Contrasting Effects of Cyclosporine and Rapamycin in De Novo Generation of Alloantigen-Specific Regulatory T Cells

The outcome of T‐cell‐mediated responses, immunity or tolerance, critically depends on the balance of cytopathic versus regulatory T (T_reg) cells. In the creation of stable tolerance to MHC incompatible allografts, reducing the unusually large mass of donor‐reactive cytopathic T effector (T_eff) cells via apoptosis is often required. Cyclosporine (CsA) blocks activation‐induced cell death (AICD) of T_eff cells, and is detrimental to tolerance induction by costimulation blockade, whereas Rapamycin (RPM) preserves AICD, and augments the potential of costimulation blockade to create tolerance. While differences between CsA and RPM in influencing apoptosis of activated graft‐destructive T_eff cells are apparent, their effects on graft‐protective T_reg cells remain enigmatic. Moreover, it is unclear whether tolerizing regimens foster conversion of naïve peripheral T cells into alloantigen‐specific T_reg cells for graft protection. Here we show, using reporter mice for T_reg marker Foxp3, that RPM promotes de novo conversion of alloantigen‐specific T_reg cells, whereas CsA completely inhibits this process. Upon transfer, in vivo converted T_reg cells potently suppress the rejection of donor but not third party skin grafts. Thus, the differential effects of RPM and CsA on T_eff and T_reg cells favor the use of RPM in shifting the balance of aggressive to protective type alloimmunity.     

Glutamic acid decarboxylase 65 and islet cell antigen 512/IA-2 autoantibodies in relation to human leukocyte antigen class II DR and DQ alleles and haplotypes in type 1 diabetes mellitus

The frequencies of autoantibodies against glutamic acid decarboxylase 65 (GAD65) and islet cell antigen (ICA) 512/IA-2 (512/IA-2) are functions of the specific human leukocyte antigen (HLA) in type 1 diabetes mellitus (T1D). We investigated the association of HLA class II (DR and DQ) alleles and haplotypes with the presence of GAD and IA-2 autoantibodies in T1D. Autoantibodies were tested in 88 Tunisian T1D patients and 112 age- and gender-matched normoglycemic control subjects by enzyme immunoassay. Among T1D patients, mean anti-GAD antibody titers were higher in the DRB1*030101 allele (P < 0.001), together with the DRB1*030101/DQB1*0201 (P < 0.001) and DRB1*040101/DQB1*0302 (P = 0.002) haplotypes, while lower anti-GAD titers were associated with the DRB1*070101 (P = 0.001) and DRB1*110101 (P < 0.001) alleles and DRB1*070101/DQB1*0201 (P = 0.001) and DRB1*110101/DQB1*030101 (P = 0.001) haplotypes. Mean anti-IA-2 antibody titers were higher in the DRB1*040101 allele (P = 0.007) and DRB1*040101/DQB1*0302 (P = 0.001) haplotypes but were lower in the DRB1*110101 allele (P = 0.010) and the DRB1*110101 (P < 0.001) and DRB1*110101/DQB1*030101 (P = 0.025) haplotypes. Multinomial regression analysis confirmed the positive association of DRB1*030101 and the negative association of DRB1*110101 and DQB1*030101, along with the DRB1*070101/DQB1*0201 and DRB1*110101/DQB1*030101 haplotypes, with anti-GAD levels. In contrast, only the DRB1*040101/DQB1*0302 haplotype was positively associated with altered anti-IA-2 titers. Increased GAD65 and IA-2 antibody positivity is differentially associated with select HLA class II alleles and haplotypes, confirming the heterogeneous nature of T1D.     

Specific HLA-DRB and -DQB alleles and haplotypes confer disease susceptibility or resistance in Bahraini type 1 diabetes patients

Insofar as genetic susceptibility to type 1 diabetes is associated with HLA class II genes, with certain allelic combinations conferring disease susceptibility or resistance, this study assessed the distributions of HLA-DR and -DQ among 107 unrelated patients with type 1 diabetes and 88 healthy controls from Bahrain, all of Arab origin. The HLA-DRB and -DQB genotypes were determined by PCR-sequence-specific priming. The following alleles showed the strongest association with type 1 diabetes among patients versus controls according to their frequencies: DRB1*030101 (0.430 versus 0.097; P < 0.001), DRB1*040101 (0.243 versus 0.034; P < 0.001), DQB1*0201 (0.467 versus 0.193; P < 0.001), and DQB1*0302 (0.229 versus 0.091; P < 0.001). When the frequencies of alleles in controls were compared to those in patients, negative associations were seen for DRB1*100101 (0.085 versus 0.014; P < 0.001), DRB1*110101 (0.210 versus 0.060; P < 0.001), DQB1*030101 (0.170 versus 0.075; P = 0.006), and DQB1*050101 (0.335 versus 0.121; P < 0.001). In addition, the DRB1*030101-DQB1*0201 (70.1 versus 22.7%; P < 0.001) and DRB1*030101-DQB1*0302 (21.5 versus 0.0%; P < 0.001) genotypes were more prevalent among patients, thereby conferring disease susceptibility, whereas the DRB1*100101-DQB1*050101 (20.5 versus 2.8%; P < 0.001), DRB1*110101-DQB1*030101 (28.4 versus 8.4%; P < 0.001), and DRB1*110101-DQB1*050101 (30.7 versus 0.9%; P < 0.001) genotypes were more prevalent among controls, thus assigning a protective role. These results confirm the association of specific HLA-DR and -DQ alleles and haplotypes with type 1 diabetes and may underline several characteristics that distinguish Bahraini patients from other Caucasians patients.     

