and pneumocystosis. NXT-2 was highly immunogenic and immunized animals had decreased mortality and morbidity compared to nonvaccinated animals following induction of immunosuppression and challenge with Aspergillus, Candida, or Pneumocystis. Data in multiple animal models support the concept that immunization with a pan-fungal vaccine prior to immunosuppression induces broad, cross-protective antifungal immunity in at-risk individuals.
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Affiliation(s)
- Emily Rayens
- Center for Vaccines and Immunology, University of Georgia, Athens, GA 30602, USA
| | - Whitney Rabacal
- Center for Vaccines and Immunology, University of Georgia, Athens, GA 30602, USA
| | | | - Gabrielle M Kirton
- Center for Vaccines and Immunology, University of Georgia, Athens, GA 30602, USA
| | - James P Barber
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA
| | - Jarrod J Mousa
- Center for Vaccines and Immunology, University of Georgia, Athens, GA 30602, USA
| | - Brandi N Celia-Sanchez
- Fungal Biology Group, Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Michelle Momany
- Fungal Biology Group, Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
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Alsayed AR, Al-Dulaimi A, Alkhatib M, Al Maqbali M, Al-Najjar MAA, Al-Rshaidat MMD. A comprehensive clinical guide for Pneumocystis jirovecii pneumonia: a missing therapeutic target in HIV-uninfected patients. Expert Rev Respir Med 2022; 16:1167-1190. [PMID: 36440485 DOI: 10.1080/17476348.2022.2152332] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Pneumocystis jirovecii is an opportunistic, human-specific fungus that causes Pneumocystis pneumonia (PCP). PCP symptoms are nonspecific. A patient with P. jirovecii and another lung infection faces a diagnostic challenge. It may be difficult to determine which of these agents is responsible for the clinical symptoms, preventing effective treatment. Diagnostic and treatment efforts have been made more difficult by the rising frequency with which coronavirus 2019 (COVID-19) and PCP co-occur. AREAS COVERED Herein, we provide a comprehensive review of clinical and pharmacological recommendations along with a literature review of PCP in immunocompromised patients focusing on HIV-uninfected patients. EXPERT OPINION PCP may be masked by identifying co-existing pathogens that are not necessarily responsible for the observed infection. Patients with severe form COVID-19 should be examined for underlying immunodeficiency, and co-infections must be considered as co-infection with P. jirovecii may worsen COVID-19's severity and fatality. PCP should be investigated in patients with PCP risk factors who come with pneumonia and suggestive radiographic symptoms but have not previously received PCP prophylaxis. PCP prophylaxis should be explored in individuals with various conditions that impair the immune system, depending on their PCP risk.
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Affiliation(s)
- Ahmad R Alsayed
- Department of Clinical Pharmacy and Therapeutics, Faculty of Pharmacy, Applied Science Private University, Amman, Jordan
| | - Abdullah Al-Dulaimi
- Department of Clinical Pharmacy and Therapeutics, Faculty of Pharmacy, Applied Science Private University, Amman, Jordan
| | - Mohammad Alkhatib
- Department of Experimental Medicine, University of Rome "Tor Vergata", Roma, Italy
| | - Mohammed Al Maqbali
- Department of Nursing Midwifery and Health, Northumbria University, Newcastle-Upon-Tyne, UK
| | - Mohammad A A Al-Najjar
- Department of Pharmaceutical Sciences and Pharmaceutics, Applied Science Private University, Amman, Kingdom of Jordan
| | - Mamoon M D Al-Rshaidat
- Laboratory for Molecular and Microbial Ecology (LaMME), Department of Biological Sciences, School of Sciences, The University of Jordan, Amman, Jordan
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Charpentier E, Ménard S, Marques C, Berry A, Iriart X. Immune Response in Pneumocystis Infections According to the Host Immune System Status. J Fungi (Basel) 2021; 7:jof7080625. [PMID: 34436164 PMCID: PMC8399367 DOI: 10.3390/jof7080625] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 12/12/2022] Open
Abstract
The host immune response is critical in Pneumocystis pneumonia (PCP). Immunocompetent hosts can eliminate the fungus without symptoms, while immunodeficient hosts develop PCP with an unsuitable excessive inflammatory response leading to lung damage. From studies based on rodent models or clinical studies, this review aimed to better understand the pathophysiology of Pneumocystis infection by analysing the role of immune cells, mostly lymphocytes, according to the immune status of the infected host. Hence, this review first describes the immune physiological response in infected immunocompetent hosts that are able to eliminate the fungus. The objective of the second part is to identify the immune elements required for the control of the fungus, focusing on specific immune deficiencies. Finally, the third part concentrates on the effect of the different immune elements in immunocompromised subjects during PCP, to better understand which cells are detrimental, and which, on the contrary, are beneficial once the disease has started. This work highlights that the immune response associated with a favourable outcome of the infection may differ according to the immune status of the host. In the case of immunocompetency, a close communication between B cells and TCD4 within tertiary lymphocyte structures appears critical to activate M2 macrophages without much inflammation. Conversely, in the case of immunodeficiency, a pro-inflammatory response including Th1 CD4, cytotoxic CD8, NK cells, and IFNγ release seems beneficial for M1 macrophage activation, despite the impact of inflammation on lung tissue.
