Expression of human CD46 modulates inflammation associated with GalTKO lung xenograft injury.

Evaluation of lungs from GalTKO.hCD46 pigs, genetically modified to lack the galactose-α(1,3)-galactose epitope (GalTKO) and to express human CD46, a complement regulatory protein, has not previously been described. Physiologic, hematologic and biochemical parameters during perfusion with heparinized fresh human blood were measured for 33 GalTKO.hCD46, GalTKO (n = 16), and WT pig lungs (n = 16), and 12 pig lungs perfused with autologous pig blood. Median GalTKO.hCD46 lung survival was 171 min compared to 120 for GalTKO (p = 0.27) and 10 for WT lungs (p < 0.001). Complement activation, platelet activation and histamine elaboration were significantly reduced during the first 2 h of perfusion in GalTKO.hCD46 lungs compared to GalTKO (ΔC3a at 120' 812 ± 230 vs. 1412 ± 1047, p = 0.02; ΔCD62P at 120' 9.8 ± 7.2 vs. 25.4 ± 18.2, p < 0.01; Δhistamine at 60' 97 ± 62 vs. 189 ± 194, p = 0.03). We conclude that, in addition to significant down-modulation of complement activation, hCD46 expression in GalTKO lungs diminished platelet and coagulation cascade activation, neutrophil sequestration and histamine release. Because GalTKO.hCD46 lung failure kinetics correlated directly with platelet and neutrophil sequestration, coagulation cascade activation and a rise in histamine levels within the first hour of perfusion, further progress will likely depend upon improved control of these pathways, by rationally targeted additional modifications to pigs and pharmacologic interventions.

Selective CD28 blockade attenuates acute and chronic rejection of murine cardiac allografts in a CTLA-4-dependent manner.

Selective blockade of CD28 is a promising therapy to inhibit pathogenic alloimmunity. However, evaluation of this approach in transplantation has been very limited. Using a novel nonactivating single-chain Fv-based reagent (α28scFv), we have investigated the role of CD28 and cytotoxic T lymphocyte antigen 4 (CTLA-4) in a murine cardiac transplant model. Blockade of CD28 for 2 weeks after engraftment promoted allograft survival, and significantly attenuated chronic rejection when combined with transient CD154-blockade or calcineurin inhibition. Graft acceptance was associated with decreased alloantibody production, increased proportion of early graft infiltration by regulatory T cells and increased expression of regulatory dendritic cell genes. Blockade of CTLA-4 during α28scFv-based treatments led to prompt rejection in all animals and inhibited expression of forkhead box P3 (Foxp3), programmed death (PD)-1 and 2,3-indoleamine dioxygenase (IDO) in the graft. These results show that CD28 signaling during the first weeks after transplant is a pivotal mediator of pathogenic alloimmunity, and that selective CD28 blockade prolongs graft acceptance by at least two immunomodulatory mechanisms. Selective CD28 inhibition while sparing CTLA-4 is thus a promising approach to inhibit pathogenic alloimmunity.

[How to improve ART results? Is France behind other countries? Strategy for single embryo transfer: The value of embryo selection and embryo freezing]. / Comment améliorer nos résultats en AMP? La France est-elle en retard? Stratégie de transfert de l'embryon unique: la place du choix de l'embryon et de la congélation embryonnaire.

Multiple embryo transfer is associated with a high frequency of twin pregnancies with costly complications involving both mother and child. As a result high priority is currently being given to the development of single embryo transfer (SET) programs. France seems to be lagging behind Northern European countries in the development of SET and widespread use of SET will depend on convincing physicians that this policy will not have a negative impact on success rate, as has been the case for many protocols described in the literature as well as in our own experience. Our SET program includes patients less than 36 years of age undergoing their first FIV-ICSI. If two embryos showing satisfactory morphology are obtained, one is selected transferred and the other is systematically frozen. Selection for transfer is based on two criteria, i.e. observation of even early cleavage 26 hours after FIV-ICSI and evaluation of embryo morphology score on day 2. Embryo morphology score is based on the presence of four blastomeres and absence of blastomere irregularities and anucleated fragmentation. Last, a prerequisite for SET is an effective freezing program. A pregnancy rate of 13% per thawing was sufficient enough to obtain a cumulative pregnancy rate after SET (N = 205) and subsequent frozen embryo transfer (FET) similar to the cumulative pregnancy rate obtained after double embryo transfer (N = 394) and subsequent FET (46.3 vs 46.7%, NS). Twin delivery rate were respectively 2,6% after SET and 26,6% after double embryo transfer (P < 0.01).

Papaverine as a replacement for pentoxifylline to select thawed testicular or epididymal spermatozoa before ICSI.

OBJECTIVES: Pentoxifylline has been used to improve sperm motility in Assisted Reproductive Technology mainly by initiating sperm motility in immotile spermatozoa samples obtained surgically. Indeed, as Intracytoplasmic Sperm Injection leads to very poor results when using immotile gametes, pentoxifylline gives better results by easing the selection of viable sperm mobilized after incubation. In 2011, the French Haute Autorité de santé decided that pentoxifylline used for in vivo purpose proposed Insufficient Medical Service and pentoxifylline was thus withdrawn from the French materia medica. We here assessed the efficacy on spermatozoa motility and the safety of papaverine, another phosphodiesterase inhibitor, for the replacement of pentoxifylline. METHODS: Sixteen frozen-thawed epididymal or testicular samples displaying no or very poor spontaneous motility (≤5% total motility) were subjected to both pentoxifylline (3.6mM) and papaverine (93µM). A duplicate Mouse Embryo Assay and an In Vitro Fertilization Mouse Assay in duplo were used to discard any toxic effect of papaverine. RESULTS: Papaverine gave better results than pentoxifylline (mean total motility: 27% vs 23%, P<0.05). No Effect Level were observed in the two different Mouse Embryo Assays performed. CONCLUSION: Papaverine is a useful tool to replace pentoxifylline in ICSI programs to select viable spermatozoa in frozen-thawed sperm samples displaying no or very poor motility.

Relationship between even early cleavage and day 2 embryo score and assessment of their predictive value for pregnancy.

The aim of this study was, firstly, to define the different patterns of early cleavage (EC) observed at 26 h after either IVF or intracytoplasmic sperm injection (ICSI) and, secondly, to assess the predictive value of one of these patterns, even EC (EEC), on pregnancy rate in combination with day 2 embryo score. In the first part of the study, the relationship between three different EC patterns (EEC, uneven EC and EC with fragmentation of the day 2 embryo) and embryo morphology was determined. EEC was shown to be strongly associated with good embryo morphology. In the second part of the study, it was shown that EEC used in combination with embryo score improved selection of embryos for transfer. The presence of EEC significantly (P < 0.001) enhanced mean implantation rate in all transfer categories involving identically scored embryos, in both compulsory single embryo transfers and elective single embryo transfers. Multivariate analysis demonstrated that EEC and embryo score had strong complementary predictive value for pregnancy. Based on these findings, it was concluded that even though they are associated, EEC and embryo score could be combined to increase pregnancy rate, especially in elective single embryo transfer programmes.