DNA microarray-based screening of differentially expressed genes related to acute lung injury and functional analysis.

OBJECTIVES: The purpose of this study was to identify differentially expressed genes (DEGs) related to acute lung injury (ALI) induced by sepsis with DNA microarray. MATERIALS AND METHODS: Gene expression profile GSE10474 was downloaded from Gene Expression Omnibus (GEO) database which includes 34 samples, among which 13 patients with ALI + sepsis and 21 patients with sepsis alone. The DEGs were identified between ALI + sepsis and sepsis alone samples using R, which were further analyzed using bioinformatics methods. Firstly, HitPredict was used to search protein-protein interactions of the DEGs. Secondly, WebGestalt was adopted for functional enrichment analysis of genes in the interaction networks. Finally, DNA methylation was analyzed to explain the differential expression. RESULTS: A total of 12 genes were identified as DEGs by comparing chip data from ALI + sepsis samples and those from sepsis alone samples, among which occludin (OCLN) and major histocompatibility complex, class II, DQ beta 1 (HLA-DQB1) had 21 and 6 interactors, respectively. Functional enrichment analysis revealed several significantly over-represented terms: cellular component organization, macromolecular organization and biosynthesis, and response to stimulus. In addition, methylation was found in the promoters of OCLN and HLA-DQB1. CONCLUSIONS: We screened DEGs in septic ALI samples, and several interesting genes were obtained, especially OCLN and HLA-DQB1. They may be developed into marker genes for diagnosis or treatment of ALI.

Functional interaction between human histocompatibility leukocyte antigen (HLA) class II and mouse CD4 molecule in antigen recognition by T cells in HLA-DR and DQ transgenic mice.

Studies in vitro have suggested that a species barrier exists in functional interaction between human histocompatibility leukocyte antigen (HLA) class II and mouse CD4 molecules. However, whether mouse CD4+ T cells restricted by HLA class II molecules are generated in HLA class II transgenic mice and respond to peptide antigens across this barrier has remained unclear. In an analysis of T cell responses to synthetic peptides in mice transgenic for HLA-DR51 and -DQ6, we found that DR51 and DQ6 transgenic mice acquired significant T cell response to influenza hemagglutinin-derived peptide 307-319 (HA 307) and Streptococcus pyogenes M12 protein-derived peptide 347-397 (M6C2), respectively. Inhibition studies with several monoclonal antibodies showed that transgenic HLA class II molecules presented these peptides to mouse CD4+ T cells. Furthermore, T cell lines specific for HA 307 or M6C2 obtained from the transgenic mice could respond to the peptide in the context of relevant HLA class II molecules expressed on mouse L cell transfectants that lack the expression of mouse MHC class II. These findings indicate that interaction between HLA class II and mouse CD4 molecules is sufficient for provoking peptide-specific HLA class II-restricted T cell responses in HLA class II transgenic mice.

In vivo evidence for the contribution of human histocompatibility leukocyte antigen (HLA)-DQ molecules to the development of diabetes.

Although DQA1*0301/DQB1*0302 is the human histocompatibility leukocyte antigen (HLA) class II gene most commonly associated with human type 1 diabetes, direct in vivo experimental evidence for its diabetogenic role is lacking. Therefore, we generated C57BL/6 transgenic mice that bear this molecule and do not express mouse major histocompatibility complex (MHC) class II molecules (DQ8(+)/mII(-)). They did not develop insulitis or spontaneous diabetes. However, when DQ8(+)/mII(-) mice were bred with C57BL/6 mice expressing costimulatory molecule B7-1 on beta cells (which normally do not develop diabetes), 81% of the DQ8(+)/mII(-)/B7-1(+) mice developed spontaneous diabetes. The diabetes was accompanied by severe insulitis composed of both T cells (CD4(+) and CD8(+)) and B cells. T cells from the diabetic mice secreted large amounts of interferon gamma, but not interleukin 4, in response to DQ8(+) islets and the putative islet autoantigens, insulin and glutamic acid decarboxylase (GAD). Diabetes could also be adoptively transferred to irradiated nondiabetic DQ8(+)/mII(-)/B7-1(+) mice. In striking contrast, none of the transgenic mice in which the diabetes protective allele (DQA1*0103/DQB1*0601, DQ6 for short) was substituted for mouse MHC class II molecules but remained for the expression of B7-1 on pancreatic beta cells (DQ6(+)/mII(-)/B7-1(+)) developed diabetes. Only 7% of DQ(-)/mII(-)/B7-1(+) mice developed diabetes at an older age, and none of the DQ(-)/mII(+)/B7-1(+) mice or DQ8(+)/mII(+)/B7-1(+) mice developed diabetes. In conclusion, substitution of HLA-DQA1*0301/DQB1*0302, but not HLA-DQA1*0103/DQB1*0601, for murine MHC class II provokes autoimmune diabetes in non-diabetes-prone rat insulin promoter (RIP).B7-1 C57BL/6 mice. Our data provide direct in vivo evidence for the diabetogenic effect of this human MHC class II molecule and a unique "humanized" animal model of spontaneous diabetes.