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Affiliation(s)
- Eléna Charpentier
- Department of Parasitology-Mycology, Toulouse University Hospital, 31059 Toulouse, France;
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
- Correspondence: (E.C.); (X.I.)
| | - Sandie Ménard
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
| | - Catherine Marques
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
| | - Antoine Berry
- Department of Parasitology-Mycology, Toulouse University Hospital, 31059 Toulouse, France;
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
| | - Xavier Iriart
- Department of Parasitology-Mycology, Toulouse University Hospital, 31059 Toulouse, France;
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
- Correspondence: (E.C.); (X.I.)
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Rayens E, Noble B, Vicencio A, Goldman DL, Bunyavanich S, Norris KA. Relationship of Pneumocystis antibody responses to paediatric asthma severity. BMJ Open Respir Res 2021; 8:8/1/e000842. [PMID: 33762359 PMCID: PMC7993353 DOI: 10.1136/bmjresp-2020-000842] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Although asthma is the most commonly diagnosed respiratory disease, its pathogenesis is complex, involving both genetic and environmental factors. A role for the respiratory microbiome in modifying asthma severity has been recently recognised. Airway colonisation by Pneumocystis jirovecii has previously been associated with multiple chronic lung diseases, including chronic obstructive pulmonary disease (COPD) and severe asthma (SA). Decreased incidence of Pneumocystis pneumonia in HIV-infected individuals and reduced severity of COPD is associated with naturally occurring antibody responses to the Pneumocystis antigen, Kexin (KEX1). METHODS 104 paediatric patients were screened for KEX1 IgG reciprocal end point titre (RET), including 51 with SA, 20 with mild/moderate asthma, 20 non-asthma and 13 with cystic fibrosis (CF) in a cross-sectional study. RESULTS Patients with SA had significantly reduced Pneumocystis KEX1 titres compared with patients with mild/moderate asthma (p=0.018) and CF (p=0.003). A binary KEX1 RET indicator was determined at a threshold of KEX1 RET=1000. Patients with SA had 4.40 (95% CI 1.28 to 13.25, p=0.014) and 17.92 (95% CI 4.15 to 66.62, p<0.001) times the odds of falling below that threshold compared with mild/moderate asthma and patients with CF, respectively. Moreover, KEX1 IgG RET did not correlate with tetanus toxoid IgG (r=0.21, p=0.82) or total IgE (r=0.03, p=0.76), indicating findings are specific to antibody responses to KEX1. CONCLUSIONS Paediatric patients with SA may be at higher risk for chronic Pneumocystis infections and asthma symptom exacerbation due to reduced levels of protective antibodies. Plasma KEX1 IgG titre may be a useful parameter in determining the clinical course of treatment for paediatric patients with asthma.
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Affiliation(s)
- Emily Rayens
- Center for Vaccines and Immunology, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
| | - Brenda Noble
- Center for Vaccines and Immunology, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
| | - Alfin Vicencio
- Pediatrics, Division of Pediatric Pulmonology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - David L Goldman
- Departments of Pediatrics, Microbiology & Immunology, Children's Hospital at Montefiore, Bronx, New York, USA
| | - Supinda Bunyavanich
- Pediatrics, Division of Pediatric Pulmonology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Karen A Norris
- Center for Vaccines and Immunology, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
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Gingerich AD, Norris KA, Mousa JJ. Pneumocystis Pneumonia: Immunity, Vaccines, and Treatments. Pathogens 2021; 10:pathogens10020236. [PMID: 33669726 PMCID: PMC7921922 DOI: 10.3390/pathogens10020236] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/11/2021] [Accepted: 02/16/2021] [Indexed: 12/18/2022] Open
Abstract
For individuals who are immunocompromised, the opportunistic fungal pathogen Pneumocystis jirovecii is capable of causing life-threatening pneumonia as the causative agent of Pneumocystis pneumonia (PCP). PCP remains an acquired immunodeficiency disease (AIDS)-defining illness in the era of antiretroviral therapy. In addition, a rise in non-human immunodeficiency virus (HIV)-associated PCP has been observed due to increased usage of immunosuppressive and immunomodulating therapies. With the persistence of HIV-related PCP cases and associated morbidity and mortality, as well as difficult to diagnose non-HIV-related PCP cases, an improvement over current treatment and prevention standards is warranted. Current therapeutic strategies have primarily focused on the administration of trimethoprim-sulfamethoxazole, which is effective at disease prevention. However, current treatments are inadequate for treatment of PCP and prevention of PCP-related death, as evidenced by consistently high mortality rates for those hospitalized with PCP. There are no vaccines in clinical trials for the prevention of PCP, and significant obstacles exist that have slowed development, including host range specificity, and the inability to culture Pneumocystis spp. in vitro. In this review, we overview the immune response to Pneumocystis spp., and discuss current progress on novel vaccines and therapies currently in the preclinical and clinical pipeline.
