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Insect-specific viruses belonging to significant arboviral families have recently been discovered. These viruses appear to be maintained within the insect population without the requirement for replication in a vertebrate host. Mosquitoes collected from Badu Island in the Torres Strait in 2003 were analysed for insect-specific viruses. A novel bunyavirus was isolated in high prevalence from Culex spp. The new virus, provisionally called Badu virus (BADUV), replicated in mosquito cells of both Culex and Aedes origin, but failed to replicate in vertebrate cells. Genomic sequencing revealed that the virus was distinct from sequenced bunyavirus isolates reported to date, but phylogenetically clustered most closely with recently discovered mosquito-borne, insect-specific bunyaviruses in the newly proposed Goukovirus genus. The detection of a functional furin cleavage motif upstream of the two glycoproteins in the M segment-encoded polyprotein suggests that BADUV may employ a unique strategy to process the virion glycoproteins., (Copyright © 2016 Elsevier Inc. All rights reserved.)

We report on three Aboriginal Australian siblings with a unique phenotype which overlaps with known megalencephaly syndromes and RASopathies, including Costello syndrome. A gain-of-function mutation in MTOR was identified and represents the first reported human condition due to a germline, familial MTOR mutation. We describe the findings in this family to highlight that (i) the path to determination of pathogenicity was confounded by the lack of genomic reference data for Australian Aboriginals and that (ii) the disease biology, functional analyses in this family, and studies on the tuberous sclerosis complex support consideration of an mTOR inhibitor as a therapeutic agent., (© 2015 Wiley Periodicals, Inc.)

The recent epidemic of the arthritogenic alphavirus, chikungunya virus (CHIKV) has prompted a quest to understand the correlates of protection against virus and disease in order to inform development of new interventions. Herein we highlight the propensity of CHIKV infections to persist long term, both as persistent, steady-state, viraemias in multiple B cell deficient mouse strains, and as persistent RNA (including negative-strand RNA) in wild-type mice. The knockout mouse studies provided evidence for a role for T cells (but not NK cells) in viraemia suppression, and confirmed the role of T cells in arthritis promotion, with vaccine-induced T cells also shown to be arthritogenic in the absence of antibody responses. However, MHC class II-restricted T cells were not required for production of anti-viral IgG2c responses post CHIKV infection. The anti-viral cytokines, TNF and IFNγ, were persistently elevated in persistently infected B and T cell deficient mice, with adoptive transfer of anti-CHIKV antibodies unable to clear permanently the viraemia from these, or B cell deficient, mice. The NOD background increased viraemia and promoted arthritis, with B, T and NK deficient NOD mice showing high-levels of persistent viraemia and ultimately succumbing to encephalitic disease. In wild-type mice persistent CHIKV RNA and negative strand RNA (detected for up to 100 days post infection) was associated with persistence of cellular infiltrates, CHIKV antigen and stimulation of IFNα/β and T cell responses. These studies highlight that, secondary to antibodies, several factors are involved in virus control, and suggest that chronic arthritic disease is a consequence of persistent, replicating and transcriptionally active CHIKV RNA.

The Kokobera group of flaviviruses circulates in Australia and Papua, New Guinea, and has been associated with occasional human polyarticular disease. To facilitate future studies to identify virulence determinants, the complete coding regions of the Stratford virus, and isolates of the Bainyik virus and Torres virus were obtained., (Copyright © 2014 Warrilow et al.)

Here we describe Casuarina virus (CASV), a new virus in the family Mesoniviridae. This is the first report of a mesonivirus in Australia, which extends the geographical range of this virus family to 3 continents. The virus was isolated in 2010 from Coquillettidia xanthogaster mosquitoes during surveillance in the suburbs of Darwin, the capital of the Northern Territory. Cryo-electron microscopy of the CASV virions revealed spherical particles of 65 nm in size with large club-shaped projections of approximately 15 nm in length. The new virus was most closely related to Alphamesonivirus 1, the only currently recognized species in the family. In 2013 a further 5 putative new mesonivirus species were described: Hana, Méno, Nsé, Moumo and Dak Nong viruses. The evolutionary distance between CASV and two of its closest relatives, Cavally and Hana viruses (Jones-Taylor-Thornton distance of 0.151 and 0.224, respectively), along with its isolation from a different genus of mosquitoes captured on a separate continent indicate that CASV is a new species.

