High viral load detection of human Cosavirus in Iranian pediatric patients with acute gastroenteritis

AIM

The present study implemented an RT-qPCR assay for the detection and quantification of human cosavirus in stool specimens from pediatric patients involved in acute gastroenteritis.

BACKGROUND

Human cosavirus is a newly recognized virus that seems to be partly related to acute gastroenteritis in pediatric patients. However, the relationship between human cosavirus and diseases in humans is unclear.

METHODS

From January 2018 to December 2019, a total of 160 stool samples were collected from pediatric patients presenting with acute gastroenteritis in a hospital in Karaj, Iran. After viral RNA extraction, RT-qPCR was performed to amplify the 5'UTR region of the human cosavirus genome and viral load was analyzed.

RESULTS

The human cosavirus genomic RNA was detected in 4/160 (2.5%) stool samples tested. The maximum viral load was determined to be 4.6×10⁶ copies/ml in one sample obtained from a 4-year-old patient.

CONCLUSION

The human cosavirus as a new member of the Picornaviridae family was illustrated in fecal samples from pediatric patients with acute gastroenteritis in Iran. This is the first documentation of human cosavirus circulation in Iranian children.

A Real-Time RT-PCR Assay for Genotyping of Rotavirus

Background

Human rotavirus (HRV) is the causative agent of severe gastroenteritis in children and responsible for two million hospitalizations and more than a half-million deaths annually. Sequence characteristics of the gene segments encoding the VP7 and VP4 proteins are used for the genotype classification of rotavirus. A wide variety of molecular methods are available, mainly based on reverse transcription PCR for rapid, specific and sensitive genotyping of rotaviruses. This study describes an alternative real-time PCR assay for genotyping of rotavirus.

Methods

The samples of stools studied in this research have been collected from patients referred to Children's Medical Centers, Tehran, Iran. Rotavirus detection and genotyping were performed using the RT-PCR and semi-nested RT-PCR, respectively. Samples were then genotyped with a new real-time PCR.

Results

The real-time PCR was able to genotype all positive samples with a mean Ct of 28.2. Besides, a concordance rate of 100% was detected between real-time PCR and semi-nested RT-PCR.

Conclusion

In this study, the genotyping of rotavirus with real-time PCR showed that this method can provide several favorable features, including high sensitivity and specificity, and a wide dynamic range for rotavirus genotyping.

First Occurrence of Saffold Virus in Sewage and River Water Samples in Karaj, Iran

Saffold virus as a newly discovered virus, which seems to be related to acute gastroenteritis as with other enteric viruses and to human airway diseases in children belongs to Cardiovirus genus in picornaviridae family with 11 genotypes. Saffold virus initially was detected in America from infant stool sample. Saffold virus has also been detected in environmental water samples. Until now, two reports have demonstrated that sewage water sources are contaminated with Saffold viruses. Molecular detection of Saffold virus mostly depended on reverse transcription PCR methods and RT-qPCR, which had targeted 5'UTR region of the viral genome. The present study aims to evaluate the molecular detection and quantity of Saffold virus in sewage water and river water specimens by RT-qPCR assay in Karaj, Iran. Fifty samples collected from environmental waters containing treated and untreated sewage water and river water samples were included in this study. After viral RNA extraction, the Real-time PCR was developed to amplify the 5'UTR sequence of Saffold virus genome and viral load was assessed. Out of the 50 samples tested (consisting 28 river water samples and 22 sewage water samples), the Saffold virus genomic RNA was identified in 10/28 (35.7%) of river water samples and in 4/12 (33.3%) of treated and 4/10 (40%) of untreated sewage samples. The maximum viral load was 6.8 × 10⁶ copies/l in untreated sewage water sample in December, and the lower viral load was 1.2 × 10⁶ copies/l related to treated sewage water taken in October. Our results for the first time indicate that Saffold virus has apparently been circulating among Iranian peoples. Also, the viral prevalence of Saffold virus in each of the three sets of tested samples was within moderate to high in range.

