Influence of carbon particles on superoxide and hydrogen peroxide radical release during the killing of Mycobacterium bovis by alveolar macrophages

Attwood, E.M.; Weich, D.J.V.; Oosthuizen, J. M. C.

doi:10.1016/s0962-8479(96)90121-5

Cited by 4 publications

(3 citation statements)

References 21 publications

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“…Carbon-loaded macrophages are reported to have a diminished capacity to produce reactive oxygen intermediates (15), possess a reduced amount of lysosomal enzymes (16), and show impaired phagocytosis (17,18). Our current study, in common with previous analyses of AM from TB patients in Africa, noted that many of the patients had AM that were extensively loaded with carbon, probably from wood fires.…”

Section: Discussionsupporting

confidence: 82%

“…Coinfection with MTB and HIV in an individual could affect either arm of macrophage physiology. AM operate at the interface between the host and the environment and can therefore also be influenced by external factors, including carbon from wood fires (15)(16)(17)(18)(19). In Malawi there is a very high prevalence of both tuberculous and HIV infections, and the majority of the population live in simple housing in close proximity to wood fires.…”

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confidence: 99%

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Mycobacterium tuberculosis Resides in Nonacidified Vacuoles in Endocytically Competent Alveolar Macrophages from Patients with Tuberculosis and HIV Infection

Mwandumba

Russell

Nyirenda

et al. 2004

The Journal of Immunology

120

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Alveolar macrophages (AM) are the first professional phagocytes encountered by aerosols containing infections in the lungs, and their phagocytic capacity may be affected by these infections or environmental particles. The aim of this study was to evaluate the innate endocytic and phagocytic properties of human AM obtained from patients with pulmonary tuberculosis and to characterize the vacuoles in which Mycobacterium tuberculosis bacilli reside in vivo. AM were obtained by bronchoalveolar lavage from patients with suspected tuberculosis and from asymptomatic volunteers (controls). Clinical case definitions were based on mycobacterial culture of respiratory specimens and HIV serology. To assess phagocytosis, endocytosis, and acidification of the endosomal system, AM were cultured with IgG-coated polystyrene beads, dextran, and a pH-sensitive reporter (3-(2,4-dinitroanilino)-3-amino-N-methyldipropylamine) and were evaluated by light and immunoelectron microscopy. Cells from 89 patients and 10 controls were studied. We found no significant difference between the two groups in the ability of AM either to ingest beads and dextran or to deliver them to acidified lysosomes. In AM from patients with tuberculosis, the bacilli were located in vacuoles that failed to accumulate endocytosed material and were not acidified. We concluded that AM from patients with tuberculosis and HIV infections were competent to endocytose and phagocytose material and to deliver the material to functional, acidified lysosomes. M. tuberculosis residing in these AM arrests the progression of their phagosomes, which fail to fuse with acidified lysosomes. This confirms, for the first time in humans with tuberculosis and HIV, the conclusions from previous animal and in vitro studies.

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Section: Discussionsupporting

confidence: 82%

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confidence: 99%

Mycobacterium tuberculosis Resides in Nonacidified Vacuoles in Endocytically Competent Alveolar Macrophages from Patients with Tuberculosis and HIV Infection

Mwandumba

Russell

Nyirenda

et al. 2004

The Journal of Immunology

120

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“…Microscopic examination of macrophages exposed to (RB-NPs)-GP revealed the presence of internalized particles within macrophages (Figure 1). Phagocytosis of particles has been construed as an activation signal, depending on particle size, surface properties and chemical composition of the particles [9,28,29]. The uptake of these particles by uninfected and infected macrophage was followed by rapid induction of ROS upon exposure (Figure 2(A)).…”

Section: Discussionmentioning

confidence: 99%

Nano-Rifabutin entrapment within glucan microparticles enhances protection against intracellular Mycobacterium tuberculosis