Background: Aicardi-Goutières syndrome (AGS) is an inflammatory disorder caused by mutations in any of six genes (TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, and ADAR). The disease is severe and effective treatments are urgently needed. We investigated the status of interferon-related biomarkers in patients with AGS with a view to future use in diagnosis and clinical trials., Methods: In this case-control study, samples were collected prospectively from patients with mutation-proven AGS. The expression of six interferon-stimulated genes (ISGs) was measured by quantitative PCR, and the median fold change, when compared with the median of healthy controls, was used to create an interferon score for each patient. Scores higher than the mean of controls plus two SD (>2·466) were designated as positive. Additionally, we collated historical data for interferon activity, measured with a viral cytopathic assay, in CSF and serum from mutation-positive patients with AGS. We also undertook neutralisation assays of interferon activity in serum, and looked for the presence of autoantibodies against a panel of interferon proteins., Findings: 74 (90%) of 82 patients had a positive interferon score (median 12·90, IQR 6·14-20·41) compared with two (7%) of 29 controls (median 0·93, IQR 0·57-1·30). Of the eight patients with a negative interferon score, seven had mutations in RNASEH2B (seven [27%] of all 26 patients with mutations in this gene). Repeat sampling in 16 patients was consistent for the presence or absence of an interferon signature on 39 of 41 occasions. Interferon activity (tested in 147 patients) was negatively correlated with age (CSF, r=-0·604; serum, r=-0·289), and was higher in CSF than in serum in 104 of 136 paired samples. Neutralisation assays suggested that measurable antiviral activity was related to interferon α production. We did not record significantly increased concentrations of autoantibodies to interferon subtypes in patients with AGS, or an association between the presence of autoantibodies and interferon score or serum interferon activity., Interpretation: AGS is consistently associated with an interferon signature, which is apparently sustained over time and can thus be used to differentiate patients with AGS from controls. If future studies show that interferon status is a reactive biomarker, the measurement of an interferon score might prove useful in the assessment of treatment efficacy in clinical trials., Funding: European Union's Seventh Framework Programme; European Research Council., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Human disease incidence attributed to arbovirus infection is increasing throughout the world, with effective control interventions limited by issues of sustainability, insecticide resistance and the lack of effective vaccines. Several promising control strategies are currently under development, such as the release of mosquitoes trans-infected with virus-blocking Wolbachia bacteria. Implementation of any control program is dependent on effective virus surveillance and a thorough understanding of virus-vector interactions. Massively parallel sequencing has enormous potential for providing comprehensive genomic information that can be used to assess many aspects of arbovirus ecology, as well as to evaluate novel control strategies. To demonstrate proof-of-principle, we analyzed Aedes aegypti or Aedes albopictus experimentally infected with dengue, yellow fever or chikungunya viruses. Random amplification was used to prepare sufficient template for sequencing on the Personal Genome Machine. Viral sequences were present in all infected mosquitoes. In addition, in most cases, we were also able to identify the mosquito species and mosquito micro-organisms, including the bacterial endosymbiont Wolbachia. Importantly, naturally occurring Wolbachia strains could be differentiated from strains that had been trans-infected into the mosquito. The method allowed us to assemble near full-length viral genomes and detect other micro-organisms without prior sequence knowledge, in a single reaction. This is a step toward the application of massively parallel sequencing as an arbovirus surveillance tool. It has the potential to provide insight into virus transmission dynamics, and has applicability to the post-release monitoring of Wolbachia in mosquito populations.

Here we demonstrate a cost effective and scalable microbial ecology sequencing platform using the Ion Torrent Personal Genome Machine (PGM). We assessed both PCR amplified 16S rRNA and shotgun metagenomic approaches and generated 100,000+ to 1,000,000+ reads using 'post-light' based sequencing technology within different sized semi-conductor chips. Further development of Golay barcoded Ion Tags allowed multiplex analyses of microbial communities with substantially reduced costs compared with platforms such as 454/GS-FLX. Using these protocols we assessed the bacterial and archaeal dynamics within covered anaerobic digesters used to treat piggery wastes. Analysis of these sequence data showed that these novel methanogenic waste treatment systems are dominated by bacterial taxa, in particular Clostridium, Synergistia and Bacteroides that were maintained as a stable community over extended time periods. Archaeal community dynamics were more stochastic with the key methanogenic taxa more difficult to resolve, principally due to the poor congruence seen between community structures generated either by nested PCR or metagenomic approaches for archaeal analyses. Our results show that for microbial community structure and function analyses, the PGM platform provides a low cost, scalable and high throughput solution for both Tag sequencing and metagenomic analyses., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Susceptibility to sIBM is strongly associated with the HLA-DRB1*03 allele and the 8.1 MHC ancestral haplotype (HLA-A1, B8, DRB1*03) but little is known about the effects of allelic interactions at the DRB1 locus or disease-modifying effects of HLA alleles. HLA-A, B and DRB1 genotyping was performed in 80 Australian sIBM cases and the frequencies of different alleles and allele combinations were compared with those in a group of 190 healthy controls. Genotype-phenotype correlations were also investigated. Amongst carriers of the HLA-DRB1*03 allele, DRB1*03/*01 heterozygotes were over-represented in the sIBM group (p<0.003) while. DRB1*03/*04 heterozygotes were under-represented (p<0.008). The mean age-at-onset (AAO) was 6.5 years earlier in DRB1*03/*01 heterozygotes who also had more severe quadriceps muscle weakness than the rest of the cohort. The findings indicate that interactions between the HLA-DRB1*03 allele and other alleles at the DRB1 locus can influence disease susceptibility and the clinical phenotype in sIBM.

