Shoshana Israel

A new method for reconstitution of highly fusogenic sendai virus envelopes

A new way for reconstituting highly fusogenic Sendai virus envelopes is described. As opposed to previously described methods, in the present one the detergent (Triton X-100) is removed by direct addition of SM-2 Bio-beads to the detergent solubilized mixture of the viral phospholipids and glycoproteins, thus avoiding the long dialysis step. The vesicles obtained in the present work resemble, in their composition, size and features, envelopes of intact Sendai virus particles. The present method allows the enclosure of low and high molecular weight material within the reconstituted viral envelopes.

Immunogenetics of HLA class II in Israeli Ashkenazi Jewish, Israeli non-Ashkenazi Jewish, and in Israeli Arab IDDM patients

The distribution of HLA class II alleles and genotypes in IDDM patients was examined in the three main Israeli ethnic groups: Ashkenazi Jews, non-Ashkenazi Jews, and Arabs. Molecular sequence specific oligonucleotide probe analysis was performed for DRB1, DQA1, and DQB1 genes. The DRB1*03011, DQA1*05 DQB1*02/DRB1*0402, DQA1*03, DQB1*0302 genotype was found to be the main susceptibility genotype in all three groups, with differences in the degree of association. In addition to DRB1*0402 (more frequent among Ashkenazi Jews), DRB1*0405, another subtype of DRB1*04, was found to be more prevalent among non-Ashkenazi Jews and Arabs. Many alleles were found to be negatively associated with insulin dependent diabetes mellitus (IDDM). This could be a result of the high frequency of susceptible alleles, or of linkage disequilibrium to a primary negatively associated allele. The strongest negative association was observed for DQB1*0301 in all three ethnic groups. The alleles DRB1*1401, DRB1*1501, DQB1*05031, DQB1*0602, and DQB1*0609 were not detected in any of the 202 IDDM patients, and are probably either strongly protective or in linkage with such alleles. Despite the differences found between the three ethnic groups, an overall analysis shows that the DRB1*04 alleles that account for susceptibility to IDDM in the Israeli population (DRB1*0402 and *0405) are the same as those responsible for susceptibility to IDDM in a number of other Mediterranean populations. In contrast, the susceptible allele in most Caucasian populations is DRB1*0401. It is noteworthy that the susceptible alleles DRB1*0402/05 for Mediterranean and DRB1*0401 for Caucasian populations are also frequent in the respective healthy populations. These findings support the results obtained in other studies, which point to a genetic relationship between the Israeli and Mediterranean populations.

A possible involvement of virus-associated protease in the fusion of sendai virus envelopes with human erythrocytes

A proteolytic activity is shown to be associated with relatively purified preparations of intact Sendai virus particles or with their reconstituted envelopes which are vesicles containing mainly the viral glycoproteins. Intact Sendai virus as well as reconstituted Sendai virus envelopes have been shown to be able to hydrolyze various protein molecules such as the human erythrocyte membrane polypeptide designated as band 3 and soluble polypeptides such as histone and insulin B-chain. The results of the present work raise the possibility that a direct correlation exists between the virus-associated proteolytic activity and the ability of the virions to lyse cells, to fuse with their membranes, and to promote cell-cell fusion. Inhibitors of proteolytic enzymes such as phenylmethylsulfonyl fluoride, tosyllysinechloromethylketone and tosylamidephenylethylchloromethylketone, or combinations thereof, inhibit the virus-associated proteolytic activity concomitantly with inhibition of its hemolytic and fusogenic activities. Electron microscopic studies showed that the various inhibitors did not affect the binding ability of the virus preparations. The possible involvement of a protease in the process of virus-membrane fusion is discussed.