Upadhyay

Fatima

Sharma

et al. 2019

Artificial Cells, Nanomedicine, and Biotechnology

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Recently, yeast-derived glucan particles (GP) have emerged as novel drug delivery agents that provide for receptor-mediated uptake by phagocytic cells expressing b-glucan receptors. In our previous study, we prepared GP loaded with high payload (40.5 þ 1.9%) of rifabutin (RB) nano-particles [(RB-NPs)-GP]. We investigated the anti-mycobacterial efficacy and cellular activation responses within Mycobacterium tuberculosis (M. tuberculosis) infected J774 macrophage cells following exposure to the (RB-NPs)-GP formulation. The exposure was seen to augment a robust innate immune response including the induction of reactive oxygen and nitrogen species, autophagy and apoptosis within M. tuberculosis infected macrophage. Further, the efficacy testing of these particles in murine macrophage exhibited that the (RB-NPs)-GP formulation enhanced the efficacy of RB drug by $2.5 fold. The study suggests that the set of innate responses conducive to killing intracellular bacteria evoked by (RB-NPs)-GP play a pivotal role in impeding the intracellular M. tuberculosis survival, resulting in enhanced efficacy of the formulation. Our results establish that the (RB-NPs)-GP formulation not only activate M. tuberculosis infected, immune-suppressed macrophage, but also adds significantly to the efficacy of loaded drug, and thus forms a promising approach that should be explored further as an alternative or adjunct form of TB therapy. HIGHLIGHTS Nano-Rifabutin loaded Glucan microparticles [(RB-NPs)-GP] administered to M. tuberculosis infected macrophage. (RB-NPs)-GP induces appropriate innate immune responses in host macrophage. Mycobactericidal Effect of Rifabutin was markedly enhanced by its nano-entrapment in GP. Intracellular drug delivery supplements the innate response in M. tuberculosis infected macrophage.

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A review of the effects of wildfire smoke on the health and behavior of wildlife

Sanderfoot

Bassing

Brusa

et al. 2021

Environ. Res. Lett.

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Climate change is intensifying global wildfire activity, and people and wildlife are increasingly exposed to hazardous air pollution during large-scale smoke events. Although wildfire smoke is considered a growing risk to public health, few studies have investigated the impacts of wildfire smoke on wildlife, particularly among species that are vulnerable to smoke inhalation. In this review, we synthesized research to date on how wildfire smoke affects the health and behavior of wildlife. After executing a systematic search using Web of Science, we found only 41 relevant studies. We synthesized findings from this literature and incorporated knowledge gained from fields outside wildlife science, specifically veterinary medicine and air pollution toxicology. Although studies that directly investigated effects of smoke on wildlife were few in number, they show that wildfire smoke contributes to adverse acute and chronic health outcomes in wildlife and influences animal behavior. Our review demonstrates that smoke inhalation can lead to carbon monoxide poisoning, respiratory distress, neurological impairment, respiratory and cardiovascular disease, oxidative stress, and immunosuppression in wildlife, including terrestrial and aquatic species, and these health effects can contribute to changes in movement and vocalization. Some species also use smoke as a cue to engage in fire-avoidance behaviors or to conserve energy. However, our review also highlights significant gaps in our understanding of the impacts of wildfire smoke on wildlife. Most notably, the lack of robust air pollution measurements in existing studies limits meta-analyses and hinders construction of dose-response relationships, thereby precluding predictions of health outcomes and behaviors under different air quality conditions, especially during extreme smoke events. We recommend that future studies leverage existing data sets, infrastructure, and tools to rapidly advance research on this important conservation topic and highlight the potential value of interdisciplinary collaborations between ecologists and atmospheric chemists.

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Influence of carbon particles on superoxide and hydrogen peroxide radical release during the killing of Mycobacterium bovis by alveolar macrophages

Cited by 4 publications

References 21 publications

Mycobacterium tuberculosis Resides in Nonacidified Vacuoles in Endocytically Competent Alveolar Macrophages from Patients with Tuberculosis and HIV Infection

Mycobacterium tuberculosis Resides in Nonacidified Vacuoles in Endocytically Competent Alveolar Macrophages from Patients with Tuberculosis and HIV Infection

Nano-Rifabutin entrapment within glucan microparticles enhances protection against intracellular Mycobacterium tuberculosis

A review of the effects of wildfire smoke on the health and behavior of wildlife

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