1
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Chan JA, Loughland JR, de la Parte L, Okano S, Ssewanyana I, Nalubega M, Nankya F, Musinguzi K, Rek J, Arinaitwe E, Tipping P, Bourke P, Andrew D, Dooley N, SheelaNair A, Wines BD, Hogarth PM, Beeson JG, Greenhouse B, Dorsey G, Kamya M, Hartel G, Minigo G, Feeney M, Jagannathan P, Boyle MJ. Age-dependent changes in circulating Tfh cells influence development of functional malaria antibodies in children. Nat Commun 2022; 13:4159. [PMID: 35851033 PMCID: PMC9293980 DOI: 10.1038/s41467-022-31880-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 07/08/2022] [Indexed: 01/29/2023] Open
Abstract
T-follicular helper (Tfh) cells are key drivers of antibodies that protect from malaria. However, little is known regarding the host and parasite factors that influence Tfh and functional antibody development. Here, we use samples from a large cross-sectional study of children residing in an area of high malaria transmission in Uganda to characterize Tfh cells and functional antibodies to multiple parasites stages. We identify a dramatic re-distribution of the Tfh cell compartment with age that is independent of malaria exposure, with Th2-Tfh cells predominating in early childhood, while Th1-Tfh cell gradually increase to adult levels over the first decade of life. Functional antibody acquisition is age-dependent and hierarchical acquired based on parasite stage, with merozoite responses followed by sporozoite and gametocyte antibodies. Antibodies are boosted in children with current infection, and are higher in females. The children with the very highest antibody levels have increased Tfh cell activation and proliferation, consistent with a key role of Tfh cells in antibody development. Together, these data reveal a complex relationship between the circulating Tfh compartment, antibody development and protection from malaria.
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Affiliation(s)
- Jo-Anne Chan
- Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia
| | - Jessica R Loughland
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia.,Global and Tropical Health Division, Menzies School of Health Research, Tiwi, Australia
| | | | - Satomi Okano
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Isaac Ssewanyana
- Infectious Diseases Research Collaboration, Kampala, Uganda.,London School of Hygiene and Tropical Medicine, London, UK
| | - Mayimuna Nalubega
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia.,Infectious Diseases Research Collaboration, Kampala, Uganda.,Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
| | | | | | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Peta Tipping
- Global and Tropical Health Division, Menzies School of Health Research, Tiwi, Australia
| | - Peter Bourke
- Division of Medicine, Cairns Hospital, Manunda, QLD, Australia
| | - Dean Andrew
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Nicholas Dooley
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia.,Griffith University, Brisbane, QLD, Australia
| | - Arya SheelaNair
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Bruce D Wines
- Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Clinical Pathology, The University of Melbourne, Parkville, VIC, Australia
| | - P Mark Hogarth
- Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Clinical Pathology, The University of Melbourne, Parkville, VIC, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia.,Department of Microbiology, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | | | - Grant Dorsey
- University of California San Francisco, San Francisco, CA, USA
| | - Moses Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Gunter Hartel
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Gabriela Minigo
- Global and Tropical Health Division, Menzies School of Health Research, Tiwi, Australia.,College of Health and Human Sciences, Charles Darwin University, Darwin, NT, Australia
| | - Margaret Feeney
- University of California San Francisco, San Francisco, CA, USA
| | | | - Michelle J Boyle
- Burnet Institute, Melbourne, VIC, Australia. .,QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia. .,Global and Tropical Health Division, Menzies School of Health Research, Tiwi, Australia. .,Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia. .,Griffith University, Brisbane, QLD, Australia.
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2
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Bachman CM, Cate DM, Grant B, Burkot S, Mulondo J, Hsieh HV, Chamai M, Odongo B, Olwoch P, Nalubega M, Ochokoru H, Kasozi J, Ategeka J, Nichols KP, Weigl BH, Greenhouse B. A Novel Malaria Lateral Flow Assay for Detecting Plasmodium falciparum Lactate Dehydrogenase in Busia, Uganda. Am J Trop Med Hyg 2022; 106:850-852. [PMID: 35026727 PMCID: PMC8922488 DOI: 10.4269/ajtmh.21-0956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 11/18/2021] [Indexed: 01/18/2023] Open
Abstract
Rapid diagnostic tests (RDTs) for Plasmodium falciparum commonly detect histidine-rich protein 2 (HRP-2), but HRP-2 deletions are increasingly recognized. We evaluated a prototype test detecting parasite lactate dehydrogenase (pLDH) and compared it to commercially available RDTs at a health facility in Uganda, using quantitative polymerase chain reaction as a gold standard. The prototype pLDH test had a high sensitivity for infections with at least 100 parasites/µL (98%), comparable to HRP-2, and greater than an existing pLDH RDT (89%). Specificity for the prototype test was 99.5%, which is greater than the HRP-2 tests (93-95%). Therefore, the prototype pLDH test may be an attractive alternative malaria diagnostic.
