SEARCH · Search PubMed

Results for “HLA class II”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources

PubMed2006

The association of CTLA-4 and HLA class II autoimmune risk genotype with regulatory T cell marker expression in 5-year-old children.

Regulatory T cells (Treg) are involved in the maintenance of peripheral tolerance by suppression of autoreactive lymphocytes that have avoided thymic depletion. The defective function of Treg cells has recently attracted attention in autoimmune diseases such as type 1 diabetes (T1D), rheumatoid arthritis and multiple sclerosis. Susceptibility to these diseases is associated with specific human leucocyte antigen (HLA) class II and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) gene polymorphisms. This study aimed to investigate the relationship between HLA class II and CTLA +49 A/G polymorphisms associated with susceptibility to T1D and the number and characteristics of Treg cells in children. Samples from 47 5-year-old children who participated in the All Babies in South-east Sweden (ABIS) follow-up study were grouped according to the presence of the T1D risk-associated HLA genotype (DQA1*0501-DQB1*0201, DQA1*0301-DQB1*0302) or neutral HLA genotypes. Lower percentages of CD4+ T cells (P = 0.03) and CD4+ CD25high cells (P = 0.06) expressing intracellular CTLA-4 were detected in samples from children with CTLA-4 +49GG compared to children with the +49AA genotype. Similarly, lower percentages of CD4+ (P = 0.002) and CD4+ CD25high (P = 0.002) cells expressing CTLA-4 were observed in children positive for HLA DQA1*0501-DQB1*0201 and DQA1*0301-DQB1*0302 (P = 0.04 for CD4+ and P = 0.02 for CD4+ CD25high) risk haplotypes when compared to children without these alleles. The percentage of CD25high cells among CD4+ cells was correlated inversely with CTLA-4 mRNA expression in PBMC (r = -0.56, P = 0.03). Decreased levels of CTLA-4 in CD4+ and CD4+ CD25high cells in individuals with CTLA-4 and HLA class II alleles associated with T1D may contribute to the initiation and/or progression of autoimmune response.

Antigens, CD↗

PubMed1999

High resolution molecular typing of HLA class II region in the population of the island of Krk, Croatia.

The HLA class II alleles (DRB1, DRB3, DRB5, DQA1, and DQB1) and haplotypic associations were studied in the population of the island of Krk using the PCR-SSOP method and the 12th International Histocompatibility Workshop primers and probes. Allele and haplotypic frequencies were compared with the general Croatian population. Significant differences were observed between the population of the island of Krk and Croatians for: a) three broad specificities at DRB1 locus (DRB1*01, *15, and *07), b) one allele at DRB3 locus (DRB3*0301), c) one allele at DQA1 locus (DQA1*0201), d) one allele at DQB1 locus (DQB1*0303). Four unusual haplotypic associations, which have not yet been described in the Croatian population, DRB1*1301-DQA1*0103-DQB1*0607, DRB1*1302-DQA1*0102-DQB1*0605, DRB1*1305-DQA1*0102-DQB1*0605 and DRB1*1305-DQA1*0103-DQB1*0603 were observed in the population from the island of Krk.

Croatia↗

PubMed1993

Primary biliary cirrhosis: contribution of HLA class II allele DR8.

Primary biliary cirrhosis is a chronic cholestatic disease of unknown aetiology which predominantly affects middle-aged women. It is thought to be autoimmune in nature, but unlike many autoimmune diseases no clear HLA association has been described. Several studies have suggested conflicting associations with HLA class II, although a DR8 association is most frequently described. To test the hypothesis that primary biliary cirrhosis is associated with a certain HLA class II locus we genotyped 130 patients with the disease from the north-east region of England and 363 local healthy controls. HLA-DRB1 and confirmatory DQA and DQB genotypes were determined by TaqI restriction fragment DNA length polymorphism analysis. In addition, a polymerase chain reaction technique (double ARMS) was used to investigate the DRB3 locus (DR52) in 98 primary biliary cirrhosis patients and 107 local controls. We found an increased frequency of HLA-DR8 (18.5% vs 9.2%, p < 0.005, relative risk of 2.0 [1.3-3.1]) in the primary biliary cirrhosis group. HLA-DR8-positive primary biliary cirrhosis patients had a higher serum bilirubin level (p = 0.03) than DR8-negative patients. There was no difference in the DR52 frequencies and no association with markers of disease severity. These results support earlier serological findings, although the association between primary biliary cirrhosis and DR8 is weaker than previously described. In addition, DR8-positivity may identify a clinical subgroup with a worse prognosis.

