Accumulation of common T cell clonotypes in the salivary glands of patients with human T lymphotropic virus type I-associated and idiopathic Sjögren's syndrome

Potential common molecular mechanisms between Sjögren syndrome and inclusion body myositis: a bioinformatic analysis and in vivo validation

Background

Inclusion body myositis (IBM) is a slowly progressive inflammatory myopathy that typically affects the quadriceps and finger flexors. Sjögren's syndrome (SS), an autoimmune disorder characterized by lymphocytic infiltration of exocrine glands has been reported to share common genetic and autoimmune pathways with IBM. However, the exact mechanism underlying their commonality remains unclear. In this study, we investigated the common pathological mechanisms involved in both SS and IBM using a bioinformatic approach.

Methods

IBM and SS gene expression profiles were obtained from the Gene Expression Omnibus (GEO). SS and IBM coexpression modules were identified using weighted gene coexpression network analysis (WGCNA), and differentially expressed gene (DEG) analysis was applied to identify their shared DEGs. The hidden biological pathways were revealed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Furthermore, protein-protein interaction (PPI) networks, cluster analyses, and hub shared gene identification were conducted. The expression of hub genes was validated by reverse transcription quantitative polymerase chain reaction (RT-qPCR). We then analyzed immune cell abundance patterns in SS and IBM using single-sample gene set enrichment analysis (ssGSEA) and investigated their association with hub genes. Finally, NetworkAnalyst was used to construct a common transcription factor (TF)-gene network.

Results

Using WGCNA, we found that 172 intersecting genes were closely related to viral infection and antigen processing/presentation. Based on DEG analysis, 29 shared genes were found to be upregulated and enriched in similar biological pathways. By intersecting the top 20 potential hub genes from the WGCNA and DEG sets, three shared hub genes (PSMB9, CD74, and HLA-F) were derived and validated to be active transcripts, which all exhibited diagnostic values for SS and IBM. Furthermore, ssGSEA showed similar infiltration profiles in IBM and SS, and the hub genes were positively correlated with the abundance of immune cells. Ultimately, two TFs (HDGF and WRNIP1) were identified as possible key TFs.

Conclusion

Our study identified that IBM shares common immunologic and transcriptional pathways with SS, such as viral infection and antigen processing/presentation. Furthermore, both IBM and SS have almost identical immune infiltration microenvironments, indicating similar immune responses may contribute to their association.

Role of Viral Infections in the Pathogenesis of Sjögren's Syndrome: Different Characteristics of Epstein-Barr Virus and HTLV-1

Viruses are possible pathogenic agents in several autoimmune diseases. Sjögren’s syndrome (SS), which involves exocrine dysfunction and the appearance of autoantibodies, shows salivary gland- and lacrimal gland-oriented clinical features. Epstein-Barr virus (EBV) is the most investigated pathogen as a candidate that directly induces the phenotype found in SS. The reactivation of the virus with various stimuli induced a dysregulated form of EBV that has the potential to infect SS-specific B cells and plasma cells that are closely associated with the function of an ectopic lymphoid structure that contains a germinal center (GC) in the salivary glands of individuals with SS. The involvement of human T-cell leukemia virus type 1 (HTLV-1) in SS has been epidemiologically established, but the disease concept of HTLV-1-associated SS remains unexplained due to limited evidence from basic research. Unlike the cell-to-cell contact between lymphocytes, biofilm-like structures are candidates as the mode of HTLV-1 infection of salivary gland epithelial cells (SGECs). HTLV-1 can infect SGECs with enhanced levels of inflammatory cytokines and chemokines that are secreted from SGECs. Regardless of the different targets that viruses have with respect to affinitive lymphocytes, viruses are involved in the formation of pathological alterations with immunological modifications in SS.

What is the evidence for Sjögren's syndrome being triggered by viral infection? Subplot: infections that cause clinical features of Sjögren's syndrome

PURPOSE OF REVIEW

To clarify the involvement of viral infections in the pathogenesis of Sjögren's syndrome and to discuss whether viruses can be a trigger for the development of Sjögren's syndrome.

