Analysis of immunocompetent cells in the middle ear mucosa.
A quantitative analysis of immunocompetent cells in the middle ear mucosa of mice was carried out by an indirect immunostaining method using various monoclonal antibodies. Mice bred in germ-free, specific pathogen-free, and conventional conditions were used to examine nonimmunized middle ear mucosa. Middle ear mucosae of otitis media-induced mice were also examined. In normal middle ear mucosa, mast cells were substantial, followed by Mac-1-positive cells and lymphocytes. Even though IgA-, IgM-, and Lyt-1-positive cells were seen in the mucosa of conventional mice, IgM-positive cells were seen only in mucosae of specific pathogen-free and germ-free mice. In otitis media-induced mice by inoculation with nontypable Haemophilus influenzae or lipopolysaccharide, Mac-1-positive cells were dominant. Although the numbers of IgM- and Lyt-1-positive cells increased markedly, the numbers of other lymphocyte subsets did not increase until 14 days after inoculation. These findings suggest that the middle ear is immunologically a potential organ as long as it is not exposed to antigenic stimulation. It is considered to be an immunoreactive site only after it has been activated with pathogens.
Ichimiya
I
I
Department of Otolaryngology, Medical College of Oita, Japan.
Kawauchi
H
H
Mogi
G
G
D000818:Animals; D000911:Antibodies, Monoclonal; D004432:Ear, Middle / Q000166:cytology*; D005856:Germ-Free Life; D007124:Immunoenzyme Techniques; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D009092:Mucous Membrane / Q000166:cytology; D010033:Otitis Media / Q000276:immunology / Q000473:pathology*
D000911:Antibodies, Monoclonal