Occurrence of Salivirus in Sewage and River Water Samples in Karaj, Iran

Salivirus is a newly discovered virus which seems to be related to acute gastroenteritis in children. Salivirus may infect susceptible children by fecal-oral route after exposure to contaminated water. The present study aims to evaluate the occurrence and quantity of Salivirus in treated and untreated sewage water and river water samples collected in the city of Karaj, Iran by reverse transcription-quantitative PCR assay. A total of 50 samples were collected from environmental waters containing 22 treated and untreated sewage water in volume of 1 l and 28 river water samples in volume of 5 l were included in this study. After viral RNA extraction, the Real-time PCR was performed to amplify the 5'UTR sequence of Salivirus genome and viral load was assessed. Out of the 50 samples tested, the Salivirus genomic RNA was identified in 5/12 (41.6%) of treated and 3/10 (30%) of untreated sewage samples and in 8/28 (28.5%) of river water samples. The maximum viral load was 4.8 × 10⁶ copies/l in treated sewage water sample in September and the lower viral load was 4 × 10⁵ copies/l related to treated sewage water taken in December. This is the first report of Salivirus occurrence in the environmental waters in Iran. The viral prevalence of Salivirus in each of the three sets of tested samples was within low to moderate in range.

Optimization of RT-qPCR for Detection of Aichi Virus in Sewage and River Water Samples in Karaj, Iran

BACKGROUND

Aichi virus (AiV) is an emerging virus, which belongs to Kobuvirus genus of the Picornaviridae family. AiV was recently determined as an etiologic agent of gastroenteritis in susceptible humans. After shedding of virus particles from affected people, AiV particles can contaminate water sources. Then, infection with this virus occurs in humans by the fecal-oral route after exposure with contaminated waters. Thus far, some research around the world demonstrated that different kinds of water sources including river water, ground water and treated or untreated sewage water have contamination with AiVs. Molecular detection of AiV has been mostly depended on reverse transcription polymerase chain reaction (RT-PCR) methods, which targeted 3CD junction region of the virus genome.

METHODS

The present study aims to assess the molecular detection of AiVs in treated and untreated sewage water and river water specimens by the development of reverse transcription-quantitative PCR (RT-qPCR) assay for all AiV genotypes.

RESULTS

Out of 50 samples tested (consisting of 28 river water samples and 22 sewage water samples), the AiV genomic RNA was identified in 15/28 (~50%) river water samples and in 14/22 (~70%) sewage samples.

CONCLUSION

Our results, for the first time, indicate that AiVs have been circulating in Iran.

A comparative approach between heterologous prime-boost vaccination strategy and DNA vaccinations for rabies

BACKGROUND AND AIM

Rabies is a widespread neurological zoonotic disease causing significant mortality rates, especially in developing countries. Although a vaccine for rabies is available, its production and scheduling are costly in such countries. Advances in recombinant DNA technology have made it a good candidate for an affordable vaccine. Among the proteins of rabies virus, the Glycoprotein (RVG) has been the major target for new vaccine development which plays the principal role in providing complete protection against RV challenge. The aim of this study is to produce recombinant RVG which could be a DNA vaccine candidate and to evaluate the efficiency of this construct in a prime-boost vaccination regimen, compared to commercial vaccine.

METHODS

Cloning to pcDNA3.1(+) and expression of rabies virus glycoprotein gene in BSR cell  line were performed followed by SDS-PAGE and Western blot analysis of the expressed glycoprotein. The resulting genetic construct was used as a DNA vaccine by injecting 80 µg of the plasmid to MNRI mice twice. Prime-Boost vaccination strategy was performed using 80 µg plasmid construct as prime dose and the second dose of an inactivated rabies virus vaccine. Production of rabies virus neutralizing antibody (RVNA) titers of the serum samples were determined by RFFIT.

RESULTS

In comparisons between heterologous prime-boost vaccination strategy and DNA vaccinations, the potency of group D that received Prime-Boost vaccine with the second dose of pcDNA3.1(+)-Gp was enhanced significantly compared to the group C which had received pcDNA3.1(+)-Gp as first injection.