Human CD4-major histocompatibility complex class II (DQw6) transgenic mice in an endogenous CD4/CD8-deficient background: reconstitution of phenotype and human-restricted function.

To reconstitute the human immune system in mice, transgenic mice expressing human CD4 and human major histocompatibility complex (MHC) class II (DQw6) molecules in an endogenous CD4- and CD8-deficient background (mCD4/8-/-), after homologous recombination, have been generated. We report that expression of human CD4 molecule in mCD4/8-/- mice rescues thymocyte development and completely restores the T cell compartment in peripheral lymphoid organs. Upon vesicular stomatitis virus (VSV) challenge, the reconstituted mature T cell population effectively provide T help to B cells in immunoglobulin class switching from IgM to specific IgG-neutralizing antibodies. Human CD4+DQw6+ double transgenic mice are tolerant to DQw6 and the DQw6 molecule functions in antigen presentation, effectively generating a human MHC class II-restricted T cell response to streptococcal M6C2 peptide. These data show that both the hCD4 and DQw6 molecules are functional in mCD4/8-/- mice, fully and stably reconstituting this limb of the human immune system in mice. This animal model provides a powerful in vivo tool to dissect the human CD4-human class II MHC interaction, especially its role in human autoimmune diseases, superantigen-mediated diseases, and acquired immunodeficiency syndrome (AIDS).

Ventilatory chemoresponsiveness, narcolepsy-cataplexy and human leukocyte antigen DQB1*0602 status.

We hypothesised that hypocretin (orexin) plays a role in the determination of ventilatory chemosensitivity. 130 patients with narcolepsy-cataplexy (mean ± SD age 20 ± 10 yrs, 69% male) and 117 controls (22 ± 6.9 yrs, 62% male) were recruited and tested for human leukocyte antigen (HLA)-DQB1*0602 status, hyperoxia hypercapnic (change in minute ventilation (δV'(E))/carbon dioxide tension (δP(CO(2))) L·min(-1)·mmHg(-1)) and hypoxic (δV'(E) /change in arterial oxygen saturation measured by probe oximetry (δS(p,O(2))) L·min(-1) per %S(p,O(2))) responsiveness, and by spirometry. Hypocretin deficiency was determined either by measures of cerebrospinal fluid hypocretin-1 (37 patients) or by positive HLA-DQB1*0602 status. All patients and 49% of controls underwent polysomnography and multiple sleep latency testing. Despite similar spirometric values, patients had a higher apnoea/hypopnoea index (AHI) (2.8 ± 5.4 versus 0.8 ± 1.6 h(-1); p = 0.03) and lower minimal oxygen saturation during sleep (87% ± 7 versus 91 ± 4%; p = 0.0002), independent of age, sex and body mass index. Patients had depressed hypoxic responsiveness (0.13 ± 0.09 versus 0.19 ± 0.13 L·min(-1) per %S(p,O(2)); p<0.0001), independent of AHI, but hypercapnic responsiveness did not differ. Examined by HLA status, positive (26 out of 117) controls had lower hypoxic but similar hypercapnic responsiveness than those marker-negative (0.13 ± 0.08 versus 0.20 ± 0.14 L·min(-1) per %S(p,O(2)); p<0.0001). Thus, a lower hypoxic responsiveness in the narcolepsy-cataplexy group is a result of DQB1*0602 status rather than the clinical features of disease.

Body mass index-independent metabolic alterations in narcolepsy with cataplexy.

