Adenovirus vector technology: an efficient method for constructing recombinant adenovirus and on/off switching of gene expression

An efficient method of constructing recombinant adenoviruses (Ad) has been established. The expression unit to be introduced into recombinant Ad was first inserted into the unique SwaI site of the full-length Ad genome cloned in a cassette cosmid. The cassette bearing the expression unit was then cotransfected to 293 cells together with the Ad DNA-terminal protein complex digested at several sites with EcoT22I. The use of the parent Ad DNA-terminal protein complex instead of the deproteinized Ad genome DNA allowed very efficient recovery of the desired recombinant Ad, and the restriction digestion drastically reduced regeneration of the parent virus. This method may facilitate the application of recombinant Ad and should be useful for further improvement of Ad vectors. Also a recombinant adenovirus expressing Cre recombinase derived from bacteriophage P1 was constructed. To assay the Cre activity in mammalian cells, another recombinant Ad bearing an on/off switching reporter unit, where a LacZ-expression unit can be activated by the Cre-mediated excisional deletion of an interposed stuffer DNA, was also constructed. Co-infection experiments together with the Cre-expressing and the reporter recombinant Ad showed that the Cre-mediated switching of gene expression was detected in nearly 100% of cultured CV1 cells. These results suggest that the recombinant Ad efficiently expressed functional Cre and offers a basis for establishing a powerful on/off switching strategy of gene expression in cultured mammalian cells and presumably in future gene therapy.

Expression of inflammatory cytokine genes in vivo by human alveolar bone-derived polymorphonuclear leukocytes isolated from chronically inflamed sites of bone resorption

Alveolar bone-derived polymorphonuclear leukocytes (PMNs) were characterized for their ability to produce inflammatory cytokines such as interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor alpha (TNF alpha), and IL-6 in vivo. Periapical exudates (PE) were collected from periapical lesions with chronic periapical periodontitis through root canals. Cells and noncellular supernatants were then isolated by centrifugation. The concentration of cytokines present in the noncellular supernatants were determined by ELISA. High concentrations of IL-1 alpha, IL-1 beta, and IL-6 were detected in PE, however, TNF alpha was not. PE contains predominantly PMNs ( > 95% of residing cells) with a few percent of lymphocytes and/or macrophages. These alveolar bone-derived PMNs were purified by the Ficoll-Hypaque gradient method and were analyzed for cytokine mRNA expression using the cytokine-specific reverse-transcription polymerase chain reaction. Highly purified PMNs ( > 99.5%) isolated from PE expressed significant levels of mRNA for IL-alpha, IL-1 beta, and TNF alpha. IL-6 mRNA was not detected, although a high concentration of IL-6 was detected in supernatants of PE by ELISA. The IL-6 secretion in PE could be derived from macrophages, T lymphocytes, osteoblasts, or fibroblasts around periapical lesions. These data strongly suggest that human PMNs derived from alveolar bone can spontaneously produce IL-1 alpha, IL-1 beta, and TNF alpha at sites of inflammation, and probably initiate inflammation and regulate augmentation of bone resorption in vivo.

Efficient generation of recombinant adenoviruses using adenovirus DNA-terminal protein complex and a cosmid bearing the full-length virus genome

An efficient method of constructing recombinant adenoviruses (Ads) has been established. The expression unit to be introduced into recombinant Ad was first inserted into the unique Swa I site of the full-length Ad genome cloned in a cassette cosmid. The cassette bearing the expression unit was then cotransfected into human embryonic kidney 293 cells together with the Ad DNA-terminal protein complex digested at several sites with Eco T22I or Ase I/EcoRI. The use of the parent Ad DNA-terminal protein complex instead of the deproteinized Ad genome DNA allowed very efficient recovery of the desired recombinant Ad, and the above restriction digestion drastically reduced regeneration of the parent virus. Several hundred virus clones were readily obtained in each experiment, and about 70% of the clones were the desired recombinant viruses. Furthermore, because the cassette contained the full-length Ad genome, any position of the genome could be easily modified to develop a new vector design. We established construction systems for two types of Ad vectors, the E1-substitution type and the E4-insertion type. This method may greatly facilitate the application of recombinant Ads and should be useful for further improvement of Ad vectors.