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Affiliation(s)
- Christine M. Bachman
- Global Health Laboratories, Bellevue, Washington;,Address correspondence to Christine M. Bachman, Global Health Laboratories, Bellevue, WA. E-mail:
| | | | - Ben Grant
- Global Health Laboratories, Bellevue, Washington
| | | | - Jerry Mulondo
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Martin Chamai
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Bakar Odongo
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Peter Olwoch
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Joseph Kasozi
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - John Ategeka
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Bryan Greenhouse
- University of California at San Francisco, San Francisco, California
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3
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Soon MSF, Nalubega M, Boyle MJ. T-follicular helper cells in malaria infection and roles in antibody induction. Oxf Open Immunol 2021; 2:iqab008. [PMID: 36845571 PMCID: PMC9914587 DOI: 10.1093/oxfimm/iqab008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/03/2021] [Accepted: 03/08/2021] [Indexed: 01/29/2023] Open
Abstract
Immunity to malaria is mediated by antibodies that block parasite replication to limit parasite burden and prevent disease. Cytophilic antibodies have been consistently shown to be associated with protection, and recent work has improved our understanding of the direct and Fc-mediated mechanisms of protective antibodies. Antibodies also have important roles in vaccine-mediated immunity. Antibody induction is driven by the specialized CD4+ T cells, T-follicular helper (Tfh) cells, which function within the germinal centre to drive B-cell activation and antibody induction. In humans, circulating Tfh cells can be identified in peripheral blood and are differentiated into subsets that appear to have pathogen/vaccination-specific roles in antibody induction. Tfh cell responses are essential for protective immunity from Plasmodium infection in murine models of malaria. Our understanding of the activation of Tfh cells during human malaria infection and the importance of different Tfh cell subsets in antibody development is still emerging. This review will discuss our current knowledge of Tfh cell activation and development in malaria, and the potential avenues and pitfalls of targeting Tfh cells to improve malaria vaccines.
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Affiliation(s)
- Megan S F Soon
- Department of Infectious Diseases, QIMR-Berghofer, 300 Herston Road, Herston, QLD, 4006, Australia
| | - Mayimuna Nalubega
- Infectious Diseases Research Collaboration, Tororo District Hospital, Tororo, Uganda
| | - Michelle J Boyle
- Department of Infectious Diseases, QIMR-Berghofer, 300 Herston Road, Herston, QLD, 4006, Australia,Correspondence address. QIMR Berghofer Medical Research Institute, Brisbane, Australia. E-mail:
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4
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Prahl M, Odorizzi P, Gingrich D, Muhindo M, McIntyre T, Budker R, Jagannathan P, Farrington L, Nalubega M, Nankya F, Sikyomu E, Musinguzi K, Naluwu K, Auma A, Kakuru A, Kamya MR, Dorsey G, Aweeka F, Feeney ME. Exposure to pesticides in utero impacts the fetal immune system and response to vaccination in infancy. Nat Commun 2021; 12:132. [PMID: 33420104 PMCID: PMC7794579 DOI: 10.1038/s41467-020-20475-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/01/2020] [Indexed: 12/30/2022] Open
Abstract
The use of pesticides to reduce mosquito vector populations is a cornerstone of global malaria control efforts, but the biological impact of most pesticides on human populations, including pregnant women and infants, is not known. Some pesticides, including carbamates, have been shown to perturb the human immune system. We measure the systemic absorption and immunologic effects of bendiocarb, a commonly used carbamate pesticide, following household spraying in a cohort of pregnant Ugandan women and their infants. We find that bendiocarb is present at high levels in maternal, umbilical cord, and infant plasma of individuals exposed during pregnancy, indicating that it is systemically absorbed and trans-placentally transferred to the fetus. Moreover, bendiocarb exposure is associated with numerous changes in fetal immune cell homeostasis and function, including a dose-dependent decrease in regulatory CD4 T cells, increased cytokine production, and inhibition of antigen-driven proliferation. Additionally, prenatal bendiocarb exposure is associated with higher post-vaccination measles titers at one year of age, suggesting that its impact on functional immunity may persist for many months after birth. These data indicate that in utero bendiocarb exposure has multiple previously unrecognized biological effects on the fetal immune system.
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Affiliation(s)
- Mary Prahl
- Department of Pediatrics, University of California San Francisco, San Francisco, 94143, USA
| | - Pamela Odorizzi
- Department of Medicine, Zuckerberg San Francisco General Hospital, University of California San Francisco, San Francisco, 94143, USA
| | - David Gingrich
- Department of Clinical Pharmacy, University of California San Francisco, Drug Research Unit, San Francisco, CA, 94143, USA
| | - Mary Muhindo
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Tara McIntyre
- Department of Medicine, Zuckerberg San Francisco General Hospital, University of California San Francisco, San Francisco, 94143, USA
| | - Rachel Budker
- Department of Medicine, Zuckerberg San Francisco General Hospital, University of California San Francisco, San Francisco, 94143, USA
| | | | - Lila Farrington
- Department of Medicine, Zuckerberg San Francisco General Hospital, University of California San Francisco, San Francisco, 94143, USA
| | | | | | - Esther Sikyomu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Kate Naluwu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Ann Auma
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Abel Kakuru
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda.,Department of Medicine, Makerere University, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, Zuckerberg San Francisco General Hospital, University of California San Francisco, San Francisco, 94143, USA
| | - Francesca Aweeka
- Department of Clinical Pharmacy, University of California San Francisco, Drug Research Unit, San Francisco, CA, 94143, USA
| | - Margaret E Feeney
- Department of Pediatrics, University of California San Francisco, San Francisco, 94143, USA. .,Department of Medicine, Zuckerberg San Francisco General Hospital, University of California San Francisco, San Francisco, 94143, USA.