STUDY OBJECTIVES: To contribute to the anthropometric and metabolic phenotyping of orexin-A-deficient narcoleptic patients, and to explore a possible risk of their developing a metabolic syndrome. DESIGN: We performed a cross-sectional study comparing metabolic alterations in patients with narcolepsy with cataplexy (NC) and patients with idiopathic hypersomnia without long sleep time. SETTING: University hospital. PATIENTS: Fourteen patients with narcolepsy with cataplexy and 14 sex and age-matched patients with idiopathic hypersomnia without long sleep time. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Metabolic parameters were evaluated by measuring body mass index (BMI), waist circumference (also with abdominal computed tomography), blood pressure, and daily calorie intake (3-day diary). Chronotypes were assessed through the morningness-eveningness questionnaire. Lumbar puncture for cerebrospinal fluid orexin-A determination and HLA typing were performed. Patients with narcolepsy with cataplexy (all HLA DQB1*0602 positive and with cerebrospinal fluid orexin-A levels < 110 pg/mL) had a higher BMI and BMI-independent metabolic alterations, namely waist circumference, high-density lipoprotein cholesterol, and glucose/insulin ratio (an insulin resistance index), with respect to patients with idiopathic hypersomnia without long sleep time (cerebrospinal fluid orexin-A levels > 300 pg/mL). Despite lower daily food intake, patients with narcolepsy with cataplexy displayed significant alterations in metabolic parameters resulting in a diagnosis of metabolic syndrome in more than half the cases. CONCLUSIONS: BMI-independent metabolic alterations and the relative hypophagia of patients with narcolepsy with cataplexy, as compared with patients with idiopathic hypersomnia without long sleep time, suggest that orexin-A influences the etiology of this phenotype. Moreover, considering that these dysmetabolic alterations are present from a young age, a careful metabolic follow-up of patients diagnosed with narcolepsy with cataplexy is mandatory.

MHC loci affecting cervical cancer risk: distinguishing the effects of HLA-DQB1 and non-HLA genes TNF, LTA, TAP1 and TAP2.

Cervical cancer has been associated with specific human leukocyte antigen (HLA) haplotypes/alleles and with polymorphisms at the nearby non-HLA loci TNF, LTA, TAP1 and TAP2. Distinguishing effects of individual loci in the major histocompatibility complex (MHC) region are difficult due to the complex linkage disequilibrium (LD) pattern characterized by high LD, punctuated by recombination hot spots. We have evaluated the association of polymorphism at HLA class II DQB1 and the TNF, LTA, TAP1 and TAP2 genes with cervical cancer risk, using 1306 familial cases and 288 controls. DQB1 was strongly associated; alleles *0301, *0402 and (*)0602 increased cancer susceptibility, whereas *0501 and *0603 decreased susceptibility. Among the non-HLA loci, association was only detected for the TAP2 665 polymorphism, and interallelic disequilibrium analysis indicated that this could be due to LD with DQB1. As the TAP2 665 association was seen predominantly in non-carriers of DQB1 susceptibility alleles, we hypothesized that TAP2 665 may have an effect not attributable to LD with DQB1. However, a logistic regression analysis suggested that TAP2 665 was strongly influenced by LD with DQB1. Our results emphasize the importance of large sample sizes and underscore the necessity of examining both HLA and non-HLA loci in the MHC to assign association to the correct locus.

DQB1*0301 and DQB1*0601 modulate narcolepsy susceptibility in Koreans.