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Affiliation(s)
- Aaron D. Gingerich
- Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (A.D.G.); (K.A.N.)
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Karen A. Norris
- Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (A.D.G.); (K.A.N.)
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Jarrod J. Mousa
- Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (A.D.G.); (K.A.N.)
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Correspondence:
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7
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Detection of anti-Pneumocystis jirovecii antibodies in human serum using a recombinant synthetic multi-epitope kexin-based antigen. Eur J Clin Microbiol Infect Dis 2020; 39:2205-2209. [PMID: 32557324 PMCID: PMC7561569 DOI: 10.1007/s10096-020-03936-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 05/26/2020] [Indexed: 11/22/2022]
Abstract
Interest in the detection of specific anti-Pneumocystis jirovecii antibodies has emerged as less-invasive alternative diagnostic approaches. Here is presented the performance of an ELISA based on a recombinant synthetic multi-epitope kexin 1 (Kex1) antigen of P. jirovecii, previously developed. Results showed that IgM anti-Kex1 levels were found significantly increased in patients with Pneumocystis pneumonia (PcP) compared with non-PcP cases (p < 0.001), allowing a diagnostic performance of PcP with a 70.8% sensitivity and a 75.0% specificity. These results suggest that this Kex1-based ELISA is a promising tool toward the serodiagnosis of PcP when the standard methods are difficult to perform.
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8
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Tomás AL, de Almeida MP, Cardoso F, Pinto M, Pereira E, Franco R, Matos O. Development of a Gold Nanoparticle-Based Lateral-Flow Immunoassay for Pneumocystis Pneumonia Serological Diagnosis at Point-of-Care. Front Microbiol 2019; 10:2917. [PMID: 31921081 PMCID: PMC6931265 DOI: 10.3389/fmicb.2019.02917] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 12/03/2019] [Indexed: 12/29/2022] Open
Abstract
Pneumocystis jirovecii pneumonia (PcP) is a major human immunodeficiency virus (HIV)-related illness, rising among immunocompromised non-HIV patients and in developing countries. Presently, the diagnosis requires respiratory specimens obtained through invasive and costly techniques that are difficult to perform in all patients or implement in all economic settings. Therefore, the development of a faster, cost-effective, non-invasive and field-friendly test to diagnose PcP would be a significant advance. In this study, recombinant synthetic antigens (RSA) of P. jirovecii's major surface glycoprotein (Msg) and kexin-like serine protease (Kex1) were produced and purified. These RSA were applied as antigenic tools in immunoenzymatic assays for detection of specific anti-P. jirovecii antibodies (IgG and IgM) in sera of patients with (n = 48) and without (n = 28) PcP. Results showed that only IgM anti-P. jirovecii levels were significantly increased in patients with PcP compared with patients without P. jirovecii infection (p ≤ 0.001 with both RSA). Thus, two strip lateral flow immunoassays (LFIA), based on the detection of specific IgM anti-P. jirovecii antibodies in human sera samples, were developed using the innovative association of P. jirovecii's RSA with spherical gold nanoparticles (AuNPs). For that, alkanethiol-functionalized spherical AuNPs with ca. ~40 nm in diameter were synthetized and conjugated with the two RSA (Msg or Kex1) produced. These AuNP-RSA conjugates were characterized by agarose gel electrophoresis (AGE) and optimized to improve their ability to interact specifically with serum IgM anti-P. jirovecii antibodies. Finally, two LFIA prototypes were developed and tested with pools of sera from patients with (positive sample) and without (negative sample) PcP. Both LFIA had the expected performance, namely, the presence of a test and control red colored lines with the positive sample, and only a control red colored line with the negative sample. These results provide valuable insights into the possibility of PcP serodiagnosis at point-of-care. The optimization, validation and implementation of this strip-based approach may help to reduce the high cost of medical diagnosis and subsequent treatment of PcP both in industrialized and low-income regions, helping to manage the disease all around the world.
