Histamine receptors H3/H4 involvement in a mouse model of dermatitis

JULIETA ALCAIN; SOLEDAD GORI; GABRIELA SALAMONE; MONICA VERMEULEN

Congreso; 63 Reuni¨®n Cient¨ªfica Anual de la Sociedad Argentina de Inmunol; 2016

Leukotriene C4 (LTC4) is an important lipid mediator involved in the genesis of chronic inflammatory responses. Its effects are mediated through the cysteinyl receptor 1 and 2 (CysLTR1/2). In previous works, it has been demonstrated that LTC4 is able to chemotaxis of dendritic cells (DC) and their activation, with the ability to interfere with their maturation. Here, we studied the capacity of LTC4 to break the gut tolerance. For this,BALB/c mice were orally inoculated with a single dose of PBS (Ct) or LTC4 (0.01 ¦ÌM in 100¦Ìl of PBS) at the beginning of Ovalbumin tolerance (100 mg/day in drinking water for 5 days). After 12 days, histological examination of small intestine showed that the intestine was extensively modified by the exposure to LTC4, mainly evidenced through the shortening of villi, increased protrusion of goblet cells and edema in the lamina propria, together with a marked recruitment of leukocytes, mainly eosinophilic-granulocytes.Then, we decided to evaluate the populations recruited in mesenteric lymph node after treatment. In the first place, LTC4 inhibited the CD11c+ CD103+ dendritic cells (DC), the main population associated to mucosal tolerance (mean% CD11c+CD103+ DC ¡À SEM: PBS 2.1 ¡À 0.25, LTC4 0.92 ¡À 0.1, p¡Ü0.05, n = 4). Also, we observed a greater expression of CysLTR1compared to CysLTR2 (mean band ratio/b-actin; CysLTR1 vs CysLTR2: 1.2 ¡À 0.08; 0.4 ¡À 0.03; * p