The association of narcolepsy with HLA-DQB1*0602 is established in Japanese, African-Americans, European, and North American Caucasians. We examined DRB1, DRB3, DRB4, DRB5, DQA1, and DQB1 in 163 patients with centrally mediated daytime sleepiness (100 with narcolepsy) and 211 Korean controls. In this population, the DQB1*0602 association was always evident in the context of the DRB1*1501-DQA1*0102-DQB1*0602 haplotype. The DQB1*0602 association was highest in cases with hypocretin deficiency (100% vs 13% in controls), most of which had narcolepsy-cataplexy (81%). A weaker DQB1*0602 (45%) association was present in cases without cataplexy. No human leukocyte antigen (HLA) association was present in idiopathic hypersomnia or in cases with normal cerebrospinal fluid (CSF) hypocretin-1. As in other populations, DQB1*0602 homozygosity increased risk in cases with cataplexy and/or hypocretin deficiency (odds ratio = 2.0 vs heterozygotes). Non-DQB1*0602 allelic effects were also observed but could not be interpreted in the context of DQB1*0602 overabundance and linkage disequilibrium. We therefore next analyzed compound heterozygote effects in 77 subjects with either hypocretin deficiency or cataplexy and one copy of DRB1*1501-DQA1*0102-DQB1*0602, a sample constructed to maximize etiologic homogeneity. In this analysis, we found additional predisposing effects of DQB1*0301 and protective effects for DQA1*0103-DQB1*0601. Unexpectedly, the predisposing effects of DQB1*0301 were present in the context of various DQA1-bearing haplotypes. A predisposing effect of DQA1*0303 was also suggested. These results indicate a remarkable consistency in the complex HLA association present in narcolepsy across multiple ethnic groups.

A functional variant in the CD209 promoter is associated with DQ2-negative celiac disease in the Spanish population.

AIM: To address the role of CD209 in celiac disease (CD) patients. Non-human leukocyte antigen (HLA) genetic factors in CD predisposition are poorly understood, and environmental factors like infectious pathogens may play a role. CD209 is a dendritic and macrophage surface molecule involved in pathogen recognition and immune activation. Recently, a functional variant in the promoter of the CD209 gene (-336A/G) has been shown to affect the transcriptional CD209 activity in vitro and it has been associated with a higher susceptibility to/or severity of infection. METHODS: The study population was composed of two case-control cohorts of 103 and 386 CD patients and 312 y 419 healthy controls as well as a panel of 257 celiac families. Genotyping for the -336A/G CD209 promoter polymorphism was performed using a TaqMan 5' allelic discrimination assay. HLA-DQ was determined by hybridization with allele specific probes. RESULTS: Initially, the case-control and familial studies did not find any association of the -336 A/G CD209 genetic variant with CD susceptibility. However, the stratification by HLA-DQ2 did reveal a significant association of CD209 promoter polymorphism in the HLA-DQ2 (-) group (carrier A vs GG in DQ2 (-) vs DQ2 (+) patients (P = 0.026, OR = 3.71). CONCLUSION: The -336G CD209 allele seems to be involved in CD susceptibility in HLA-DQ2 (-) patients. Our results might suggest a possible role of pathogens in the onset of a minor group of CD patients.

Immunohistologic evidence of myocardial disease in apparently healthy relatives of patients with dilated cardiomyopathy.

OBJECTIVES: This study investigated whether apparently healthy relatives of patients with idiopathic dilated cardiomyopathy (DCM) who have left ventricular enlargement (LVE) have biopsy evidence of underlying myocardial disease. BACKGROUND: Left ventricular enlargement with normal systolic function is common among asymptomatic relatives of patients with DCM. Although there is circumstantial evidence to suggest that LVE may be a marker of early DCM, its pathophysiologic significance remains uncertain. METHODS: Over six years, 767 asymptomatic relatives of 183 consecutive patients with DCM were evaluated: 37 (5%) had DCM and 104 (14%) had LVE (left ventricular end-diastolic dimension >112% predicted) with normal systolic function. Right ventricular biopsy was performed in 32 relatives with LVE, 14 patients with symptomatic DCM and 6 control subjects with normal ventricular function undergoing elective coronary artery bypass graft surgery. Histologic and immunohistochemical analyses, including quantitative double immunofluorescence, were performed for leukocyte markers (CD3 and CD68), intercellular adhesion molecule-1 (ICAM-1) and human leukocyte antigen class II antigens (DR and DQ). RESULTS: Histologic findings consistent with DCM were present in 50% of the patients with DCM, 25% of the relatives with LVE and 0% of the control subjects. The median CD3 count was 2.4/mm(2) in patients with DCM, 4/mm(2) in relatives with LVE and 0 in control subjects (p = 0.04). Using a threshold of >7 cells/mm(2), 21% of patients with DCM and 25% of relatives with LVE were CD3-positive (p = 0.01). Quantitative analysis demonstrated DR expression on 55.8+/-22.8%, 63.5+/-18.8% and 30.9+/-15.7% of the endothelial surface in patients with DCM, relatives and control subjects, respectively (p = 0.003). Corresponding values for ICAM expression were 35.6+/-15.1%, 36.7+/-14.5% and 17.3+/-7.9% (p = 0.013). When combining inflammatory and histologic changes, 28 (86%) of LVE, 14 (100%) of DCM and no control biopsies were abnormal (p < 0.001). CONCLUSIONS: Most asymptomatic relatives of patients with DCM with LVE have histopathologic and immunopathologic findings similar to those of patients with established disease. Clinical identification and follow-up of such individuals are warranted to prevent presentation with advanced DCM and to enable assessment of interventions aimed at attenuating disease progression.

