Exposure to endotoxin or other bacterial components might protect against the development of atopy
Tóm tắt
Several recent studies have shown that growing up on a farm confers significant protection against the development of atopy. These findings point particularly towards the importance of exposure to stable dust and farm animals. It has furthermore been reported that endotoxin, an intrinsic part of the outer membrane of gram negative bacteria, is abundant in environments where livestock and poultry is kept.
The
Eighty‐four farming and nonfarming families were identified in rural areas in Southern Germany and Switzerland. Samples of settled and airborne dust were collected in stables, and of settled dust indoors from kitchen floors and the children's mattresses. Endotoxin concentrations were determined by a kinetic Limulus assay.
Endotoxin concentrations were highest in stables of farming families, but were also significantly higher indoors in dust from kitchen floors (143 EU/mg vs 39 EU/mg,
We propose that the level of environmental exposure to endotoxin and other bacterial wall components is an important protective determinant for the development of atopic diseases in childhood.
Từ khóa
Tài liệu tham khảo
1998.
Rietschel ET, 1982, Bacterial endotoxins: chemical structure, biological activity, and role in septicaemia, Scand J Infect Di Suppl, 31, 8
Macatonia SE, 1995, Dendritic cells produce IL‐12 and direct the development of Th1 cells from naive CD4+ T cells, J Immunol, 154, 5071, 10.4049/jimmunol.154.10.5071
Baldini M, 1999, A polymorphism in the 5′‐flanking region of the CD14 gene is associated with circulating soluble CD14 levels and with total serum IgE, Am J Respir Cell Mol Biol, 20, 976, 10.1165/ajrcmb.20.5.3494
Lee SM, 1996, Decreased interleukin‐12 (IL‐12) from activated cord versus adult peripheral blood mononuclear cells and upregulation of interferon‐γ, natural killer, and lymphokine‐activated killer activity by IL‐12 in cord blood mononuclear cells, Blood, 88, 945, 10.1182/blood.V88.3.945.945
Abou‐Zeid C, 1997, Induction of a type 1 immune responses to a recombinant antigen from Mycobacterium tuberculosis expressed in Mycobacterium vaccae, Infect Immun, 65, 1856, 10.1128/iai.65.5.1856-1862.1997
Cleveland MG, 1996, Lipoteichooic acid preparations of gram‐positive bacteria induce interleukin‐12 through a CD14‐dependent pathway, Infect Immun, 64, 1906, 10.1128/iai.64.6.1906-1912.1996