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Affiliation(s)
- Ana Luísa Tomás
- Medical Parasitology Unit, Group of Opportunistic Protozoa/HIV and Other Protozoa, Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, Lisbon, Portugal.,UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Miguel P de Almeida
- REQUIMTE/LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - Fernando Cardoso
- Medical Parasitology Unit, Group of Opportunistic Protozoa/HIV and Other Protozoa, Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Mafalda Pinto
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Eulália Pereira
- REQUIMTE/LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - Ricardo Franco
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Olga Matos
- Medical Parasitology Unit, Group of Opportunistic Protozoa/HIV and Other Protozoa, Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, Lisbon, Portugal
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Cobos Jiménez V, Rabacal W, Rayens E, Norris KA. Immunization with Pneumocystis recombinant KEX1 induces robust and durable humoral responses in immunocompromised non-human primates. Hum Vaccin Immunother 2019; 15:2075-2080. [PMID: 31348719 PMCID: PMC6773377 DOI: 10.1080/21645515.2019.1631135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Infection with the opportunistic fungal pathogen, Pneumocystis jirovecii causes life-threatening pneumonia in immunocompromised individuals. In addition to HIV-1 infected patients, individuals at risk of Pneumocystis infection include those receiving immunosuppressive therapies due to transplantation, cancer or autoimmune disease. Antibiotic treatment is not always successful, and it does not prevent obstructive lung disease after clearance of the pathogen. Therefore, it is essential to develop therapeutic alternatives that are more effective against PCP. We reported that Pneumocystis recombinant protein KEX1 induces protective immunity against the development of PCP in a non-human primate model of HIV-induced immunosuppression. In this study, we tested the immunogenicity KEX1 immunization of healthy rhesus macaques and the durability of these responses during drug-induced immunosuppression using tacrolimus (FK506) and methylprednisolone. We observed that vaccination with KEX1 prior to the start of the immunosuppressive regimen generated a robust and long-lasting antibody response that was maintained throughout the immunosuppressive treatment. Furthermore, boosting with KEX1 during immunosuppression induced recall of memory responses against recombinant KEX1. The durability of the anti-KEX1 response and the ability to induce a recall response during immunosuppressive therapy provide a proof-of-concept data supporting further investigation of the KEX1 as a prophylactic vaccine to prevent PCP in drug-induced immunosuppression. This approach provides fundamental knowledge for the elaboration of therapeutic and prophylactic alternatives for PCP in patients undergoing severe immunosuppressive therapy.
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Affiliation(s)
- Viviana Cobos Jiménez
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia , Athens , USA
| | - Whitney Rabacal
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia , Athens , USA
| | - Emily Rayens
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia , Athens , USA
| | - Karen A Norris
- Center for Vaccines and Immunology, Department of Infectious Diseases, University of Georgia , Athens , USA
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Ma L, Cissé OH, Kovacs JA. A Molecular Window into the Biology and Epidemiology of Pneumocystis spp. Clin Microbiol Rev 2018; 31:e00009-18. [PMID: 29899010 PMCID: PMC6056843 DOI: 10.1128/cmr.00009-18] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pneumocystis, a unique atypical fungus with an elusive lifestyle, has had an important medical history. It came to prominence as an opportunistic pathogen that not only can cause life-threatening pneumonia in patients with HIV infection and other immunodeficiencies but also can colonize the lungs of healthy individuals from a very early age. The genus Pneumocystis includes a group of closely related but heterogeneous organisms that have a worldwide distribution, have been detected in multiple mammalian species, are highly host species specific, inhabit the lungs almost exclusively, and have never convincingly been cultured in vitro, making Pneumocystis a fascinating but difficult-to-study organism. Improved molecular biologic methodologies have opened a new window into the biology and epidemiology of Pneumocystis. Advances include an improved taxonomic classification, identification of an extremely reduced genome and concomitant inability to metabolize and grow independent of the host lungs, insights into its transmission mode, recognition of its widespread colonization in both immunocompetent and immunodeficient hosts, and utilization of strain variation to study drug resistance, epidemiology, and outbreaks of infection among transplant patients. This review summarizes these advances and also identifies some major questions and challenges that need to be addressed to better understand Pneumocystis biology and its relevance to clinical care.
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Affiliation(s)
- Liang Ma
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
| | - Ousmane H Cissé
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
| | - Joseph A Kovacs
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
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Kolls JK. An Emerging Role of B Cell Immunity in Susceptibility to Pneumocystis Pneumonia. Am J Respir Cell Mol Biol 2018; 56:279-280. [PMID: 28248133 DOI: 10.1165/rcmb.2016-0360ed] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Jay K Kolls
- 1 Richard King Mellon Institute for Pediatric Research Department of Pediatrics and.,2 University of Pittsburgh School of Medicine Pittsburgh, Pennsylvania
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12
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Overcoming Hurdles to Development of a Vaccine against Pneumocystis jirovecii. Infect Immun 2017; 85:IAI.00035-17. [PMID: 28115507 DOI: 10.1128/iai.00035-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Development of Pneumocystis pneumonia (PCP) is a common problem among immunosuppressed individuals. There are windows of opportunity in which vaccination would be beneficial, but to date, no vaccines have made it to clinical trials. Significant hurdles to vaccine development include host range specificity, making it difficult to translate from animal models to humans. Discovery of cross-reactive epitopes is critical to moving vaccine candidates from preclinical animal studies to clinical trials.