Functional expression and analysis of a human HLA-DQ restricted, nickel-reactive T cell receptor in mouse hybridoma cells.

Nickel-induced contact dermatitis represents a T cell mediated delayed type hyperreactivity. The elucidation of the molecular basis of T cell activation by Ni2+ ions may serve as a model for the understanding of other metal allergies. We describe here the expression of hybrid T cell antigen receptor (TCR) alpha- and beta-genes, containing rearranged human Ni-reactive variable and mouse constant regions, together with human CD4 in a mouse T cell hybridoma. The resulting hybridoma specifically responds to IL-2 secretion to Ni, but not to other metal ions in the presence of HLA-matched antigen-presenting cells. Loss of CD4 decreases, but does not completely abrogate this reactivity. The restricting HLA-DQ element is identified as consisting of DQA1*0101 and DQB1*0501; however, only some of the B cell lines homozygous for these molecules effectively present Ni to the hybridoma. We interpret these data to show that (i) Ni-reactivity is definitely mediated by alpha beta TCR variable regions; (ii) as for peptide-specific TCR, the CD4 co-receptor enhances Ni-reactivity, but is not absolutely essential; (iii) Ni2+ ions like nominal peptide antigens require HLA (here class II) molecules of the APC for presentation; (iv) the restricting molecule may require a special conformation or the association with a particular type of peptide or an as yet unidentified other surface structure on the antigen-presenting cell for effective Ni-presentation.

HLA-DQB1-associated susceptibility that distinguishes Hashimoto's thyroiditis from Graves' disease in type I diabetic patients.

Insulin-dependent diabetes (IDDM) is frequently associated with autoimmune thyroid disease (ATD) within families. In these families, HLA polymorphism may modulate the susceptibility to each disease. Families with IDDM were further categorized as to the presence of ATD. IDDM-affected subjects from families without ATD were compared with subjects with ATD or with IDDM and ATD from IDDM/ATD families and with a control group. IDDM susceptibility in IDDM/ATD families was negatively associated with the presence of DQB1*0602 [relative risk (RR) = 0.038; P = 0.0001; corrected P (Pc) = 0.0005] and *0301 (RR = 0.3; P = 0.002; Pc = 0.01) and positively associated with the presence of DQB1*0201 (RR = 3.4; P = 0.0007; Pc = 0.0035) and *0302 (RR = 5; P = 0.0001; Pc = 0.0005), regardless of ATD. Compared with the IDDM-only group, the ATD-only group had an increased frequency of subjects with DQB1*0602 (RR = 0.14; P = 0.031), suggesting that the known IDDM-protective effect of this allele may be independent of susceptibility to ATD; however, this difference was not significant when the P value was correlated for the number of alleles tested. In these families, susceptibility to ATD was only associated with DQB1*0201 (RR = 5.71; P = 0.0043; Pc = 0.021). Among subjects with DQB1*0201, there was a weak negative association between the presence of DQB1*0302 on the second haplotype and Hashimoto's thyroiditis (RR = 0.237; P = 0.026; Pc > 0.05). We conclude that in IDDM/ATD families, IDDM-affected subjects are at risk for ATD, especially those carrying DQB1*0201. This risk may be influenced by the alleles carried on the second haplotype, with DQB1*0302 (or a closely linked gene) protecting from Hashimoto's thyroiditis and favoring Graves' disease.

Different role of human HLA-DR and -DQ molecules in xenogeneic transplantation using transgenic mice.