Adult↗

PubMed2004

Identification of two novel HLA class II alleles, DQB1030503 and DRB10447.

Two novel human leukocyte antigen (HLA) class II alleles have been identified in routine typing of bone marrow donors for the Australian Bone Marrow Donor Registry in Sydney, Australia. Sequence analysis of exon 2 of both the DQB1 and DRB1 genes revealed the novel polymorphism. A silent substitution of G to A at nucleotide position 210 has been identified for the DQB1*030503 allele when compared to the closest matched allele, DQB1*030501. There is no associated amino acid difference between the translated products of the two alleles. The second new allele is a variant of the DRB1 gene. The DRB1*0447 allele was identified with three nucleotide substitutions compared to the closest matched allele DRB1*0436. There is a silent mutation at nucleotide position 303, G to C and two substitutions at adjacent nucleotide positions 344 and 345, T to G and G to T, respectively. The latter two substitutions result in an amino acid change from valine to glycine at position 86, implicating a different specificity and affinity of antigen binding.

Alleles↗

PubMed2000

Identification by sequencing based typing and complete coding region analysis of three new HLA class II alleles: DRB30210, DRB30211 and DQB1*0310.

The study of HLA class II polymorphism by direct exon 2 DNA sequencing analysis has been established to be a reliable and accurate high-resolution typing procedure. This approach shows some advantages in relation to previous methods, polymerase chain reaction using sequence-specific oligonucleotides (PCR-SSO) and sequence-specific primers (PCR-SSP), basically due to the capability of analysis for the complete sequenced genomic region, including non-polymorphic motifs. DRB3 and DQB1 sequencing based typing (SBT) in unrelated bone marrow donor searching allowed us to detect three new alleles. The complete coding region sequences were characterised from cDNA. Two new DRB3 alleles, DRB3*0210 and DRB3*0211, were described in two Caucasian bone marrow donors. Both sequences showed single point mutations regarding DRB3*0202, producing amino acid replacements at positions 51 (Asp to Thr) and 67 (Leu to Ile), respectively. These two point mutations can be found in other DRB alleles, and suggest that gene conversion would be involved in the origin of both alleles. A new DQB1 sequence was found in a Spanish patient that showed two nucleotide differences, positions 134 and 141, with regard to its close similar DQB1*03011 allele. Only substitution at position 134 provoked amino acid replacement at residue 45, Glu to Gly. This single amino acid change would be involved in the lack of serologic recognition of this new molecule by DQ7-specific reagents.

Alleles↗

PubMed1999

Peptide specificity, HLA class II restriction, and T-cell subsets of the T-cell clones specific to either Cry j 1 or Cry j 2, the major allergens of Japanese cedar (Cryptomeria japonica) pollen.