Measurement of interleukin-4 and histamine in superficial cells of conjunctiva in patients with allergic conjunctivitis

Interleukin 4 (IL-4) may play a role in the development of allergic disease. We questioned whether IL-4 related phenomenon occurred on the surface of the conjunctiva during allergic conjunctivitis. Ten patients with cedar pollen-allergic conjunctivitis and 10 patients with postsurgical conjunctivitis were enrolled in this study. Cells were collected by brush cytology from the upper palpebral conjunctiva. After the cells were cultured for 24 hours, the levels of IL-4, IgE, and histamine were measured in the supernatants. An ELISA was used for histamine and a highly sensitive sandwich ELISA for IL-4 and IgE. Conjunctival cells were also stained and fixed by May-Grunwalds stain solution. The number of superficial cells, especially lymphocytes, were compared in the two groups. The total number of cells collected by brush cytology did not differ in allergic vs., postsurgical conjunctivitis. Lymphocytes were similarly present in such specimens. The levels of IL-4 (p = 0.01) and histamine (p = 0.02) significantly increased in the specimens from patients with allergic conjunctivitis, although IgE was not detected in both groups. There was a correlation between the level of IL-4 and histamine (p = 0.0001). Conjunctival cells in allergic conjunctivitis produced a larger amount of IL-4 and histamine for cedar pollen compared to the postsurgical conjunctivitis. As with other allergic diseases, IL-4 may play a role similar to that of histamine in the development of allergic conjunctivitis.

Efficient adenovirus-mediated gene transfer into human cancer cell lines derived from digestive tract

The efficiency of gene transfer into human cancer cells from digestive tract was evaluated using a replication-deficient recombinant adenovirus (Ad) vector harboring a lacZ gene of E. coli as a reporter gene (AxCALacZ). Average percent X-gal staining of esophageal cancer cell lines was 46%, that of gastric cancer cell lines 82% and that of colon cancer cell lines 70% at 3 days after Ad vector infection. X-gal staining in vitro continued 2 months after infection. By the direct injection of adenovirus vector to the tumors in nude mice, a certain percentage of tumor cells was stained by the X-gal. Colon26 cell line infected with AxCALacZ was implanted in BALB/c mice immunized with AxCALacZ, and tumor growth was suppressed. We presume this was due to anti-adenoviral immunity.

A neural cell-type-specific expression system using recombinant adenovirus vectors

We demonstrated neural cell-type-specific gene expression using an adenovirus vector, which is useful for delivering foreign genes into quiescent neural cells. We produced eight recombinant replication-defective adenoviruses carrying the lacZ reporter gene driven by various promoters, including those of the L7/PCP2 gene (highly restricted expression in cerebellar Purkinje cells), and the myelin basic protein (in oligodendrocytes) gene. We demonstrated in vitro and in vivo promoter-driven, neural cell-type-specific gene expression by recombinant adenoviruses. The genes were transferred into these recombinant adenoviruses and expressed with high levels of efficiency in vitro and in vivo. In primary culture, the recombinant adenoviruses AdexL7-NL-LacZ and AdexMBP-NL-LacZ appeared to be expressed in a Purkinje cell and oligodendrocyte-specific manner. Introduction of 10(8) pfu of these viruses into the adult rat cerebellum by stereotactic injection yielded neural cell-type-specific expression without apparent toxicity to the animals. Thus, adenovirus vectors are useful for cell-type-specific therapeutic uses and in studies requiring neural cell-type-specific gene expression.

Induction of antibodies against structural proteins of hepatitis C virus in mice using recombinant adenovirus

Replication-deficient recombinant adenoviruses expressing structural proteins of hepatitis C virus (HCV) were constructed. Each recombinant lacks adenoviral E1A and E3 genes and bears expression units for HCV structural proteins. The expression units contain HCV cDNAs coding for either the protein or core, one of two envelopes (E1 and E2) or all of these structural proteins (core, E1 and E2) under the control of the SR alpha promoter. In HeLa or HepG2 cells, the recombinants can express efficiently HCV genes after infection without replication of the recombinants. We detected 22-kDa core, 35-kDa E1 and 58-kDa E2 proteins of HCV in these cells. The recombinant expressing all three HCV structural proteins was inoculated into mice. Antibodies to each of the three HCV proteins were detected in all of the ten mice tested. The results indicate that the recombinant adenoviruses efficiently express HCV genes and induce specific antibody against the expressed HCV proteins in animals.

The presence of costimulatory molecules CD86 and CD28 in rheumatoid arthritis synovium

OBJECTIVE

To investigate the expressions of co-stimulatory molecules CD86 (B7-2, B70) and CD28 by cells obtained from the synovial tissues (ST) and synovial fluids (SF) of patients with rheumatoid arthritis (RA).