HLA class II immunogenetics of IDDM in Yemenite Jews

The association between HLA-DR and DQ and insulin dependent diabetes mellitus (IDDM) was analyzed in 47 patients and 76 controls of Yemenite Jewish origin. The IDDM susceptibility alleles DRB1*03011, DQA1*0501, DQB1*02 and DRB1*0402, DQA1*0301, DQB1*0302 found in Caucasians had a very strong predisposing effect also in the Yemenite IDDM group. The DRB1*07, DQA1*0201 and DQB1*02 alleles were found to have a strong negative association with IDDM. None of the patients carried DRB1*07 and DQA1*0201 compared with healthy controls (43.7%). Our analysis revealed that the DRB1*03011 DQA1*0501 DQB1*02/DRB1*04 DQA1*03 DQB1*0302 heterozygous genotype confers the highest susceptibility (59.6% in patients vs. 0% in controls). The homozygous DRB1*03 and DRB1*04 genotypes were also found to be positively associated with the disease. 81% of the patients compared to 1.3% of controls carried the susceptibility alleles on both haplotypes. In conclusion, the development of IDDM in Yemenite Jews is strongly dependent on the presence of the susceptibility HLA alleles and on the absence of the DRB1*07 haplotype. The Yemenite Jewish group is uniquely homogenous with regard to genetic susceptibility factors involved in the process of IDDM, and may thus be an ideal model for further genetic studies.

A bioluminescence assay for gene expression by continuously growing mammalian cells: application for detection of human immunodeficiency virus type 1 (HIV-1)

An in-situ assay for monitoring regulated gene expression in continuously growing mammalian cells is described. This technique can be used for the detection of the transactivator (Tat) protein in human immunodeficiency virus(HIV)-infected cells. Human kidney cells 293, harboring the luc gene, and fused to the HIV-1 long terminal repeat, were isolated and served as tester cells. Tat is supplied by transfection with a tat-carrying plasmid, or alternatively by addition of Tat-containing cell extracts, made from virus-infected or plasmid-transfected cells. Light emitted from the tester cells is recorded on film continuously, or by a photo sensor. Transactivation by HIV Tat results in a pronounced increase in light emission from the tester cells (up to 3000-fold). This assay, which detects HIV-specific gene products, may be used as a diagnostic tool for the detection of active HIV present in peripheral blood.

Genetic variation of three tetrameric tandem repeats in four distinct Israeli ethnic groups.

The allele frequency distributions of three STR loci amplified by PCR have been studied in four Israeli communities: Ashkenazi Jews and three non-Ashkenazi groups, namely Moroccan, Yemenite, and Ethiopian Jews. The loci analyzed were CSF1PO, TPOX, and HUMTHO1. The typing was performed in sequencing polyacrylamide gels under denaturing conditions that could separate alleles with differences of a single base. The population data were analyzed with respect to Hardy-Weinberg (H-W) equilibrium and found that all loci meet the H-W expectations. No-ticeable differences were encountered between the four Jewish ethnic groups studied hereby indicating the importance of establishing a local database to be used in human identity testing in these different Israeli Jewish groups.

Analysis of allelic association between D6S461 marker and multiple sclerosis in Ashkenazi and Iraqi Jewish patients.

A genetic factor contributing to multiple sclerosis (MS) disease risk is evident by the increased prevalence of disease among siblings of probands. A recent genome screen on Canadian sib pairs suffering from MS identified linkage between the genetic marker D6S461 and MS, and showed disequilibrium in transmission of its 260-bp allele from heterozygous parents to affected siblings (Ebers et al., 1996). The present study examined the allelic segregation of this marker among MS patients of Iraqi Jewish and Ashkenazi origin, two homogeneous ethnic groups that differ considerably from Caucasians. The frequency of the 260-bp allele reached 28.3% among Iraqi MS patients (n=30) and 25.2% among the Ashkenazi patients (n = 121) compared with 19.6% (n=28) and 21.3% (n=115) in respective origin-matched controls (for the combined data set, p=0.18). A secondary analysis of the frequency of the 260-bp allele in clinical subgroups showed a frequency of 38.1% among patients with juvenile MS (i.e., onset by 21 yr of age) of Ashkenazi origin (n=21, p=0.019) and 38.8% in the combined pool (n=27, p=0.0045). Most (90%) of the juvenile MS patients belonged to the relapsing-remitting subgroup, which itself showed a frequency of 28.5% of the 260-bp allele (n=121, p=0.045). The results suggest that the D6S461 region may contain a locus contributing to an early onset of relapsing-remitting MS.