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5
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Farrington LA, Callaway PC, Vance HM, Baskevitch K, Lutz E, Warrier L, McIntyre TI, Budker R, Jagannathan P, Nankya F, Musinguzi K, Nalubega M, Sikyomu E, Naluwu K, Arinaitwe E, Dorsey G, Kamya MR, Feeney ME. Opsonized antigen activates Vδ2+ T cells via CD16/FCγRIIIa in individuals with chronic malaria exposure. PLoS Pathog 2020; 16:e1008997. [PMID: 33085728 PMCID: PMC7605717 DOI: 10.1371/journal.ppat.1008997] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 11/02/2020] [Accepted: 09/18/2020] [Indexed: 12/19/2022] Open
Abstract
Vγ9Vδ2 T cells rapidly respond to phosphoantigens produced by Plasmodium falciparum in an innate-like manner, without prior antigen exposure or processing. Vδ2 T cells have been shown to inhibit parasite replication in vitro and are associated with protection from P. falciparum parasitemia in vivo. Although a marked expansion of Vδ2 T cells is seen after acute malaria infection in naïve individuals, repeated malaria causes Vδ2 T cells to decline both in frequency and in malaria-responsiveness, and to exhibit numerous transcriptional and phenotypic changes, including upregulation of the Fc receptor CD16. Here we investigate the functional role of CD16 on Vδ2 T cells in the immune response to malaria. We show that CD16+ Vδ2 T cells possess more cytolytic potential than their CD16- counterparts, and bear many of the hallmarks of mature NK cells, including KIR expression. Furthermore, we demonstrate that Vδ2 T cells from heavily malaria-exposed individuals are able to respond to opsonized P.falciparum-infected red blood cells through CD16, representing a second, distinct pathway by which Vδ2 T cells may contribute to anti-parasite effector functions. This response was independent of TCR engagement, as demonstrated by blockade of the phosphoantigen presenting molecule Butyrophilin 3A1. Together these results indicate that Vδ2 T cells in heavily malaria-exposed individuals retain the capacity for antimalarial effector function, and demonstrate their activation by opsonized parasite antigen. This represents a new role both for Vδ2 T cells and for opsonizing antibodies in parasite clearance, emphasizing cooperation between the cellular and humoral arms of the immune system.
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Affiliation(s)
- Lila A. Farrington
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Perri C. Callaway
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Infectious Disease and Immunity Graduate Group, University of California Berkeley, California, United States of America
| | - Hilary M. Vance
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Kayla Baskevitch
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Emma Lutz
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Lakshmi Warrier
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Tara I. McIntyre
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Rachel Budker
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Prasanna Jagannathan
- Department of Medicine, Stanford University, Stanford, California, United States of America
| | | | | | | | - Ester Sikyomu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Kate Naluwu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Grant Dorsey
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Moses R. Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Margaret E. Feeney
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
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6
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Odorizzi PM, Jagannathan P, McIntyre TI, Budker R, Prahl M, Auma A, Burt TD, Nankya F, Nalubega M, Sikyomu E, Musinguzi K, Naluwu K, Kakuru A, Dorsey G, Kamya MR, Feeney ME. In utero priming of highly functional effector T cell responses to human malaria. Sci Transl Med 2019; 10:10/463/eaat6176. [PMID: 30333241 DOI: 10.1126/scitranslmed.aat6176] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 05/10/2018] [Accepted: 09/17/2018] [Indexed: 12/14/2022]
Abstract
Malaria remains a significant cause of morbidity and mortality worldwide, particularly in infants and children. Some studies have reported that exposure to malaria antigens in utero results in the development of tolerance, which could contribute to poor immunity to malaria in early life. However, the effector T cell response to pathogen-derived antigens encountered in utero, including malaria, has not been well characterized. Here, we assessed the frequency, phenotype, and function of cord blood T cells from Ugandan infants born to mothers with and without placental malaria. We found that infants born to mothers with active placental malaria had elevated frequencies of proliferating effector memory fetal CD4+ T cells and higher frequencies of CD4+ and CD8+ T cells that produced inflammatory cytokines. Fetal CD4+ and CD8+ T cells from placental malaria-exposed infants exhibited greater in vitro proliferation to malaria antigens. Malaria-specific CD4+ T cell proliferation correlated with prospective protection from malaria during childhood. These data demonstrate that placental malaria is associated with the generation of proinflammatory malaria-responsive fetal T cells. These findings add to our current understanding of fetal immunity and indicate that a functional and protective pathogen-specific T cell response can be generated in utero.
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Affiliation(s)
- Pamela M Odorizzi
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA 94110 USA
| | | | - Tara I McIntyre
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA 94110 USA
| | - Rachel Budker
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA 94110 USA
| | - Mary Prahl
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94110, USA
| | - Ann Auma
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - Trevor D Burt
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94110, USA.,Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | | | - Esther Sikyomu
- Infectious Disease Research Collaboration, Kampala, Uganda
| | | | - Kate Naluwu
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - Abel Kakuru
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA 94110 USA
| | - Moses R Kamya
- School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Margaret E Feeney
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA 94110 USA. .,Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94110, USA
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7
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Al Kindi A, Alkahtani AM, Nalubega M, El-Chami C, O'Neill C, Arkwright PD, Pennock JL. Staphylococcus aureus Internalized by Skin Keratinocytes Evade Antibiotic Killing. Front Microbiol 2019; 10:2242. [PMID: 31608046 PMCID: PMC6771413 DOI: 10.3389/fmicb.2019.02242] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/12/2019] [Indexed: 12/20/2022] Open
Abstract
Staphylococcus aureus causes the majority of skin and soft tissue infections. Half of patients treated for primary skin infections suffer recurrences within 6 months despite appropriate antibiotic sensitivities and infection control measures. We investigated whether S. aureus internalized by human skin keratinocytes are effectively eradicated by standard anti-staphylococcal antibiotics. S. aureus, but not S. epidermidis, were internalized and survive within keratinocytes without inducing cytotoxicity or releasing the IL-33 danger signal. Except for rifampicin, anti-staphylococcal antibiotics in regular clinical use, including flucloxacillin, teicoplanin, clindamycin, and linezolid, did not kill internalized S. aureus, even at 20-fold their standard minimal inhibitory concentration. We conclude that internalization of S. aureus by human skin keratinocytes allows the bacteria to evade killing by most anti-staphylococcal antibiotics. Antimicrobial strategies, including antibiotic combinations better able to penetrate into mammalian cells are required if intracellular S. aureus are to be effectively eradicated and recurrent infections prevented.