CONCLUSION

In this study, RVGP expressing construct was used in a comparative approach between Prime-Boost vaccination strategy and DNA vaccination and compared with the standard method of rabies vaccination. It was concluded that this strategy could lead to induction of acceptable humoral immunity.

microRNA expression signatures of gastrointestinal stromal tumours: associations with imatinib resistance and patient outcome

BACKGROUND

Gastrointestinal stromal tumour (GIST) is mainly initialised by receptor tyrosine kinase gene mutations. Although the tyrosine kinase inhibitor imatinib mesylate considerably improved the outcome of patients, imatinib resistance still remains a major therapeutic challenge in GIST therapy. Herein we evaluated the clinical impact of microRNAs in imatinib-treated GISTs.

METHODS

The expression levels of microRNAs were quantified using microarray and RT-qPCR in GIST specimens from patients treated with neoadjuvant imatinib. The functional roles of miR-125a-5p and PTPN18 were evaluated in GIST cells. PTPN18 expression was quantified by western blotting in GIST samples.

RESULTS

We showed that overexpression levels of miR-125a-5p and miR-107 were associated with imatinib resistance in GIST specimens. Functionally, miR-125a-5p expression modulated imatinib sensitivity in GIST882 cells with a homozygous KIT mutation but not in GIST48 cells with double KIT mutations. Overexpression of miR-125a-5p suppressed PTPN18 expression, and silencing of PTPN18 expression increased cell viability in GIST882 cells upon imatinib treatment. PTPN18 protein levels were significantly lower in the imatinib-resistant GISTs and inversely correlated with miR-125a-5p. Furthermore, several microRNAs were significantly associated with metastasis, KIT mutational status and survival.

CONCLUSIONS

Our findings highlight a novel functional role of miR-125a-5p on imatinib response through PTPN18 regulation in GIST.

HCV NS3 Blocking Effect on IFN Induced ISGs Like Viperin and IL28 With and Without NS4A

BACKGROUND

Hepatitis C virus (HCV) is able to down-regulate innate immune response. It is important to know the immune pathways that this virus interacts with. HCV non-structural protein 3 (NS3) plays an important role in this viral feature. HCV NS3 protein could affect the expression of antiviral protein such as viperin, and interleukin 28whichare important proteins in antiviral response.

OBJECTIVES

HCV has developed different mechanisms to maintain a persistent infection, especially by disrupting type I interferon response and subsequent suppression of expression of Interferon stimulatory genes (ISGs). Viperin, a member of ISGs, is considered as a host antiviral protein, which interferes with viral replication. Since it is a good target for some viruses to evade host responses, it is interesting to study if HCV has evolved a mechanism to interfere with this member of ISGs.

MATERIALS AND METHODS

We evaluated the impact of NS3, NS3/4A and a mutated nonfunctional NS3 on ISGs expression such as viperin and IL-28 after the induction of IFN signaling Jak-STAT pathway using IFN-.

RESULTS

NS3 protein disrupted the expressions of viperin gene and IL-28, an inducer for the expression of ISGs and viperin itself. By comparing the roles of NS3 and NS3/4A protease activities in suppressing the innate immune responses, we also showed that NS3 (without NS4A) has the ability to down-regulate ISGs expression, similar to that of NS3/4A.

CONCLUSIONS

ISGs expression is impeded by NS3 protease activity and its interaction with Jak-STAT pathway proteins. In addition, the NS3/4A substrates spectrum seems to be similar to those of NS3.

Construction of an eGFP Expression Plasmid under Control of T7 Promoter and IRES Sequence for Assay of T7 RNA Polymerase Activity in Mammalian Cell Lines

BACKGROUND

Recently, the use of T7 RNA polymerase instead of other viral and cellular promoters is increasing due to high efficacy of transcription in the cell cytoplasm by this polymerase. In order to translate the transcripts produced by T7 RNA polymerase in mammalian cell lines, it is necessary to include Internal Ribosome Entry Site (IRES) sequences. In addition, if sequence of poly A signal would be included after interested gene, the rate of expression could be increased in the cells.

METHODS

For expression of eGFP in HEK-293 and T7-BHK cells by T7 RNA polymerase, the sequence of eGFP as well as IRES sequences upstream of eGFP gene and poly A signal were inserted into a pUC57 plasmid. On the other hand, gene of T7 RNA polymerase was cloned into modified pIRES2-EGFP plasmid. Then, the constructed plasmids were transfected into HEK-293 cells. T7-BHK cell was used for control of T7 RNA polymerase activity.