RECENT FINDINGS

Although some viruses are candidate triggers of Sjögren's syndrome, we focus on human T lymphotropic virus type I (HTLV-I). Clinicoepidemiological studies show a relationship between HTLV-I and Sjögren's syndrome with a low frequency of salivary gland damage in magnetic resonance imaging, autoantibody production and ectopic germinal center in HTLV-I-associated myelopathy (HAM) patients with Sjögren's syndrome. Our recent study showed that HTLV-I has the potential to infect salivary gland epithelial cells (SGECs). After a coculture of HCT-5 (an HTLV-I-infected T-cell line derived from the cerebrospinal fluid) of an HAM patient and SGECs, we observed time-dependent increases in the levels of soluble intracellular adhesion molecule1, interferon gamma-induced protein 10 kDa and regulated on activation, normal T-cell expressed and secreted. In addition, SGECs themselves express these molecules along with the expression of HTLV-I proteins.

SUMMARY

HTLV-I is involved in the pathogenesis of HTLV-I-seropositive patients with Sjögren's syndrome. By infecting CD4 T cells in vivo, HTLV-I induces specific clinicopathological conditions. In addition, HTLV-I-infected SGECs have the potential to augment the expression of molecules involved in cell adhesion, inflammation and migration.

Single-cell analysis of glandular T cell receptors in Sjögren's syndrome

CD4⁺ T cells predominate in salivary gland (SG) inflammatory lesions in Sjögren's syndrome (SS). However, their antigen specificity, degree of clonal expansion, and relationship to clinical disease features remain unknown. We used multiplex reverse-transcriptase PCR to amplify paired T cell receptor α (TCRα) and β transcripts of single CD4⁺CD45RA^- T cells from SG and peripheral blood (PB) of 10 individuals with primary SS, 9 of whom shared the HLA DR3/DQ2 risk haplotype. TCRα and β sequences were obtained from a median of 91 SG and 107 PB cells per subject. The degree of clonal expansion and frequency of cells expressing two productively rearranged α genes were increased in SG versus PB. Expanded clones from SG exhibited complementary-determining region 3 (CDR3) sequence similarity both within and among subjects, suggesting antigenic selection and shared antigen recognition. CDR3 similarities were shared among expanded clones from individuals discordant for canonical Ro and La autoantibodies, suggesting recognition of alternative SG antigen(s). The extent of SG clonal expansion correlated with reduced saliva production and increased SG fibrosis, linking expanded SG T cells with glandular dysfunction. Knowledge of paired TCRα and β sequences enables further work toward identification of target antigens and development of novel therapies.

Loss of interleukin-21 leads to atrophic germinal centers in multicentric Castleman's disease

Both multicentric Castleman's disease (MCD) and immunoglobulin (Ig)G4-related disease (IgG4-RD) are systemic diseases, presenting with hypergammaglobulinemia and elevated serum levels of IgG4. However, with regard to histopathological findings, MCD shows atrophic germinal centers. On the other hand, expanded germinal centers are detected in IgG4-RD. We extracted germinal centers from specimens of each disorder by microdissection and analyzed the expression of mRNAs by real-time polymerase chain reaction to clarify the mechanisms underlying atrophied germinal centers in MCD. This analysis disclosed loss of interleukin (IL)-21 and B cell lymphoma (Bcl)-6 in the germinal centers of MCD. Loss of IL-21 is considered to be involved in the disappearance of Bcl-6 and leads to atrophied germinal centers in MCD.

Beyond the Glands: An in-Depth Perspective of Neurological Manifestations in Sjögren's Syndrome

Primary Sjögren’s Syndrome (pSjS) is an autoimmune disease characterized by sicca (xerophthalmia or xerostomia) symptoms, anti-SS-A (Ro) or anti-SS-B (La) autoantibodies, and lymphocytic infiltrates in the exocrine glands. Disease incidence is estimated to be 0.1–3% of the general population with 0.4–3.1 million individuals in the US with women being nine times more likely to be afflicted with SjS than men. The frequency continues to rise accompanied with the multi-factorial etiology making it a challenging disease to manage and treat. Treatment of this disease remains problematic due to the lack of therapeutic treatments relying on replacement therapies such as artificial saliva and eye lubricants or immunosuppressive agents. To further complicate the management of the disease, there are number of multi-systemic manifestations specifically peripheral neuropathy associated with later stage of disease onset. Increasingly, there is mounting evidence that suggests the involvement of central nervous system. It remains to be determined the underlying cause and effect of the dysregulated immune response and the neuropathy associated with SjS. In this review, we provided an in-depth look at key neurological dysfunctions documented to occur in pSjS. Specifically, we discussed the prevalence, symptomology, and current treatments.

Autoimmunity and infection in Sjögren's syndrome

PURPOSE OF REVIEW

To summarize the recent developments concerning the potential viral pathomechanisms and involvement of viruses in Sjögren's syndrome, and to highlight the areas for future research and therapies.