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Affiliation(s)
- Arwa Al Kindi
- Lydia Becker Institute of Immunology and Inflammation, The University of Manchester, Manchester, United Kingdom.,Division of Infection, Immunity and Respiratory Medicine, The University of Manchester, Manchester, United Kingdom
| | | | - Mayimuna Nalubega
- Lydia Becker Institute of Immunology and Inflammation, The University of Manchester, Manchester, United Kingdom.,Division of Infection, Immunity and Respiratory Medicine, The University of Manchester, Manchester, United Kingdom
| | - Cecile El-Chami
- Division of Musculoskeletal and Dermatological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Catherine O'Neill
- Division of Musculoskeletal and Dermatological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Peter D Arkwright
- Lydia Becker Institute of Immunology and Inflammation, The University of Manchester, Manchester, United Kingdom.,Division of Infection, Immunity and Respiratory Medicine, The University of Manchester, Manchester, United Kingdom
| | - Joanne L Pennock
- Lydia Becker Institute of Immunology and Inflammation, The University of Manchester, Manchester, United Kingdom.,Division of Infection, Immunity and Respiratory Medicine, The University of Manchester, Manchester, United Kingdom
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8
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Jagannathan P, Lutwama F, Boyle MJ, Nankya F, Farrington LA, McIntyre TI, Bowen K, Naluwu K, Nalubega M, Musinguzi K, Sikyomu E, Budker R, Katureebe A, Rek J, Greenhouse B, Dorsey G, Kamya MR, Feeney ME. Vδ2+ T cell response to malaria correlates with protection from infection but is attenuated with repeated exposure. Sci Rep 2017; 7:11487. [PMID: 28904345 PMCID: PMC5597587 DOI: 10.1038/s41598-017-10624-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/11/2017] [Indexed: 12/20/2022] Open
Abstract
Vδ2+ γδ T cells are semi-innate T cells that expand markedly following P. falciparum (Pf) infection in naïve adults, but are lost and become dysfunctional among children repeatedly exposed to malaria. The role of these cells in mediating clinical immunity (i.e. protection against symptoms) to malaria remains unclear. We measured Vδ2+ T cell absolute counts at acute and convalescent malaria timepoints (n = 43), and Vδ2+ counts, cellular phenotype, and cytokine production following in vitro stimulation at asymptomatic visits (n = 377), among children aged 6 months to 10 years living in Uganda. Increasing age was associated with diminished in vivo expansion following malaria, and lower Vδ2 absolute counts overall, among children living in a high transmission setting. Microscopic parasitemia and expression of the immunoregulatory markers Tim-3 and CD57 were associated with diminished Vδ2+ T cell pro-inflammatory cytokine production. Higher Vδ2 pro-inflammatory cytokine production was associated with protection from subsequent Pf infection, but also with an increased odds of symptoms once infected. Vδ2+ T cells may play a role in preventing malaria infection in children living in endemic settings; progressive loss and dysfunction of these cells may represent a disease tolerance mechanism that contributes to the development of clinical immunity to malaria.
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Affiliation(s)
- Prasanna Jagannathan
- Department of Medicine, Stanford University, Stanford, CA, USA.
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA.
| | - Fredrick Lutwama
- Infectious Diseases Institute, Kampala, Uganda
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Michelle J Boyle
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
- Burnet Institute, Disease Elimination (Malaria), Melbourne, Australia
| | | | - Lila A Farrington
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Tara I McIntyre
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Katherine Bowen
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Kate Naluwu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Esther Sikyomu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Rachel Budker
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | | | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Bryan Greenhouse
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Grant Dorsey
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Moses R Kamya
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Margaret E Feeney
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA.
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA.
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9
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Prahl M, Jagannathan P, McIntyre TI, Auma A, Wamala S, Nalubega M, Musinguzi K, Naluwu K, Sikyoma E, Budker R, Odorizzi P, Kakuru A, Havlir DV, Kamya MR, Dorsey G, Feeney ME. Sex Disparity in Cord Blood FoxP3 + CD4 T Regulatory Cells in Infants Exposed to Malaria In Utero. Open Forum Infect Dis 2017; 4:ofx022. [PMID: 28480292 PMCID: PMC5414097 DOI: 10.1093/ofid/ofx022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/06/2017] [Indexed: 11/21/2022] Open
Abstract
Sex differences in the immune response and in infectious disease susceptibility have been well described, although the mechanisms underlying these differences remain incompletely understood. We evaluated the frequency of cord blood CD4 T cell subsets in a highly malaria-exposed birth cohort of mother-infant pairs in Uganda by sex. We found that frequencies of cord blood regulatory T cell ([Treg] CD4+CD25+FoxP3+CD127lo/−) differed by infant sex, with significantly lower frequencies of Tregs in female than in male neonates (P = .006). When stratified by in utero malaria exposure status, this difference was observed in the exposed, but not in the unexposed infants.
