Activation of macrophages by silicones: phenotype and production of oxidant metabolites.
BACKGROUND
The effect of silicones on the immune function is not fully characterized. In clinical and experimental studies, immune alterations associated with silicone gel seem to be related to macrophage activation. In this work we examined in vivo, phenotypic and functional changes on peritoneal macrophages early (24 h or 48 h) and late (45 days) after the intraperitoneal (i.p.) injection of dimethylpolysiloxane (DMPS) (silicone). We studied the expression of adhesion and co-stimulatory molecules and both the spontaneous and the stimulated production of reactive oxygen intermediates and nitric oxide (NO).


RESULTS
The results presented here demonstrate that the fluid compound DMPS induced a persistent cell recruitment at the site of the injection. Besides, cell activation was still evident 45 days after the silicone injection: activated macrophages exhibited an increased expression of adhesion (CD54 and CD44) and co-stimulatory molecules (CD86) and an enhanced production of oxidant metabolites and NO.


CONCLUSIONS
Silicones induced a persistent recruitment of leukocytes at the site of the injection and macrophage activation was still evident 45 days after the injection.
Iribarren
Pablo
P
Inmunología, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000, Córdoba, Argentina. piribarr@bioclin.fcq.unc.edu.ar
Correa
Silvia G
SG
Sodero
Natalia
N
Riera
Clelia M
CM
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D004129:Dimethylpolysiloxanes / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D006861:Hydrogen Peroxide / Q000378:metabolism; D016130:Immunophenotyping; D008262:Macrophage Activation / Q000187:drug effects*; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D015703:Antigens, CD; D004129:Dimethylpolysiloxanes; D009569:Nitric Oxide; D006861:Hydrogen Peroxide