RECENT FINDINGS

Activated IFN-1 pathway plays an important part in the autoimmune disease process of Sjögren's syndrome; therefore, several therapies aiming to reduce or inhibit the IFN-1 production and its effects may be a target for future treatment plans. Activated aryl hydrocarbon receptor may interact with latent Epstein-Barr virus (EBV) infection, which in turn may predispose to the development of Sjögren's syndrome. It is estimated that the population is 95% positive for EBV serology. Microbial factors may incite autoimmune disease. Although this hypothesis is proven in a few illnesses such as rheumatic fever, there is no definitive evidence of an infectious environmental trigger in Sjögren's syndrome. However, there are circumstantial data with regard to viruses and several potential mechanisms of disease. These include antigen mimicry, polyclonal lymphocyte activation, and infection-mediated innate end-organ inflammation. In addition, hepatitis C virus infection clearly causes a Sjögren's-syndrome-like illness.

SUMMARY

Data continue to implicate viral infection in the cause of Sjögren's syndrome, but there are no definitive studies incriminating a particular virus.

Selective localization of T helper subsets in labial salivary glands from primary Sjögren's syndrome patients

The aim of this study was to investigate the initiation and progression of autoimmune damage in the lesions of labial salivary glands (LSGs) from primary Sjögren's syndrome (SS) patients by examining the selective localization of T helper (Th) subsets such as Th1, Th2, Th17 regulatory T cells (T_regs) and follicular T helper cells (Tfh). The expression of cytokines and transcription factors associated with these Th subsets in the LSGs from 54 SS patients and 16 healthy controls was examined using real-time polymerase chain reaction (PCR) and immunostaining. Additionally, infiltrating lymphocytes without germinal centre (GC^-) and with GC (GC⁺) in the LSGs specimens from eight SS patients were extracted selectively by laser capture microdissection (LCM). The mRNA expression of these molecules was compared between the two sample groups of GC^- and GC⁺ by real-time PCR. The mRNA expression of cytokines and transcription factors of all T helper (Th) subsets in the LSGs from the SS patients was increased significantly in comparison with controls. In LSGs from the SS patients, Th2 and Tfh was associated closely with strong lymphocytic infiltration; however, Th1, Th17 and T_regs was not. In the selectively extracted lesions of LSGs, Th1 and Th17-related molecules were detected strongly in the GC^-, while Th2 and Tfh-related molecules were detected in the GC⁺. In contrast, no significant association with strong lymphocytic infiltration was observed in T_reg-related molecules. These results indicate that SS has selective localization of Th subsets such as Th1, Th2, Th17 and Tfh in the LSGs, which is associated closely with disease severity and/or status. SS might be initiated by Th1 and Th17 cells, and then progressed by Th2 and Tfh cells via GC formation.

Cytokine/chemokine profiles contribute to understanding the pathogenesis and diagnosis of primary Sjögren's syndrome

To investigate the pathogenesis of localized autoimmune damage in Sjögren's syndrome (SS) by examining the expression patterns of cytokines, chemokines and chemokine receptors at sites of autoimmune damage. mRNA expression of these molecules in the labial salivary glands (LSGs) and peripheral blood mononuclear cells (PBMCs) from 36 SS patients was examined using a real-time polymerase chain reaction-based method. Subsets of the infiltrating lymphocytes and chemokines/chemokine receptors expression in the LSG specimens were examined by immunohistochemistry. Cytokines/chemokine concentrations in the saliva were analysed using flow cytometry or enzyme-linked immunosorbent assay. mRNA expression of T helper type 1 (Th1) cytokines, chemokines and chemokine receptors was higher in LSGs than in PBMCs. In contrast, mRNA expression of Th2 cytokines, chemokines [thymus and activation-regulated chemokine (TARC/CCL17), macrophage-derived chemokine (MDC/CCL22)] and chemokine receptor (CCR4) was associated closely with strong lymphocytic accumulation in LSGs. Furthermore, TARC and MDC were detected immunohistochemically in/around the ductal epithelial cells in LSGs, whereas CCR4 was detected on infiltrating lymphocytes. The concentrations of these cytokines/chemokines were significantly higher in the saliva from SS patients than those from controls, and the concentrations of Th2 cytokines/chemokines were associated closely with strong lymphocytic accumulation in LSGs. These results suggest that SS might be initiated and/or maintained by Th1 and Th17 cells and progress in association with Th2 cells via the interaction between particular chemokines/chemokine receptors. Furthermore, the measurement of cytokines/chemokines in saliva is suggested to be useful for diagnosis and also to reveal disease status.