RESULTS

Our results showed that using T7 RNA polymerase for expression of foreign genes in mammalian cell lines is highly efficient.

CONCLUSION

Highly efficient eGFP expression in HEK-293 cells showed that T7 RNA polymerase could be used for cytoplasmic RNA transcription such as production of anti-cancer proteins and oncolytic viral genomic RNA by reverse genetics.

MICA gene polymorphism in the pathogenesis of type 1 diabetes

Type 1 diabetes mellitus (T1DM) is a typical autoimmune disease and results from the destruction of insulin-producing beta cells of the pancreas. It develops in the presence of genetic susceptibility, even though more than 85% of patients with T1DM do not have a close relative with the disorder. The etiology of T1DM is complex, and both genetic and environmental factors play important roles. A permissive genetic background is required for the development of the islet autoimmune process. The strongest genetic association idengified is that with HLA class II genes located on the short arm of chromosome 6. It is well known that both HLA DRB1*04-DQA1*0301-DQB1*0302 (DR4-DQ8) and DRB1*03-DQA1*0501-DQB1*0201 (DR3-DQ2) are positively, and DRB1*15-DQA1*0102-DQB1*0602 is negatively, associated with T1DM. However, only a minority of the subjects carrying the high-risk haplotypes/genotypes develops the disease, which suggests that additional genes play a crucial role in conferring either protection or susceptibility to T1DM. Major histocompatibility complex (MHC) class I chain-related A (MICA) is located in a candidate susceptibility region and activates natural killer (NK) cells, T cells and gammadelta CD8 T cells by its receptor NKG2D. The polymorphism of the MICA gene is associated with T1DM in different populations as demonstrated in several papers published in the last 7 years.

Contribution of MHC class I chain-related A (MICA) gene polymorphism to genetic susceptibility for systemic lupus erythematosus

OBJECTIVE

To evaluate the contribution of the MHC class I chain-related A (MICA) gene polymorphism to the genetic risk of systemic lupus erythematosus (SLE).

METHODS

HLA-DRB1-DQA1-DQB1 genotyping, MICA exon 5 microsatellite genotyping and HLA-B8 genotyping were performed in 48 Italian SLE patients and in 158 healthy control subjects.

RESULTS

Of HLA class II haplotypes, only DRB1*03-DQA1*0501-DQB1*0201 (DR3-DQ2) was significantly more frequent among SLE patients than among healthy control subjects [odds ratio (OR) = 6.5, corrected P < 0.0026]. HLA-B8 was detected in 31% SLE patients and 13% healthy control subjects (OR = 3.0, P = 0.005). The allele-wise comparison between patients and controls showed that both MICA5 (OR = 2.5, corrected P < 0.0005) and MICA5.1 (OR = 2.4, corrected P < 0.0005) were positively and MICA9 (OR = 0.2, corrected P < 0.0005) was negatively associated with the disease. The MICA5/5.1 genotype was positively associated with SLE (OR = 28.9, corrected P < 0.0015) also in subjects negative for DR3-DQ2 (OR > 22.6, corrected P < 0.011). The simultaneous presence of DR3-DQ2 and MICA5.1 was detected in 15/48 (31%) SLE and in 10/158 (6%) healthy control subjects (OR = 6.7, corrected P < 0.011). The simultaneous combination of DR3-DQ2 and MICA5 was found in 10/48 (21%) SLE patients and in only 1/158 healthy control subjects (OR = 41.3, corrected P < 0.011). Logistic regression analysis showed the independent positive associations of MICA5 and MICA5.1 and negative association of MICA9 with the disease, and revealed that the interaction of the three major markers (DR3-DQ2, MICA5 and MICA5.1) was associated with increasing genetic risk, which was highest (OR > 30.3) in DR3-DQ2-positive subjects carrying the MICA5-5.1 genotype.

CONCLUSIONS

Our study provides the first demonstration of the independent association of the MICA gene polymorphism with genetic risk of SLE.