BACKGROUND: The role of T lymphocytes in graft rejection in xenotransplantation is still unclear. The ability of the human HLA class II molecules DR and DQ to function as xenoantigens was investigated in a murine model of skin grafting, using HLA-DR1 and -DQ6-transgenic mice. METHODS: Skin from HLA-DR1- or -DQ6-transgenic mice was transplanted in control littermates. Spleen cells from donors or recipients were tested in mixed lymphocyte reaction and cytotoxic assay. RESULTS: Skin from HLA-DR1-transgenic mice was rejected and spleen cells from rejecting mice were able to proliferate to donor cells, although no rejection was observed when the skin of HLA-DQ6-transgenic mice was engrafted in control littermates. No cytotoxicity was observed in any models. CONCLUSIONS: Taken all together these results clearly suggest a hierarchy in the xenogeneic potency of human HLA class II molecules, with the HLA-DR1 molecule functioning as a potent xenoantigen when compared with the HLA-DQ6 molecule.

Narcolepsy and the HLA region.

Narcolepsy was first shown to be tightly associated with HLA-DR2 and DQ1 in 1983, suggesting a possible autoimmune mechanism. Early investigations failed to demonstrate this hypothesis, postulating that HLA-DR2 was only a linkage marker for another, unknown narcolepsy-causing gene. The autoimmune hypothesis is now being re-evaluated under the light of recent results. Like many other autoimmune disorders, narcolepsy usually starts during adolescence, is human leukocyte antigen (HLA)-associated, multigenic and environmentally influenced. Furthermore, HLA-association studies indicated a primary HLA-DQ effect with complex HLA class II allele interactions and a partial contribution of HLA to overall genetic susceptibility. Finally, recent result suggests that human narcolepsy is associated with the destruction of a small number of hypothalamic neurons containing the peptide hypocretins (orexins). This data is consistent with an immune destruction of hypocretin-containing cells as the most common etiology for human narcolepsy.

Functional analysis of MHC class II-restricted T cells derived from a Caucasian with a DR4, Dw15, DQw8 haplotype.

Rabies virus-specific CD4+ T lymphocyte clones were isolated from a Caucasian male vaccine recipient (DR4/7, DQw2/w8; DPw4) and studied for their major histocompatibility complex restricting elements. None of the rabies-specific T-cell clones could be induced to proliferate to antigen by either lymphoblastoid cells or DR-transfected L cells expressing DR4 molecules of the Dw subtypes commonly found on Caucasian individuals (Dw4, Dw10, Dw13, Dw14). The HLA-Dw subtype of the rabies vaccine recipient was determined by conventional mixed lymphocyte culture, and the results revealed that this individual had a DR4 (Dw15), DR7 (Dw7) phenotype. The presence of the DR4, Dw15 antigen was confirmed by nucleotide sequencing of the DR4B1 gene corresponding to the DRB1*0405 allele. Significant antigen-induced T-cell proliferative responses were obtained with two DR4, Dw15, DQw4 homozygous lymphoblastoid cell lines of Japanese origin (HAS-15 and KT-3) and with a L-cell transfectant expressing the DR4, Dw15 molecule. The existence of the DR4, Dw15 antigen in the Japanese has been reported to be associated with the DQw4 specificity. However, the presence of DQw8 (previously designated DQw3.2) and the absence of DQw4 in the lymphoblastoid cells of the Caucasian rabies vaccine was confirmed with monoclonal antibodies IVD12 (anti-DQw7 + DQw8 + DQw9) and HU46 (anti-DQw4) and by the reactivity of a DQw8-restricted antigen-specific T-cell clone. These studies indicate, contrary to previous findings, that the DR4, Dw15 molecule may be present in Caucasian (non-Japanese) individuals in association with DQw8.

HLA-DR1-positive patients suffering from rheumatoid arthritis are at high risk for developing mucocutaneous side effects upon gold therapy.

Population studies suggest an association between RA and, depending on the ethnic background, HLA-DR1 and/or -DR4. One standard regimen for the treatment of RA is the use of gold compounds like SATM to arrest progression of the disease. In the present study, the immunogenetic background of RA patients developing side effects upon SATM treatment was determined. A total of 53 patients under SATM therapy were tested for their HLA-DRB and -DQ alleles by DNA typing; a significantly higher frequency of HLA-DR1 (p < 0.004, uncorrected) was observed in patients presenting with mucocutaneous side effects (MCT) when compared with patients without MCT. The RR was 6.85. Thus, HLA-DR1 seems to be a marker for the susceptibility of gold adverse reactions.