Possible involvement of cytokines, chemokines and chemokine receptors in the initiation and progression of chronic GVHD

Chronic GVHD (cGVHD) after allogeneic hematopoietic SCT (HSCT) is characterized by an infiltration of T cells into target organs including the oral mucosa and salivary glands. This study was designed to clarify the molecular mechanism of the local accumulation of pathogenic T cells in cGVHD. The expression of cytokines, chemokines and chemokine receptors in the buccal mucosa (BM), labial salivary glands (LSG) and PBMC from 16 patients with cGVHD after allogeneic HSCT was examined. The mRNA expression of T helper 1 (Th1) and Th2 cytokines, and several chemokines and chemokine receptors was significantly increased in the BM and LSG from cGVHD patients, in comparison with both those in the BM and LSG from controls, respectively, and also with those in the PBMC from cGVHD patients. Furthermore, the mRNA expression of Th2 cytokines, macrophage-derived chemokine and CC chemokine receptor 4 was closely associated with a strong T-cell infiltration in the BM and LSG from cGVHD patients. These results suggest that cGVHD might be initiated and/or maintained by Th1/Th0 cells and thereafter progresses in association with Th2 cell accumulation via the interaction of particular chemokine and chemokine receptors.

Detection of HTLV-1 in the Labial Salivary Glands of Patients with Sjögren’s Syndrome: A Distinct Clinical Subgroup?

Objective.

To examine whether patients with Sjögren’s syndrome (SS) can be distinguished based on the expression of human T cell lymphotrophic virus type I (HTLV-1) and, if so, whether the subgroups differ in their clinical features and serological measures.

Methods.

Polymerase chain reaction (PCR) and nested PCR were used to amplify viral DNA from peripheral blood mononuclear cells (PBMC) in 53 patients with SS, using primers from the HTLV-1 pX, p19, pol, and tax regions. Minor salivary gland biopsy specimens from 33 patients with SS were examined for the presence of HTLV-1 p19 or tax proteins immunohistochemically. The sociodemographic, glandular, and extraglandular manifestations, and laboratory findings including autoantibodies, complement, and immunoglobulin levels, were analyzed.

Results.

The HTLV-1 tax gene was detected in PBMC samples from 2 of 53 patients (3.8%), whereas the HTLV-1 pX, p19, and pol genes were not expressed. As well, 100% of PBMC samples from 4 family members of patients in whom the tax gene was detected also expressed the tax gene. Immunohistochemical staining for HTLV-1 p19 and tax was seen in 10 out of 33 (30.3%) patients with SS each. Overall, 14 (42.4%) patients expressed HTLV-1 p19 or tax proteins, and they had lower rheumatoid factor and C3 levels (p = 0.015 and p = 0.005, respectively) and higher lymphocyte counts (p = 0.016). The prevalence of glandular and extraglandular manifestations did not differ between the HTLV-1-positive and negative patients.

Conclusion.

Our findings suggest that HTLV-1 in the salivary glands is involved in the pathogenesis of a subpopulation of SS, and HTLV-1-associated SS might have different immunological patterns than idiopathic SS.

Th2 and regulatory immune reactions contribute to IgG4 production and the initiation of Mikulicz disease

OBJECTIVE

Mikulicz disease has been considered to be a subtype of Sjögren's syndrome (SS). However, recent studies have suggested that Mikulicz disease is an IgG4-related disease and is distinguishable from SS. In addition, it has been reported that both interleukin-4 (IL-4) and IL-10 induce IgG4 production and inhibit IgE. This study was undertaken to examine the expression of these cytokines in patients with Mikulicz disease and patients with SS.

METHODS

Labial salivary gland (LSG) sections from 15 patients with Mikulicz disease and 18 patients with SS were examined for subsets of the infiltrating lymphocytes, expression patterns of messenger RNA (mRNA) for cytokines/chemokines, and relationships between the IgG4:IgG ratio and the expression of mRNA for IL-4 or IL-10.