Lack of association of human chemokine receptor gene polymorphisms CCR2-64I and CCR5-Delta32 with autoimmune Addison's disease

The attraction of leukocytes to tissues is essential for inflammation and the initiation of the autoimmune reaction. The process is controlled by chemokines, which are chemotactic cytokines. We investigated whether human chemokine receptor gene polymorphisms, namely CCR5-Delta32 and CCR2-64I, are associated with susceptibility to autoimmune Addison's disease. Genotyping was performed in 56 patients and 127 healthy controls by a new method using pyrosequencing for CCR2-64I and by polymerase chain reaction and detecting gel for CCR5-Delta32. None of the CCR2 or CCR5 alleles was found to be associated, either positively or negatively, with disease risk. Our results indicate that the CCR2-64I and CCR5-Delta32 gene polymorphisms do not play a major role in conferring genetic risk for, and/or protection against, autoimmune Addison's disease.

MHC class I chain-related gene alleles 5 and 5.1 are transmitted more frequently to type 1 diabetes offspring in HBDI families

Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by autoimmune destruction of pancreatic beta cells. Genetic and environmental factors contribute in this disease. There is evidence that MHC class I chain-related gene (MIC-A) plays a role in the susceptibility to this and other autoimmune diseases. There are five alleles of the MIC-A gene, which consist of different repetitions of GCT. In particular, MIC-A alleles 5 and 5.1 (the former with five repetitions of GCT, the latter with five repetitions and one additional insertion of nucleotide G) have been found to be associated with susceptibility to and age at onset of T1DM. The aim of our study was to analyze the transmission of these MIC-A alleles to T1DM-affected offsprings in HBDI families. These are multiplex families with affected offsprings and unaffected parents. DNA samples were amplified for MIC-A using fluorescence-labeled primers and analyzed on an ABI prism DNA sequencer. The transmission of alleles was then analyzed using pedigrees of families also obtained from HBDI. We analyzed 78 families and found that MIC-A alleles 5 and 5.1 are present and transmitted more frequently than expected. Heterozygotic parents for MIC-A alleles 5 and 5.1 were excluded from the study. Our results suggest that MIC-A alleles 5 and 5.1 are associated with susceptibility to T1DM in family studies.

MHC class I chain-related gene a alleles distinguish malnutrition-modulated diabetes, insulin-dependent diabetes, and non-insulin- dependent diabetes mellitus patients from eastern India

Insulin-dependent diabetes mellitus (IDDM) is a polygenic disorder with an autoimmune basis for disease development. In addition to HLA, a second susceptibility locus for IDDM has been identified to lie in the major histocompatibility class III region. MIC-A is located in the MHC class III region and is expressed by monocytes, keratinocytes, and endothelial cells. Sequence determination of the MIC-A gene identifies trinucleotide repeat (GCT) microsatellite polymorphism in exon 5. Five alleles with 4, 5, 6, and 9 repetitions of GCT or 5 repetitions of GCT with 1 additional nucleotide insertion (GGCT) are identified. The alleles are A4, A5, A5.1, A6, and A9. The aim of our study was to find the association of MIC-A alleles with IDDM, malnutrition-modulated diabetes mellitus (MMDM), and non-insulin-dependent diabetes mellitus (NIDDM) patients. IDDM (n = 52), MMDM (n = 41), NIDDM (n = 212), and healthy controls (n = 73) from Cuttack, in eastern India, were studied. Of the 212 NIDDM patients analyzed, 96 of them were found to be positive for either GAD65 or IA-2 antibodies. Autoantibodies to GAD65 and IA-2 were measured by radioligand binding assay using (35)S-labeled recombinant human GAD65 and IA-2 in an in vitro transcription/translation system. Autoantibody-positive NIDDM patients (n = 96) and adult healthy controls for NIDDM (n = 113) were also compared. These autoantibody-positive NIDDM patients are considered as slow-onset IDDM or latent autoimmune diabetes in adults (LADA) patients. The samples were analyzed for MIC-A by PCR amplification, and fragment sizes were determined in an ABI prism DNA sequencer. The results of the MIC-A typing are: allele 9 of MIC-A is positively associated (OR 3.62; P < 0.001), and allele 4 is negatively associated (OR 0.31; P < 0.05) with MMDM patients compared to controls. Allele 5 is positively associated with IDDM (OR 2.64; P < 0.05) when compared to controls. Allele 5.1 is positively associated in the autoantibody-positive NIDDM patients compared to adult controls. Our findings of a significant increase of allele A9 in MMDM patients compared to healthy controls suggest that MMDM is immunogenetically different from IDDM in eastern India. MIC-A is important in the pathogenesis of MMDM patients from Cuttack. MIC-A alleles distinguish acute-onset IDDM from slow-onset IDDM, indicating that this molecule may be important for delaying the onset of IDDM with the result that these patients are diagnosed clinically as NIDDM.

