Autophagy can promote but is not required for epithelial cell extrusion in the amnioserosa of the Drosophila embryo.

During Drosophila embryogenesis the majority of the extra-embryonic epithelium known as the amnioserosa (AS) undergoes programmed cell death (PCD) following the completion of the morphogenetic process of dorsal closure. Approximately ten percent of AS cells, however, are eliminated during dorsal closure by extrusion from the epithelium. Using biosensors that report autophagy and caspase activity in vivo, we demonstrate that AS cell extrusion occurs in the context of elevated autophagy and caspase activation. Furthermore, we evaluate AS extrusion rates, autophagy, and caspase activation in embryos in which caspase activity or autophagy are altered by genetic manipulation. This includes using the GAL4/UAS system to drive expression of p35, reaper, dINR (ACT) and Atg1 in the AS; we also analyze embryos lacking both maternal and zygotic expression of Atg1. Based on our results we suggest that autophagy can promote, but is not required for, epithelial extrusion and caspase activation in the amnioserosa.

Association of HLA-DRB1, DQA1 and DQB1 Alleles and Haplotypes with Common Variable Immunodeficiency in Iranian Patients.

Common Variable Immunodeficiency (CVID) is an antibody deficiency syndrome that often co-occurs in families with selective IgA deficiency (IgAD). This study was designed to investigate the frequency of DR and DQ loci of HLA class II region in common variable immunodeficiency (CVID) patients. Fifteen Iranian patients with CVID or IgAD (mean age 14.6±5.4, range 4-25 years; 9 male and 6 female) and 63 healthy controls were studied. Establishment of B-lymphoblastoid cell lines was performed using Epstein-Barr-virus (EBV) immortalization technique and HLA alleles were typed using polymerase chain reaction based on sequence specific primers (PCR-SSP). DRB1 alleles including DRB1 *04 (p=0.03) and DRB1 *11 (p=0.01) significantly showed higher frequency in the studied subjects. In contrast, DRB1 *301 (p=0.04) and DRB1 *07 (p=0.02) alleles were negatively associated with CVID. For DQB1 and DQA1 loci, DQB1 *0302 (p=0.047) and DQA1 *03011 (p=0.001) demonstrated high frequency in cases, while DQB1 *0201 (p=0.02) and DQA1 *0201 (p=0.01) were detected to be low when compared to controls. Haplotype analysis indicated that frequency of DRB1*04-DQB1*03011-DQA1 *03011 (p=0.02), DRB1 *11-DQB1 *03011-DQA1 *0505 (p=0.047), DRB1 *11-DQA1 *0505 (p=0.04) and DRB1*04-DQA1*03011 (p=0.02) haplotypes were significantly higher in patient group, while only the frequency of the DRB1 *07-DQA1 *0201 haplotype gene was statistically lower in control group (p=0.02). According to the results, it could be deduced that the HLA-DR and DQ loci may contribute to the pathogenesis of CVID or they might be considered as suitable markers for the possibility of the occurrence of this genetic defect.

Autophagy promotes caspase-dependent cell death during Drosophila development.

The relationship between autophagic cell death and apoptosis is a poorly understood aspect of programmed cell death (PCD). We have examined this relationship by studying the elimination of an extra-embryonic tissue, known as the amnioserosa (AS), during Drosophila development. The AS becomes autophagic during the final stages of embryogenesis; ultimately, however, the elimination of the AS involves caspase-dependent nuclear fragmentation, tissue dissociation and engulfment by phagocytic macrophages. Mutants that are defective in the activation or execution of caspase-dependent PCD fail to degrade and eliminate the AS but show no abatement in AS autophagy. Sustained autophagy does not, therefore, necessarily result in cell death. Surprisingly, the downregulation of autophagy also results in a persistent AS phenotype and reduced cell death. Conversely, upregulation of autophagy results in caspase-dependent premature AS dissociation. These observations are consistent with the interpretation that autophagy is a prerequisite for caspase-dependent cell death in the AS.

HLA-DRB1, DQA1 and DQB1 alleles and haplotypes frequencies in Iranian healthy adult responders and non-responders to recombinant hepatitis B vaccine.

BACKGROUND: Different studies have demonstrated that a small proportion of healthy individuals receiving the hepatitis B (HB) vaccine do not produce protective levels of anti-HB antibody, a phenomenon which could be linked to certain human leukocyte antigen (HLA) class-II alleles or haplotypes. OBJECTIVES: The present study was undertaken to determine the frequency of HLA class-II alleles in Iranian healthy adult responders and non-responders to HB vaccine. METHODS: Twelve non-responders (anti-HBs antibody<10 IU/L) and 46 responders (anti-HBs antibody>100 IU/L) were tissue typed for HLA class-II. HLA-DRB1, DQB1 and DQA1 alleles were determined using polymerase chain reaction based on sequence specific primers (PCR-SSP) technique. Accessibility to excess amount of genomic DNA was possible using Epstein-Barr virus (EBV)-transformed B-cells established from all vaccinees. RESULTS: Our results demonstrated increased frequencies of HLA- DRB107, DRB103, DRB104, DQB10201, DQA10201 alleles and HLA- DRB107/DQB10201/DQA10201 and DRB104/DQB10302/DQA103011 haplotypes in the non-responder group. Comparison between responders and non-responders revealed only a significant difference for DQB10201 allele (p<0.05). CONCLUSION: These findings confirm the association of certain HLA alleles and haplotypes with the lack of antibody response to HB vaccine in an Iranian population.