BACKGROUND: Cry j 1 and Cry j 2 are thought to be the major allergens of Japanese cedar pollen. HLA class II types capable of presenting T-cell epitopes in both allergens and their role in induction of T-cell subsets are not well known. METHODS: CD4+ T (Th)-cell clones (TCCs) specific to either Cry j 1 or Cry j 2 were generated. HLA class II restrictions were determined by their reactivity to the T-cell epitope in the presence of antigen presenting cells sharing matched types. Interleukin (IL)-2, interferon-gamma, IL-4, and IL-5 contents in the supernatants of TCCs were estimated using enzyme immunoassay. RESULTS: Peripheral blood mononuclear cells (PBMC) from patients induced proliferation with 100 microgram/ml Cry j 1 or 3-10 microgram/ml rCry j 2 stimulation. T-cell epitopes in Cry j 1 were presented to Th cells by the gene products of DRA1*01/DRB1*0901, DRA1*01/DRB5*0101, DQA1* 0102/DQB1*0602, and DPA1*01/DPB1*0501; those in Cry j 2 were restricted by DRA1*01/DRB1*0901, DRA1* 01/DRB1*1501, DRA1*01/DRB4*01, DRA1*01/DRB5* 0101, DQA1*0102/DQB1*0602, DPA1*01/DPB1*0201, and DPA1*01 and *0202/DPB1*0501. Type 2-like cells were preferentially induced in Cry j 1 stimulation, while an almost equal number of type 2- and type 1-like cells was induced in rCry j 2. CONCLUSIONS: No clear correlation existed between peptide specificity, HLA class II restriction and induction of Th-cell subsets, suggesting that the requirement of different dose of Cry j 1 or Cry j 2 to induce proliferation in PBMC may lead to distinguishable difference in induction of Th subsets between TCCs specific to Cry j 1 and Cry j 2.

Adult↗

PubMed1991

Mononuclear leukocytes, expression of HLA class II antigens and intercellular adhesion molecule 1 in focal segmental glomerulosclerosis.

Immunophenotyping of infiltrating glomerular and interstitial mononuclear leukocytes performed in renal tissues of 15 patients with focal segmental glomerulosclerosis (FSGS) was compared to 15 normal kidneys in order to investigate a possible role for cell-mediated immunity (CMI) in FSGS. In addition, distribution of HLA class II (-DQ, -DR, -DP and -DY) antigens and of the intercellular adhesion molecule 1 (ICAM-1) as well as the expression of well-defined renal antigens along the human nephron was analyzed. In comparison to normal kidneys, a reduction in HLA class II antigens of ICAM-1 and of renal antigens defined by the monoclonal antibodies TN8-TN10 was observed in sclerotic glomeruli. Furthermore, an increased number of T lymphocytes was found in glomeruli of FSGS with slight predominance of the CD8+ subset. Interstitial inflammation was present in all FSGS cases except 1 with T lymphocytes and monocytes/macrophages constituting the predominant infiltrating cell types. In contrast to the glomerular T cells, the number of interstitial CD4+ cells was greater than the number of CD8+ cells in almost all cases. As a sign of activation, most interstitial inflammatory cells carried HLA class II antigens and some of them also expressed ICAM-1. Proximal tubular epithelial cells often presented an abnormal expression of HLA-DQ and HLA-DP antigens associated with aberrant expression of ICAM-1 and TN8. The number of interstitial mononuclear leukocytes was correlated to serum creatinine levels at the time of renal biopsy. The present results provide further support for the involvement of CMI in the pathogenesis of FSGS.

Adult↗

PubMed1992

Induction of HLA class II molecules on human T cells: relationship to immunoregulation and the pathogenesis of AIDS.

Human T cells express HLA class II molecules upon activation. The factors that regulate the induction of expression of these molecules are for the most part unknown. Here we report preliminary results indicating that tumor necrosis factor-alpha (TNF-alpha) regulates the induction of cell-surface HLA-DR, DO, and DP molecules in human T cells stimulated with PHA. In contrast, recombinant interferon-gamma (rIFN-gamma), recombinant interleukin-1 alpha (rIL-1 alpha), or rIL-4 appear to have no effect on class II expression. The role of class II molecules on activated T cells is discussed in relationship to immunoregulation and the progression of HIV infection. Three non-mutually exclusive hypotheses are discussed. In the first hypothesis, we consider the role of these class II molecules in antigen presentation of endogenously synthesized HIV envelope by CD4+ cells. The second is a clonal inactivation of virus-specific helper T cells that might occur as a consequence of a direct T cell to T cell interaction and a bypass of the "accessory signal" normally delivered by antigen-presenting cells such as macrophages. The third is a molecular mimicry between HIV envelope proteins and HLA class II molecules, which may lead to the development of autoimmunity against CD4+ T-cell-expressing class II molecules.

