Cyclophilin A-deficient mice are resistant to immunosuppression by cyclosporine

Cyclosporine is an immunosuppressive drug that is widely used to prevent organ transplant rejection. Known intracellular ligands for cyclosporine include the cyclophilins, a large family of phylogenetically conserved proteins that potentially regulate protein folding in cells. Immunosuppression by cyclosporine is thought to result from the formation of a drug-cyclophilin complex that binds to and inhibits calcineurin, a serine/threonine phosphatase that is activated by TCR engagement. Amino acids within the cyclophilins that are critical for binding to cyclosporine have been identified. Most of these residues are highly conserved within the 15 mammalian cyclophilins, suggesting that many are potential targets for the drug. We examined the effects of cyclosporine on immune cells and mice lacking Ppia, the gene encoding the prototypical cyclophilin protein cyclophilin A. TCR-induced proliferation and signal transduction by Ppia(-/-) CD4(+) T cells were resistant to cyclosporine, an effect that was attributable to diminished calcineurin inhibition. Immunosuppressive doses of cyclosporine failed to block the responses of Ppia(-/-) mice to allogeneic challenge. Rag2(-/-) mice reconstituted with Ppia(-/-) splenocytes were also cyclosporine resistant, indicating that this property is intrinsic to Ppia(-/-) immune cells. Thus, among multiple potential ligands, CypA is the primary mediator of immunosuppression by cyclosporine.     

Preliminary experience with subcutaneous human ovarian cortex transplantation in the NOD-SCID mouse.

Xenogeneic transplantation of ovarian cortex into an immunodeficient animal host may be an approach toward fertility preservation for young female patients undergoing cancer therapy. Our objective was to evaluate the development of follicles in human ovarian cortex placed s.c. in non-obese diabetic-severe combined immune deficiency (NOD-SCID) mice (n = 54). The following variables were compared: 1) male versus female mice as hosts, 2) intact versus pituitary down-regulated mice, and 3) warm versus cold tissue transport. After 2 wk, 37 of 50 (74%) of the human xenografts contained follicles. At 12 wk after transplantation, exogenous gonadotropin stimulation resulted in follicle growth in 19 of 37 (51%) of the grafts, including the development of antral follicles, which could be palpated and visualized through the mouse skin. Significantly more developing follicles were identified in male versus female mice (13 of 17 vs. 6 of 20, respectively; p = 0.013) after stimulation. No difference was found between intact and pituitary down-regulated mice as hosts. Follicular survival was significantly increased by warm versus cold tissue transport. Our results suggest that s.c. ovarian cortex xenografting into NOD-SCID mice is feasible. Primordial follicles in ovarian xenografts retain their developmental potential and form antral follicles following gonadotropin stimulation.     

Some observations on the effect of Daflon (micronized purified flavonoid fraction of Rutaceae aurantiae) in bancroftian filarial lymphoedema

BACKGROUND: Morbidity management is a core component of the global programme for the elimination of lymphatic filariasis. In a double-blind clinical trial, the tolerability and efficacy of Daflon (500 mg) + DEC (25 mg) or DEC (25 mg) alone, twice daily for 90 days, was studied in 26 patients with bancroftian filarial lymphoedema. RESULTS: None of the patients in either drug group reported any adverse reaction throughout the treatment period (90 days). Haematological and biochemical parameters were within normal limits and there was no significant difference between the pre-treatment (day 0) and post-treatment (day 90) values. The group receiving Daflon showed significant reduction in oedema volume from day 90 (140.6 PlusMinus; 18.8 ml) to day 360 (71.8 PlusMinus; 20.7 ml) compared to the pre-treatment (day 0, 198.4 PlusMinus; 16.5 ml) value. This accounted for a 63.8% reduction in oedema volume by day 360 (considering the pre-treatment (day 0) as 100%). In the DEC group, the changes in oedema volume (between day 1 and day 360) were not significant when compared to the pre-treatment (day 0) value. The percentage reduction at day 360 was only 9%, which was not significant (P > 0.05). CONCLUSION: This study has shown that Daflon (500 mg, twice a day for 90 days) is both safe and efficacious in reducing oedema volume in bancroftian filarial lymphoedema. Further clinical trials are essential for strengthening the evidence base on the role of this drug in the morbidity management of lymphatic filariasis.     

HOIL-1L Interacting Protein (HOIP) as an NF-κB Regulating Component of the CD40 Signaling Complex

The tumor necrosis factor receptor (TNFR) superfamily mediates signals critical for regulation of the immune system. One family member, CD40, is important for the efficient activation of antibody-producing B cells and other antigen-presenting cells. The molecules and mechanisms that mediate CD40 signaling are only partially characterized. Proteins known to interact with the cytoplasmic domain of CD40 include members of the TNF receptor-associated factor (TRAF) family, which regulate signaling and serve as links to other signaling molecules. To identify additional proteins important for CD40 signaling, we used a combined stimulation/immunoprecipitation procedure to isolate CD40 signaling complexes from B cells and characterized the associated proteins by mass spectrometry. In addition to known CD40-interacting proteins, we detected SMAC/DIABLO, HTRA2/Omi, and HOIP/RNF31/PAUL/ZIBRA. We found that these previously unknown CD40-interacting partners were recruited in a TRAF2-dependent manner. HOIP is a ubiquitin ligase capable of mediating NF-κB activation through the ubiquitin-dependent activation of IKKγ. We found that a mutant HOIP molecule engineered to lack ubiquitin ligase activity inhibited the CD40-mediated activation of NF-κB. Together, our results demonstrate a powerful approach for the identification of signaling molecules associated with cell surface receptors and indicate an important role for the ubiquitin ligase activity of HOIP in proximal CD40 signaling.     

Antimicrobial aspects of inflammatory resolution in the mucosa: a role for proresolving mediators

Mucosal surfaces function as selectively permeable barriers between the host and the outside world. Given their close proximity to microbial Ags, mucosal surfaces have evolved sophisticated mechanisms for maintaining homeostasis and preventing excessive acute inflammatory reactions. The role attributed to epithelial cells was historically limited to serving as a selective barrier; in recent years, numerous findings implicate an active role of the epithelium with proresolving mediators in the maintenance of immunological equilibrium. In this brief review, we highlight new evidence that the epithelium actively contributes to coordination and resolution of inflammation, principally through the generation of anti-inflammatory and proresolution lipid mediators. These autacoids, derived from ω-6 and ω-3 polyunsaturated fatty acids, are implicated in the initiation, progression, and resolution of acute inflammation and display specific, epithelial-directed actions focused on mucosal homeostasis. We also summarize present knowledge of mechanisms for resolution via regulation of epithelial-derived antimicrobial peptides in response to proresolving lipid mediators.