ABSTRACT
Macrophages function as phagocytes and antigen-presenting cells in the body. As has been demonstrated in mammals, administration of clodronate [dichloromethylene bisphosphonate (Cl2MBP)] encapsulated liposomes results in depletion of macrophages. Although this compound has been used in chickens, its effectiveness in depleting macrophages has yet to be fully determined. Here, we show that a single administration of clodronate liposomes to chickens results in a significant depletion of macrophages within the spleen and lungs of chickens up to 4 d post-treatment. This finding suggests that, in order to obtain depletion of macrophages in chickens for greater than 5 d, it is necessary to administer clodronate liposomes 4 d apart. The study also showed that 2 treatments of clodronate liposomes at 4-day intervals resulted in the depletion of macrophages for up to 10 d. The findings of the present study will encourage more precise studies to be done on the potential roles of macrophages in immune responses and in the pathogenesis of microbial infections in chickens.
Les macrophages agissent comme phagocytes et cellules présentatrices d'antigènes dans l'organisme. Tel que démontré chez les mammifères, l'administration de liposomes encapsulés de clodronate [biphosphanate de dichlorométhylène (Cl2MBP)] cause une déplétion des macrophages. Bien que ce composé ait été utilisé chez les poulets, son efficacité à causer une déplétion des macrophages reste encore à être entièrement déterminée. Nous démontrons ici que l'administration d'une dose unique de liposomes de clodronate à des poulets a causé une déplétion significative des macrophages dans la rate et les poumons de poulets jusqu'à 4 j post-traitement. Cette trouvaille suggère qu'afin d'obtenir une déplétion des macrophages chez les poulets pour plus de 5 j, il est nécessaire d'administrer des liposomes de clodronate à un intervalle de 4 j. Cette étude a aussi démontré que deux traitements de liposomes de clodronate à 4 j d'intervalle a causé une déplétion des macrophages pour une durée allant jusqu'à 10 j. Les présentes trouvailles encourageront la mise en place d'études plus précises sur les rôles potentiels des macrophages dans la réponse immunitaire et dans la pathogénèse des infections microbiennes chez les poulets.(Traduit par Docteur Serge Messier).
Subject(s)
Chickens/immunology , Clodronic Acid/pharmacology , Lung/immunology , Macrophages/immunology , Spleen/immunology , Animals , Clodronic Acid/administration & dosage , Flow Cytometry/veterinary , Immunohistochemistry/veterinary , Liposomes/administration & dosage , Lung/cytology , Macrophages/drug effects , Spleen/cytologyABSTRACT
BACKGROUND: Cidofovir has been reported to have activity against human papillomavirus (HPV) type 16, but no laboratory studies have been performed on HPV type 6, the main cause of recurrent respiratory papillomatosis (RRP). METHODS: HPV6b E6 cDNA-based C33A (non-HPV cervical carcinoma) cell line was produced. Two different doses of cidofovir were applied to parent C33A, C33AT6E6, and C33AT16E6 (HPV 16). Growth and flow cytometry analysis were performed. RESULTS: Polymerase chain reaction confirmed HPV6 E6 expression in C33AT6E6 cells. High-dose cidofovir was found to be toxic to all cell lines. Low-dose exposure was found to be toxic to C33AT16E6 cells at 3 days, whereas C33A and C33AT6E6 showed minimal toxicity at 6 days and earlier recovery following drug withdrawal. CONCLUSIONS: Cidofovir showed nonspecific toxicity against all 3 cell lines tested. HPV16 E6 expressing cells were more sensitive than parent or HPV6 E6 expressing cells. Cidofovir has no selective advantage for the RRP-related HPV6 E6 expressing cell line.
