Immunopathological mechanisms of human T cell lymphotropic virus type 1 (HTLV-I) uveitis. Detection of HTLV-I-infected T cells in the eye and their constitutive cytokine production

Human T-cell Leukemia Virus Type 1 (HTLV-1)-induced Uveitis

Human T-cell leukemia virus type 1 (HTLV-1) is a human retrovirus that causes T-cell malignant diseases (adult T-cell leukemia/lymphoma) and HTLV-1-related non-malignant inflammatory diseases, such as HTLV-1 uveitis. Although the symptoms and signs of HTLV-1 uveitis are nonspecific, intermediate uveitis with various degrees of vitreous opacity is the most common clinical presentation. It can occur in one or both eyes and its onset is acute or subacute. Intraocular inflammation can be managed with topical and/or systemic corticosteroids; however, recurrence of uveitis is common. The visual prognosis is generally favorable, but a certain proportion of patients have a poor visual prognosis. Systemic complications of patients with HTLV-1 uveitis include Graves' disease and HTLV-1-associated myelopathy/tropical spastic paraparesis. This review describes the clinical characteristics, diagnosis, ocular manifestations, management, and immunopathogenic mechanisms of HTLV-1 uveitis.

Safety of intraocular anti-VEGF antibody treatment under in vitro HTLV-1 infection

Introduction

HTLV-1 (human T-cell lymphotropic virus type 1) is a retrovirus that infects approximately 20 million people worldwide. Many diseases are caused by this virus, including HTLV-1-associated myelopathy, adult T-cell leukemia, and HTLV-1 uveitis. Intraocular anti-vascular endothelial growth factor (VEGF) antibody injection has been widely used in ophthalmology, and it is reportedly effective against age-related macular degeneration, complications of diabetic retinopathy, and retinal vein occlusions. HTLV-1 mimics VEGF₁₆₅, the predominant isoform of VEGF, to recruit neuropilin-1 and heparan sulfate proteoglycans. VEGF₁₆₅ is also a selective competitor of HTLV-1 entry. Here, we investigated the effects of an anti-VEGF antibody on ocular status under conditions of HTLV-1 infection in vitro.

Methods

We used MT2 and TL-Om1 cells as HTLV-1-infected cells and Jurkat cells as controls. Primary human retinal pigment epithelial cells (HRPEpiCs) and ARPE19 HRPEpiCs were used as ocular cells; MT2/TL-Om1/Jurkat cells and HRPEpiCs/ARPE19 cells were co-cultured to simulate the intraocular environment of HTLV-1-infected patients. Aflibercept was administered as an anti-VEGF antibody. To avoid possible T-cell adhesion, we lethally irradiated MT2/TL-Om1/Jurkat cells prior to the experiments.

Results

Anti-VEGF antibody treatment had no effect on activated NF-κB production, inflammatory cytokines, chemokines, HTLV-1 proviral load (PVL), or cell counts in the retinal pigment epithelium (RPE) under MT2 co-culture conditions. Under TL-Om1 co-culture conditions, anti-VEGF antibody treatment did not affect the production of activated NF-κB, chemokines, PVL, or cell counts, but production of the inflammatory cytokine IL-6 was increased. In addition, anti-VEGF treatment did not affect PVL in HTLV-1-infected T cells.

Conclusion

This preliminary in vitro assessment indicates that intraocular anti-VEGF antibody treatment for HTLV-1 infection does not exacerbate HTLV-1-related inflammation and thus may be safe for use.

Clinical and Public Health Implications of Human T-Lymphotropic Virus Type 1 Infection

Human T-lymphotropic virus type 1 (HTLV-1) is estimated to affect 5 to 10 million people globally and can cause severe and potentially fatal disease, including adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The burden of HTLV-1 infection appears to be geographically concentrated, with high prevalence in discrete regions and populations. While most high-income countries have introduced HTLV-1 screening of blood donations, few other public health measures have been implemented to prevent infection or its consequences. Recent advocacy from concerned researchers, clinicians, and community members has emphasized the potential for improved prevention and management of HTLV-1 infection. Despite all that has been learned in the 4 decades following the discovery of HTLV-1, gaps in knowledge across clinical and public health aspects persist, impeding optimal control and prevention, as well as the development of policies and guidelines. Awareness of HTLV-1 among health care providers, communities, and affected individuals remains limited, even in countries of endemicity. This review provides a comprehensive overview on HTLV-1 epidemiology and on clinical and public health and highlights key areas for further research and collaboration to advance the health of people with and at risk of HTLV-1 infection.

