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Biomedical subjects

C Brautbar

Publications and source records attributed to C Brautbar.

At least 145 records · Page 8Linked to original sources

Polymorphism of the HLA DR1 haplotype in the Israeli population investigated at the serological, cellular, and genomic levels.

In the present report, we used serological, cellular, and restriction fragment length polymorphism (RFLP) to investigate the DR1 haplotype in the Israeli population. We describe an Israeli homozygous typing cell (HTC), HLA-Dw"LVA", which defines a new lymphocyte-activating determinant associated with Bw65, DR1 and distinct from Dw1. The parents of this donor, non-Ashkenazi Algerian Jews, are first cousins and share HLA-Cw8,Bw65,BfS,DR1,DQw1,DPw4. No specificity could be assigned to HLA-Dw"LVA" using the 91 Ninth Workshop HTCs. Two families and forty unrelated DR1 individuals were studied with Dw"LVA" and a panel of DR1/Dw1 HTCs. HLA-Dw"LVA" showed segregation as a single determinant within families. This new specificity was present in 24 out of 40 (60%) unrelated DR1 individuals, indicating that in the Israeli population Dw"LVA" is the main lymphocyte-defined determinant associated with the serologically defined DR1 specificity, in contrast to non-Jewish Caucasoids where DR1 is significantly associated with Dw1. The vast majority of Dw"LVA"-positive carriers were also Bw65 carriers, indicating that Bw65,DR1, Dw"LVA" may represent a typical allele combination in the Israeli population. The RFLP analysis established the correlation of certain RFLPs with Dw1 and Dw"LVA". In addition, we describe a cluster of FRLPs that may correspond to a new Dw subtype associated with DR1, for which no serological and cellular reagents have been described so far.

DNA Restriction Enzymes↗

HLA-DR2-associated Dw subtypes correlate with RFLP clusters: most DR2 IDDM patients belong to one of these clusters.

Two variants of the serologically defined HLA-DR2 specificity have been reported: DR2 long and DR2 short. Distinct HLA-DR2-associated Dw subtypes have been described at the cellular level. In the Israeli population, DR2 individuals may be grouped into three clusters: DR2/Dw2, DR2/Dw12, and DR2/Dw"AZH". A new approach for the study of the polymorphism of HLA class II genes is to investigate restriction endonuclease fragments obtained from genomic DNA with specific class II cDNA probes. Previous analysis of DQ beta restriction endonuclease fragments subdivided the DR2 haplotypes into two subsets: a DQR1-positive subset and a DQR2.6-positive subset. These two subsets behave in the population as alleles that split HLA DQw1. In the present study, we have analyzed class II DQ alpha, DQ beta, and DR beta restriction fragment length polymorphism (RFLP) in HLA-DR2/Dw-typed healthy, unrelated Israeli individuals, as well as in 11 French HLA-DR2 insulin-dependent diabetes mellitus (IDDM) patients and 11 French DR-matched controls. Three DQ beta allelic clusters (DQR2.6, DQR1, and DQR12) were observed among the DR2 haplotypes and clearly correlated with Dw2, Dw"AZH", and Dw12, respectively. The vast majority of the DR2 IDDM patients (9 out of 11) fit into the DQR1 cluster which correlates with Dw"AZH", while only two patients (2 out of 11) belong to the DQR2.6 cluster (Dw2-like). In contrast, among 11 DR-matched healthy controls, 9 belonged to the DQR2.6 cluster and only 2 belonged to the DQR1 cluster. These studies establish the correlation between the DR2-associated Dw subtypes with specific RFLPs, and indicate that the frequency of the DQR1 subset which correlates with Dw"AZH" is increased in DR2 IDDM patients.

DNA Restriction Enzymes↗

Genetic control of HLA-linked immune responsiveness to (H,G)-A-L.

