Elham Rekabdar

Phylogenetic Analysis of Clinical Herpes Simplex Virus Type 1 Isolates Identified Three Genetic Groups and Recombinant Viruses

ABSTRACT Herpes simplex virus type 1 (HSV-1) is a ubiquitous human pathogen which establishes lifelong infections. In the present study, we determined the sequence diversity of the complete genes coding for glycoproteins G (gG), I (gI), and E (gE), comprising 2.3% of the HSV-1 genome and located within the unique short (US) region, for 28 clinical HSV-1 isolates inducing oral lesions, genital lesions, or encephalitis. Laboratory strains F and KOS321 were sequenced in parallel. Phylogenetic analysis, including analysis of laboratory strain 17 (GenBank), revealed that the sequences were separated into three genetic groups. The identification of different genogroups facilitated the detection of recombinant viruses by using specific nucleotide substitutions as recombination markers. Seven of the isolates and strain 17 displayed sequences consistent with intergenic recombination, and at least four isolates were intragenic recombinants. The observed frequency of recombination based on an analysis of a short stretch of the US region suggests that most full-length HSV-1 genomes consist of a mosaic of segments from different genetic groups. Polymorphic tandem repeat regions, consisting of two to eight blocks of 21 nucleotides in the gI gene and seven to eight repeats of 3 nucleotides in the gG gene, were also detected. Laboratory strain KOS321 displayed a frameshift mutation in the gI gene with a subsequent alteration of the deduced intracellular portion of the protein. The presence of polymorphic tandem repeat regions and the different genogroup identities can be used for molecular epidemiology studies and for further detection of recombination in the HSV-1 genome.

Herpesvirus DNA Detection in Cerebral Spinal Fluid: Differences in Clinical Presentation between Alpha-, Beta-, and Gamma-Herpesviruses

To evaluate the role of 6 human herpesviruses (cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), herpes simplex virus (HSV) types 1 and 2 and varicella zoster virus (VZV)) in infections of the nervous system, cerebrospinal fluid (CSF) samples from 662 patients with suspected viral aetiology to neurological symptoms were investigated for presence of herpesviral DNA in a PCR-based study. Of the 69 patients (2 patients had 2 herpesvirus DNA detected in CSF) who had herpesvirus DNA detected in the CSF, 60 (87%) were non-immunocompromised (CMV 7; HHV-6 6; EBV 16; HSV-1 18; HSV-2 9 and VZV 6) and 9 (13%) were immunocompromised (CMV 3; HHV-6 0; EBV 5; HSV-1 0; HSV-2 1 and VZV 0). The study was performed in a retrospective/prospective manner. The HSV-1, HSV-2, VZV and CMV DNA-positive patients usually had typical clinical syndromes, such as encephalitis/myelitis and meningitis, but also other neurological conditions were associated with findings of these viruses. HHV-6 and EBV DNA were detected in patients presenting with a variety of neurological symptoms, and in some of the cases, concurrent with diagnosis of other infections of the central nervous system. Despite the overall variability of clinical conditions seen, a pattern associated with each investigated herpesvirus was discernable as regards clinical presentation.To evaluate the role of 6 human herpesviruses (cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), herpes simplex virus (HSV) types 1 and 2 and varicella zoster virus (VZV)) in infections of the nervous system, cerebrospinal fluid (CSF) samples from 662 patients with suspected viral aetiology to neurological symptoms were investigated for presence of herpesviral DNA in a PCR-based study. Of the 69 patients (2 patients had 2 herpesvirus DNA detected in CSF) who had herpesvirus DNA detected in the CSF, 60 (87%) were non-immunocompromised (CMV 7; HHV-6 6; EBV 16; HSV-1 18; HSV-2 9 and VZV 6) and 9 (13%) were immunocompromised (CMV 3; HHV-6 0; EBV 5; HSV-1 0; HSV-2 1 and VZV 0). The study was performed in a retrospective/prospective manner. The HSV-1, HSV-2, VZV and CMV DNA-positive patients usually had typical clinical syndromes, such as encephalitis/myelitis and meningitis, but also other neurological conditions were associated with findings of these viruses. HHV-6 and EBV DNA were detected in patients presenting with a variety of neurological symptoms, and in some of the cases, concurrent with diagnosis of other infections of the central nervous system. Despite the overall variability of clinical conditions seen, a pattern associated with each investigated herpesvirus was discernable as regards clinical presentation.

Mutations and sequence variation in the human myosin heavy chain IIa gene (MYH2).