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13
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Ruan S, Cai Y, Ramsay AJ, Welsh DA, Norris K, Shellito JE. B cell and antibody responses in mice induced by a putative cell surface peptidase of Pneumocystis murina protect against experimental infection. Vaccine 2017; 35:672-679. [PMID: 28012778 PMCID: PMC5241231 DOI: 10.1016/j.vaccine.2016.11.073] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 10/21/2016] [Accepted: 11/22/2016] [Indexed: 10/20/2022]
Abstract
RATIONALE Pneumocystis pneumonia is a major cause of morbidity and mortality in HIV-infected subjects, cancer patients undergoing chemotherapy and solid organ transplant recipients. No vaccine is currently available. By chemical labeling coupled with proteomic approach, we have identified a putative surface protein (SPD1, Broad Institute gene accession number PNEG_01848) derived from single suspended P. murina cysts. SPD1 was expressed in an insect cell line and tested for vaccine development. METHODS Mice were immunized with SPD1 plus adjuvant MF-59 by subcutaneous injection. Three weeks after the last immunization, CD4+ cells were depleted with anti-CD4 antibody GK1.5. The mice were then challenged with 2×105Pneumocystis organisms. Mice were sacrificed at 4 and 6weeks after PC challenge. Spleen/lung cells and serum were harvested. B cells and memory B cells were assessed via flow cytometry. Specific Pneumocystis IgG antibody was measured by ELISA before and after challenge. Infection burden was measured as real-time PCR for P. murina rRNA. RESULTS Normal mice infected with Pneumocystis mounted a serum IgG antibody response to SPD1. Serum from rhesus macaques exposed to Pneumocystis showed a similar serum IgG response to purified SPD1. SPD1 immunization increased B cell and memory B cell absolute cell counts in CD4-depleted Balb/c mice post Pneumocystis challenge in spleen and lung. Immunization with SPD1 significantly increased specific Pneumocystis IgG antibody production before and after challenge. Mice immunized with SPD1 showed significantly decreased P. murina copy number compared with mice that did not receive SPD1 at 6weeks after challenge. CONCLUSION Immunization with SPD1 provides protective efficacy against P. murina infection. SPD1 protection against Pneumocystis challenge is associated with enhanced memory B cell production and higher anti-Pneumocystis IgG antibody production. SPD1 is a potential vaccine candidate to prevent or treat pulmonary infection with Pneumocystis.
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MESH Headings
- Animals
- Antibodies, Fungal/blood
- Antibody Formation
- Antigens, Fungal/genetics
- Antigens, Fungal/immunology
- B-Lymphocytes/immunology
- Colony Count, Microbial
- Disease Models, Animal
- Enzyme-Linked Immunosorbent Assay
- Female
- Fungal Vaccines/administration & dosage
- Fungal Vaccines/genetics
- Fungal Vaccines/immunology
- Lung/microbiology
- Macaca mulatta
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Mice, Inbred BALB C
- Peptide Hydrolases/genetics
- Peptide Hydrolases/immunology
- Pneumocystis/enzymology
- Pneumocystis/immunology
- Pneumonia, Pneumocystis/prevention & control
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Sanbao Ruan
- Section of Pulmonary, Critical Care Medicine, and Allergy/Immunology, LSU Health Sciences Center, New Orleans, United States
| | - Yang Cai
- The Research Institute for Children, Children's Hospital, New Orleans and Department of Chemistry, University of New Orleans, United States
| | - Alistair J Ramsay
- Department of Microbiology, Immunology, and Parasitology, LSU Health Sciences Center, New Orleans, United States
| | - David A Welsh
- Section of Pulmonary, Critical Care Medicine, and Allergy/Immunology, LSU Health Sciences Center, New Orleans, United States
| | - Karen Norris
- Department of Immunology, University of Pittsburgh, United States
| | - Judd E Shellito
- Section of Pulmonary, Critical Care Medicine, and Allergy/Immunology, LSU Health Sciences Center, New Orleans, United States.
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14
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Tomás AL, Cardoso F, Esteves F, Matos O. Serological diagnosis of pneumocystosis: production of a synthetic recombinant antigen for immunodetection of Pneumocystis jirovecii. Sci Rep 2016; 6:36287. [PMID: 27824115 PMCID: PMC5099754 DOI: 10.1038/srep36287] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 10/13/2016] [Indexed: 11/30/2022] Open
Abstract
Diagnosis of Pneumocystis pneumonia (PcP) relies on the detection of P. jirovecii in respiratory specimens obtained by invasive techniques. Thus, the development of a serological test is urgently needed as it will allow the diagnosis of PcP using blood, an inexpensive and non-invasive specimen. This study aims to combine the production of a multi-epitope synthetic recombinant antigen (RSA) and an ELISA test for detection of anti-P. jirovecii antibodies, in order to develop a new approach for PcP diagnosis. The RSA was selected and designed based on the study of the immunogenicity of the carboxyl-terminal domain of the major surface glycoprotein. This antigen was purified and used as an antigenic tool in an ELISA technique for detection of Ig, IgG and IgM antibodies anti-P. jirovecii (patent-pending no. PT109078). Serum specimens from 88 patients previously categorized in distinct clinical subgroups and 17 blood donors, were analysed. The IgM anti-P. jirovecii levels were statistically increased in patients with PcP (p = 0.001) and the ELISA IgM anti-P. jirovecii test presented a sensitivity of 100% and a specificity of 80.8%, when associated with the clinical diagnosis criteria. This innovative approach, provides good insights about what can be done in the future serum testing for PcP diagnosis.