METHODS

Monoclonal antibodies (MAb) against CD86 and CD28 were used for immunochemical study of synovia from 18 RA patients, 4 osteoarthritis (OA) patients, and 4 normal subjects. These MAb were also used for flow cytometry of isolated ST cells from 8 RA and 5 OA patients and of SF mononuclear cells from 5 RA and 5 OA patients.

RESULTS

Immunohistochemical examination revealed that CD86+ cells occurred in 11 of the 18 RA synovia, but in none of the 4 OA or 4 normal synovia. Most of the positive cells had macrophage-like morphology, and surrounded lymphoid aggregates. Most cells within lymphoid aggregates were stained positively for CD28. Flow cytometry showed that CD86+ cells comprised 2.9-33.4% (average 14.3%) of the total ST cells and 2.1-14.9% (average 6.1%) of the total SF mononuclear cells from RA patients. Approximately 40% of the CD86+ cells expressed CD14. A majority (mean 72%, range 57-89%) of the T cells in ST and SF expressed CD28. RA synovia expressed more CD86 molecules than did OA synovia (mean frequency of positive cells 14.3% versus 2.8%; mean fluorescence intensity 104.6 versus 40.9).

Interleukin-4 and IgE in seasonal allergic conjunctivitis

We measured interleukin-4 (IL-4) and IgE to study their presence in patients with seasonal allergic conjunctivitis. Twenty patients and 10 normal subjects were enrolled in this study, and their brush cytology samples and peripheral blood lymphocytes (PBL) were cultured for 3 or 24 h. IL-4 levels were measured using ELISA in the supernatants. Measurements of serum IgE were also performed. IL-4 was detected in 4 of 40 brush cytology samples and 10 of 40 PBL samples, but not from the controls. IL-4 positivity rate of patients was significantly higher than normal in 24-hour cultured PBL (p = 0.03). Patients' serum IgE was also significantly higher (p = 0.006). IL-4 may contribute to the development of seasonal allergic conjunctivitis.

Quantitative analysis of repeat adenovirus-mediated gene transfer into injured canine femoral arteries

We quantitatively evaluated the effectiveness of a repeat administration of a recombinant adenoviral vector expressing bacterial Escherichia coli lacZ into the same arterial site of a relatively large animal, the dog. The replication-defective adenoviral vector was introduced percutaneously into balloon-injured femoral arteries through a double-balloon catheter. After a single dose of adenoviral vector, up to 90% of surface (73 +/- 16%, n = 7) and smooth muscle cells in multiple layers of the media showed transgene expression as evaluated by 5-bromo-4-chloro-3-indoyl beta-D-galactopyranoside histostaining without extralocal expression, as assessed by polymerase chain reaction. High-level expression (measured as beta-galactosidase activity) peaked 7 days after transfer and was transient, although it was retained for a month. Second does of the same adenovirus to the same arterial site were given 1, 2, 5, or 8 weeks after the first administration. At 1 week the second dose significantly enhanced lacZ expression. At 2, 5, or 8 weeks the second dose reinduced lacZ expression at 25% to 30% of the full expression. lacZ expression was also detected in preimmuned dogs, although the expression levels correlated inversely to the titer of neutralizing antibodies in their serum. These results demonstrate that arterial gene expression can be enhanced by a second administration of the same adenovirus after a short interval and that a repeat dose after a long interval partially but significantly reinduces gene expression despite the presence of an immune response. These data may provide an additional scientific foundation for the use of adenovirus-mediated arterial gene transfer in future clinical practice.

Expression of hepatitis C virus envelope proteins in transgenic mice

In an attempt to establish a model for hepatitis C virus (HCV) infection, we produced mice transgenic for the HCV envelope genes, E1 and E2, under the control of a regulatory element from hepatitis B virus. F1-generation mice from the established founders demonstrated expression of both E1 and E2 proteins as glycosylated forms in their organs including the liver. Immunostaining revealed the localization of envelope proteins principally in the cytoplasm of hepatocytes around the hepatic central veins. Furthermore, E1 and E2 proteins were shown by immunoprecipitation to be associated with each other in the mouse liver. There was no evidence of tissue pathology in the mouse liver up to 16 months of age, suggesting that E1 and E2 proteins per se may not have direct pathogenic effects. Our results demonstrate the first successful expression of HCV gene products in the mouse liver and the association of in vivo expressed HCV envelope proteins. This transgenic mouse would be a good model to study the virus-cell interactions of HCV such as intracellular transport and assembly of envelope proteins. Also it may be a good model system to determine the role of these proteins in the pathogenesis of hepatitis or extra-hepatic manifestations in HCV infection by the introduction of cytotoxic T lymphocytes specific for the envelope proteins.