RESULTS

Immunohistochemical analysis showed lymphocyte infiltration of various subsets in the LSGs of SS patients, and the selective infiltration of IgG4-positive plasma cells and Treg cells in the LSGs of Mikulicz disease patients. The levels of mRNA for both Th1 and Th2 cytokines and chemokines in LSGs from patients with SS were significantly higher than in controls, while the expression of both Th2 and Treg cells was significantly higher in the patients with Mikulicz disease than in controls. Furthermore, the expression of IL-4 or IL-10 in the LSGs was correlated with the IgG4:IgG ratio.

CONCLUSION

These results suggest that the pathogenesis of Mikulicz disease is different from that of SS. Mikulicz disease is a unique inflammatory disorder characterized by Th2 and regulatory immune reactions that might play key roles in IgG4 production.

Human T-lymphotropic virus 1 (HTLV-1) infection--dermatological implications

Human T-lymphotropic virus type 1 (HTLV-1) is a type C retrovirus primarily endemic to Japan, Central and South America, the Middle East, regions of Africa, and the Caribbean. Currently, an estimated 10-20 million people worldwide are infected with this virus. Although the majority of infected individuals remain asymptomatic, HTLV-1 is the causative agent of a number of disorders, notably adult T-cell leukemia/lymphoma (ATLL) and a progressive demyelinating neurological disorder, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). In addition to ATLL and HAM/TSP, HTLV-1 has been associated with a spectrum of skin disorders, such as infective dermatitis associated with HTLV-1, crusted scabies, and leprosy. The understanding of the interaction between virus and host response has improved markedly, but there are still few treatment options.

Is Sjögren's syndrome a retroviral disease?

Circumstantial evidence suggests that retroviruses play a role in the pathogenesis of Sjögren's syndrome. Such evidence, derived from studies of patients with Sjögren's syndrome, includes the following: the presence of serum antibodies cross-reactive with retroviral Gag proteins; the occurrence of reverse transcriptase activity in salivary glands; the detection of retroviral antigens, retrovirus-like particles, or novel retroviral sequences in salivary glands; the occurrence of Sjögren's syndrome-like illnesses in patients having confirmed systematic infections with retroviruses such as human immunodeficiency virus-1 (HIV-1) and human T lymphotropic virus type 1; and the beneficial effect of anti-retroviral treatment on the occurrence of HIV-1-associated sicca syndrome. Additional evidence is provided by animal models.

Bias in the αβ T-cell repertoire: implications for disease pathogenesis and vaccination

The naïve T-cell repertoire is vast, containing millions of unique T-cell receptor (TCR) structures. Faced with such diversity, the mobilization of TCR structures from this enormous pool was once thought to be a stochastic, even chaotic, process. However, steady and systematic dissection over the last 20 years has revealed that this is not the case. Instead, the TCR repertoire deployed against individual antigens is routinely ordered and biased. Often, identical and near-identical TCR repertoires can be observed across different individuals, suggesting that the system encompasses an element of predictability. This review provides a catalog of αβ TCR bias by disease and by species, and discusses the mechanisms that govern this inherent and widespread phenomenon.

Salivary anti-Ro60 and anti-Ro52 antibody profiles to diagnose Sjogren's Syndrome

Simple and non-invasive saliva-based diagnostics may be useful for the identification, understanding, and monitoring of autoimmune and infectious diseases. Previously, Luciferase Immunoprecipitation Systems (LIPS) were used for sensitive detection of patient serum autoantibodies in Sjögren's Syndrome (SjS), a chronic autoimmune disease affecting the salivary and lacrimal glands. Here we explored the ability of LIPS to diagnose SjS based on IgG autoantibodies in patient saliva. From LIPS testing, anti-Ro60 autoantibodies were detected in the saliva of 70% (19/27) of SjS patients with 96% specificity. Positive anti-Ro60 autoantibodies were also found in 70% of the matched serum samples (96% specificity). LIPS detected Ro52 autoantibodies in the saliva and serum of 67% of SjS patients with 100% specificity. Overall, the autoantibody titers in saliva were approximately 4000-fold lower by volume than serum, but still distinguished seropositive patients from controls. These results suggest that LIPS salivary-based testing for SjS autoantibodies is a practical alternative to serum and compatible with point-of-care testing.

Peripheral CD4+ T cells showing a Th2 phenotype in a patient with Mikulicz's disease associated with lymphadenopathy and pleural effusion

Mikulicz's disease (MD) is a unique IgG4-related systemic disease indicated by enlargement of the lachrymal and salivary glands and which differs substantially from Sjögren's syndrome. A male patient with pleural effusion, swelling of the submandibular glands, and swelling of the paraaortic, mediastinal, and pararenal lymph nodes was diagnosed with MD. Analysis of peripheral CD4+ T cells from the patient revealed deviation of the Th1/Th2 balance to Th2. Prednisolone therapy ameliorated the disease and corrected the Th1/Th2 imbalance.