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Affiliation(s)
- A. L. Tomás
- Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outros Protozoários, Instituto de Higiene e Medicina Tropical, Global Health and Tropical Medicine, Universidade Nova de Lisboa, Lisboa, Portugal
| | - F. Cardoso
- Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outros Protozoários, Instituto de Higiene e Medicina Tropical, Global Health and Tropical Medicine, Universidade Nova de Lisboa, Lisboa, Portugal
| | - F. Esteves
- Centro de Toxicogenómica e Saúde Humana (ToxOmics), Departamento de Genética, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
| | - O. Matos
- Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outros Protozoários, Instituto de Higiene e Medicina Tropical, Global Health and Tropical Medicine, Universidade Nova de Lisboa, Lisboa, Portugal
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15
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Kling HM, Norris KA. Vaccine-Induced Immunogenicity and Protection Against Pneumocystis Pneumonia in a Nonhuman Primate Model of HIV and Pneumocystis Coinfection. J Infect Dis 2016; 213:1586-95. [PMID: 26823337 PMCID: PMC4837913 DOI: 10.1093/infdis/jiw032] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 01/20/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The ubiquitous opportunistic pathogen Pneumocystis jirovecii causes pneumonia in immunocompromised individuals, including human immunodeficiency virus (HIV)-infected individuals, and pulmonary colonization with P. jirovecii is believed to be a cofactor in the development of chronic obstructive pulmonary disease. There is no vaccine for P. jirovecii; however, most adults are seropositive, indicating natural immune priming to this pathogen. We have shown that humoral response to a recombinant subunit of the P. jirovecii protease kexin (KEX1) correlates with protection from P. jirovecii colonization and pneumonia. METHODS Here we evaluated the immunogenicity and protective capacity of the recombinant KEX1 peptide vaccine in a preclinical, nonhuman primate model of HIV-induced immunosuppression and Pneumocystis coinfection. RESULTS Immunization with KEX1 induced a robust humoral response remained at protective levels despite chronic simian immunodeficiency virus/HIV-induced immunosuppression. KEX1-immunized macaques were protected from Pneumocystis pneumonia, compared with mock-immunized animals (P= .047), following immunosuppression and subsequent natural, airborne exposure to Pneumocystis CONCLUSIONS These data support the concept that stimulation of preexisting immunological memory to Pneumocystis with a recombinant KEX1 vaccine prior to immunosuppression induces durable memory responses and protection in the context of chronic, complex immunosuppression.
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Affiliation(s)
- Heather M Kling
- Department of Immunology, University of Pittsburgh, Pennsylvania
| | - Karen A Norris
- Department of Immunology, University of Pittsburgh, Pennsylvania
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16
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de la Rua NM, Samuelson DR, Charles TP, Welsh DA, Shellito JE. CD4(+) T-Cell-Independent Secondary Immune Responses to Pneumocystis Pneumonia. Front Immunol 2016; 7:178. [PMID: 27242785 PMCID: PMC4862974 DOI: 10.3389/fimmu.2016.00178] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 04/25/2016] [Indexed: 01/12/2023] Open
Abstract
Pneumocystis pneumonia is a major cause of morbidity and mortality among immunocompromised patients, especially in the context of HIV/AIDS. In the murine model of Pneumocystis pneumonia, CD4+ T-cells are required for clearance of a primary infection of Pneumocystis, but not the memory recall response. We hypothesized that the memory recall response in the absence of CD4+ T-cells is mediated by a robust memory humoral response, CD8+ T-cells, and IgG-mediated phagocytosis by alveolar macrophages. To investigate the role of CD8+ T-cells and alveolar macrophages in the immune memory response to Pneumocystis, mice previously challenged with Pneumocystis were depleted of CD8+ T-cells or alveolar macrophages prior to re-infection. Mice depleted of CD4+ T-cells prior to secondary challenge cleared Pneumocystis infection within 48 h identical to immunocompetent mice during a secondary memory recall response. However, loss of CD8+ T-cells or macrophages prior to the memory recall response significantly impaired Pneumocystis clearance. Specifically, mice depleted of CD8+ T-cells or alveolar macrophages had significantly higher fungal burden in the lungs. Furthermore, loss of alveolar macrophages significantly skewed the lung CD8+ T-cell response toward a terminally differentiated effector memory population and increased the percentage of IFN-γ+ CD8+ T-cells. Finally, Pneumocystis-infected animals produced significantly more bone marrow plasma cells and Pneumocystis-specific IgG significantly increased macrophage-mediated killing of Pneumocystis in vitro. These data suggest that secondary immune memory responses to Pneumocystis are mediated, in part, by CD8+ T-cells, alveolar macrophages, and the production of Pneumocystis-specific IgG.