In situ hybridization study of vascular cell adhesion molecule-1 messenger RNA expression in rheumatoid synovium

Upregulation of vascular cell adhesion molecule-1 (VCAM-1) has been implicated in various pathological conditions. In this study, we used in situ hybridization to determine the cell types expressing VCAM-1 mRNA in rheumatoid synovium. Synovial tissues from seven rheumatoid arthritis (RA) and four osteoarthritis (OA) patients were examined for VCAM-1 mRNA expression. In situ hybridization as well as immunohistochemical analysis showed that VCAM-1 expression was mainly localized to the hyperplastic synovial lining cells and to a lesser extent endothelial cells and synovial fibroblasts in rheumatoid synovium. VCAM-1 expression in OA is less prominent. Hyperplastic synovial lining cells expressing VCAM-1 were mainly CD13+, CD14+, CD33+ and HLA-DR+. Together with morphological features, this suggests that they are type A macrophage-like synovial cells. Our findings indicate that overexpression of VCAM-1 may contribute to the formation of hyperplastic lining layers in the synovium seen in this disorder.

NMR characterization of guanine DNA site alkylated by kapurimycin A3, an antitumour antibiotic from Streptomyces sp

The kapurimycin A3-guanine adduct was formed by alkylation of the antitumour antibiotic with d(CGCG)2. The site of alkylation of the guanine was confirmed by comparative NMR studies with N-7-methyl-guanine in DMSO-d6.

Measurement of IL-4 in tears of patients with seasonal allergic conjunctivitis and vernal keratoconjunctivitis

To elucidate the mechanism of ocular surface allergic disease, we focused on IL-4, which is one of the key factors in regulating IgE production, and thus determined the concentration of IL-4 in tears. IL-4 concentration was determined in the tears of 15 patients with seasonal allergic conjunctivitis, 15 vernal keratoconjunctivitis (VKC), 10 giant papillary conjunctivitis (GPC), 10 patients with non-allergic conjunctivitis and post-cataract surgical conjunctivitis as intermediate conjunctivitis, and 10 normal subjects using a highly sensitive sandwich ELISA. The mean level of IL-4 in normal controls was low, and seasonal allergic conjunctivitis, VKC and GPC showed a significant elevation (P < 0.05), respectively. IL-4 of VKC and GPC were also significantly higher than allergic conjunctivitis, and non-allergic conjunctivitis and post-cataract surgical conjunctivitis were not higher than normal. These results raise the possibility that the increased level of IL-4 in tears could play a role in allergic disease and its severity in patients.

Immunohistologic analysis of synovium in infrapatellar fat pad after anterior cruciate ligament injury

To clarify the natural course of synovitis after anterior cruciate ligament injury, we took synovial tissues at various periods after injury and analyzed them immunohistologically. Twelve patients with isolated anterior cruciate ligament injuries participated in the study. Inflammation intensity was graded semiquantitatively based on the following parameters: synovial lining cell depth, synovial hyperplasia, vascular hyperplasia, lymphocyte infiltration, and the expression of cell adhesion molecules. The expression of fibrogenic cytokines and the degree of fibrosis were also investigated to elucidate the mechanisms of arthrofibrosis. The results demonstrated that synovitis in the infrapatellar fat pad subsides within 3 months after injury with the progression of fibrosis. Fibrogenic cytokines, platelet-derived growth factor and transforming growth factor-beta, were detected at fibrotic sites, suggesting their involvement in arthrofibrosis. An increased incidence of arthrofibrosis recently has been recognized to occur when anterior cruciate ligament reconstruction is performed within several weeks after injury. We speculate that when anterior cruciate ligament reconstruction is performed during the stage of acute synovitis, the operation may further promote the synovitis, accelerating the arthrofibrotic reaction. Waiting to perform the anterior cruciate ligament reconstruction until the synovitis resolves may possibly decrease the motion problems seen postoperatively.