The epidemiology of deliberate self-poisoning presentations to the emergency department (ED) of Ninewells Hospital was reviewed over a six-month period. The results were related to previously published Scottish data. During the six month period, 530 patients presented (2.1% of total). There was a female preponderance with over 65% of patients aged less than 40 years. Patients lived more commonly in areas of higher deprivation. The drugs most commonly involved were paracetamol (39.25%) and antidepressants (35.1%). Of the presentatons 80.2% required no treatment apart from basic observations. Only 1.51% received activated charcoal and no gastric lavages were performed. Of the presentations, 75.6% were discharged after observation in the ED, 8.9% were admitted to a psychiatric hospital and 5.5% were admitted to general medicine department. Deliberate self-poisoning continues to be a major cause of hospital admissions in Scotland. In Tayside, it is predominantly a problem of the young and socially deprived. Consistent with recent national trends, paracetamol was the most common drug relating to overdose. The use of an ED observation ward is supported as a vast majority of patients are admitted for less than 24 hours and require no active treatment.

In humans, susceptibility to several immunopathologic diseases maps to a conserved block encompassing the polymorphic BAT1, NFKBIL1 (IKBL) and TNF genes in the central MHC. As a pre-requisite for studies of these genes in animal models, we characterized Bat1a and Nfkbil1 in inbred mice differing in their H2 haplotype. We identified two indels and nine single nucleotide polymorphisms (SNP) upstream of Nfkbil1, one indel, nine SNP upstream of Bat1a and a synonymous SNP in exon 2 of Bat1a. H2(g7) and H2(b) mice yielded identical Bat1a and Nfkbil1 sequences. Real time PCR (RT-PCR) showed Bat1a was expressed in adult brain, heart, kidney, liver, lung, pancreas and spleen. Expression of Bat1a was higher in brain and liver of 15-day embryos compared to 1-day old mice and increased moderately in liver and lung of adult mice 2-4 h after LPS challenge. Nfkbil1 expression was low or undetetectable in all tissues and cell lines.

Numerous studies have associated carriage of HLA-DRB1*1501, DQA1*0102 and DQB1*0602 (DR15, DQ6) with dominant resistance to type 1 diabetes and have concluded that one or more of the component HLA class II molecules mediate this effect. Mechanisms for MHC class II-mediated resistance to diabetes have been proposed from studies of transgenic mice, usually using the diabetes-prone non-obese diabetic (NOD) strain. However, these studies have not reached any consensus on a plausible mechanism. In this study we question why the role of central MHC genes in resistance to diabetes has not been addressed, as the central MHC carries markers of susceptibility to diabetes in linkage disequilibrium with several genes with known or putative immunoregulatory functions. To illustrate the type of studies required to address this issue, we selected diabetes patients and control subjects for carriage of HLA-DR15 and the C allele at position +738 in the inhibitor of kappa B-like gene (IKBL). These alleles mark the 7.1 haplotype (HLA-A3, B7, IKBL738*C, DR15, DQ6). HLA-DR15 was the most effective marker of resistance, but an effect may be evident with IKBL738*C in a larger study. Moreover, carriage of the entire haplotype was particularly rare in patients. The best explanation for this is that the critical gene lies between IKBL and HLA-DRB1, and is more closely linked to HLA-DRB1. Candidate genes at the centromeric end of the central MHC are reviewed, highlighting the need for further study.