Genetic interactions between RAD51 and its paralogues for centrosome fragmentation and ploidy control, independently of the sensitivity to genotoxic stresses

We evaluate here whether RAD51 and its paralogues XRCC2 and XRCC3 act via a common pathway for sensitivity to genotoxic stress, centrosome fragmentation and chromosome stability. We expressed the RAD51 dominant-negative SMRAD51 in irs1 and irs1SF cells, defective for XRCC2 and XRCC3, respectively, and in their corresponding wild-type cells (V79 and AA8, respectively). V79-SMRAD51 cells are sensitive to mitomycin C (MMC), but SMRAD51 did not further sensitize irs1 cells to MMC, showing that SMRAD51 and XRCC2 act on the same pathway for resistance to MMC. However, in contrast to irs1 and irs1SF cells, SMRAD51-V79 and SMRAD51-AA8 cells are not sensitive to gamma-rays or UV-C. Despite these differences in sensitivity, SMRAD51-expressing cells and xrcc2- or xrcc3-defective cells show similar increased levels of centrosome fragmentation. This spontaneous centrosome fragmentation is resistant to caffeine, suggesting that ATM and ATR are not involved. Consistent with centrosome fragmentation, increased aneuploidy was measured in irs1 and SMRAD51-expressing cells. Expression of SMRAD51 in irs1 or irs1SF cells did not increase further the frequency of multipolar cells. Thus, RAD51, XRCC2 and XRCC3 act in the same pathway for centrosome fragmentation, independently of the sensitivity to exogenous genotoxic stresses and of the ATM/ATR pathway.     

The use of long-term defunctionalized bladder in renal transplantation: is it safe?

OBJECTIVE: Evaluation of the use of defunctionalized bladder in renal transplantation, concerning surgical complications. METHODS: In order to assess the complication rate of ureteral reimplantation in long-term defunctionalized bladder, we compared 20 patients on haemodialysis for more than 15 years (group I) with another 20 patients on haemodialysis for less than 5 years (group II). None of these patients had renal failure due to urological causes or neurogenic bladder. Non-stented extravesical ureteroneocystostomy was done routinely in all patients except 1 in group II who underwent Politano-Leadbetter ureteroneocystostomy and 7 patients in group I who underwent Politano-Leadbetter (3 patients) and pyelo-ureteral anastomosis using the recipient's native ureter (4 patients). The amount of residual urine was insignificant (<100 cm(3)) in both groups. RESULTS: The mean postoperative bladder catheterization period was 7.8 days in group I and 4.2 days in group II. Postoperative urinary tract infections were observed in 9 cases of group I and in 4 cases of group II. No surgical complications occurred in patients of group II, while there were 6 patients with surgical complications in group I: stenosis after a pyelo-ureteral anastomosis (1 case), stenosis after a ureterovesical anastomosis with Politano-Leadbetter technique (1 case), urinary fistulae (3 cases; 1 with Politano-Leadbetter ureteroneocystostomy and 2 cases with pyelo-ureteral anastomosis), and vesico-ureteral reflux (1 case with Politano-Leadbetter ureteroneocystostomy). These 6 cases had the lowest bladder capacity (30-150 cm(3)) among our 40 patients. Graft losses were comparable between the two groups and were not due to surgical complications. CONCLUSION: Small defunctionalized bladders can be used in kidney transplantation, but it may represent an increased surgical risk due to difficulty in performing ureteral reimplantation.     

Sequential recognition of antigenic markers of <Emphasis Type=Italic>Toxoplasma gondii</Emphasis> tachyzoite by pooled sera of mice with experimental toxoplasmosis

Accurate diagnosis of maternal toxoplasmosis can enhance the success of medical treatment and prevent congenital transmission. The current diagnostic methods have many limits, and they poorly differentiate between recent and latent infections. The present work was conducted to record the sequential recognition of antigenic markers of both Toxoplasma tachyzoites whole extract and glycosylinositolphospholipids (GIPLs)-enriched fraction by specific IgG and IgM, respectively, by immunoblotting analysis of the antigens against daily pooled serum samples from mice with experimentally induced recent and latent toxoplasmosis. IgG avidity immunoblotting was tested by using a wash with 6 M urea solution as antigen-antibody disrupting agent. Band of 10 kDa reacted exclusively with low-avidity IgG in pooled sera of mice with recent infection. Band of 39 kDa was a good marker for the infection; reacting with both low-avidity IgG in recent infection and with high-avidity IgG in latent one. Bands of 15, 23, 30, 60, 66, and 97 kDa reacted with variable avidity in both phases of infection. Two antigenic bands were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the GIPLs-enriched fraction of tachyzoite, the 14- and 30-kDa band. The 14-kDa band was recognized by IgM in pooled serum samples of recently infected mice only, while the 30-kDa band was recognized by serum samples of both recent and latent phases of infections. The study highlights the value of avidity immunoblotting assay to discriminate between recent and latent experimental toxoplasmosis. Further study must be carried on human to evaluate the values of the used technique.     

Curcumin nanoparticles: the topical antimycotic suspension treating oral candidiasis

Odontology - Phytotherapeutics is widely used nowadays as an alternative to the current antifungal drugs to reduce their side effects. Curcumin, with its wide therapeutic array as antioxidant and...     

ASO Visual Abstract: The Association of Frailty with Outcomes After Cancer Surgery—A Systematic Review and Meta-Analysis

Annals of Surgical Oncology -