Microsatellite allele 5 of MHC class I chain-related gene a increases the risk for insulin-dependent diabetes mellitus in latvians

Insulin-dependent diabetes mellitus (IDDM) is one of the most common chronic diseases. It is an autoimmune, polygenic disease, associated with several genes on different chromosomes. The most important gene is human leukocyte antigen (HLA), also known as major histocompatibility complex (MHC), which is located on chromosome 6p21.3. HLA-DQ8/DR4 and DQ2/DR3 are positively associated with IDDM and DQ6 is negatively associated with IDDM in most Caucasian populations. The MICA gene is located in the MHC class I region and is expressed by monocytes, keratinocytes, and endothelial cells. Sequence determination of the MICA gene identifies 5 alleles with 4, 5, 6, and 9 repetitions of GCT or 5 repetitions of GCT with 1 additional insertion (GGCT), and the alleles are referred to as A4, A5, A5.1, A6, and A9. Analysis of allele distribution among 93 Latvian IDDM patients and 108 healthy controls showed that allele A5 of MICA is significantly increased in IDDM patients [33/93 (35%)] compared to healthy controls [22/108 (20%)] (OR = 2.15; P = 0.016). In conclusion, we believe that MICA may play an important role in the etiopathogenesis of IDDM.

Tumor necrosis factor A and MHC class I chain related gene A (MIC-A) polymorphisms in Swedish patients with cervical cancer

Human papillomaviruses type 16 and 18 are the major cause of cervical cancer. However, genetic factors contribute to the propensity of persistent HPV infection and cervical carcinoma. Allelic variants of the human leukocyte genes have shown to be associated with cervical neoplasia. The strongest associations have been found with the genes in the HLA class II region. The aim of this study was to analyze the association of two non-HLA class II markers with invasive cervical cancer. Microsatellite polymorphism of the TNFA gene located in the class III region and a short tandem repeat polymorphism of the MICA gene located in the centromeric end of the HLA class I region were analyzed. Eighty-five patients and 120 matched control individuals from a population-based cohort from Northern Sweden participated in this nested case-control study. MICA was not associated with cervical carcinoma. TNFa-11 frequency was increased in the HPV18 DNA positive patients (OR = 2.84, p = 0.0481, CI = 1.04-7.78, pc = NS). TNFa-11 was not associated with susceptibility to HPV16 infection, but it increased the risk for cervical cancer with the HLA DQ6 (DQA 1*0102-DQB 1*0602) haplotype. Our findings indicate that the association of TNFA with cervical cancer is different with CIN. The extended HLA DQ6-TNFa-11 haplotype is increasing the risk for development of cervical cancer significantly (OR = 3.08, p = 0.0104, CI = 1.30-7.31).