The onset of pulmonary hypertension in patients with systemic sclerosis carries a poor prognosis. Atrial septostomy has been used successfully to palliate endstage primary pulmonary hypertension but has not been attempted in other forms of pulmonary vascular disease. We report substantial clinical improvement following atrial septostomy in a patient with systemic sclerosis complicated by severe, isolated pulmonary hypertension. After the procedure, exercise capacity was improved and exertional syncope abolished. We suggest that this procedure should be considered for other patients with this diagnosis.

Background: BAT1 belongs to the DEAD-box family of RNA-binding proteins and is encoded in the central MHC. To determine whether it affects immune responses and hence diseases influenced by MHC haplotypes, U937, THP1 and Jurkat cells were stably transfected with anti-sense DNA corresponding to exons 2-5 of BAT1 using a retroviral vector., Results: Anti-sense transfectants carried anti-sense DNA and expressed anti-sense mRNA. After mitogenic stimulation, they produced higher levels of TNFalpha, IL-1 and IL-6 than equivalent cells carrying the vector alone, suggesting that BAT1 may down-regulate acute phase cytokine production. Polyclonal antibodies raised against a peptide in exon 8 of BAT1 recognized approximately 50 kDa and approximately 38 kDa proteins in all cell lines tested, including the anti-sense transfectants. Expression was localized to the nucleolus in dividing fibroblasts. However the immunochemistry may be confounded by a recently described gene, DDXL, on chromosome 19, which shares a 89% amino acid identity with BAT1. RT-PCR analyses established that BAT1 and DDXL mRNA are expressed in resting U937, THP1 and Jurkat cells. BAT1 and DDXL are divergent in the exons selected for the anti-sense study., Conclusions: BAT1 is a negative regulator of inflammation. Future studies should address how its functions relate to those of DDXL.

Background & Aims: IKBL gene lies telomeric of the tumor necrosis factor cluster in the central major histocompatibility complex and carries a structural polymorphism at position +738. In the Spanish white population, we found the IKBL+738(C) allele in haplotypes carrying either HLA-DRB1(*)1501 or -DRB1(*)0103. Because these HLA class II alleles may confer susceptibility to ulcerative colitis, we investigated an association between IKBL+738(C) and this disease., Methods: DNA-based techniques were used to type individual alleles of HLA-DRB1 and IKBL+738. The frequencies of these alleles were compared among ethnically matched populations comprising 155 patients and 298 controls., Results: IKBL+738(C) allele was exclusively increased in patients with extensive and/or intractable disease. HLA-DRB1(*)0103 was the only HLA-DRB1 allele to be significantly increased in frequency in patients with UC compared with controls. It was found in patients with extensive and distal disease. In the HLA-DRB1(*)0103-negative population, patients with extensive disease still had a significant association with IKBL+738(C). The difference between the 2 groups of patients was statistically significant (13.7% vs. 1.7% in patients with distal disease; odds ratio, 9.25; P = 0.01)., Conclusions: HLA-DRB1(*)0103 is associated with susceptibility to ulcerative colitis, and IKBL+738(C) marks a propensity to extensive and more severe disease.

Background: Primary pulmonary hypertension (PPH), resulting from occlusion of small pulmonary arteries, is a devastating condition. Mutations of the bone morphogenetic protein receptor type II gene (BMPR2), a component of the transforming growth factor beta (TGF-beta) family which plays a key role in cell growth, have recently been identified as causing familial PPH. We have searched for BMPR2 gene mutations in sporadic PPH patients to determine whether the same genetic defect underlies the more common form of the disorder., Methods: We investigated 50 unrelated patients, with a clinical diagnosis of PPH and no identifiable family history of pulmonary hypertension, by direct sequencing of the entire coding region and intron/exon boundaries of the BMPR2 gene. DNA from available parent pairs (n=5) was used to assess the occurrence of spontaneous (de novo) mutations contributing to sporadic PPH., Results: We found a total of 11 different heterozygous germline mutations of the BMPR2 gene in 13 of the 50 PPH patients studied, including missense (n=3), nonsense (n=3), and frameshift (n=5) mutations each predicted to alter the cell signalling response to specific ligands. Parental analysis showed three occurrences of paternal transmission and two of de novo mutation of the BMPR2 gene in sporadic PPH., Conclusion: The sporadic form of PPH is associated with germline mutations of the gene encoding the receptor protein BMPR-II in at least 26% of cases. A molecular classification of PPH, based upon the presence or absence of BMPR2 mutations, has important implications for patient management and screening of relatives.

