Pulmonary macrophages in birds (barn owl,Tyto tyto alba), domestic fowl (Gallus gallus f. domestica), Quail (Coturnix coturnix), and pigeons (Columbia livia)

Qualitative and quantitative attributes of the free respiratory macrophages (FRMs) of the lung -air sac systems of the domestic fowl (Gallus gallus variant domesticus) and the muscovy duck (Cairina moschata) were compared with those of the alveolar macrophages of the lung of the black rat (Rattus rattus). The birds had significantly fewer FRMs compared to the rat. In the birds, the FRMs were found both in the lungs and in the air sacs. Under similar experimental conditions, the most robust FRMs were those of the domestic fowl followed by those of the rat and the duck. Flux of macrophages onto the respiratory surface from the subepithelial compartment and probably also from the pulmonary vasculature was observed in the birds but not in the rat. In the duck and the domestic fowl, a phagocytic epithelium that constituted over 70% of the surface area of the blood-gas (tissue) barrier lines the atrial muscles, the atria and the infundibulae. The epithelial cells of the upper respiratory airways contain abundant lysosomes, suggesting a high lytic capacity. By inference, the various defence strategies in the avian lung may explain the dearth of FRMs on the respiratory surface. We counter-propose that rather than arising directly from paucity of FRMs, an aspect that has been over-stressed by most investigators, the purported high susceptibility of birds (particularly table birds) to respiratory ailments and afflictions may be explained by factors such as inadequate management and husbandry practices and severe genetic manipulation for fast growth and high productivity, manipulations that may have weakened cellular and immunological defences.

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“…Qureshi et al. 1994; Klika et al. 1996; Lorz & Lopez, 1997) have been reported in the lung – air sac system of birds.…”

Section: Discussionmentioning

confidence: 99%

“…In cage and poultry birds in particular, respiratory diseases are said to be the greatest cause of mortality and hence economic loss (Rosskopf & Woerpel, 1996; Spira, 1996). Lack of FARMs has been remarked on by Klika et al. (1996) and Lorz & Lopez (1997) while paucity of the cells has been reported by Ficken et al.…”

Section: Introductionmentioning

confidence: 92%

Composite cellular defence stratagem in the avian respiratory system: functional morphology of the free (surface) macrophages and specialized pulmonary epithelia

Nganpiep

Maina

2002

Journal of Anatomy

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“…There are large number of macrophages in the avian lung (de Geus et al, ; Härtle and Kaspers, ), which are distributed in the interstitium of interatrial septa and air‐blood capillary region. A minor proportion of lung macrophages is found in the lumen of air passages (Toth et al, ), which then are referred to as “free avian respiratory macrophages” (FARM) (Toth and Siegel, ), but other authors did not find any macrophages in the air passages (Qureshi et al, ; Klika et al, ).…”

Section: Discussionmentioning

confidence: 99%

“…In mammals, the alveolar macrophages are found inside the alveoli, therefore they are in contact with the surfactant, which influences their functional activity; the opsonization of bacteria and viruses, enhances the endocytosis of lung macrophages (Gaynor et al, ; Pikaar et al, ; LeVine et al, ; Restrepo et al, ; Crouch et al, ) and modulates innate immunity (Sano and Kuroki, ). However, in birds the majority of lung macrophages lie in the interstitial tissue among air and blood capillaries; in other words, they are not inside the air capillaries (Klika et al, ; Bernhard et al, ). Therefore, the chicken surfactant proteins which are secreted into the air passages have no direct contact with the free avian respiratory macrophages (Toth and Siegel, ).…”

Section: Introductionmentioning

confidence: 99%

Dual secretion locations on type II cells in the avian lung suggest local as well as general roles of surfactant

Bódi

Kocsis

Benyeda³

et al. 2016

Journal of Morphology

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Transmission electron microscopy indicates that the avian lung surfactant may be secreted in two directions: a) into air passages of parabronchus, atrium and infundibulum where it forms a trilaminar substance serving the respiratory role and b) to the basolateral surface-intercellular space-of type II pneumocytes, contributing to the innate and adoptive immune responses of lung. Basolateral secretion may be confirmed by the presence of trilaminal substance in the intercellular space of type II pneumocytes. Fusion of surfactant containing vesicles with the lateral plasma membrane may result in membrane fusion of neighboring cells and subsequently formation of multinucleated giant cell. The indistinct and in some places discontinuous basal lamina in the parabronchial atrium and infundibulum permits the hydrophilic surfactant proteins to spread into the interstitium of air-blood capillary region. The hydrophilic surfactant proteins may activate lung interstitial macrophages to migrate into the air passages where they appear as "free avian respiratory macrophages." Therefore, in the interstitium the hydrophilic surfactant proteins are essential soluble components of innate immunity. J. Morphol. 277:1062-1071, 2016. © 2016 Wiley Periodicals, Inc.

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“…This distribution pattern of macrophages in the avian lung suggests that, even under non-inflammatory conditions, phagocytes can migrate from the connective tissue to the surface of the gas exchange area [64,65], even though some authors have argued against this happening [70]. Repeated lung lavages lead to an increase in macrophage numbers in the lavage fluid, indicating that macrophages can transmigrate into the air space either from the connective tissue or from the vascular system [67].…”

Section: The Phagocytic System Of the Respiratory Tractmentioning

confidence: 99%

The Avian Respiratory Immune System

Härtle

Kaspers

2014

Avian Immunology

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Pulmonary macrophages in birds (barn owl,Tyto tyto alba), domestic fowl (Gallus gallus f. domestica), Quail (Coturnix coturnix), and pigeons (Columbia livia)

Cited by 50 publications

References 9 publications

Composite cellular defence stratagem in the avian respiratory system: functional morphology of the free (surface) macrophages and specialized pulmonary epithelia

Composite cellular defence stratagem in the avian respiratory system: functional morphology of the free (surface) macrophages and specialized pulmonary epithelia

Dual secretion locations on type II cells in the avian lung suggest local as well as general roles of surfactant

The Avian Respiratory Immune System

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