RESUMO
The autocrine/paracrine peptide signaling molecules such as growth factors have many promising biologic activities for clinical applications. However, one cannot expect specific therapeutic effects of the factors administered by ordinary drug delivery systems as they have limited target specificity and short half-lives in vivo. To overcome the difficulties in using growth factors as therapeutic agents, we have produced fusion proteins consisting of growth factor moieties and a collagen-binding domain (CBD) derived from Clostridium histolyticum collagenase. The fusion proteins carrying the epidermal growth factor (EGF) or basic fibroblast growth factor (bFGF) at the N terminal of CBD (CBEGF/CBFGF) tightly bound to insoluble collagen and stimulated the growth of BALB/c 3T3 fibroblasts as much as the unfused counterparts. CBEGF, when injected subcutaneously into nude mice, remained at the sites of injection for up to 10 days, whereas EGF was not detectable 24 h after injection. Although CBEGF did not exert a growth-promoting effect in vivo, CBFGF, but not bFGF, strongly stimulated the DNA synthesis in stromal cells at 5 days and 7 days after injection. These results indicate that CBD may be used as an anchoring unit to produce fusion proteins nondiffusible and long-lasting in vivo.
Assuntos
Colágeno/genética , Colágeno/metabolismo , Sistemas de Liberação de Medicamentos , Fator de Crescimento Epidérmico/genética , Fator de Crescimento Epidérmico/metabolismo , Células 3T3 , Administração Cutânea , Animais , Divisão Celular/efeitos dos fármacos , Clostridium , Colágeno/administração & dosagem , Colágeno/química , Colagenases/química , Colagenases/genética , Fator de Crescimento Epidérmico/administração & dosagem , Fator de Crescimento Epidérmico/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Ligação Proteica , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Células Estromais/efeitos dos fármacos , Células Estromais/patologiaRESUMO
Macrolide antibiotics have a variety of actions other than antimicrobial activities. Recently, it has been suggested that macrolide antibiotics act as immunomodulators. In this study, we evaluated the effects of macrolide antibiotics on macrophage functions. For the macrophage, we used the mouse macrophage cell line J774.1. The following effects of macrolide antibiotics on macrophage functions were evaluated: the effect of macrolide antibiotics on macrophage growth; the phagocytosis of beads; cytocidal activity against Candida albicans; and chemotaxis to lipopolysaccharide (LPS). Macrolide antibiotics except for azithromycin significantly stimulated the growth of the macrophage. In addition, pretreatment with macrolide antibiotics except for roxithromycin significantly stimulated the macrophage phagocytosis of beads, macrophage chemotaxis to LPS, and macrophage cytocidal activity against Candida albicans. These results suggest that macrolide antibiotics stimulate macrophage functions.
