Legionella pneumophila:Innate and Adaptive Immunity

Hoffman, Paul S.; Friedman, Herman; Bendinelli, Mauro

doi:10.1007/978-0-387-70896-6_9

Cited by 2 publications

(3 citation statements)

References 57 publications

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“…The L. pneumophila cocktail was inoculated (6.7 × 10 4 CFU/mL from plate counts and 6.78 × 10 6 gene copies/mL). Furthermore, recent studies indicated that V. vermiformis may be a more relevant protozoan host for L. pneumophila and had naturally colonized the SGWHs during experiment A2 via the GAC filtered Blacksburg, VA water [ 11 , 35 , 36 ]. At the start of A3, additional V. vermiformis was inoculated into all SGWHs in this modified research phase (1.46 × 10 3 amoeba/mL and 1.69 × 10 3 gene copies/mL).…”

Section: Methodsmentioning

confidence: 99%

Relationship between Organic Carbon and Opportunistic Pathogens in Simulated Glass Water Heaters

et al. 2015

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Controlling organic carbon levels in municipal water has been hypothesized to limit downstream growth of bacteria and opportunistic pathogens in premise plumbing (OPPPs). Here, the relationships between influent organic carbon (0–15,000 µg ozonated fulvic acid /L) and the number of total bacteria [16S rRNA genes and heterotrophic plate counts (HPCs)] and a wide range of OPPPs (gene copy numbers of Acanthamoeba polyphaga, Vermamoeba vermiformis, Legionella pneumophila, and Mycobacterium avium) were examined in the bulk water of 120-mL simulated glass water heaters (SGWHs). The SGWHs were operated at 32–37 °C, which is representative of conditions encountered at the bottom of electric water heaters, with water changes of 80% three times per week to simulate low use. This design presented advantages of controlled and replicated (triplicate) conditions and avoided other potential limitations to OPPP growth in order to isolate the variable of organic carbon. Over seventeen months, strong correlations were observed between total organic carbon (TOC) and both 16S rRNA gene copy numbers and HPC counts (avg. R2 > 0.89). Although M. avium gene copies were occasionally correlated with TOC (avg. R2 = 0.82 to 0.97, for 2 out of 4 time points) and over a limited TOC range (0–1000 µg/L), no other correlations were identified between other OPPPs and added TOC. These results suggest that reducing organic carbon in distributed water is not adequate as a sole strategy for controlling OPPPs, although it may have promise in conjunction with other approaches.

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Section: Methodsmentioning

confidence: 99%

Relationship between Organic Carbon and Opportunistic Pathogens in Simulated Glass Water Heaters

et al. 2015

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“…This delay is highly significant when compared to lung infection by other intracellular pathogens such as influenza or Legionella pneumophila, where adaptive responses are seen as early as 2-3 days in the MLN [52, 53] and in the lung 6-7 days postinfection [18, 54, 55]. This may suggest that such delay is due to insufficient bacteria or bacterial products in the lymph node required for T-cell priming [40].…”

Section: Initiation Of Adaptive T-cell Activation In the Mediastinmentioning

confidence: 99%

“…While much controversy surrounds the generation of adaptive immune responses following M.tb , it is now widely accepted that the earliest antigen-specific T-cells are not observed for at least 10 days postinfection, appearing first in the MLNs [ 51 ] ( Figure 2 ). This delay is highly significant when compared to lung infection by other intracellular pathogens such as influenza or Legionella pneumophila, where adaptive responses are seen as early as 2-3 days in the MLN [ 52 , 53 ] and in the lung 6-7 days postinfection [ 18 , 54 , 55 ]. This may suggest that such delay is due to insufficient bacteria or bacterial products in the lymph node required for T-cell priming [ 40 ].…”

Section: Initiation Of Adaptive T-cell Activation In the Mediastinmentioning

confidence: 99%

Understanding Delayed T-Cell Priming, Lung Recruitment, and Airway Luminal T-Cell Responses in Host Defense against Pulmonary Tuberculosis

Shaler

Horvath

Lai

et al. 2012

Clinical and Developmental Immunology

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Mycobacterium tuberculosis(M.tb), the causative bacterium of pulmonary tuberculosis (TB), is a serious global health concern. Central toM.tbeffective immune avoidance is its ability to modulate the early innate inflammatory response and prevent the establishment of adaptive T-cell immunity for nearly three weeks. When compared with other intracellular bacterial lung pathogens, such asLegionella pneumophila, or even closely related mycobacterial species such asM. smegmatis, this delay is astonishing. Customarily, the alveolar macrophage (AM) acts as a sentinel, detecting and alerting surrounding cells to the presence of an invader. However, in the case ofM.tb,this may be impaired, thus delaying the recruitment of antigen-presenting cells (APCs) to the lung. Upon uptake by APC populations,M.tbis able to subvert and delay the processing of antigen, MHC class II loading, and the priming of effector T cell populations. This delay ultimately results in the deferred recruitment of effector T cells to not only the lung interstitium but also the airway lumen. Therefore, it is of upmost importance to dissect the mechanisms that contribute to the delayed onset of immune responses followingM.tbinfection. Such knowledge will help design the most effective vaccination strategies against pulmonary TB.

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Legionella pneumophila:Innate and Adaptive Immunity

Cited by 2 publications

References 57 publications

Relationship between Organic Carbon and Opportunistic Pathogens in Simulated Glass Water Heaters

Relationship between Organic Carbon and Opportunistic Pathogens in Simulated Glass Water Heaters

Understanding Delayed T-Cell Priming, Lung Recruitment, and Airway Luminal T-Cell Responses in Host Defense against Pulmonary Tuberculosis

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