Two distinct MICA gene markers discriminate major autoimmune diabetes types

The polymorphism of the major histocompatibility complex class I chain-related A gene is associated with type 1 diabetes mellitus. The major histocompatibility complex class I chain-related A gene 5 allele is significantly more frequent in Caucasian type 1 diabetes mellitus children than in healthy subjects, but no information is available on the association with adult-onset type 1 diabetes mellitus or with the so-called slowly progressive latent autoimmune diabetes of the adult in the same ethnic group. In this study we estimated the frequency of major histocompatibility complex class I chain- related A gene alleles and human leukocyte antigen-DRB1*03-DQA1*0501-DQB1*0201 and human leukocyte antigen-DRB1*04- DQA1*0301-DQB1*0302 in 195 type 1 diabetes mellitus subjects, in 80 latent autoimmune diabetes of the adult subjects, and in 158 healthy subjects from central Italy. Major histocompatibility complex class I chain-related A gene 5 was significantly associated with type 1 diabetes mellitus only in the 1-25 yr age group at diagnosis, and the odds ratio of the simultaneous presence of both major histocompatibility complex class I chain-related A gene 5 and human leukocyte antigen-DRB1*03- DQA1*0501-DQB1*0201 and/or human leukocyte antigen-DRB1*04-DQA1*0301-DQB1*0302 was as high as 54 and higher than 388 when compared with double negative individuals. Adult-onset type 1 diabetes mellitus (age at diagnosis, >25 yr) and latent autoimmune diabetes of the adult were significantly associated with major histocompatibility complex class I chain-related A gene 5.1, which was not significantly increased among diabetic children. Only the combination of major histocompatibility complex class I chain-related A gene 5.1 and human leukocyte antigen-DRB1*03-DQA1*0501-DQB1*0201 and/or human leukocyte antigen-DRB1*04-DQA1*0301-DQB1*0302 conferred increased risk for adult-onset type 1 diabetes mellitus or for latent autoimmune diabetes of the adult. Our study provides demonstration of the existence of distinct genetic markers for childhood/young-onset type 1 diabetes mellitus and for adult-onset type 1 diabetes mellitus/latent autoimmune diabetes of the adult, namely major histocompatibility complex class I chain-related A gene 5 and major histocompatibility complex class I chain-related A gene 5.1, respectively.

Tumor necrosis factor a-11 and DR15-DQ6 (B*0602) haplotype increase the risk for cervical intraepithelial neoplasia in human papillomavirus 16 seropositive women in Northern Sweden

HLA genes have been shown to be associated with cervical intraepithelial neoplasia (CIN), a precursor of cervical cancer. The human papillomaviruses (HPV) types 16 and 18 are the major environmental cause of this disease. Because the immune system plays an important role in the control of HPV infection, the association of polymorphic HLA could lead to a different immune response to control the development of cervical cancer. The aim of this study was to analyze the association between CIN and a microsatellite polymorphism of tumor necrosis factor (TNFa) taking HPV exposure and CIN-associated HLA haplotypes into account. In a nested case-control study in northern Sweden, 64 patients and 147 controls matched for age and sex and derived from the same population-based cohort were typed for TNFA, HLA-DR, and DQ and assayed for antibodies to HPV types 16 and 18. TNFa polymorphism was not associated with CIN per se. However, there was a significant increase in the frequency of TNFa-11 among HPV16-positive and HLA DR15-DQ6 (B*0602) patients compared with HPV16- and HLA-DQ6-negative patients (odds ratios, 5.4 and 9.3, respectively). The relative risk for CIN conferred by the combination of TNFa-11, HLA-DQ6, and HPV 16 positivity was 15. Our study suggests that the TNFa-11 allele is associated with HPV16 infection and associated with CIN in combination with HLA-DQ6 but not by itself.

Association of MHC Class I chain-related A (MIC-A) gene polymorphism with Type I diabetes

AIMS/HYPOTHESIS

A distinct family of MHC genes has been identified in the class III region and denominated MHC Class I chain-related genes (MIC). The MIC-A gene is located between the TNFA and the HLA-B genes. The aim of our study was to test the association of the polymorphism of the MIC-A gene with Type I (insulin-dependent) diabetes mellitus and evaluate the interaction between MIC-A and TNFA, HLA-B, HLA-DR and HLA-DQ gene polymorphism.

METHODS

Type I diabetic (n =95) and healthy (n = 98) Italian subjects were typed for exon 5 of MIC-A and for HLA-DRB1, HLA-DQA1, HLA-DQB1 and TNFA alleles. All subjects were also typed for the presence of HLA-B8 or HLA-B15.