Extracellular Vesicles in HTLV-1 Communication: The Story of an Invisible Messenger

Human T-cell lymphotropic virus type 1 (HTLV-1) infects 5-10 million people worldwide and is the causative agent of adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) as well as other inflammatory diseases. A major concern is that the most majority of individuals with HTLV-1 are asymptomatic carriers and that there is limited global attention by health care officials, setting up potential conditions for increased viral spread. HTLV-1 transmission occurs primarily through sexual intercourse, blood transfusion, intravenous drug usage, and breast feeding. Currently, there is no cure for HTLV-1 infection and only limited treatment options exist, such as class I interferons (IFN) and Zidovudine (AZT), with poor prognosis. Recently, small membrane-bound structures, known as extracellular vesicles (EVs), have received increased attention due to their potential to carry viral cargo (RNA and proteins) in multiple pathogenic infections (i.e., human immunodeficiency virus type I (HIV-1), Zika virus, and HTLV-1). In the case of HTLV-1, EVs isolated from the peripheral blood and cerebral spinal fluid (CSF) of HAM/TSP patients contained the viral transactivator protein Tax. Additionally, EVs derived from HTLV-1-infected cells (HTLV-1 EVs) promote functional effects such as cell aggregation which enhance viral spread. In this review, we present current knowledge surrounding EVs and their potential role as immune-modulating agents in cancer and other infectious diseases such as HTLV-1 and HIV-1. We discuss various features of EVs that make them prime targets for possible vehicles of future diagnostics and therapies.

HTLV-1 in Ophthalmology

Human T-cell leukemia virus type 1 (HTLV-1) was the first retrovirus described as a causative agent for human disease. In the field of ophthalmology, a close relationship between HTLV-1 infection and uveitis was identified through a series of clinical and laboratory studies in the late 1980s-1990s. Since then, HTLV-1-related ocular manifestations such as keratoconjunctivitis sicca, interstitial keratitis, optic neuritis and adult T-cell leukemia/lymphoma (ATL)-related ocular manifestations have continuously been reported. During the three decades since the association between HTLV-1 and ocular pathologies was discovered, ophthalmic practice and research have advanced with the incorporation of new technologies into the field of ophthalmology. Accordingly, new findings from recent research have provided many insights into HTLV-1-associated ocular diseases. Advanced molecular technologies such as multiplex polymerase chain reaction (PCR)/broad-range PCR using ocular samples have enabled rapid and accurate diagnosis. Advanced ophthalmic technologies such as widefield fundus camera and optical coherence tomography (OCT) have clarified various features of HTLV-1-associated ocular manifestations, and identified characteristics such as the "knob-like ATL cell multiple ocular infiltration" (KAMOI) sign. Advanced drug delivery methods such as intravitreal injection and sub-Tenon injection have led to progress in preventing disease progression. This article describes global topics and the latest research findings for HTLV-1-associated ocular diseases, with reference to a large-scale nationwide survey of ophthalmologists. Current approaches and unmet needs for HTLV-1 infection in ophthalmology are also discussed.

Safety of Infliximab for the Eye Under Human T-Cell Leukemia Virus Type 1 Infectious Conditions in vitro

