Ontogeny of macrophage function to release superoxide anion in conventional and germfree mice

Abstract

To deterinne whether the presence of bacterial flora contributes to the ontogenic development of macrophage function, the ability of macrophages to release superoxide anion (O2-) in response to stimulation with phorbol myristate acetate was compared in conventional and germfree mice of various ages after birth.

The role of the Lps gene in experimental ulcerative colitis in mice

“…However, the role of these microorganisms or their products in the inductive phase has not been supported by studies in germ-free mice, since they develop colitis in response to DSS (2). On the other hand, germ-free mice have altered macrophage functions and may not be comparable in their reactivity with those that have been exposed to intestinal flora since birth (19,20).…”

Microbiota and their role in the pathogenesis of oral mucositis

“…Teeth, gingival sulcus, gingiva, tongue, cheek, lip, hard and soft palate are all microbial habitats that are colonized by distinct microbial communities which form biofilms of different complexities (Mager et al, 2003;Aas et al, 2005). Those biofilms protect the host against pathogens through mechanisms such as competition for nutrients (Momose et al, 2008) or adhesion receptors (Servin and Coconnier, 2003), production of inhibitory metabolites or anti-microbial agents against pathogens (Servin, 2004), modulation of toxin production or action (Czerucka et al, 1994;Brandão et al, 1998), and modifying inflammatory responses (Starling and Balish, 1981;Mitsuyama et al, 1986;Ohkubo et al, 1990;Clarke et al, 2010;Fagundes et al, 2012).…”

Review Environmental factors and primary T‐cell sensitisation to inhalant allergens in infancy: reappraisal of the role of infections and air pollution

“…The answer from the experimental literature is clearly the nature and intensity of microbial stimulation from the environment, in particular the gut flora and its counterpart in the upper respiratory tract. Aside from providing maturation signals for local T-cell-dependent immune function(s) at niucosal surfaces (761, the microbial flora stimulate the functional maturation of the seticuloendothelial system throughout the body, including distal macrophage populations such as those in the peritoneal cavity (77)(78)(79) and also in the lung (80-81). Denial (or reduction) of these maturational signals via maintenance of animals in artificial germ free or pathogen-free states markedly inhibits development of both the effector function(s) of macrophage populations (such as mediator secretion), as well as their capacity to respond to activation stimuli (77-8 1 ), and would accordingly be likely to reduce their effectiveness in cell-cell interactions such as those described in Fig.…”