Acquired Immunodeficiency Syndrome↗

PubMed1988

1,25-Dihydroxyvitamin D3 decreases expression of HLA class II molecules in a melanoma cell line.

An HLA class II-positive melanoma cell line, DU-Mel 17, was treated with three compounds known to induce differentiation in various cell lines. Neither retinoic acid nor dibutyryl cAMP altered levels of DR alpha mRNA, but 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) significantly decreased the level of DR alpha mRNA 48 h after treatment. Optimal effect of the hormone on DR alpha mRNA was reached by 72 h. DU-Mel 17 cells were responsive to 1,25(OH)2D3 in a dose-dependent manner, and a reduction in DR alpha mRNA was seen at concentrations as low as 5 x 10(-13) M. The action of 1,25(OH)2D3 on DR alpha mRNA levels was dependent on protein synthesis as evidenced by inhibition of its effect upon addition of cycloheximide. Both DR and DQ protein levels on the surface of DU-Mel 17 were beginning to decline by 72 h after 1,25(OH)2D3 treatment, and by 96 h these proteins were decreased by 65%. 1,25(OH)2D3 was not capable of altering expression of class II molecules on three different class II-positive B lymphoblastoid cell lines, although one of these lines was shown to express the receptor for 1,25(OH)2D3. These findings are important because 1) there is no known physiologic regulator that actively down-regulates class II molecules that are present in and/or on cells, 2) levels of mRNA derived from a very limited number of genes are known to be altered by 1,25(OH)2D3, and 3) they support the contention that 1,25(OH)2D3 may alter the differentiation state of these cells and the activity of the normal counterpart of these cells in an immune response.

Calcitriol↗

PubMed1991

The importance of class I and class II HLA in cadaveric renal transplantation.

The importance of avoiding mismatches (MM) at Class I and Class II HLA antigens in cyclosporine-treated renal allograft patients is controversial. In order to assess the role of HLA, 200 consecutive cadaveric renal allografts over a 4-year period were analysed. All patients received cyclosporine/predinisone immunosuppression and 75% were induced with ALG. Minimum follow-up period was one year. HLA A, B, DR, DQ, and DRw52/53 typing were available on 77-100% of allografts. A beneficial effect was noted at the HLA A locus. One-year survival was 87.2% in the 0 and 1 HLA A MM group combined vs 73.8% in the 2 HLA A MM group (p less than 0.05). The mean creatinine level at one year was also lower in the 0 plus 1 MM vs 2 MM group: 152.8 mumol/L vs 184.8 mumol/L, respectively (p less than 0.05). Significantly fewer rejection episodes occurred in the 0 and 1 HLA DQ MM group combined vs the 2 MM group. Steroid-resistant rejection episodes (SRRE) were not associated with the number of HLA MM. Patients who had an SRRE had significantly higher mean current and historical peak panel reactive antibodies (PRA) than patients who did not have SRRE. These results indicate that avoiding mismatches at the HLA A locus may improve renal allograft survival, and matching at HLA DQ may predispose patients to a more quiescent post-transplant course. The degree of preoperative sensitization may be an important etiologic factor in SRRE.

Cadaver↗

PubMed1987

Cytotoxic human HLA class II restricted purified protein derivative-reactive T-lymphocyte clones. IV. Analysis of HLA restriction pattern and mycobacterial antigen specificity.