Susceptibility to multiple sclerosis (MS) is clearly associated with human leukocyte antigen (HLA)-DRB1*1501, but some studies show associations with HLA-B7 and -B18. These are often co-expressed with DRB1*1501 in the ancestral haplotypes (AH) denoted 7.1 (HLA-A3, B7, tumor necrosis factor [TNF]a11b4, DRB1*1501) and 18.1 (HLA-A25, B18, TNFa10b4, DRB 1*1501). Here we present a systematic study of 218 patients and 274 controls typed at all standard class II and TNF microsatellite loci, and a novel non-synonymous polymorphism in the central major histocompatibility complex gene, inhibitor of kappa B-like protein (IKBL). The C allele at IKBL+738 is only found on the 7.1 haplotype. HLA-DRB1*1501 was associated with disease, as expected. When subjects expressing DRB 1*501 were analyzed separately, TNFa11b4 and IKBL+738C were less common in the patients and, hence, mark an allele that mediates resistance which lies telomeric of IKBL. TNFa10b4 and TNFa1b5 were more common in DRB1*1501 patients than in controls. These alleles have been associated with the 18.1 and 18.2 AH, respectively. Since no component of these haplotypes was an independent risk factor in this study, it appears likely that a gene linked to TNFa10b4 and TNFa1b5 modifies the effect of the susceptibility locus marked by HLA-DRB1*1501. Potential candidate genes telomeric of the TNF cluster are discussed.

Susceptibility to several disorders, including insulin-dependent diabetes mellitus and multiple sclerosis, has been associated with alleles of HLA class II genes and loci in the TNF cluster in the central major histocompatibility complex (MHC) region. As recombination within this region is rare, it is difficult to determine which genes are important. This will be facilitated by the identification of functional polymorphisms. Hence we are sequencing reverse transcription-polymerase chain reaction products derived from central MHC genes in well characterized and conserved ancestral haplotypes. Here we address the IKBL gene, which lies near the TNF cluster at the telomeric end of the central MHC. Although the IKBL cDNA sequence was conserved between most ancestral haplotypes, a synonymous nucleotide substitution, a 3' untranslated region substitution, and a single nonsynonymous substitution were identified. The latter (IKBL+738) was present in multiple examples of the 7.1 haplotype [HLA-A3, B7, DR2 (DR15)] and resulted in a cysteine to arginine substitution in a predicted protein kinase C phosphorylation site. This polymorphism did not occur in 18 other common haplotypes from the 10th International Histocompatibility Workshop and thus appears haplospecific. A role for IKBL+738 in the association between HLA-A3,B7,DR2(DR15) and susceptibility to multiple sclerosis is discussed.

An individual's major histocompatibility complex (MHC) ancestral haplotype (AH) is the clearest single determinant of susceptibility to MHC associated immunopathological disease, as it defines the alleles carried at all loci in the MHC. However, the direct effects of any of the 150-200 genes that constitute the MHC are difficult to determine since recombination only occurs at defined hotspots. This review concerns the 8.1 AH (HLA-A1, C7, B8, C4AQ0, C4B1, DR3, DQ2), which is carried by most Caucasians with HLA-B8. It is associated with accelerated human immunodeficiency virus (HIV) disease, and susceptibility to insulin-dependent diabetes mellitus (IDDM), systemic lupus erythematosus, dermatitis herpetiformis, common variable immunodeficiency and IgA deficiency, myasthenia gravis and several other conditions. We have mapped susceptibility genes for HIV, IDDM and myasthenia gravis to the central MHC between HLA-B and the tumour necrosis factor or complement genes. Here we consider which of the remaining 8.1-associated diseases are more closely associated with HLA-DR3 and/or DQ2. Several candidate genes in the central MHC have the potential to modulate immune or inflammatory responses in an antigen-independent manner, as is seen in studies of cultured cells from healthy carriers of the 8.1 AH. Hence these genes may act as a common co-factor in the diverse immunopathological conditions associated with the 8.1 AH.

The BAT1 gene (D6S81E) encodes a member of the DEAD-box family of RNA-binding proteins, and lies in the central MHC. This region contains genes which affect susceptibility to immunopathological diseases. A 14-kb section of the human MHC containing the BAT1 gene and a further 5-kb telomeric of BAT1 was sequenced using DNA from individuals homozygous for HLA-A1, B8, DR3 and HLA- A1, B57, DR7. Analysis of our sequences and the previously reported human cDNA sequence showed that the expressed sequence of the 8.1 and 57.1 haplotypes is identical with only minor substitutions in the introns. Phylogenetic analysis suggests BAT1 may be a translation initiation factor. Screening of cells and tissues for BAT1 mRNA suggests an abundant member of a family of proteins expressed in multiple cell types, notably macrophages and hepatocytes. Expression was independent of MHC haplotype, consistent with the lack of sequence polymorphism.