Expression of inflammatory cytokines and adhesion molecules in haemodialysis-associated amyloidosis

BACKGROUND

The occurrence of various arthropathies including carpal-tunnel syndrome (CTS) in dialysis-associated amyloidosis, a condition caused by the deposition of beta 2 microglobulin (beta 2MG), has been emphasized for several years. We attempted to analyse the pathogenesis of CTS in haemodialysis-associated amyloidosis (HA).

METHODS

The expression of cell adhesion molecules and inflammatory cytokines in tenosynovial tissues was determined by using both reverse-transcriptase polymerase chain reaction (RT-PCR) and immunostaining.

RESULTS

There was a marked expression of ICAM-1, VCAM-1, E-selectin mRNAs together with increased mRNA expression of inflammatory cytokines (IL-1 beta, TNF alpha, IL-6 and MCP-1) in proliferating synovial tissues. ICAM-1 was expressed not only on vascular endothelial cells, but also on synovial cells. In contrast, both VCAM-1 and E-selectin were exclusively expressed on endothelial cells. Mononuclear cells bearing CD13, CD14, CD33 and HLA-DR with macrophage-like morphology were accumulated in the perivascular area and expressed VLA-4, LFA-1 and Mac-1. Moreover, synovial lining cells, vascular endothelial cells and infiltrated mononuclear cells expressed chemokines such as MCP-1 and MIP-1 alpha.

CONCLUSIONS

These data suggest that upregulated expression of inflammatory cytokines and adhesion molecules promotes activation and infiltration of macrophages causing CTS in haemodialysis-associated amyloidosis patients.

Gene transfer and expression in mouse preimplantation embryos by recombinant adenovirus vector

Replication-defective recombinant adenovirus, Adex4SRLacZL, was used as a vector for transferring exogenous genes in mouse zona pellucida-free eggs at the pronuclear stage. The vector contained the E. coli LacZ reporter gene under the control of the SR alpha promoter (SV40 early promoter-fused HTLV-I LTR), and the expression of the reporter gene was examined during preimplantation development in culture. Histochemical staining of the embryos for beta-galactosidase activity showed that the exogenous LacZ gene as expressed in 98% of the embryos at the morula-blastocyst stages. As in the microinjection method, the exogenous genes could be pursued from the 2-cell stage. Neither apparent morphological changes nor cytotoxic effects were observed. Both the percentages of embryos expressing reporter genes and the rate of development to the blastocyst stage were higher in the adenovirus vector-treated embryos than in the microinjected ones. These results suggest that the adenovirus vector system is a useful tool in investigating the genetic control of early mammalian development.

Nitric oxide production and inducible nitric oxide synthase expression in inflammatory arthritides

In this study, we have identified the source of nitric oxide (NO) produced in the human inflammatory joints by analyzing expression of inducible NO synthase. In ex vivo organ cultures, both inflammatory synovium and cartilage from patients with rheumatoid arthritis produced NO. The NO production was suppressed by NG-monomethyl-L-arginine, an inhibitor of NO synthase. The amount of NO produced by the synovium correlated with the proportion of CD14+ cells in the corresponding tissue (r = 0.8, P < 0.05). Immunohistochemical analysis as well as in situ hybridization showed that inducible NO synthase was predominantly expressed in synovial lining cells, endothelial cells, chondrocytes, and to a lesser extent, in infiltrating mononuclear cells and synovial fibroblasts. The synovial lining cells and the infiltrating cells expressing inducible NO synthase were identified where CD14+ cells were located. Together with morphological features, this suggests that they are type A synoviocytes. NO production from freshly isolated synoviocytes and chondrocytes was up-regulated by in vitro stimulation with a combination of IL-TNF-beta, TNF-alpha, and LPS. In summary, the present results suggest that NO is produced primarily by CD14+ synoviocytes, chondrocytes, and endothelial cells in inflammatory joints of arthritides. NO production can be upregulated by cytokines present in inflamed joints. The increased NO production may thus contribute to the pathological features in inflammatory arthritides.

Shwachman syndrome associated with de novo reciprocal translocation t(6;12)(q16.2;q21.2)

We describe a de novo apparently balanced reciprocal translocation t(6;12)(q16.2; q21.2) in an 18 month old girl with Shwachman syndrome, characterised by exocrine pancreatic insufficiency and bone marrow dysfunction. The cause of this syndrome is unknown, although autosomal recessive inheritance has been proposed. The translocation breakpoints in the present patient may be candidate regions for a gene responsible for Shwachman syndrome.