Fifty-three donors belonging to seven families were tested for their immune response potential to (H,G)-A-L. Most of these donors had been previously tested for their ability to respond to (T,G)-A-L and were all HLA typed as well. The heredity of the ability to respond to (H,G)-A-L by the production of an antigen-specific helper T cell factor is compatible with an autosomal dominant trait linked to HLA. The genotype of an HLA-A/B recombinant individual suggested that a gene controlling the immune response to (H,G)-A-L is linked to HLA-A. Lod scores also suggested a linkage between immune response potential to (H,G)-A-L and HLA-A. The different patterns of responses to (T,G)-A-L and (H,G)-A-L observed in many individuals are compatible with the notion that separate loci are governing the immune responses to the two synthetic polypeptides.

Female↗

Differentiation-dependent sensitivity of human B-cell-derived lines to major histocompatibility complex-restricted T-cell cytotoxicity.

Sets of Burkitt lymphoma lines and Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs) derived from the same individuals were compared for sensitivity to cytotoxic T-lymphocyte (CTL) clones. Major histocompatibility complex class I antigen-restricted CTL clones were generated by stimulating the lymphocytes of an EBV-seropositive individual with the autologous LCL. One clone (BK-20) lysed the autologous and allogeneic HLA-A11-expressing LCLs but not mitogen-induced B lymphoblasts. Thus the clone was selectively cytotoxic for LCLs. Allospecific CTL clones directed against the HLA-A11 antigen were generated from an EBV-seronegative individual. One clone (WP-36) was selectively cytotoxic for the appropriate allospecific LCL, whereas another clone (WP-21) lysed also T and B lymphoblasts. None of the four Burkitt lymphoma lines established in parallel with the CTL-sensitive LCLs were lysed. Two of the Burkitt lymphoma lines were EBV-negative, and EBV-positive sublines were derived from these by in vitro infection. One but not the other of the two convertants became sensitive to all three types of CTL clones. The CTL-sensitive converted line had also acquired some LCL characteristics: increased cell size, aggregation, and a shift in several of the B-cell-specific surface markers. The CTL-resistant convertant expressed EBV antigens but showed no phenotypic change. These findings suggest that the cellular phenotype plays a decisive role in the sensitivity of B-cell-derived lines to the lytic effect of LCL-selective autologous and allogeneic CTLs.

Antigens, Surface↗

Immunogenetics of rheumatoid arthritis in Israel.

In an attempt to study the variation of associations between HLA and rheumatoid disease a population of 44 Ashkenazi and 29 non-Ashkenazi patients with Rheumatoid Arthritis were tested for HLA-A, B, C and DR antigens and compared with the relevant control groups. In contrast to the results obtained in Middle European or North American Caucasians, Rheumatoid Arthritis in Israel is not associated with B15 and Cw3, indicating that it is very unlikely that B- and C-locus antigens are involved in coding for disease susceptibility for RA. The allele DR4 which is found associated with RA in almost all populations tested so far was in the total patient group (47.9%) slightly but not significantly more frequent than in the control group (38.3%). This difference was entirely due to a nonsignificant increase in the frequency of DR4 in the Ashkenazi patients (54.5%) compared to controls (40%), while the frequency of DR4 in non-Ashkenazi patients and controls was virtually identical (38.0% vs 36.7%). Another surprising finding was that the frequency of HLA-DR1, which has been reported to be increased in different populations of patients with RA was found to be completely normal in the present study on Israeli patients. The alleles of the Bf and the GLO system did not show any significant difference between patients and controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Antinuclear↗

Antigen-presenting cells in human decidual tissue.

The responses of peripheral blood human T lymphocytes supported by decidual antigen-presenting cells (DAPCs) to a variety of immunogenic stimuli were studied and compared to those of T cells supported by peripheral blood antigen-presenting cells (PAPCs). Antigen-presenting cells were isolated from early normal decidual tissue or peripheral blood by elution with ethylenediamine tetraacetic acid of cells that after Ficoll-Paque separation bear receptors for all have bound to fibronectin. DAPCs pulsed with soluble or particulate antigens induced proliferation of T cells with an efficiency equivalent to PAPCs. Decidual tissue APCs also showed the ability to stimulate auto- and alloreactivity. Treatment with anti-human lymphocyte antigen (HLA) class II antibody and ultraviolet radiation resulted in substantial inhibition of the accessory cell function of DAPCs as well as of PAPCs. Bromodeoxyuridine and light treatment of alloreactive T cells generated in vitro was used to demonstrate that DAPCs primed with a synthetic polypeptide antigen (T,G)-A-L can stimulate only HLA class II-compatible T lymphocytes.