Modulation of insulitis and type 1 diabetes by transgenic HLA-DR3 and DQ8 in NOD mice lacking endogenous MHC class II.

To evaluate the contributions of DR3 and DQ8 to the etiopathogenesis of type 1 diabetes in a diabetes-predisposing milieu, we developed human leukocyte antigen (HLA) transgenic mice on the nonobese diabetic (NOD) background in the absence of the endogenous class II molecule, I-A(g7) and studied the incidence of both spontaneous and experimental (induced) autoimmune diabetes. Transgenic expression of HLA-DR3 and -DQ8 (either alone or in combination) did not confer susceptibility to spontaneous or cyclophosphamide-induced type 1 diabetes. Expression of I-A(g7) was mandatory for development of spontaneous or cyclophosphamide-induced diabetes. However, multiple low doses of streptozotocin could induce diabetes in all groups of mice independent of the class II molecules expressed. In unmanipulated mice, only islets from I-A(g7+/+) mice revealed significant intra-islet infiltration. Although a characteristic peri-insulitis/peri-ductulitis was present in Abeta(0)/NOD mice, islets from DR3, DQ8 and DR3 x DQ8 double transgenic mice demonstrated significantly less infiltration. In conclusion, transgenic expression of HLA-DR3 and -DQ8 associated with predisposition to type 1 diabetes alone is not sufficient to induce spontaneous diabetes in NOD mice lacking endogenous class II molecules.

Nocturnal sleep and daytime sleepiness in normal subjects with HLA-DQB1*0602.

Narcolepsy, a neurological disorder characterized by excessive daytime sleepiness and abnormal REM sleep, is known to be tightly associated with the Human Leukocyte Antigen (HLA) DQ allele DQB1*0602. In this study, we have explored the possibility that normal subjects carrying this HLA allele (25% of the general population) could display subclinical REM sleep abnormalities and increased daytime sleepiness. Data from 525 middle-aged adults enrolled in the Wisconsin Sleep Cohort study were used for this analysis. Nocturnal polysomnography, sleep latency during the multiple sleep latency test (MSLT), and questionnaire items pertaining to excessive daytime sleepiness were compared between DQB1*0602 positive (n = 132) and negative (n = 393) participants. Results indicate shorter REM latency whether or not the latency was adjusted for wake after sleep onset (p = 0.003) and p = 0.02 respectively), increased sleep efficiency (p = 0.06) and decreased percent time spent in stage I sleep (p = 0.02) during nocturnal polysomnography in DQB1*0602 subjects. Data gathered using the Multiple Sleep Latency Test or the Epworth and Stanford sleepiness scales did not differentiate between DQB1*0602 positive and negative subjects. These results support the hypothesis that polymorphisms at the level of HLA DQ modulates sleep tendencies in humans.

Molecular properties of HLA-DQ alleles conferring susceptibility to or protection from insulin-dependent diabetes mellitus: keys to the fate of islet beta-cells.

The major histocompatibility complex Class II alleles, HLA-DQ, and the related HLA-DR, are the chief genetic elements of human type 1 diabetes. These genes code for polymorphic heterodimeric proteins, whose chief function is to trap peptide antigens in the endosome and present them on the surface of antigen-presenting cells (dendritic cells, B lymphocytes, monocytes/macrophages) to CD4(+) T helper cells. A systematic investigation of the molecular properties of HLA-DQ alleles linked to susceptibility or resistance to type 1 diabetes has shown that these properties segregate along lines of susceptibility or resistance. A correlation of these features with the function of each particular segment of the HLA-DQ molecule yields interesting insights into the possible pathways leading to type 1 diabetes. There remain, however, areas to be clarified, including mechanisms by which dominant protection is conferred by certain alleles, the interplay between HLA-DQ and the related locus HLA-DR, that also shows autoantigen-specific reactivity, and the cross-Class help delivered to CD8(+) T cells, the final effectors in pancreatic beta-cell destruction. Clarification of these issues may lead to ways to prevent diabetes in predisposed individuals already exhibiting the genetic and immunological characteristics, and perhaps a cure in those with the disease, by means of transplantation, and measures for prevention of disease recurrence.