title: [CD11b-positive cells expression in rectal mucosa from ovalbumin sensitized and challenged rabbits].
abstract: Rabbit MAC-1 receptor, homologue to human CD11b is present in macrophages. The aim of the study was to determine quantitative and distributive modifications of CD11b-positive cells that participate in immune response at rectal mucosa, in an animal model of mucosal immunity. New Zealand rabbits were divided into three groups. G1: control; G2: ovalbumin (OVA) sensitized; G3: OVA-senstitized and rectal challenged. Animals were subcutaneously sensitized twice with 70 microg OVA and 30 ml aluminium hydroxide in 2 ml saline solution. Rectal challenge was developed with a solution of 50 mg OVA in 5 ml saline solution. Sensitized groups (G2 and G3) showed a positive PCA (Passive Cutaneous Anaphylaxis) at 1/160 fold dilutions. In G3 we observed a patchy mucosal edema, lymphangiectasis and eosinophil leucocyte infiltration. Cells were counted as the number of cells per high power field. G1: 9.64 (SE 0.22); G2: 18.10 (SE 0.09) and G3: 23.60 (SE 0.29). (G2 vs G1 p < 0.001; G3 vs G1 p < 0.001; G3 vs G2 p < 0.001). We conclude that there is a close relationship between the food antigen OVA penetration (after challenge) and the increase of CD11b positive cells in rectal mucosa. This fact could be due to the cellular influx to the inflammatory site by the action of chemotactic factors released after challenge.
authors.affiliation: Cátedra de Histología, Citología y Embriología, Facultad de Medicina de Rosario, Universidad Abierta Interamericana, Rosario, Argentina. norbassan@sinectis.com.ar
authors.forename: Norberto
authors.initials: N
authors.lastname: Bassan
authors.forename: Miguel
authors.initials: M
authors.lastname: Vinuesa
authors.forename: Stella
authors.initials: S
authors.lastname: Roma
mesh_terms: D000818:Animals; D039481:CD11b Antigen / Q000276:immunology*; D002452:Cell Count; D004195:Disease Models, Animal; D005512:Food Hypersensitivity / Q000276:immunology*; D018928:Immunity, Mucosal / Q000276:immunology; D007114:Immunization; D007073:Immunoglobulin E / Q000276:immunology; D016177:Macrophage-1 Antigen / Q000276:immunology*; D008297:Male; D009092:Mucous Membrane / Q000166:cytology / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology*; D011817:Rabbits; D012007:Rectum / Q000166:cytology* / Q000276:immunology
chemical_list: D039481:CD11b Antigen; D016177:Macrophage-1 Antigen; D007073:Immunoglobulin E; D010047:Ovalbumin