Adult↗

In vitro suppression of murine blastocysts growth by sera from women with reproductive disorders.

Early mouse embryos at the two-cell stage were cultured in medium supplemented with sera from women with primary and secondary multiple spontaneous abortions and with long term unexplained infertility as compared to sera obtained from normal fertile women and pooled human male sera. On the basis of microscopic observation and uptake of 3H-thymidine we report a relationship between reproductive histories and the presence of a serum embryo inhibition factor in eight of ten sera samples from women with primary habitual abortions, six of ten sera from women with secondary habitual abortions, and ten of ten sera from women with unexplained infertility. This activity occurs independently of positive maternal antipaternal lymphocytotoxicity. Fractionation of serum samples by ammonium sulphate precipitation, resulted in removal of the embryo-inhibition factor with the IgG fraction in four of five primary habitual abortion cases and in two of five secondary habitual abortion patients, but not in the case of unexplained infertility. We propose that the appearance of such inhibition factor may be of relevance in the etiologies discussed in this paper and may possibly provide the basis for a new classification of idiopathic spontaneous habitual abortions, i.e. positive or negative for the embryo inhibition factor.

Abortion, Habitual↗

Antigen specific immune response potential and HLA typing of Israeli patients with thyroid autoimmune diseases (TAD).

The immune response potential to the synthetic polypeptide antigen (T,G)-A--L was studied in 35 patients with thyroid autoimmune diseases (TAD). For this purpose the ability of their antigen activated peripheral blood lymphocytes (PBL) to generate a (T,G)-A--L specific helper factor was tested. In addition, the patients were typed for their HLA determinants. The results of the study have shown that 20/35 (57%) patients responded to (T,G)-A--L, a similar proportion to that found among healthy donors that were tested as control. No significant difference was found in the rate of responses between patients with Graves' disease and Hashimoto's thyroiditis. The responses in these groups of patients were shown to be 13/22 (59%) and 7/13 (54%) respectively. HLA typing of 26 patients with TAD did not demonstrate any association of the disease or the immune response potential with any specific HLA determinant. It is proposed that unlike the general lack of regulation that we have previously observed in patients with systemic lupus erythematosus, the abnormal autoimmune reaction in TAD and probably in other organ-specific autoimmune diseases, is towards a specific organ without affecting other arms and functions of the immune system.

Autoimmune Diseases↗

Analysis of antigen specific T cell helper function in first degree relatives of patients with systemic lupus erythematosus (SLE).

Fourteen families with first degree relatives of patients with systemic lupus erythematosus (SLE) were studied for the ability of their members to respond to the synthetic polypeptide antigen (T,G)-A-L. The family members were also tested for their HLA determinants. All SLE patients tested responded to (T,G)-A-L as measured by the production of (T,G)-A-L specific T cell helper factors by their antigen activated T cells, confirming our previous findings that 100% of SLE donors responded to (T,G)-A-L in contrast to 50% responders in a control population of healthy donors. The general defect in the regulation of immune responses in SLE patients was further indicated by the demonstration that an SLE patient who is a daughter of non-responder parents to (T,G)-A-L, responded to this genetically regulated antigen. In contrast to our observations with SLE patients, the genetic regulation of the ability to respond to (T,G)-A-L was shown not to be impaired in healthy first degree family members of SLE patients and the segregation of the immune response potential in these families was as expected from an inherited dominant trait.

Animals↗

Association between HLA-DR4 and production of collagen-specific antibodies in Israeli patients with rheumatoid arthritis.

Antibodies to native human Type I + III collagen were measured by a radioimmunoassay in sera samples of 42 rheumatoid arthritis (RA) patients. Sixteen patients (38%) had significant antibody titers. Although the frequency of HLA-DR antigens of RA patients did not differ from that of the random Israeli population, there was a significant association (P less than 0.01) between the presence of collagen antibodies and HLA-DR4.

