Myeloid blood dendritic cells and monocyte-derived dendritic cells differ in their endocytosing capability.

Human dendritic cells (DCs) constitute a heterogeneous population of antigen-presenting cells characterized by a unique capacity to stimulate naïve T cells. The functions of DCs depend on the particular subset and in this study we compare two types of myeloid DCs: freshly isolated blood mDCs and in vitro generated monocyte-derived DCs (MoDCs), in their ability to accomplish endocytosis. In our hands, these two DC subtypes showed similarities in the expression of surface markers, but displayed clear differences in endocytic capacity. Freshly isolated blood mDCs showed a high propensity to capture and endocytose particles compared to in vitro generated MoDCs. The blood mDCs also showed a clear receptor-enhanced endocytosis when zeolite particles were co-adsorbed with IgG. On the other hand, the MoDCs differed remarkably compared to blood mDCs in the capture of ovalbumin and immune complexes. Interestingly, the MoDCs showed low endocytosis of IgG-coated particles but an efficient capture of immune complexes. The MoDCs also showed a high capacity to capture ovalbumin although with a relatively low degree of internalization. These data indicate distinct differences in the early process of endocytosis featured by mDCs and MoDCs, which is important to consider when choosing DC populations for future functional or clinical applications.

Adjuvant effect of Cliptox on the protective immune response induced by an inactivated vaccine against foot and mouth disease virus in mice.

Foot and Mouth Disease (FMD) is an acute disease caused by Foot and Mouth Disease Virus (FMDV) which causes important economy losses, this is why it is necessary to obtain a vaccine that stimulates a rapid and long-lasting protective immune response. Cliptox is a mineral microparticle that in earlier studies has shown adjuvant activity against different antigens. In this study we have examined the effects of Cliptox on the magnitude and type of immunity elicited in response to inactivated FMDV (iFMDV) vaccine. It was demonstrated that iFMDV-Cliptox stimulates a specific antibody response detected in mucosal and in sera. The different isotype profiles elicited by inoculation with this vaccine indicate a Th1/Th2 response. Also, an increase in dendritic cells and macrophages in the spleen in comparison with the iFMDV vaccine iFMDV-Cliptox was detected. The Cliptox-iFMDV formulation was non toxic by using egg embryos and yielded increased protection against challenge with FMDV in the murine model. Our results show that the incorporation of Cliptox into FMDVi vaccine induces an increase of the specific protective immune response in mice and clearly indicate that Cliptox TM exert an (important) up-regulation on DC and MPhi. Additionally, Cliptox TM adjuvant can be used in vaccines for induction of mucosal immune response.

Effectiveness and immunomodulation of chemotherapeutants against scuticociliate Philasterides dicentrarchi in olive flounder.

Philasterides dicentrarchi is a histophagous scuticociliate causes fatal scuticociliatosis in farmed olive flounder Paralichthys olivaceus. The average monthly prevalence of scuticociliatosis due to P. dicentrarchi infections was increased from May to July (40+/-3.1% to 79.4+/-1.7%) and it decreased from August to November (63+/-2.3% to 30+/-2.6%) in olive flounder farms at Jeju Island, South Korea during 2000-2006. The prevalence of mixed infection along with Vibrio spp. bacterial infection was 49+/-7.2% than that of other mixed infection. At present no effective control measure for P. dicentrarchi infection has been described and large production losses continue. In the present study, formalin, hydrogen peroxide and Jenoclean chemotheraputants were used for bath treatment. Among Jenoclean at a low concentration of 50ppm proved effective. The results were confirmed with in vitro motility assessments and morphological changes scoring system in P. dicentrarchi. On the other hand, similar trend was noted following hydrogen peroxide treatment at this concentration, but formalin was only moderately effective. Either hydrogen peroxide or Jenoclean are the promising compounds effective at low concentrations with short application time for P. dicentrarchi. Therefore, these substances were evaluated on day 10, 20 and 30 for their ability to enhance innate immune response and disease resistance against P. dicentrarchi in olive flounder after chemotheraputants bath treatment with 100ppm for 30min per day. All the tested immune parameters were enhanced by treatment with Jenoclean, but not formalin and hydrogen peroxide. These findings suggest that Jenoclean bath treatment can be used for ensuring the heath of cultured marine fish against internal parasites such as P. dicentrarchi.