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Affiliation(s)
| | | | | | - Ann Auma
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Samuel Wamala
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Kate Naluwu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Esther Sikyoma
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Abel Kakuru
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Moses R Kamya
- School of Medicine, Makerere University of College of Health Sciences, College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Medicine, University of California-San Francisco
| | - Margaret E Feeney
- Departments of Pediatrics and.,Medicine, University of California-San Francisco
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10
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Jagannathan P, Bowen K, Nankya F, McIntyre TI, Auma A, Wamala S, Sikyomu E, Naluwu K, Nalubega M, Boyle MJ, Farrington LA, Bigira V, Kapisi J, Aweeka F, Greenhouse B, Kamya M, Dorsey G, Feeney ME. Effective Antimalarial Chemoprevention in Childhood Enhances the Quality of CD4+ T Cells and Limits Their Production of Immunoregulatory Interleukin 10. J Infect Dis 2016; 214:329-38. [PMID: 27067196 DOI: 10.1093/infdis/jiw147] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Accepted: 04/04/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Experimental inoculation of viable Plasmodium falciparum sporozoites administered with chemoprevention targeting blood-stage parasites results in protective immunity. It is unclear whether chemoprevention similarly enhances immunity following natural exposure to malaria. METHODS We assessed P. falciparum-specific T-cell responses among Ugandan children who were randomly assigned to receive monthly dihydroartemisinin-piperaquine (DP; n = 87) or no chemoprevention (n = 90) from 6 to 24 months of age, with pharmacologic assessments for adherence, and then clinically followed for an additional year. RESULTS During the intervention, monthly DP reduced malaria episodes by 55% overall (P < .001) and by 97% among children who were highly adherent to DP (P < .001). In the year after the cessation of chemoprevention, children who were highly adherent to DP had a 55% reduction in malaria incidence as compared to children given no chemoprevention (P = .004). Children randomly assigned to receive DP had higher frequencies of blood-stage specific CD4(+) T cells coproducing interleukin-2 and tumor necrosis factor α (P = .003), which were associated with protection from subsequent clinical malaria and parasitemia, and fewer blood-stage specific CD4(+) T cells coproducing interleukin-10 and interferon γ (P = .001), which were associated with increased risk of malaria. CONCLUSIONS In this setting, effective antimalarial chemoprevention fostered the development of CD4(+) T cells that coproduced interleukin 2 and tumor necrosis factor α and were associated with prospective protection, while limiting CD4(+) T-cell production of the immunoregulatory cytokine IL-10.
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Affiliation(s)
| | | | | | | | - Ann Auma
- Infectious Diseases Research Collaboration
| | | | | | | | | | - Michelle J Boyle
- Department of Medicine, San Francisco General Hospital Center for Biomedical Research, The Burnet Institute, Melbourne, Australia
| | | | | | | | | | | | - Moses Kamya
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital
| | - Margaret E Feeney
- Department of Medicine, San Francisco General Hospital Department of Pediatrics, University of California-San Francisco
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11
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Farrington LA, Jagannathan P, McIntyre TI, Vance HM, Bowen K, Boyle MJ, Nankya F, Wamala S, Auma A, Nalubega M, Sikyomu E, Naluwu K, Bigira V, Kapisi J, Dorsey G, Kamya MR, Feeney ME. Frequent Malaria Drives Progressive Vδ2 T-Cell Loss, Dysfunction, and CD16 Up-regulation During Early Childhood. J Infect Dis 2015; 213:1483-90. [PMID: 26667315 DOI: 10.1093/infdis/jiv600] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/04/2015] [Indexed: 12/13/2022] Open
Abstract
γδ T cells expressing Vδ2 may be instrumental in the control of malaria, because they inhibit the replication of blood-stage parasites in vitro and expand during acute malaria infection. However, Vδ2 T-cell frequencies and function are lower among children with heavy prior malaria exposure. It remains unclear whether malaria itself is driving this loss. Here we measure Vδ2 T-cell frequency, cytokine production, and degranulation longitudinally in Ugandan children enrolled in a malaria chemoprevention trial from 6 to 36 months of age. We observed a progressive attenuation of the Vδ2 response only among children incurring high rates of malaria. Unresponsive Vδ2 T cells were marked by expression of CD16, which was elevated in the setting of high malaria transmission. Moreover, chemoprevention during early childhood prevented the development of dysfunctional Vδ2 T cells. These observations provide insight into the role of Vδ2 T cells in the immune response to chronic malaria.
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Affiliation(s)
| | | | - Tara I McIntyre
- Departments of Medicine, University of California San Francisco
| | - Hilary M Vance
- Departments of Medicine, University of California San Francisco
| | - Katherine Bowen
- Departments of Medicine, University of California San Francisco
| | - Michelle J Boyle
- Departments of Medicine, University of California San Francisco Center for Biomedical Research, The Burnet Institute, Melbourne, Victoria, Australia
| | - Felistas Nankya
- Infectious Diseases Research Collaboration, Makerere University College of Health Sciences, Kampala, Uganda
| | - Samuel Wamala
- Infectious Diseases Research Collaboration, Makerere University College of Health Sciences, Kampala, Uganda
| | - Ann Auma
- Infectious Diseases Research Collaboration, Makerere University College of Health Sciences, Kampala, Uganda
| | - Mayimuna Nalubega
- Infectious Diseases Research Collaboration, Makerere University College of Health Sciences, Kampala, Uganda
| | - Esther Sikyomu
- Infectious Diseases Research Collaboration, Makerere University College of Health Sciences, Kampala, Uganda
| | - Kate Naluwu
- Infectious Diseases Research Collaboration, Makerere University College of Health Sciences, Kampala, Uganda
| | - Victor Bigira
- Infectious Diseases Research Collaboration, Makerere University College of Health Sciences, Kampala, Uganda
| | - James Kapisi
- Infectious Diseases Research Collaboration, Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Departments of Medicine, University of California San Francisco
| | - Moses R Kamya
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Margaret E Feeney
- Departments of Medicine, University of California San Francisco Pediatrics, University of California San Francisco