Adult height of subjects with nonclassical 21‐hydroxylase deficiency

To determine whether nonclassical 21‐hydroxylase deficiency (NC21OHD) compromises adult height (AH), and to establish the clinical parameters affecting AH in subjects with NC21OHD.

Transactivation of human T-cell leukemia virus type 1 by herpes simplex virus type 1

HTLV-1 transcription depends upon activation by the HTLV-1tax gene product. In addition, various substances and cellular transcription factors are also known to activate the HTLV-1 long terminal repeat (LTR)-mediated transcription in the absence of Tax. In this work we demonstrate that infection of either Jurkat or 293 cell lines with herpes simplex I (HSV-1), a widespread infectious virus of humans, activates HTLV-1 LTR-mediated gene expression. Further investigation revealed that each of the immediate-early (IE) gene products—ICPO, ICP4, and ICP27—of HSV-1 transactivates the HTLV-1 LTR-mediated gene expression in the absence of Tax. The HSV-1 activation is additive to Tax activation in its presence in the cell. Three 21 base repeats upstream of the TATA box are known as the TAX responsive elements (TRE). Recombinant HTLV-1 minimal promoter composed of the HTLV-1 TATA box fused to a synthetic 21 base TRE is responsive to Tax but not to HSV-1 activation. It thus can be concluded that HSV-1 IE gene products and Tax transactivates HTLV-1 LTR mediated gene expression through different transcription complexes. The results presented in this work may point to one possible way for the transition of HTLV-1 from a quiescent to an actively replicating stage.

Causative Drugs of Stevens‐Johnson Syndrome and Toxic Epidermal Necrolysis in Israel

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are T-cell-mediated skin eruptions that are part of a broader category known as severe cutaneous adverse drug reactions (SCAR). SJS involves less than 10%of the body surface area, whereas skin detachment in TEN is more severe and involves 30% of the body surface area. Skin detachment that falls between 10% and 30% is described as SJS-TEN overlap.1 SJS and TEN are rare syndromes, with an estimated incidence at 1 to 2 cases per 1 million inhabitants per year in European countries.2 However, these conditions may lead to mortality or severe disability of previously healthy people and have prompted the withdrawal of newly released drugs3. Drugs highly suspected to cause SJS/TEN include allopurinol, aromatic anticonvulsants (carbamazepine, phenobarbital, phenytoin, and lamotrigine), nevirapine, sulfonamides, and oxicam-NSAIDs. Weaker associations have been additionally found for paracetamol, aminopenicillins, cephalosporins, and quinolones.2,4 Although hypersensitivity reactions have been considered as “type B” or dose-independent reactions, accumulating evidence suggests that the risk may be greater with high doses and rapid dose escalation, at least for allopurinol and lamotrigine.5–7 The propensity to develop SJS and TEN varies across populations of different ethnicities. The most prominent example is the strong association between carbamazepine-induced SJS/TEN and the presence of the human leukocyte antigen (HLA) allele B*15:02 in individuals of Han Chinese and other Southeast Asian origin8 but not in Northern Europeans.9 In the latter population10 and in patients of Japanese origin,11 carbamazepine-induced cutaneous adverse reactions have been linked to another HLA allele, A*31:01. This information has been translated into an FDA boxed warning that requires screening for HLA-B*15:02 in patients of high-risk ethnic origin and a warning for HLA-A*31:01.12 Likewise, the association between HLA-B*58:01 and allopurinol-induced SCAR is strong in patients of Asian origin13 but is weaker in white populations in Europe, in which HLA-B*58:01 is also much less prevalent than in Han Chinese.14–16 The variability among ethnic groups may also apply to Israeli populations. For instance, we have recently shown that