Tropical Spastic Paraparesis/Human T Leukemia Virus Type 1--Associated Myelopathy in HIV Type 1--Coinfected Patients

BACKGROUND

Tropical spastic paraparesis/human T leukemia virus type 1 (HTLV-1)-associated myelopathy (TSP/HAM) is rarely reported in the United States. The causative agents of TSP/HAM are HTLV-1 and, possibly, its cosmopolitan variant, human T leukemia virus type 2 (HTLV-2). Among HTLV-1- or HTLV-2-monoinfected individuals, the estimated lifetime risk for development of TSP/HAM is <2%. However, it has been suggested that HIV/HTLV coinfection may increase the risk for development of TSP/HAM.

METHODS

A total of 2239 human immunodeficiency virus (HIV)-infected patients were tested for HTLV-1 and HTLV-2 infection at the New Orleans Outpatient Clinic (Louisiana) during the period 1991-1998. HTLV-1-infected patients with suspected myelopathy were referred for additional evaluation.

RESULTS

Four cases of TSP/HAM (9.7%) were identified among 41 individuals with Western blot-confirmed HTLV-1 infection. The diagnosis was confirmed with use of molecular diagnostic assays and viral isolation. No TSP/HAM cases were identified among 65 patients with HIV-HTLV-2 coinfection. An additional patient with HIV-HTLV-1 coinfection also received a diagnosis of TSP/HAM at the New Orleans Veteran's Affairs HIV Outpatient Clinic (Louisiana). All patients had normal CD4+ T cell counts at the time of diagnosis.

CONCLUSIONS

Given the high rates of HIV-HTLV coinfection in the United States, a heightened suspicion for TSP/HAM should be considered in HIV-infected patients who present with normal CD4+ T cell counts and myelopathy in the absence of other acquired immunodeficiency syndrome-defining conditions.

Lamivudine is not effective in primary Sjögren's syndrome

BACKGROUND

Retroviral infection has been implicated in the pathogenesis of primary Sjögren's syndrome.

OBJECTIVE

To examine the efficacy of the reverse transcriptase inhibitor lamivudine in patients with this syndrome.

METHODS

16 patients with primary Sjögren's syndrome were randomised to receive either lamivudine 150 mg twice daily or placebo for three months. Measures of lacrimal and salivary function, including minor salivary gland biopsies, were obtained before and after treatment.

RESULTS

Treatment with lamivudine did not result in significant improvement in the primary outcome measure of unstimulated whole salivary flow or other secondary measures, including minor salivary gland biopsy focus scores.

CONCLUSION

Lamivudine is not effective in patients with primary Sjögren's syndrome, suggesting either that a retroviral aetiology is not present or that it may be important only in early disease.

Increased proviral load in HTLV-1-infected patients with rheumatoid arthritis or connective tissue disease

BACKGROUND

Human T-lymphotropic virus type 1 (HTLV-1) proviral load is related to the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and has also been shown to be elevated in the peripheral blood in HTLV-1-infected patients with uveitis or alveolitis. Increased proliferation of HTLV-1-infected cells in, or migration of such cells into, the central nervous system is also seen in HAM/TSP. In the present study, we evaluated the proviral load in a cohort of HTLV-1-infected patients with arthritic conditions.

RESULTS

HTLV-1 proviral load in the peripheral blood from 12 patients with RA and 6 patients with connective tissue disease was significantly higher than that in matched asymptomatic HTLV-1 carriers, but similar to that in matched HAM/TSP controls. HAM/TSP was seen in one-third of the HTLV-1-infected patients with RA or connective tissue disease, but did not account for the higher proviral load compared to the asymptomatic carrier group. The proviral load was increased in the synovial fluid and tissue from an HTLV-1-infected patient with RA, the values suggesting that the majority of infiltrated cells were HTLV-1-infected. In the peripheral blood from HTLV-1-infected patients with RA or connective tissue disease, HTLV-1 proviral load correlated with the percentages of memory CD4+ T cells and activated T cells, and these percentages were shown to be markedly higher in the synovial fluid than in the peripheral blood in an HTLV-1-infected patient with RA.