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12
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Boyle MJ, Jagannathan P, Farrington LA, Eccles-James I, Wamala S, McIntyre TI, Vance HM, Bowen K, Nankya F, Auma A, Nalubega M, Sikyomu E, Naluwu K, Rek J, Katureebe A, Bigira V, Kapisi J, Tappero J, Muhindo MK, Greenhouse B, Arinaitwe E, Dorsey G, Kamya MR, Feeney ME. Decline of FoxP3+ Regulatory CD4 T Cells in Peripheral Blood of Children Heavily Exposed to Malaria. PLoS Pathog 2015; 11:e1005041. [PMID: 26182204 PMCID: PMC4504515 DOI: 10.1371/journal.ppat.1005041] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/23/2015] [Indexed: 12/27/2022] Open
Abstract
FoxP3+ regulatory CD4 T cells (Tregs) help to maintain the delicate balance between pathogen-specific immunity and immune-mediated pathology. Prior studies suggest that Tregs are induced by P. falciparum both in vivo and in vitro; however, the factors influencing Treg homeostasis during acute and chronic infections, and their role in malaria immunopathogenesis, remain unclear. We assessed the frequency and phenotype of Tregs in well-characterized cohorts of children residing in a region of high malaria endemicity in Uganda. We found that both the frequency and absolute numbers of FoxP3+ Tregs in peripheral blood declined markedly with increasing prior malaria incidence. Longitudinal measurements confirmed that this decline occurred only among highly malaria-exposed children. The decline of Tregs from peripheral blood was accompanied by reduced in vitro induction of Tregs by parasite antigen and decreased expression of TNFR2 on Tregs among children who had intense prior exposure to malaria. While Treg frequencies were not associated with protection from malaria, there was a trend toward reduced risk of symptomatic malaria once infected with P. falciparum among children with lower Treg frequencies. These data demonstrate that chronic malaria exposure results in altered Treg homeostasis, which may impact the development of antimalarial immunity in naturally exposed populations. In malaria endemic regions, immunity is slow to develop and does not provide substantial protection against reinfection. Rather, following repeated exposure, older children and adults eventually develop protection from most symptomatic manifestations of the infection. This may be due in part to the induction of immunoregulatory mechanisms by the P. falciparum parasite, such as FoxP3+ regulatory T cells (Tregs). Prior human studies have shown that Tregs are induced by malaria parasites both in vivo and in vitro, but the role of these cells in immunity in children who are chronically exposed to malaria remains unclear. In this study, we assessed the frequency and features of Tregs among children from areas of high malaria transmission in Uganda. We found that this regulatory T cell population declined markedly with increasing malaria episodes. This loss was associated with decreased expression of TNFR2, which is a protein implicated in stability of Tregs. Additionally, T cells from highly malaria exposed children demonstrated a reduced propensity to differentiate into Tregs following parasite stimulation. Together our data suggest that repeated episodes of malaria alter Treg homeostasis, which may influence the development of immunity to malaria in children.
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Affiliation(s)
- Michelle J. Boyle
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Center for Biomedical Research, The Burnet Institute, Melbourne, Australia
| | - Prasanna Jagannathan
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Lila A. Farrington
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Ijeoma Eccles-James
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Samuel Wamala
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Tara I McIntyre
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Hilary M. Vance
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Katherine Bowen
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | | | - Ann Auma
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Esther Sikyomu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Kate Naluwu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Victor Bigira
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - James Kapisi
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Mary K Muhindo
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Bryan Greenhouse
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | | | - Grant Dorsey
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Moses R. Kamya
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Margaret E. Feeney
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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13
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Jagannathan P, Nankya F, Stoyanov C, Eccles-James I, Sikyomu E, Naluwu K, Wamala S, Nalubega M, Briggs J, Bowen K, Bigira V, Kapisi J, Kamya MR, Dorsey G, Feeney ME. IFNγ Responses to Pre-erythrocytic and Blood-stage Malaria Antigens Exhibit Differential Associations With Past Exposure and Subsequent Protection. J Infect Dis 2014; 211:1987-96. [PMID: 25520427 DOI: 10.1093/infdis/jiu814] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 12/10/2014] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The malaria-specific T-cell response is believed to be important for protective immunity. Antimalarial chemoprevention may affect this response by altering exposure to malaria antigens. METHODS We performed interferon γ (IFNγ) ELISpot assays to assess the cellular immune response to blood-stage and pre-erythrocytic antigens longitudinally from 1 to 3 years of age in 196 children enrolled in a randomized trial of antimalarial chemoprevention in Tororo, Uganda, an area of high transmission intensity. RESULTS IFNγ responses to blood-stage antigens, particularly MSP1, were frequently detected, strongly associated with recent malaria exposure, and lower in those adherent to chemoprevention compared to nonadherent children and those randomized to no chemoprevention. IFNγ responses to pre-erythrocytic antigens were infrequent and similar between children randomized to chemoprevention or no chemoprevention. Responses to blood-stage antigens were not associated with subsequent protection from malaria (aHR 0.96, P = .83), but responses to pre-erythrocytic antigens were associated with protection after adjusting for prior malaria exposure (aHR 0.52, P = .009). CONCLUSIONS In this high transmission setting, IFNγ responses to blood-stage antigens were common and associated with recent exposure to malaria but not protection from subsequent malaria. Responses to pre-erythrocytic antigens were uncommon, not associated with exposure but were associated with protection from subsequent malaria.
