Effects of anti–IL-1α Ab and anti-MGL1 mAb LOM-8.7 on the formation of granulation tissue after the second antigenic challenge in the air pouch. An antigenic challenge was performed in the air pouch on days 0 and 5. Anti–IL-1α mAb, anti-MGL1 mAb LOM-8.7, or saline was subsequently injected into the air pouch on days 5, 6, and 7. Skin samples were collected on day 18 and frozen sections were prepared. (A-E) Tissue stained with hematoxylin and eosin from mAb LOM-8.7–treated mice (A), hematoxylin and eosin–stained tissue obtained from anti–IL-1α–treated mice (B), immunohistochemical staining profiles with mAb LOM-14 (anti-MGL1/2) are shown (C-E). A boxed area and a dotted boxed area in panel C are shown at higher magnifications in D and E, respectively. Very similar profiles were obtained from samples prepared on day 11 (data not shown). Scale bars represent 100 μm (A-C) and 10 μm (D-E). (F) Thickness of the granulation tissue as indicated with dotted lines in panels A and B is shown (ordinate) on days 11 and 18. ▪ represents saline-treated mice; ▥, control rat IgG instead of mAb; ▧, anti-IL-1α–treated mice; and □, anti-MGL1 mAb LOM 8.7. Mean ± standard error (SE; n = 4). Treatment with anti–IL-1α mAb significantly inhibited the formation of granulation tissues as well as the infiltration of MGL1/2-positive cells in the area far from the inner surface of the air pouch. Resident MGL1/2-positive cells in the dermis were still observed. *P < .05, **P < .01.