As MHC genes are potent determinants of susceptibility to immunopathological diseases, the mapping of SAPK2a (CSBP) and SAPK4 to chromosome 6p 21.2-21.3 suggested that these genes may mediate the effects of the MHC on disease. Here we describe the genomic structure and localisation of both genes approximately 2.3Mb centromeric of HLA-DP. Examination of the complete coding region and selected intronic regions of SAPK2a and SAPK4 from 22 human EBV-transformed B-cell lines of different MHC haplotypes and racial background revealed complete sequence conservation. There were no notable differences in levels of expression of SAPK2a and SAPK4 mRNA in cell lines of different MHC haplotypes or racial origin. Examination of the SAPK2a and SAPK4 sequences from two chimpanzees revealed 3 nucleotide differences between human and chimpanzee in each gene resulting in only one amino acid change in SAPK4, and 6 nucleotide substitutions plus 2 deletions in 600bp of intronic sequence from SAPK4. This highlights the selective pressure placed on these genes to maintain their protein sequence, but does not favour a role in genetic regulation of disease or provide evidence of linkage disequilibrium with the MHC.

We have shown that normal C57BL/6J mice are moderately resistant to infection with murine cytomegalovirus (MCMV) and that this resistance is impaired by prior infection with LP-BM5 MuLV, which causes a disease (MAIDS) similar to early HIV-induced disease. This study investigates macrophage function in MAIDS+ mice challenged with MCMV. MAIDS reduces the influx of cells into the peritoneal cavity seen in normal C57BL/6J mice 6 days after MCMV infection. The infiltrates contained cells that resembled activated macrophages, as they took up colloidal gold, expressed the macrophage marker Mac-1, had high levels of acid phosphatase activity, and were lymphocytostatic when co-cultured with activated T cells. MAIDS+ mice had a higher percentage of cells able to take up colloidal gold and higher acid phosphatase activity per cell. The cells were also more lymphocytostatic and produced higher levels of interleukin-1 and tumor necrosis factor-alpha on days 4 and 6 after MCMV infection. Hence, MAIDS enhances baseline and induced macrophage activity, but depresses infiltration into the site of inflammation.

Factors influencing MCMV infection mediated by MHC class 1 molecules were analysed further as previous studies showed that the effects of the MHC genotype on sensitivity to this virus are important in vivo. Here we show that H-2d, H-2b, H-2r and H-2v macrophages are highly sensitive to MCMV. Moreover, transfection of H-2k L-cells with Kb or Dd conferred sensitivity to MCMV. This was not affected by amino acid substitutions in Kb alpha 1 or alpha 2, although previous studies demonstrated that exchange of the alpha 1 domain of Dd with Ld alpha 1 compromised sensitivity. Here replacement of Kb alpha 3 with Ld alpha 3 reduced susceptibility to low doses of MCMV. In addition, extracellular beta 2-microglobulin (beta 2m) promoted infection of beta 2m-negative RIE/TL8X.1 cells transfected with Db with or without a beta 2m gene. Hence MCMV infection can involve beta 2m and the alpha 1 and alpha 3 domains of MHC heavy chains. MCMV infection of L-cells expressing Dd or Kb was also inhibited by heparin, but infection of the parental L-cell line was not reproducibly affected. A role for heparan sulphate proteoglycan in MHC-mediated MCMV infection was confirmed using cells pre-treated with heparinase I or III, or propagated in chlorate to inhibit the sulphation of the glycosaminoglycan chains.

In view of the difficulty encountered in distinguishing between 2 degrees renal cell carcinoma (RCC) and hemangioblastoma (HBl) in the central nervous system, the AgNOR technique has been applied empirically to a series of 16 specimens of HBl, 5 primary RCC, and 6 specimens of secondary RCC in the CNS. To avoid tautology, the nature of these was confirmed by immunostaining for epithelial membrane antigen (EMA) and factor VIII-related antigen (FVII RAg). It was found that mean nuclear AgNOR counts in the stromal and endothelial cells of HBl exceeded significantly the counts in the tumor and endothelial cells of RCC, with no overlap in values. It is suggested that the AgNOR method is a useful adjunct in achieving the differential diagnosis of HBl and RCC in the nervous system.