Solar-Simulated Ultraviolet Radiation Induces Abnormal Maturation and Defective Chemotaxis of Dendritic Cells

Exposure to ultraviolet (UV) light induces immunosuppression. Different evidences indicate that this phenomenon is mainly a consequence of the effect of UV light on skin dendritic cells (DC). To investigate the cellular and molecular basis of this type of immunosuppression, we assessed in vitro the effect of solar-simulated UV radiation on the phenotypic and functional characteristics of human monocyte-derived DC and Langerhans-like DC. UV radiation induced a decreased expression of molecules involved in antigen capture as DC-SIGN and the mannose receptor. This effect was accompanied by a diminished endocytic capacity, an enhanced expression of molecules involved in antigen presentation such as major histocompatibility complex-II and CD86, and a significant increase in their capability to stimulate T cells. Furthermore, irradiated DC failed to acquire a full mature phenotype upon treatment with lipopolysaccharide. On the other hand, solar-simulated radiation induced the secretion of tumor necrosis factor-αand interleukin (IL)-10 by DC, but no IL-12. Interestingly, solar-simulated UV radiation also caused an altered migratory phenotype, with an increased expression of CXCR4, and a lack of induction of CCR7, thus correlating with a high chemotactic response to stromal cell-derived factor 1(SDF-1) (CXCL12), but not to secondary lymphoid tissue chemokine (SLC) (CCL21). These data indicate that solar-simulated UV radiation induces a defective maturation and an anomalous migratory phenotype of DC

Variabilidad estructural inducida en BF1 ATPasa de Micrococcus lysodeikticus

Tesis Doctoral inédita leida en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura:14-04-198

Enantioselective Synthesis and Biological Activity of (3S,4R)- and (3S,4S)-3-Hydroxy-4-hydroxymethyl- 4-butanolides in Relation to PGE2

Compounds 9 and 13 were synthesized, and their structures and stereochemistry were elucidated by spectroscopic methods. In competition binding experiments, specific [3H]-PGE2 binding was significantly displaced by compound 9 and, to a lesser extent, by 13, in a dose-dependent manner. The biological properties of compound 9 were studied on HL-60 cells, and several effects were found related to those of PGE2. Compound 9 increases c-fos mRNA level as does PGE2 and antagonizes TPA-induced terminal differentiation.Peer reviewe

AM3 inhibits LPS-induced iNOS expression in mice

We have analyzed the effect of a patented glycoconjugate of natural origin, AM3 (commercially available under the name Inmunoferon) in the expression of iNOS induced by administration of LPS in mice. We have observed that oral treatment with the drug daily for 6 days reduced the levels of expression of iNOS induced by an intravenous pulse of LPS. This effect was significant in the lungs and kidneys, but it was much more marked in the liver. In addition, the levels of nitric oxide in serum were clearly decreased upon treatment with AM3. Together, these results suggest that AM3 modulates the nitric oxide response and points to a possible role for AM3 in the control of the inflammatory response