CONCLUSIONS

These biological findings are consistent with a role of the retrovirus in the development of arthritis in HTLV-1-infected patients. A high level of HTLV-1-infected lymphocytes in the peripheral blood and their accumulation in situ might play a central role in the pathogenesis of HTLV-1-associated inflammatory disorders. Alternatively, the autoimmune arthritis, its etiological factors or treatments might secondarily enhance HTLV-1 proviral load.

Adult T-cell leukemia predominantly involving exocrine glands

OBJECTIVES

We describe a rare case of adult T-cell leukemia (ATL) presenting with dry mouth and swelling of bilateral parotid and submandibular glands. The unusual involvement of these exocrine glands by malignant cells prompted us to conduct a detail characterization of these infiltrating and circulating leukemic T cells, which may provide insight to the pathogenesis of exocrine involvement in ATL.

METHODS

Immunophenotyping of peripheral ATL cells and microscopic examinations of various organs prepared by autopsy were performed. Analysis of the repertoire of T-cell receptor (TCR) of parotid gland-infiltrating ATL cells using molecular and immunohistochemical examinations were also performed.

RESULTS

Microscopic examinations of various organs prepared by autopsy revealed the predominant and specific exocrine gland infiltration of ATL cells. Reverse transcription-polymerase chain reaction (RT-PCR) followed by both TCR spectratyping and complementary determining region (CDR)-3 sequencing analysis of TCR Vbeta of parotid gland-infiltrating T cells revealed a relatively restricted but not single usage of TCR Vbeta. Immunohistochemical analyses of parotid gland specimens detected only a small number of TCR Valphabeta-positive cells in parotid gland-infiltrating ATL cells.

CONCLUSIONS

The predominant infiltration of ATL cells in exocrine glands implied that these T cells recognized exocrine gland-specific antigen. However, the absence of both TCR Vbeta mRNA transcripts and TCR Valphabeta protein expression in most ATL cells suggested that antigen recognition via TCR may not have played a major role in adhesion and subsequent infiltration into the exocrine glands in this patient. These results provide important background information to further elucidate the pathogenesis of exocrine gland-specific inflammation.

Accumulation of oligoclonal T cells in the infiltrating lymphocytes in oral lichen planus

BACKGROUND

Identification of a disease-specific and possibly pathogenic T-cell receptor (TCR) in oral lichen planus (OLP) is one of the most important steps to reveal the pathogenic antigen recognized by the T cells and thereby elucidate the pathogenesis and etiology of OLP.

METHODS

In buccal mucosa biopsy specimens and peripheral blood mononuclear cells (PBMC) from seven patients with OLP, the TCR V beta gene usage was examined by polymerase chain reaction-based and single-strand conformation polymorphism analyses.

RESULTS

The V beta families expressed in the biopsy specimens were markedly heterogeneous, but they were restricted in comparison to those observed in the PBMC. The V beta families predominantly expressed in the biopsy specimens in comparison with the PBMC were still heterogeneous in individual patients and differed from patient to patient; however, V beta 2, V beta 6, and V beta 19 were commonly predominant in the biopsy specimens from more than half of the patients. Among the V beta families predominantly expressed in the biopsy specimens, the accumulation of T-cell clonotypes was observed in the majority of the V beta families including V beta 6 and V beta 19; however, it was not observed in the minority of the V beta families including V beta 2.

CONCLUSIONS

These results suggest that unique T-cell populations bearing V beta 2, V beta 6, or V beta 19 gene products tend to expand in OLP lesions as a consequence of in situ stimulation with a restricted epitope of either a nominal antigen on the MHC molecule for the majority of the V beta families, even if only in minor populations, or of a common superantigen for the minority of the V beta families.

T-cell receptor V? gene usage by T cells reactive with the tumor-rejection antigen SART-1 in oral squamous cell carcinoma