Efficient gene activation in mammalian cells by using recombinant adenovirus expressing site-specific Cre recombinase

A recombinant adenovirus (Ad) expressing Cre recombinase derived from bacteriophage P1 was constructed. To assay the Cre activity in mammalian cells, another recombinant Ad bearing an on/off-switching reporter unit, where a LacZ-expression unit can be activated by the Cre-mediated excisional deletion of an interposed stuffer DNA, was also constructed. Co-infection experiments together with the Cre-expressing and the reporter recombinant Ads showed that the Cre-mediated switching of gene expression was detected in nearly 100% of cultured CV1, HeLa and Jurkat cells. These results suggest that the recombinant Ad efficiently expressed functional Cre and offers a basis for establishing a powerful on/off switching strategy of gene expression in cultured mammalian cells and presumably in transgenic animals. The method is also applicable to construction of recombinant Ad bearing a gene the expression of which is deleterious to propagation of recombinant Ad.

A histologically distinctive interstitial pneumonia induced by overexpression of the interleukin 6, transforming growth factor beta 1, or platelet-derived growth factor B gene

Interstitial pneumonia is characterized by alveolitis with resulting fibrosis of the interstitium. To determine the relevance of humoral factors in the pathogenesis of interstitial pneumonia, we introduced expression vectors into Wistar rats via the trachea to locally overexpress humoral factors in the lungs. Human interleukin (IL) 6 and IL-6 receptor genes induced lymphocytic alveolitis without marked fibroblast proliferation. In contrast, overexpression of human transforming growth factor beta 1 or human platelet-derived growth factor B gene induced only mild or apparent cellular infiltration in the alveoli, respectively. However, both factors induced significant proliferation of fibroblasts and deposition of collagen fibrils. These histopathologic changes induced by the transforming growth factor beta 1 and platelet-derived growth factor B gene are partly akin to those changes seen in lung tissues from patients with pulmonary fibrosis and markedly contrast with the changes induced by overexpression of the IL-6 and IL-6 receptor genes that mimics lymphocytic interstitial pneumonia.

[Long-term hemodialysis treatment using femoral vein puncture method (FV-method) as blood access in 12 patients]

It is well known that blood access is essential for long-term hemodialysis treatment. Arteriovenouos fistula (AVF) is the most widely used method. However, this method of access frequently fails (access failure) as a result of stenosis. We attempt simple femoral vein puncture (FV-method) instead of AVF in such patients and have experienced 12 patients who were undergoing hemodialysis treatment using the FV-method, three times a week for more than one year. We devised special needles (18- and 19-gauge) for the FV-method. Generally, we use a 19-gauge needle with 4 side holes. We discuss here the results of 12 patients consisting of 4 males and 8 females with a mean age of 57.9 years, a mean duration of dialysis of 10.0 years, and a mean duration of FV-method of 3.5 years. Their underlying diseases were chronic glomerulonephritis (9 patients), diabetic nephropathy (2 patients) and nephrosclerosis (1 patient). Before the use of the FV-method, AVFs were attempted a man of 3.8 times and an artificial graft, 4 times in 3 patients. Ten patients were outpatients and 2 were inpatients. As for the indications of the FV-method, 11 patients had access failure and another had suffered from heart failure resulting from an over flow of blood through AVF. KT/V, PCR and TACBUN were measured monthly and were within the normal range in almost all of the patients. Concerning complications of the FV-method, hematoma formation after detachment of the needle at the end of dialysis and pain at needle puncture were sometimes noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased levels of Epstein-Barr virus DNA in lacrimal glands of Sjögren's syndrome patients

Many Sjögren's syndrome patients complain primarily of dry eye. Epstein-Barr virus DNA has recently been found in the lacrimal glands of Sjögren's syndrome sufferers and normal individuals, and lacrimal glands are thought to be a target organ for latent Epstein-Barr virus infection. In this study, we performed lacrimal and salivary gland biopsies on 9 Sjögren's syndrome patients. Extracted Epstein-Barr virus DNA was assayed by polymerase chain reaction and compared to that of healthy individuals. An increased level of Epstein-Barr virus DNA was observed in all of the lacrimal glands and 8 of the 9 salivary glands from the Sjögren's syndrome patients. However, the amount of genome in the lacrimal gland was more than 10 times that in the salivary glands, not only in the Sjögren's syndrome patients but also in the controls. This may explain the pathogenesis of dry eye in patients with Sjögren's syndrome, and why the lacrimal gland tends to be so prominently affected. It may also suggest a therapeutic approach for this and possibly other types of dry eye.