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Affiliation(s)
- Nicholas M de la Rua
- Section of Pulmonary/Critical Care and Allergy/Immunology, Department of Medicine, Louisiana State University Health Sciences Center , New Orleans, LA , USA
| | - Derrick R Samuelson
- Section of Pulmonary/Critical Care and Allergy/Immunology, Department of Medicine, Louisiana State University Health Sciences Center , New Orleans, LA , USA
| | - Tysheena P Charles
- Section of Pulmonary/Critical Care and Allergy/Immunology, Department of Medicine, Louisiana State University Health Sciences Center , New Orleans, LA , USA
| | - David A Welsh
- Section of Pulmonary/Critical Care and Allergy/Immunology, Department of Medicine, Louisiana State University Health Sciences Center , New Orleans, LA , USA
| | - Judd E Shellito
- Section of Pulmonary/Critical Care and Allergy/Immunology, Department of Medicine, Louisiana State University Health Sciences Center , New Orleans, LA , USA
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17
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Pneumocystis jirovecii--from a commensal to pathogen: clinical and diagnostic review. Parasitol Res 2015; 114:3577-85. [PMID: 26281787 PMCID: PMC4562001 DOI: 10.1007/s00436-015-4678-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 08/07/2015] [Indexed: 01/09/2023]
Abstract
Pneumocystis pneumonia is an opportunistic disease caused by invasion of unicellular fungus Pneumocystis jirovecii. Initially, it was responsible for majority of morbidity and mortality cases among HIV-infected patients, which later have been reduced due to the introduction of anti-retroviral therapy, as well as anti-Pneumocystis prophylaxis among these patients. Pneumocystis pneumonia, however, is still a significant cause of mortality among HIV-negative patients being under immunosuppression caused by different factors, such as transplant recipients as well as oncologically treated ones. The issue of pneumocystosis among these people is particularly emphasized in the article, since rapid onset and fast progression of severe symptoms result in high mortality rate among these patients, who thereby represent the group of highest risk of developing Pneumocystis pneumonia. In contrast, fungal invasion in immunocompetent people usually leads to asymptomatic colonization, which frequent incidence among healthy infants has even suggested the possibility of its association with sudden unexpected infant death syndrome. In the face of emerging strains with different epidemiological profiles resulting from genetic diversity, including drug-resistant genotypes, the colonization phenomenon desires particular attention, discussed in this article. We also summarize specific and sensitive methods, required for detection of Pneumocystis invasion and for distinguish colonization from the disease.
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18
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Khodavaisy S, Mortaz E, Mohammadi F, Aliyali M, Fakhim H, Badali H. Pneumocystis jirovecii colonization in Chronic Obstructive Pulmonary Disease (COPD). Curr Med Mycol 2015; 1:42-48. [PMID: 28680980 PMCID: PMC5490321 DOI: 10.18869/acadpub.cmm.1.1.42] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is associated with a chronic inflammatory response in airways and lung parenchyma that results in significant morbidity and mortality worldwide. Cigarette smoking considered as an important risk factor plays a role in pathogenesis of disease. Pneumocystis jirovecii is an atypical opportunistic fungus that causes pneumonia in immunosuppressed host, although the low levels of its DNA in patients without signs and symptoms of pneumonia, which likely represents colonization. The increased prevalence of P. jirovecii colonization in COPD patients has led to an interest in understanding its role in the disease. P. jirovecii colonization in these patients could represent a problem for public health since colonized patients could act as a major reservoir and source of infection for susceptible subjects. Using sensitive molecular techniques, low levels of P. jirovecii DNA have been detected in the respiratory tract of certain individuals. It is necessary to elucidate the role of P. jirovecii colonization in the natural history of COPD patients in order to improve the clinical management of this disease. In the current review paper, we discuss P. jirovecii colonization in COPD patients.
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Affiliation(s)
- S Khodavaisy
- Department of Medical Parasitology and Mycology, Kurdistan University of Medical Sciences, Sanandaj, Iran.,Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - E Mortaz
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - F Mohammadi
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - M Aliyali
- Pulmonary and Critical Care Division, Mazandaran University of Medical Sciences, Sari, Iran
| | - H Fakhim
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - H Badali
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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19
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Armstrong-James D, Meintjes G, Brown GD. A neglected epidemic: fungal infections in HIV/AIDS. Trends Microbiol 2014; 22:120-7. [PMID: 24530175 DOI: 10.1016/j.tim.2014.01.001] [Citation(s) in RCA: 219] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 01/02/2014] [Accepted: 01/08/2014] [Indexed: 11/17/2022]
Abstract
Invasive fungal infections (IFIs) are a major cause of HIV-related mortality globally. Despite widespread rollout of combined antiretroviral therapy, there are still up to 1 million deaths annually from IFIs, accounting for 50% of all AIDS-related death. A historic failure to focus efforts on the IFIs that kill so many HIV patients has led to fundamental flaws in the management of advanced HIV infection. This review, based on the EMBO AIDS-Related Mycoses Workshop in Cape Town in July 2013, summarizes the current state of the-art in AIDS-related mycoses, and the key action points required to improve outcomes from these devastating infections.