RESULTS

The frequency of MIC-A5 was increased in diabetic subjects (53 % vs 15 %) (OR = 6.1) (corrected p, p(c) < 0.0005). Among HLA class II haplotypes, both HLA-DRB1*03-DQA1*0501-DQB1*0201 (DR3-DQ2) and DRB1*04-DQA1*0301-DQB1*0302 (DR4-DQ8) ("at-risk class II haplotypes") were positively associated with diabetes (OR = 6.7 and 6.0, respectively) (p(c) < 0.003). Also HLA-B8 was more frequent among Type I diabetic subjects than among healthy control subjects (OR = 2.8, p = 0.01). None of the TNFA alleles were statistically significantly associated with Type I diabetes. The MIC-A5 exon was negatively associated with age at clinical onset of diabetes (p = 0.012). Thus, 68 % diabetic subjects younger than 25 years and 29 % older than 25 years were carrying this allele. Both MIC-A5 and the at-risk class II haplotypes were independently associated with Type I diabetes and the combined association of the two markers had the highest relative risk (OR = 172). In subjects younger than 25 years, the OR of MIC-A5 was as high as 21.7 and was more than twofold that of at-risk class II haplotypes (OR = 9.5). The MIC-A5 exon was not in linkage disequilibrium with any of the HLA-class I, class II or TNFA alleles studied.

CONCLUSIONS/INTERPRETATION

The MIC-A gene polymorphism is associated with genetic risk for Type I diabetes and the combination of MIC-A5 and at-risk class II haplotypes is now to be seen as the strongest genetic marker for this disease.

MICA gene polymorphism and the risk to develop cervical intraepithelial neoplasia

Cervical intraepithelial neoplasia (CIN) is associated with human papillomaviruses (HPV) and the HLA genes. The MICA (MHC class I chain-related gene A) is expressed by keratinocytes and epithelial cells and interacts with gamma delta T cells. It is therefore possible that MICA might influence the pathogenesis of CIN and cervical cancer through presentation of viral or tumor antigens. To investigate this, we determined the MICA transmembrane allele frequencies in a prospective population-based cohort study from the Västerbotten County in northern Sweden. 74 women developed CIN. 153 control women who remained healthy during follow up were matched for age. Five polymorphic microsatellite alleles of MICA were identified by a polymerase chain reaction-based (PCR) technique using fluorescent-labeled primers. MICA A5 and A5.1 were the most common alleles in this population. None of the alleles of MICA were associated with disease. The frequency of MICA allele A5 was higher among HPV 18 seropositive than HPV 18 seronegative patients but this difference was not significant after the correction of p value. In conclusion, microsatellite allele polymorphism of MICA transmembrane part is not associated with cervical intraepithelial neoplasia.

Microsatellite polymorphism of the MHC class I chain-related (MIC-A and MIC-B) genes marks the risk for autoimmune Addison's disease

The major histocompatibility complex class I chain-related MIC-A and MIC-B genes are located on chromosome 6 between the histocompatibility leucocyte antigen (HLA)-B and the B-associated transcript genes. The presence of 21-hydroxylase autoantibodies is a sensitive and specific marker of autoimmune Addison's disease. We studied the polymorphism of exon 5 of the MIC-A gene, of intron 1 of the MIC-B gene, and of HLA-DRB1, -DQA1, and -DQB1 genes in 28 autoimmune (21-hydroxylase autoantibody positive) Addison's disease patients and in 75 healthy subjects from central Italy. The MIC-A5.1 allele was significantly more frequent in Addison's disease patients (79%) than in healthy subjects (36%) [odds ratio (OR) = 6.52, corrected P (Pc) = 0.0015], whereas MIC-A6 was significantly reduced in affected subjects (15% vs. 56%, OR = 0.13, Pc = 0.002). The A5.1/A5.1 genotype had an OR for autoimmune Addison's disease as high as 18.0 and an absolute risk of 1 per 1131. In the presence of MIC-A5.1, MICB-CA-25 was significantly increased in Addison's disease patients (25% vs. 4%, OR = 8.0, P = 0.0039, Pc = 0.047). The MICB-CA-17 allele was absent in Addison's disease patients, but present in more than 25% healthy individuals (OR = 0.10, P = 0.0025, Pc = 0.03). Among HLA-DR and -DQ haplotypes, only DRB1*03-DQA1*0501-DQB1*0201 (DR3/DQ2) was significantly more frequent in Addison's disease patients than in healthy subjects, but only in the presence of MIC-A5.1. The frequency of MIC-A5.1 was significantly increased in Addison's disease patients only in the presence of HLA-DR3-DQ2. Our study demonstrates that susceptibility to autoimmune Addison's disease is linked to the MIC-A microsatellite allele 5.1 and that both MIC-A5.1 and HLA-DR3/DQ2 are necessary to confer increased genetic risk for Addison's disease.