Intestinal immunity in hypopituitary dwarf mice: effects of age

Hypopituitary dwarf mice demonstrate advantages of longevity, but little is known of their colon development and intestinal immunity. Herein we found that Ames dwarf mice have shorter colon and colonic crypts, but larger ratio of mesenteric lymph nodes (MLNs) over body weight than age-matched wild type (WT) mice. In the colonic lamina propria (cLP) of juvenile Ames mice, more inflammatory neutrophils ((A) over bar: 0.15% vs. 0.03% in WT mice) and monocytes ((A) over bar: 7.97% vs. 5.15%) infiltrated, and antigen presenting cells CD11c+ dendritic cells ((A) over bar: 1.39% vs. 0.87%), CD11b+ macrophages ((A) over bar: 3.22% vs. 0.81%) and gamma delta T (gamma delta T) cells ((A) over bar: 5.56% vs. 1.35%) were increased. In adult Ames dwarf mice, adaptive immune cells, such as IL-17 producing CD4+ T helper (Th17) cells ((A) over bar: 8.3% vs. 4.7%) were augmented. In the MLNs of Ames dwarf mice, the antigen presenting and adaptive immune cells also altered when compared to WT mice, such as a decrease of T-regulatory (Treg) cells in juvenile Ames mice ((A) over bar: 7.7% vs. 10.5%), but an increase of Th17 cells ((A) over bar: 0.627% vs. 0.093%). Taken together, these data suggest that somatotropic signaling deficiency influences colon development and intestinal immunity.