We recently described a new autosomal dominant myopathy (OMIM #605637) associated with a missense mutation in the myosin heavy chain (MyHC) IIa gene (MYH2). In this study, we performed mutation analysis of MYH2 in eight Swedish patients with familial myopathy of unknown cause. In two of the eight index cases, we identified novel heterozygous missense mutations in MYH2, one in each case: V970I and L1061V. The mutations were located in subfragment 2 of the MyHC and they changed highly conserved residues. Most family members carrying the mutations had signs and symptoms consisting mainly of mild muscle weakness and myalgia. In addition, we analyzed the extent and distribution of nucleotide variation in MYH2 in 50 blood donors, who served as controls, by the complete sequencing of all 38 exons comprising the coding region. We identified only six polymorphic sites, five of which were synonymous polymorphisms. One variant, which occurred at an allele frequency of 0.01, was identical to the L1061V that was also found in one of the families with myopathy. The results of the analysis of normal variation indicate that there is strong selective pressure against mutations in MYH2. On the basis of these results, we suggest that MyHC genes should be regarded as candidate genes in cases of hereditary myopathies of unknown etiology.

Dichotomy of Glycoprotein G Gene in Herpes Simplex Virus Type 1 Isolates

ABSTRACT Herpes simplex virus type 1 (HSV-1) encodes 11 envelope glycoproteins, of which glycoprotein G-1 (gG-1) induces a type-specific antibody response. Variability of the gG-1 gene among wild-type strains may be a factor of importance for a reliable serodiagnosis and typing of HSV-1 isolates. Here, we used a gG-1 type-specific monoclonal antibody (MAb) to screen for mutations in the immunodominant region of this protein in 108 clinical HSV-1 isolates. Of these, 42 isolates showed no reactivity to the anti-gG-1 MAb. One hundred five strains were further examined by DNA sequencing of the middle part of the gG-1 gene, encompassing 106 amino acids including the immunodominant region and epitope of the anti-gG-1 MAb. By phylogenetic comparisons based on the sequence data, we observed two (main) genetic variants of the gG-1 gene among the clinical isolates corresponding to reactivity or nonreactivity to the anti-gG-1 MAb. Furthermore, four strains appeared to be recombinants of the two gG-1 variants. In addition, one strain displayed a gG-1-negative phenotype due to a frameshift mutation, in the form of insertion of a cytosine nucleotide. When immunoglobulin G reactivity to HSV-1 in sera from patients infected with either of the two variants was investigated, no significant differences were found between the two groups, either in a type-common enzyme-linked immunosorbent assay (ELISA) or in a type-specific gG-1 antigen-based ELISA. Despite the here-documented existence of two variants of the gG-1 gene affecting the immunodominant region of the protein, other circumstances, such as early phase of infection, might be sought for explaining the seronegativity to gG-1 commonly found in a proportion of the HSV-1-infected patients.

Characterisation of a Swedish cohort with orofacial granulomatosis with or without Crohn's disease

OBJECTIVE To compare oral manifestations in a Swedish cohort of patients with orofacial granulomatosis with or without Crohns disease and to assess NOD2 polymorphisms in the two groups. METHODS Twenty-nine patients with orofacial granulomatosis were included. Demographics, disease history, clinical features and concurrent Crohns disease were recorded. DNA was extracted from buccal swabs and examined for NOD2 variants Arg702Trp, Gly908Arg and Leu1007fsinsC, all previously linked to gastrointestinal Crohns disease. RESULTS Twelve of 29 patients were diagnosed with coexisting gastrointestinal Crohns disease, and of whom 21 were males. Symptom duration was significantly longer for the orofacial granulomatosis group com-pared to the group with coexisting Crohns disease (P < 0.0001). The orofacial granulomatosis patients also perceived their overall discomfort, aesthetic problems and social discomfort as more severe. No significant differences in the clinical presentation of oral lesions between the two groups were found. None of the patients with orofacial granulomatosis carried any of the NOD2 variations, whereas four of the 12 patients with coexisting Crohns disease had a NOD2 variant (Arg702Trp). CONCLUSION The two patient groups had similar phenotypic characteristics but seemed to have genotypic differences regarding NOD2. The Swedish cohort differed in their clinical characteristics from patients reported in other geographical regions.

Mutations in the genes for keratin-4 and keratin-13 in Swedish patients with white sponge nevus

BACKGROUND White sponge nevus is a rare autosomal dominant disorder that affects the non-keratinised stratified squamous epithelium. Mutations in the genes that encode mucosa-specific keratin-4 and keratin-13 are strongly linked to the manifestation of white sponge nevus. This study involved mutational analysis of the genes encoding keratin-4 and keratin-13 in two Swedish families with white sponge nevus. METHODS The diagnosis of white sponge nevus was based on disease history, clinical characteristics of the lesions and, in the majority of the cases, histopathological examination. Samples were collected from the affected buccal mucosa using buccal swabs. DNA was subsequently extracted and amplified using touchdown-PCR. The keratin-4 and keratin-13 genes were sequenced, and a genetic analysis was performed. RESULTS A novel heterozygous missense mutation was identified in exon 1A of the keratin-4 gene in Family 2. In addition, previously reported heterozygous missense mutations were identified in the keratin-4 (E449K, A72V, Q156R, R208H) and keratin-13 (L115P) genes in both families. CONCLUSION We describe a novel heterozygous missense mutation in the keratin-4 gene of a Swedish family with white sponge nevus. Our results support the notion that mutations in keratin-4 and keratin-13 are the underlying cause of white sponge nevus.