Adult↗

Immunogenetics of juvenile chronic arthritis in Israel.

Typing for HLA-A,B,C and DR antigens was performed in 61 Israeli patients with juvenile chronic arthritis (JCA) and in 120 unrelated controls. No significant associations were apparent in the overall patient group. DR5 was significantly increased in the non-Ashkenazi patients with pauciarticular onset of disease. The only three DRw8 positive patients in the study had pauciarticular onset. DR5 and DRw8 were found in 9 of 10 patients with age of onset less than 3 years. Increased frequencies of Bw50 and Cw6 were observed in patients with systemic onset. Typing for properdin factor (Bf) and glyoxylase (GLO) was carried out in 45 and 50 of the patients, respectively. No associations with alleles of the complement Bf system or the HLA linked GLO system were evident. The confirmation in the ethnically distinct Israeli population of the previously described association of DR5 with pauciarticular JCA suggests that this gene may be closely related to the disease susceptibility gene.

Adolescent↗

HLA-linked immune responsiveness to (T,G)-A-L: a family study.

The heredity of the immune response potential to the synthetic polypeptide poly(LTyr,LGlu)-poly(DLAla)-poly(LLys) [(T,G)-A-L] and its possible linkage to the major histocompatibility complex of man were studied in 24 families. Peripheral blood lymphocytes (PBL) obtained from 174 donors belonging to 24 unrelated families were educated to (T,G)-A-L on autologous antigen-pulsed adherent cells. The supernatants obtained from these activated PBL were tested for their antigen-specific helper activity in an in vitro antibody production system. All donors were typed for their HLA haplotypes. The results obtained indicated that the ability to respond to (T,G)-A-L by production of an antigen-specific T cell helper factor is inherited as an autosomal dominant trait linked to the responder HLA haplotype.

Alleles↗

Histoincompatibility in couples with unexplained infertility.

Class I human leukocyte antigens (HLA-A, -B) and class II (HLA-DR) antigens were determined in 18 carefully selected couples suffering from unexplained infertility and subsequently compared with 30 normal fertile couples with no history of secondary sterility and with a control group consisting of randomly matched women and men from our laboratory cell panel. No significant differences in the frequencies of HLA antigens were detected between infertile and control groups. The frequency of shared HLA-A, -B, and -DR antigens among members of the couples was similar in all the groups. Finally, the one-way mixed lymphocyte culture showed normal reactivity of both infertile parental pairs in all combinations tested.

Female↗

Cellular immunity in human milk.

The responses of human milk lymphocytes (MIL) to a variety of immunogenic stimuli were studied and compared to those of peripheral blood lymphocytes (PBL) from the milk donors. MIL showed a decreased proliferative response to mitogens and allogeneic leukocytes in vitro but displayed the ability to stimulate alloreactivity equivalent to PBL. Neither pretreatment with cell-free autologous milk nor co-cultured MIL were capable of suppressing the proliferative responses of PBL. Moreover, macrophages isolated from milk and pulsed with soluble antigen or allogeneic cells effectively induced proliferation by peripheral blood T cells whereas the response of milk nonadherent cells to antigen presented by peripheral macrophages was very low. MIL respond better to pathogenic enteric E. coli than PBL not as well as PBL to Yersinia enterocolitica. Treatment of MIL with monoclonal antibodies cytotoxic for T cells abolished their response to bacterial antigens. Application of an anti HLA class II antigen monoclonal antibody to mixed lymphocyte or lymphocyte-bacteria cultures resulted in substantial inhibition of the MIL response similarly to that of PBL. The relevance of these data to the immunological needs of the neonate are discussed.

Adult↗

Combined 21- and 11 beta-hydroxylase deficiency in familial congenital adrenal hyperplasia.