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Affiliation(s)
- Darius Armstrong-James
- Imperial Fungal Diseases Group, Imperial College London, Department of Infectious Diseases and Immunity, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
| | - Graeme Meintjes
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925 Cape Town, South Africa
| | - Gordon D Brown
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925 Cape Town, South Africa; Aberdeen Fungal Group, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, UK
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20
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Djawe K, Daly KR, Levin L, Zar HJ, Walzer PD. Humoral immune responses to Pneumocystis jirovecii antigens in HIV-infected and uninfected young children with pneumocystis pneumonia. PLoS One 2013; 8:e82783. [PMID: 24386119 PMCID: PMC3873266 DOI: 10.1371/journal.pone.0082783] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 10/28/2013] [Indexed: 02/02/2023] Open
Abstract
Background Humoral immune responses in human immunodeficiency virus (HIV)-infected and uninfected children with Pneumocystis pneumonia (PcP) are poorly understood. Methods Consecutive children hospitalized with acute pneumonia, tachypnea, and hypoxia in South Africa were investigated for PcP, which was diagnosed by real-time polymerase chain reaction on lower respiratory tract specimens. Serum antibody responses to recombinant fragments of the carboxyl terminus of Pneumocystis jirovecii major surface glycoprotein (MsgC) were analyzed. Results 149 children were enrolled of whom 96 (64%) were HIV-infected. PcP occurred in 69 (72%) of HIV-infected and 14 (26%) of HIV-uninfected children. HIV-infected children with PcP had significantly decreased IgG antibodies to MsgC compared to HIV-infected patients without PcP, but had similar IgM antibodies. In contrast, HIV-uninfected children with PcP showed no change in IgG antibodies to MsgC, but had significantly increased IgM antibodies compared to HIV-uninfected children without PCP. Age was an independent predictor of high IgG antibodies, whereas PcP was a predictor of low IgG antibodies and high IgM antibodies. IgG and IgM antibody levels to the most closely related MsgC fragments were predictors of survival from PcP. Conclusions Young HIV-infected children with PcP have significantly impaired humoral immune responses to MsgC, whereas HIV-uninfected children with PcP can develop active humoral immune responses. The children also exhibit a complex relationship between specific host factors and antibody levels to MsgC fragments that may be related to survival from PcP.
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Affiliation(s)
- Kpandja Djawe
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Kieran R. Daly
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- Research Service, Veterans Affairs Medical Center, Cincinnati, Ohio, United States of America
| | - Linda Levin
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Heather J. Zar
- Department of Pediatrics and Child Health, University of Cape Town, Cape Town, South Africa
| | - Peter D. Walzer
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- Research Service, Veterans Affairs Medical Center, Cincinnati, Ohio, United States of America
- * E-mail:
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21
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Abstract
The broad variety of pulmonary infections encountered in human immunodeficiency virus (HIV)-infected individuals demonstrates that the host defense network is impaired. An improved understanding of these events in the lung can lead to specific interventions aimed at restoration of deficient function. This review summarizes the pulmonary host defense deficits in HIV-infected individuals, focusing on lymphocytes, alveolar macrophages, and neutrophils.
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Affiliation(s)
- James M Beck
- Medicine Service, Veterans Affairs Eastern Colorado Health Care System, Denver, CO 80220, USA.
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22
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Abstract
Although the incidence of Pneumocystis pneumonia (PCP) has decreased since the introduction of combination antiretroviral therapy, it remains an important cause of disease in both HIV-infected and non-HIV-infected immunosuppressed populations. The epidemiology of PCP has shifted over the course of the HIV epidemic both from changes in HIV and PCP treatment and prevention and from changes in critical care medicine. Although less common in non-HIV-infected immunosuppressed patients, PCP is now more frequently seen due to the increasing numbers of organ transplants and development of novel immunotherapies. New diagnostic and treatment modalities are under investigation. The immune response is critical in preventing this disease but also results in lung damage, and future work may offer potential areas for vaccine development or immunomodulatory therapy. Colonization with Pneumocystis is an area of increasing clinical and research interest and may be important in development of lung diseases such as chronic obstructive pulmonary disease. In this review, we discuss current clinical and research topics in the study of Pneumocystis and highlight areas for future research.
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23
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Abstract
With increases in the immunocompromised patient population and aging of the HIV+ population, the risk of serious fungal infections and their complications will continue to rise. In these populations, infection with the fungal opportunistic pathogen Pneumocystis jirovecii remains a leading cause of morbidity and mortality. Infection with Pneumocystis (Pc) has been shown to be associated with the development of chronic obstructive pulmonary disease (COPD) in human subjects with and without HIV infection and in non-human primate models of HIV infection. In human studies and in a primate model of HIV/Pc co-infection, we have shown that antibody response to the Pc protein, kexin (KEX1), correlates with protection from colonization, Pc pneumonia, and COPD. These findings support the hypothesis that immunity to KEX1 may be critical to controlling Pc colonization and preventing or slowing development of COPD.
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Affiliation(s)
- Karen A Norris
- Department of Immunology, University of Pittsburgh School of Medicine, E 1057 Biomedical Science Tower, Pittsburgh, PA 15261, USA.
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