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Affiliation(s)
- Prasanna Jagannathan
- Department of Medicine, San Francisco General Hospital, University of California
| | | | - Cristina Stoyanov
- Department of Medicine, San Francisco General Hospital, University of California
| | - Ijeoma Eccles-James
- Department of Medicine, San Francisco General Hospital, University of California
| | | | | | | | | | - Jessica Briggs
- Department of Medicine, San Francisco General Hospital, University of California
| | - Katherine Bowen
- Department of Medicine, San Francisco General Hospital, University of California
| | | | | | - Moses R Kamya
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital, University of California
| | - Margaret E Feeney
- Department of Medicine, San Francisco General Hospital, University of California Department of Pediatrics, University of California, San Francisco
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14
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Bakyayita GK, Norrström AC, Nalubega M, Kulabako RN. Kinetic studies of Cd (II) and Pb (II) ions biosorption from aqueous media using untreated and chemically treated biosorbents. Water Sci Technol 2014; 69:2230-2236. [PMID: 24901616 DOI: 10.2166/wst.2014.147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Untreated and chemically treated Albizia coriaria, Erythrina abyssinica and Musa spp. were studied in batch for uptake of Cd(2+) and Pb(2+) ions at pH 2.0-9.0 and agitation time of 30-390 min. Optimum biosorption conditions were pH 4 for Pb(2+) ions and pH 5 for Cd(2+) ions, contact time was 3.5 hours at 24 ± 1 °C for 10 mg/L biosorbent dosage and initial metal ions concentration of 20 mg/L. Chemical treatment had a 10-17% biosorption efficiency enhancement for Cd(2+) ions and a 1.6-2.3% reduction effect for Pb(2+) ions. The sorption capacities for Cd(2+) and Pb(2+) ions for treated biosorbents were 1.760-1.738 mg g(-1) compared to 1.415-1.539 mg g(-1) for untreated materials. The pseudo second-order model suitably fitted the Cd(2+) and Pb(2+) ions biosorption data with regression coefficients (R(2)) of 0.9784-0.9999. Fitting of the Ho model to the experimental data showed that the biosorption mechanism for both metal ions studied was mainly a chemisorption process. Therefore, treated A. coriaria, E. abyssinica and Musa spp. were potential biosorbents for remediation of Cd(2+) ions and the untreated materials suitable for removing Pb(2+) ions from contaminated aqueous media.
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Affiliation(s)
- G K Bakyayita
- Department of Sustainable Development, Environmental Science and Engineering, Kungliga Tekniska Högskolan, Brinellvägen 28, SE-100 44 Stockholm, Sweden E-mail: ; Department of Civil and Environmental Engineering, College of Engineering, Design, Art and Technology, Makerere University, Uganda
| | - A C Norrström
- Department of Sustainable Development, Environmental Science and Engineering, Kungliga Tekniska Högskolan, Brinellvägen 28, SE-100 44 Stockholm, Sweden E-mail:
| | - M Nalubega
- Water and Sanitation Department, African Development Bank, Tunis, Tunisia
| | - R N Kulabako
- Department of Civil and Environmental Engineering, College of Engineering, Design, Art and Technology, Makerere University, Uganda
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15
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Niwagaba C, Nalubega M, Vinnerås B, Sundberg C, Jönsson H. Substrate composition and moisture in composting source-separated human faeces and food waste. Environ Technol 2009; 30:487-497. [PMID: 19507440 DOI: 10.1080/09593330902788236] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The composting of a faeces/ash mixture and food waste in relative proportions of 1:0, 1:1 and 1:3 was studied in three successive experiments conducted in Kampala, Uganda in 216 L reactors insulated with 75 mm styrofoam or not insulated. The faeces/ash mixture alone exceeded 50 degrees C for < or = 12 days in insulated reactors, but did not reach or maintain 50 degrees C in non-insulated reactors. Inclusion of food waste kept temperatures above 50 degrees C for over two weeks in insulated reactors except when the substrate was too wet. Escherichia coli and total coliform concentrations decreased below detection in material that exceeded 50 degrees C for at least six days. Enterococcus spp. decreased below detection in material that exceeded 50 degrees C for at least two weeks, but remained detectable after 1.5 months in material that exceeded 50 degrees C for less than two weeks, suggesting that a period of at least two weeks above 50 degrees C, combined with mixing, is needed to achieve sanitation. Initially substrates that were too wet proved a challenge to composting and ways of decreasing substrate moisture should be investigated. The results obtained are applicable to the management of small- to medium-scale composting of faeces/ash and food waste at household and institution levels, e.g. schools and restaurants.
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Affiliation(s)
- C Niwagaba
- Department of Civil Engineering, Makerere University, P.O. Box 7062, Kampala, Uganda.
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16
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Niwagaba C, Nalubega M, Vinnerås B, Sundberg C, Jönsson H. Bench-scale composting of source-separated human faeces for sanitation. Waste Manag 2009; 29:585-589. [PMID: 18692381 DOI: 10.1016/j.wasman.2008.06.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 06/12/2008] [Accepted: 06/19/2008] [Indexed: 05/26/2023]
Abstract
In urine-diverting toilets, urine and faeces are collected separately so that nutrient content can be recycled unmixed. Faeces should be sanitized before use in agriculture fields due to the presence of possible enteric pathogens. Composting of human faeces with food waste was evaluated as a possible method for this treatment. Temperatures were monitored in three 78-L wooden compost reactors fed with faeces-to-food waste substrates (F:FW) in wet weight ratios of 1:0, 3:1 and 1:1, which were observed for approximately 20 days. To achieve temperatures higher than 15 degrees C above ambient, insulation was required for the reactors. Use of 25-mm thick styrofoam insulation around the entire exterior of the compost reactors and turning of the compost twice a week resulted in sanitizing temperatures (>or=50 degrees C) to be maintained for 8 days in the F:FW=1:1 compost and for 4 days in the F:FW=3:1 compost. In these composts, a reduction of >3 log(10) for E. coli and >4 log(10) for Enterococcus spp. was achieved. The F:FW=1:0 compost, which did not maintain >or=50 degrees C for a sufficiently long period, was not sanitized, as the counts of E. coli and Enterococcus spp. increased between days 11 and 15. This research provides useful information on the design and operation of family-size compost units for the treatment of source-separated faeces and starchy food residues, most likely available amongst the less affluent rural/urban society in Uganda.
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Affiliation(s)
- C Niwagaba
- Department of Civil Engineering, Makerere University, P.O. Box 7062, Kampala, Uganda.