Studies in three families (A, B, and C) revealed five patients with congenital adrenal hyperplasia (CAH) due to partial and combined 21- and 11 beta-hydroxylase deficiency. One patient (A-11 1), a 23-yr-old severely virilized chromosomal female, was reared as a male, and two females (B-11 2 and C-1) complained only of hirsutism, acne, and menstrual abnormalities. Patients A-11 2 and B-11 8 (17 1/2 and 10 yr old) were asymptomatic and detected by finding an HLA genotype identical to that of their respectively affected brother and sister. Three patients (A-11 1, A-11 2, and C-1) had moderate hypertension. In spite of the wide range of clinical manifestations, all individuals had elevated androgen levels, while cortisol secretion was severely impaired only in A-11 2. 21-Hydroxylase deficiency was diagnosed on the basis of markedly increased plasma and urinary levels of 17-hydroxyprogesterone (17-OHP) and 21-deoxycortisol and their respective urinary metabolites pregnanetriol and pregnanetriolone. PRA was elevated in three patients, while urinary aldosterone was normal or increased. 11 beta-Hydroxylase deficiency was diagnosed on the basis of increased 11-deoxycortisol and deoxycorticosterone in plasma and tetrahydro-11-deoxycortisol and deoxycorticosterone in urine, particularly after ACTH administration. In contrast to classical 11 beta-hydroxylase deficiency CAH, urinary 18-hydroxycorticosterone and 18-hydroxy-11-deoxycorticosterone were normal or elevated. The nature and mechanism of a combined enzymatic defect are unknown. The coincidental presence in a single individual of the mutant genes for both 21- and 11 beta-hydroxylase deficiency CAH is very unlikely to occur. Two alternative hypotheses may explain our findings. One is the existence of a genetically inherited abnormal (or aberrant) 11 beta-hydroxylase, whose affinity for its normal substrate is changed for an abnormal one (17-OHP). As a result, 11 beta-hydroxylation of 11-deoxycortisol is deficient while 17-OHP 11 beta-hydroxylation is markedly enhanced. Thus, both 11-deoxycortisol and 21-deoxycortisol as well as their urinary metabolites accumulate. The ability for 18-hydroxylation, however, remains normal. In this case, 21-hydroxylase is not deficient, yet 21-deoxycortisol cannot be further hydroxylated to cortisol, since this steroid is not a suitable substrate for the enzyme. Such a disorder may represent a new allelic variant of 11 beta-hydroxylase deficiency CAH, which, similar to 21-hydroxylase deficiency, is completely linked to the HLA complex.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenal Hyperplasia, Congenital↗

(T,G)-A-L specific immune response potential and HLA typing of Israeli patients with systemic lupus erythematosus.

Thirty-three Israeli patients with systemic lupus erythematosus (SLE) were studied for their ability to respond to the synthetic polypeptide poly (Tyr,Glu)-poly (DLAla)-poly(Lys) [( T,G]-A-L) as measured by the production of a T cell helper factor by their antigen activated T cells. Twenty-seven of the patients were typed for their HLA phenotypes. Nineteen patients were with more active disease and 14 with a milder non-active disease. All the patients of the two groups responded to (T,G)-A-L by the production of an antigen specific helper T cell factor, in contrast to only 50% responders among healthy donors. Thus, lack of normal regulation of T cell helper function was observed among all patients with SLE, independently of their disease activity and/or treatment. A higher frequency of DR5 (75%) was observed in patients with a milder non-active disease (vs 46.6% in normal healthy control individuals) while 53.3% of patients with active disease possessed DR7 (21.8% in controls). These findings may suggest a possible association between the severity of the disease and a specific DR determinant.

Antibody Formation↗

HLA antigens in Reiter's syndrome in Israeli patients.

Major histocompatibility antigens (HLA loci A, B and C) were determined in 28 Israeli patients with Reiter's syndrome. The HLA-B27 antigen was found in only 8 (29%). Seven of the 20 B27 negative patients (35%) demonstrated crossreactive group antigens (CREG) B7, or Bw 22. HLA-B40 or Bw42 were not found. Only 3 of the 13 (22%) patients with the classical triad were B27 or Bw22 positive. In contrast, 12 of 15 patients with incomplete RS carried the B7 CREG antigens. These data suggest that in the Israeli population Reiter's syndrome is infrequently associated with HLA-B27 and that the B7 CREG antigens may be additional markers for this form of reactive arthritis.

Adult↗