Human T-lymphocyte clones specific for antigenic components of purified protein derivative (PPD) of tuberculin were generated by limiting dilution using in vitro PPD-activated peripheral blood mononuclear cells from a single donor. The HLA restriction specificity of eight clones that were cytotoxic against autologous PPD-pulsed monocyte targets, was examined against a panel of allogeneic PPD pulsed targets. In agreement with our findings with bulk-expanded PPD-reactive cytotoxic T lymphocytes, all clones were restricted by HLA class II antigens: seven by HLA-DR 2 and one by HLA-DRw10--the other HLA-DR antigen of the donor. All clones were CD3+, CD4+, CD8-. One clone exhibited, in addition to HLA-DR2 restriction, unrestricted cytotoxic alloreactivity against HLA-DR1. In monoclonal antibody-blocking experiments the latter clone was the only one that was blocked. Its lytic ability was abolished by two monoclonal antibodies against monomorphic HLA-DR determinants. The antigen specificity of the clones was studied by using autologous monocyte targets pulsed with antigens prepared from a range of different mycobacterial species. All seven HLA-DR2-restricted clones reacted with the majority of antigens tested. In contrast, the HLA-DRw10-restricted clone reacted exclusively with an antigen unique to PPD.

Antibodies, Monoclonal↗

PubMed1995

HLA class II genotyping by polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) in systemic lupus erythematosus patients.

Recently, genotyping of HLA class II alleles by digestion of polymerase chain reaction (PCR) amplified polymorphic DNA region with restriction endonucleases (PCR-RFLP) has been reported and claimed to be a simple and reliable technique. We tested the use of PCR-RFLP for genotyping of DQA 1, DQB 1, DPB 1 and DRB 1 alleles of 40 normal individuals and 19 patients with systemic lupus erythematosus (SLE). In agreement with previous reports, we observed an association of SLE with the DRB 1*1501-DQA 1*0102-DQB 1*0602 haplotype and noted an unreported association with DPB 1*0501. Although these observations must be confirmed with larger sample sizes, we believe that the PCR-RFLP is simpler and more practical than the sequence-specific oligonucleotides (PCR-SSO) for genotyping and can be invaluable to the more widespread molecular determination of HLA-class II specificities, including in non-specialized laboratories.

Genotype↗

PubMed1994

HLA class II antigens and the HIV envelope glycoprotein gp120 bind to the same face of CD4.

Although the HIV gp120 binding site of CD4 is well characterized, its interaction site with HLA class II molecules is still controversial. Sixty-seven mutations within the four extracellular domains of CD4 were examined for their effects on cell surface expression and conformational changes and for adhesion of HLA class II-expressing B lymphocytes and HIV gp120 binding to CD4-transfected COS cells. Mutations within the gp120 binding site affected both assays similarly, indicating that the two sites fully overlap. A few additional substitutions of residues mapping on the same face of domains 1 and 2 induced decreased rosette formation. Molecular modeling studies indicated that this is likely to be the consequence of conformational changes induced by the mutations. Thus, CD4 appears to interact with HLA class II molecules mainly through the HIV gp120 binding site and possibly through a second minor interaction site mapping on the same face of the molecule.

Amino Acid Sequence↗

PubMed2001

HLA class II associations with Type 1 diabetes mellitus: a multivariate approach.