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17
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Kulabako NR, Nalubega M, Thunvik R. Study of the impact of land use and hydrogeological settings on the shallow groundwater quality in a peri-urban area of Kampala, Uganda. Sci Total Environ 2007; 381:180-99. [PMID: 17512037 DOI: 10.1016/j.scitotenv.2007.03.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Revised: 03/13/2007] [Accepted: 03/16/2007] [Indexed: 05/10/2023]
Abstract
A study to assess the impacts of land use and hydrogeological characteristics on the shallow groundwater in one of Kampala's peri-urban areas (Bwaise III Parish) was undertaken for a period of 19 months. Water quality monitoring was carried out for 16 installed wells and one operational protected spring to ascertain the seasonal variation. The aspects of hydrogeological setting investigated in the study were the subsurface unconsolidated material characteristics (stratigraphy, lithology, hydraulic conductivity, porosity and chemical content), seasonal groundwater depths and spring discharge, topography and rainfall of the area. Both laboratory and field measurements were carried out to determine the soil and water characteristics. Field surveys were also undertaken to identify and locate the various land use activities that may potentially pollute. The results demonstrate that the water table in the area responds rapidly to short rains (48 h) due to the pervious (10(-5)-10(-3) ms(-1)) and shallow (<1 mbgl) vadose zone, which consists of foreign material (due to reclamation). This anthropogenically influenced vadose zone has a limited contaminant attenuation capacity resulting in water quality deterioration following the rains. There is widespread contamination of the groundwater with high organic (up to 370 mgTKN/l and 779 mgNO-3/l), thermotolerant coliforms (TTCs) and faecal streptococci (FS) (median values as high as 126E3 cfu/100 ml and 154E3 cfu/100 ml respectively) and total phosphorus (up to 13 mg/l) levels originating from multiple sources of contamination. These include animal rearing, solid waste dumping, pit latrine construction and greywater/stormwater disposal in unlined channels leading to increased localised microbial (faecal) and organic (TKN/NO-3) contamination during the rains. The spring discharge (range 1.22-1.48 m3/h) with high nitrate levels (median values of 117 and 129 mg/l in the wet and dry seasons) did not vary significantly with season (p=0.087) suggesting that this source is fed by regional base flow. However, the microbial quality deterioration observed in the spring discharge after a rain event (median values of 815TTCs cfu /100 ml and 433 FS cfu/100 ml) was attributed to the poor maintenance of the protection structure. Identification and selection of appropriate management solutions for the protection of shallow groundwater in informal settlements should not only be based on water quality problems and the causal physical characteristics as demonstrated by this study, but also institutional and socio-economic factors.
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Affiliation(s)
- N R Kulabako
- Department of Civil Engineering, Makerere University, P.O.Box 7062, Kampala, Uganda.
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18
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Kulabako NR, Nalubega M, Thunvik R. Phosphorus transport in shallow groundwater in peri-urban Kampala, Uganda: results from field and laboratory measurements. ACTA ACUST UNITED AC 2007. [DOI: 10.1007/s00254-007-0764-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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Kansiime F, Nalubega M, van Bruggen JJA, Denny P. The effect of wastewater discharge on biomass production and nutrient content of Cyperus papyrus and Miscanthidium violaceum in the Nakivubo wetland, Kampala, Uganda. Water Sci Technol 2003; 48:233-240. [PMID: 14621169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The nutrient content of representative plant parts and biomass production in the Nakivubo wetland, correlation of these with the wastewater flow patterns and determination of nutrient uptake, storage and biomass production of Cyperus papyrus (papyrus) and Miscanthidium violaceum was studied. On average papyrus vegetation under the influence of wastewater had higher nutrient content in the above ground biomass (1.6% N and 0.23% P on dry weight basis) than those not affected (0.98% N and 0.18% P). The biomass varied between 3,529-5,844 g/m2 and 883-1,156 g/m2 in the two respective sites. The juvenile plants of papyrus and Miscanthidium had higher concentrations of P and N in their organs compared to the mature ones. Considering the nutrients stored by the dominant vegetation and the current flow patterns of wastewater in the Nakivubo wetland, harvesting of the above ground biomass once a year, would remove 7.7% of the N input and 15.8% of the P input of the annual total load entering the wetland. However, if the wetland is bio-manipulated and the wastewater flow distributed over the whole wetland, up to 70% nitrogen and 76% phosphorus would be removed by harvesting above ground papyrus biomass.
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Affiliation(s)
- F Kansiime
- Makerere University Institute of Environment and Natural Resources, P.O. Box 7062, Kampala, Uganda.
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20
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Barrett M, Howard G, Pedley S, Taylor R, Nalubega M. A comparison of the extent and impacts of sewage contamination on urban groundwater in developed and developing countries. Schriftenr Ver Wasser Boden Lufthyg 2000; 105:179-85. [PMID: 10842812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
In much of the world urban groundwater is an important resource for domestic and industrial use. In many developing countries, groundwater taken directly (untreated) from individual springs and wells is the only option available to communities where comprehensive, reliable reticulated supply systems are absent. A common feature of urban groundwater in both developing and developed countries is contamination by sewage. Current and recent research is presented that shows sewer leakage impacts groundwater in developed countries whilst on-site sanitation contaminates groundwater in developing countries. In the latter case, the competing demands of sanitation and groundwater protection must be addressed. Limitations on the usefulness of accepted standard sewage indicator species in groundwater are also highlighted. As sewage contamination of groundwater is usually addressed only if an actual health risk is posed, it is vital both to developed and developing countries to understand the movement of actual pathogens in groundwater in the context of groundwater management. Further research is required on microbial survival and health risks posed by sewage contamination.
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Affiliation(s)
- M Barrett
- Robens Centre for Public and Environmental Health, University of Surrey, Guildford, UK
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