Age Dependency of the Composition of Immunocompetent Cells and the Expression of Adhesion Molecules in Rat Laryngeal Mucosa

Abstract

Clinical evidence shows that laryngeal infections in infants differ significantly from those in adults. Therefore, the composition of the mucosal immune system (granulocytes, macrophages, dendritic cells, natural killer cells, and T and B lymphocytes) and the epithelial expression of class II-MHC molecules and adhesion molecules ICAM-1, VCAM-1, and E-selectin were studied in the larynx of newborn, 5-week-old, and 3-year-old rats. With the exception of macrophages, the immunocompetent cells began to immigrate into the laryngeal mucosa after birth, indicating that the laryngeal mucosa in newborn rats is immature. In contrast, ICAM-1 was already expressed. The number of immunocompetent cells and the expression of epithelial class II-MHC and ICAM-1 increased with age. Immunocompetent cells and epithelial class II-MHC and ICAM-1 expression were mainly detected in the subglottic region, but were almost absent in the vocal fold region.

Presence of dendritic cells, T lymphocytes, macrophages, B lymphocytes and glandular tissue in the human fetal larynx

“…It is known that significant changes in the composition of the mucosal immune system can occur during the first post-natal week (23). The laryngeal mucosal immune system as it presents at birth was only studied previously in rats and was found to be structurally immature (10). Therefore, in this study we investigated in humans whether the cellular components of mucosal immunity are able to immigrate into the laryngeal mucosa before birth.…”

“…It is a matter for discussion whether those larynges which displayed high numbers of immunocompetent cells in our study had been exposed to infectious agents and the cells had immigrated reactively or whether recruitment of immunocompetent cells in the fetal period is independent of prenatal infectious stimuli. In contrast, the animals examined previously (10) were kept under specific pathogen-free conditions and thus were unlikely to have encountered any infectious stimulus before birth. DC in particular are known to immigrate into mucosal surfaces very quickly after antigen stimulation (24).…”

“…The results indicated an immature laryngeal mucosal immune system at birth (10). In contrast, it is unknown whether in humans the cellular elements of mucosal immunity that initiate an immune reaction are already present at birth.…”

Peripheral Blood Lymphocyte Subpopulations and Immunoglobulin Concentrations in Healthy Foals and Foals with Rhodococcus equi Pneumonia

“…4 In rats and humans, an age-dependent variation exists in the composition and development of immunocompetent cells in specific organs, such as the respiratory and intestinal mucosa. 30,31 On the other hand, foals are able to combat equine herpesvirus-1 and recover from disease before mechanisms of immunity, such as circulating antibody, are detectable. [32][33][34] This may occur due to functional cell-mediated immune mechanisms within the respiratory system at this age.…”

Quantitative Analysis of OX62-Positive Dendritic Cell Distribution in the Rat Laryngeal Complex

“…3,10,11,16 The glottis is a perpetual exception, in which the numbers are reduced. The rationale for this difference is not entirely clear, although it may help to explain the difference in mucosal reactivity between the glottis and the subglottis commonly seen during acute laryngotracheitis.…”