The association of HLA class II phenotype with the development of insulin-dependent (Type 1) diabetes mellitus (IDDM) is well established but the contribution of the various HLA-DR and -DQ alleles and haplotypes to disease predisposition is not fully understood. We have determined haplotype and genotype odds ratios, and further employed multivariate tree analysis to explore the contribution of individual HLA-DRDQ haplotypes to the genetic risk for developing IDDM in the Dutch population. Next to haplotype and genotype odds ratios, multivariate tree analysis techniques provide overall risk calculations for each modeled parameter, and offer insight in the interaction of the model parameters via tree-shaped reports, in which subsequent stratifications on the data can easily be followed. We compared 206 Dutch IDDM patients with 840 serologically typed random healthy unrelated Dutch Caucasoid controls. The multivariate tree analysis showed that the HLA-DR7DQ9 and DR15DQ6 haplotype were strongly associated with disease protection (OR = 0.04, P = 0.0003, and OR = 0.07, P < or = 0.0001, respectively). The highest ORs were found for the DR4DQ8/DR8DQ4 genotype (OR = 21.04, P = 0.001), followed by DR4DQ8/DR17DQ2 (OR = 12.45, P < 0.0001) and DR9DQ9/DR17DQ2 (OR = 10.87, P = 0.02). DR4DQ8 homozygous and DR17DQ2 homozygous individuals have a disease OR of 9.0 and 3.0 (P = 0.01 and 0.03), respectively. In conclusion, the results from haplotype, genotype, and tree analyses provide insight into the disease associations for combinations of HLA-DRDQ haplotypes. We confirm that the DR9DQ9/DR17DQ2 genotype is associated with susceptibility in the Dutch population, which has previously been noticed as a HLA risk genotypes in Asian populations only.

Diabetes Mellitus, Type 1↗

PubMed2003

Dichotomy of autoreactive Th1 and Th2 cell responses to desmoglein 3 in patients with pemphigus vulgaris (PV) and healthy carriers of PV-associated HLA class II alleles.

Pemphigus vulgaris (PV) is the most severe autoimmune bullous skin disorder and is primarily associated with circulating autoantibodies (autoAb) against desmoglein 3 (Dsg3). In light of recent evidence that autoreactive T cells are critical for the induction and regulation of Ab production, the goal of this study was to characterize and quantitate autoreactive T cells in patients with PV and healthy controls. Peripheral Dsg3-reactive Th cells from 28 patients with acute-onset, chronic active, and remittent PV were quantitated by MACS secretion assay. Dsg3-reactive Th2 cells were detected at similar frequencies in all studied PV patients, while the number of autoreactive Th1 cells exceeded those of Th2 cells in chronic active PV. In contrast, healthy carriers of the PV-associated HLA class II alleles, DRB1*0402 and DQB1*0503, exhibited exclusively Dsg3-reactive Th1 cell responses, while healthy carriers of other HLA class II alleles did not. Moreover, the presence of IgG1 and IgG4 against Dsg3 was directly related to the ratio of Dsg3-reactive Th1/Th2 cells. T cell recognition of Dsg3 was restricted by HLA-DRB1*0402 and DQB1*0503 in PV patients and Dsg3-responsive healthy donors. These observations strongly suggest 1) that the appearance of Dsg3-reactive Th2 cells is restricted to patients with PV; 2) that specific HLA class II alleles that are prevalent in PV are critical for T cell recognition of Dsg3 in PV patients and Dsg3-responsive healthy donors; and 3) that autoAb production is associated with both Th1 and Th2 cells.

Acute Disease↗

PubMed2003

HLA class II allele frequencies in the Lebanese population.

Human leukocyte antigens (HLA) allele determination is becoming an increasingly important aspect in the field of transplantation as well as in the area of HLA association with a number of diseases. Through Lebanon's history, this country, situated at a crossroads between Europe, Asia and Africa, has been a host for various populations of different ethnicities. The aim of our study is to determine whether allele polymorphisms in the Lebanese population present a distinguishing feature. Although data on HLA phenotypic polymorphisms in Lebanon have been reported in the literature, our study is the first to examine frequencies of HLA polymorphisms in the country at the molecular level. Allele frequencies of the Lebanese population were analyzed and compared with those of other populations. HLA class II genotyping of DRB1* and DQB1* loci by PCR-sequence-specific primer (SSP) was performed on 191 unrelated Lebanese subjects of both sexes and of different regions and sects in Lebanon. The study revealed that DRB1*1101, DRB1*0401 and DRB1*0301 were the three most common DRB1* alleles observed (respective allele frequencies of 0.302, 0.164 and 0.096). In the DQB locus allele group, DQB1*0301 (allele frequency of 0.384) was highly predominant followed by the DQB1* 0501, DQB1*0201 and DQB1*0302 with respective allele frequencies of 0.199, 0.195 and 0.103. These results confirm previous serological studies and show the high prevalence of DRB1*1101 and DQB1*0301 in Lebanon, which could be explained by the high frequency of consanguineous marriages in the population. The presence of other common alleles is consistent with historical data showing that the Lebanese population is an admixture of various ethnicities.