We recently described that the SART-1(690-698) peptide could induce HLA-A24-restricted cytotoxic T lymphocytes (CTLs), which recognize the SART-1(259) (+) tumor cells from peripheral blood mononuclear cells (PBMCs) of HLA-A24(+) cancer patients. In our study, in 5 of 14 HLA-A24(+) patients with oral squamous cell carcinomas (SCCs), CTLs could be induced with the SART-1(690-698) peptide from the PBMCs. In 2 of the patients from whom the highest CTL activities were induced, the T-cell receptor (TCR) Vbeta repertoire expressed by the SART-1(690-698)-specific CTLs was found to be restricted and multiple Vbeta families were predominantly expressed in each patient. Although the predominant Vbeta families were different between the 2 patients, Vbeta7 was highly and commonly predominant. The same predominant Vbeta families were also detected in the tumor-infiltrating lymphocytes (TILs) from each patient, and each Vbeta family contained one or more unique T-cell clonotypes. The unique T-cell clonotypes were found to be common between the TILs and SART-1(690-698)-specific CTLs from each patient, and especially 2 T-cell clonotypes with Vbeta7 were identical even in the 2 patients. One of the 2 T-cell clonotypes with Vbeta7 was detected in the TILs from 11 of 14 HLA-A24(+) patients and another was found in those from 8 of HLA-A24(+) patients, while none of 10 HLA-A24(-) patients demonstrated both T-cell clonotypes. These results strongly suggest that the T-cell clonotypes with Vbeta7 are major TCR Vbeta genes expressed by SART-1(690-698)-specific CTLs. Furthermore, autologous tumor cells from one of the HLA-A24(+) patients stimulated the PBMCs and regional lymph node cells (LNCs) to expand the same T-cell clonotypes as those in the SART-1(690-698)-specific CTLs. These results strongly suggest that the SART-1(690-698)-specific CTLs clearly accumulate in vivo, especially in the TILs, as a consequence of in situ antigenic stimulation by autologous tumor cells. The identification of the unique TCR Vbeta genes used by SART-1(259)-specific CTLs should help to improve the diagnosis of the specific immune response in patients with SART-1(259) (+) cancers, especially during anticancer immunotherapy.

Sjögren syndrome

Sjögren syndrome is a chronic systemic disease characterized by polyglandular tissue destruction leading to keratoconjunctivitis sicca (KCS) and xerostomia. Patients with primary Sjögren syndrome show evidence of KCS and xerostomia, whereas patients with secondary Sjögren syndrome suffer from KCS, xerostomia, and an autoimmune disease, most commonly rheumatoid arthritis. Certain factors cause autoimmune dysregulation leading to destruction of the acinar cells and ductal epithelia with subsequent dry eyes and dry mouth. Activated lymphocytes in patients with autoimmune diseases appear to have selective homing into the lacrimal and salivary glands leading to tissue damage. Understanding the factors involved in the immune dysregulation may improve our diagnostic and therapeutic approaches in Sjögren syndrome. Current therapeutic measures include means to increase secretion, relieve symptoms, and repair damage of the ocular surface.

Update in Sjögren syndrome

Sjögren syndrome (SS), the second most common autoimmune rheumatic disease, refers to keratoconjunctivitis sicca and xerostomia resulting from immune lymphocytes that infiltrate the lacrimal and salivary glands. However, differential diagnosis remains confusing due to the high prevalence of vague symptoms of dryness, fatigue, and myalgias in the general population. The problems of diagnosis are further compounded by the finding of "positive" antinuclear antibodies in a high percent of the general population. Unless minor salivary gland biopsies are read by experienced observers, nonspecific changes of sialadenitis are frequently confused with the focal lymphocytic infiltrates that are characteristic of SS. The distinction between fibromyalgia patients with low titer antinuclear antibodies and primary SS remains difficult. Even in patients fulfilling strict criteria for SS, the genomic search for critical genes has proven difficult due to the multigenic pattern of inheritance and strong role of currently undefined environmental factors. No single environmental factor has been detected in the majority of SS patients. SS-like syndrome has been detected in certain patients with HTLV-1 and hepatitis C infection, providing clues to pathogenesis. Even in SS patients with marked sicca symptoms, minor salivary gland biopsy shows that almost 50% of glandular cells are still detected on biopsy. These results imply the importance of immune factors such as cytokines and autoantibodies in decreasing neuro-secretory circuits and induction of glandular dysfunction. Of potential importance, an antibody against muscarinic M3 receptor that can decrease secretory function when injected into rodents is frequently found in the sera of SS patients. Newly developed topical and oral therapies can ease the oral and ocular dryness. Orally administered agonists of the muscarinic M3 receptor (pilocarpine and cevimeline) have recently been approved by the US Food and Drug Administration to increase salivary secretion. Topical ocular use of low-dose corticosteroids or cyclosporin may decrease conjunctival surface inflammation. In a Phase II double-blind study, orally administered interferon alpha (150 U) led to improved saliva flow and symptoms. In pregnant patients with evidence of fetal distress, oral dexamethasone is preferred because this agent crosses the placenta effectively. In animal models, antagonists of tumor necrosis factor and inhibitors of de novo pyrimidine synthesis appear promising.