Alleles↗

PubMed1992

Expression and gene transcript of Fc receptors for IgG, HLA class II antigens and Langerhans cells in human cervico-vaginal epithelium.

The mechanism of transmission of HIV from the male to the female genital tract or in the reverse order is not clear. CD4 glycoprotein is the receptor for HIV and Langerhans cells and the related dendritic cells could play a role in the initial transmission of HIV. Fc receptors (FcR) for IgG might be involved in antibody-mediated binding of HIV. We carried out an immunohistological study of normal human cervical and vaginal epithelia for the presence of CD4 glycoprotein, Langerhans cells and FcR to IgG. CD4+ glycoprotein was not found in the vaginal or cervical epithelium, with the exception of a few endocervical epithelial cells. A small number of CD4+ mononuclear cells were found in the endocervical epithelium of a third of the specimens but a large number of CD4+ cells was found in the submucosa of most of the cervical and vaginal specimens. Langerhans cells expressing CD4, HLA class II, Fc gamma R2 and Fc gamma R3 were detected in most vaginal, ectocervical and transformation zone epithelia and in 9/14 endocervical tissues. Fc gamma R3 was detected in about two-thirds of the columnar endocervical epithelium and the transformation zone. A smaller number of specimens expressed Fc gamma R2 in these epithelia, but Fc gamma R1 was not detected. We then demonstrated mRNA for Fc gamma R3 in the columnar endocervical epithelial cells and transformation zone by in situ hybridization, using a CD16-RNA probe. Fc gamma R3 and Fc gamma R2 gene transcripts were also found in fetal cervical tissue by applying the polymerase chain reaction to amplify portions of the Fc gamma R3 and Fc gamma R2 coding sequences in cDNA prepared from fetal RNA. HLA-DR was found in the endocervical cells, transformation zone and in Langerhans cells of all specimens. The presence of Langerhans cells, Fc gamma receptors and HLA class II antigen offers three potential mechanisms for cervico-vaginal HIV transmission: (i) direct HIV infection of Langerhans cells, (ii) binding of HIV antibody complexes to cervical epithelial Fc gamma receptors and (iii) binding of HIV infected CD4+ cells to cervical HLA class II antigen which may infect these or the adjacent CD4+ cells.

Adult↗

PubMed1996

A new lymphoblastoid cell line defective in class II HLA expression.

A lymphoblastoid cell line, HAJ, was derived by in vitro transformation with Epstein-Barr virus of peripheral blood lymphocytes (PBL) from a patient with renal insufficiency awaiting kidney graft. Cell surface expression of class I and class II HLA molecules was determined by flow cytofluorimetry using monoclonal antibodies and compared with that of cell line PAJ similarly derived from a healthy donor. HAJ cells expressed class I antigens at levels comparable with PAJ cells. In contrast, class II antigens were absent from the cell surface of HAJ cells while they were abundant on PAJ cells. Permeabilization and fixation of cells with acetone/formaldehyde solution revealed intracellular Ki-67 antigen but not class II HLA molecules. The genes for HLA-DR beta, DQ alpha and DP alpha were present in the HAJ genome as detected with polymerase chain reaction (PCR) using locus-specific primers amplifying a second exon. In RT (reverse transcriptase)-PCR, transcripts of DQA1 and DPA1 genes were easily detectable in PAJ (positive control) but not in HAJ cells. These results suggest a defect in HAJ cells of transcription of genes for all class II antigens. The cell line HAJ may prove to be an interesting model for in vitro studies of molecular mechanisms of the regulation of class II expression.

Biological Transport↗