Use of biologics has been widely advocated for inflammatory diseases recently. Anti-tumor necrosis factor (TNF)-α antibody therapy is reportedly effective against ocular inflammation. However, side effects of TNF-α inhibition have been reported, particularly in the form of exacerbation of infections such as tuberculosis. Paradoxical reactions such as exacerbated inflammation are also well known. Around 20 million humans are infected with human T-cell leukemia virus type 1 (HTLV-1) globally, and this virus can cause adult T-cell leukemia, HTLV-1-associated myelopathy and HTLV-1 uveitis. As for ophthalmic concerns, it has not been identified whether anti-TNF-α antibody stimulates HTLV-1-infected cells and ocular cells to induce HTLV-1 uveitis in HTLV-1 carriers. Here we investigated the effects of anti-TNF-α antibody on ocular status under HTLV-1 infectious conditions using ocular cells and HTLV-1-infected cells in vitro. We used the ARPE-19 human retinal pigment epithelial cell line as ocular cells considered to play an important role in the blood-ocular barrier, and the MT2 HTLV-1-infected cell line. Jurkat cells were used as controls. Infliximab (IFX) was used as an anti-TNF-α antibody to achieve TNF-α inhibition. We evaluated the production of inflammatory cytokines and intercellular adhesion molecule (ICAM)-1, proliferation of ARPE-19, expression of TNF-α receptor (TNF-R) and HTLV-1 proviral DNA, and the percentage of apoptotic ARPE-19. Inflammatory cytokines such as interleukin (IL)-6, IL-8, TNF, and ICAM-1 were significantly elevated through contact between ARPE-19 and MT2. Treatment with IFX tented to inhibit TNF production, although the level of production was low, but changes in IL-6, IL-8, and ICAM-1 remained unaffected. Expression of TNFR was unaltered by IFX treatment. HTLV-1 proviral DNA was not significantly changed with treatment. No change in cell growth rate or apoptotic rate of ARPE-19 was seen with the addition of IFX. In conclusion, IFX did not exacerbate production of inflammatory cytokines, and did not affect expression of TNFR, proliferation of ARPE-19, HTLV-1 proviral load, or apoptosis of ARPE-19. These results suggest that IFX does not exacerbate HTLV-1-related inflammation in the eye and represents an acceptable treatment option under HTLV-1 infectious conditions.

Unique features and clinical importance of acute alloreactive immune responses

Allogeneic stem cell transplantation (allo-SCT) can cure some patients with hematopoietic malignancy, but this relies on the development of a donor T cell alloreactive immune response. T cell activity in the first 2 weeks after allo-SCT is crucial in determining outcome, despite the clinical effects of the early alloreactive immune response often not appearing until later. However, the effect of the allogeneic environment on T cells is difficult to study at this time point due to the effects of profound lymphopenia. We approached this problem by comparing T cells at week 2 after allograft to T cells from autograft patients. Allograft T cells were present in small numbers but displayed intense proliferation with spontaneous cytokine production. Oligoclonal expansions at week 2 came to represent a substantial fraction of the established T cell pool and were recruited into tissues affected by graft-versus-host disease. Transcriptional analysis uncovered a range of potential targets for immune manipulation, including OX40L, TWEAK, and CD70. These findings reveal that recognition of alloantigen drives naive T cells toward a unique phenotype. Moreover, they demonstrate that early clonal T cell responses are recruited to sites of subsequent tissue damage and provide a range of targets for potential therapeutic immunomodulation.

Alloreactive response T cells at 2 weeks after allo-SCT displayed intense proliferation with spontaneous cytokine production, and were recruited into tissues affected by GvHD.

Plasma and cerebrospinal fluid levels of cytokines as disease markers of neurologic manifestation in long-term HTLV-1 infected individuals

AIM

The aim of this study is to evaluate the presence of a particular immunological profile in individuals long-term infected with HTLV-1, followed presenting different clinical courses.

MATERIALS & METHODS

Forty-eight individuals were evaluated for 19 cytokines analyzed in cerebrospinal fluid and plasma of patients with HTLV-1 presenting with and without neurological symptoms.

RESULTS

Proinflammatory cytokines and the chemokine ligand 11 (ITAC/CXCL11) were increased in individuals with HTLV-1 coursing with neurological symptoms.

CONCLUSION

Different cytokines' expression profile in the presence of neurological symptoms may help to understand and characterize the progression for severe clinical presentations.

Treatment of rheumatoid arthritis with biologics may exacerbate HTLV-1-associated conditions: A case report

RATIONALE

There are roughly 5 to 10 million persons infected with human T-lymphotropic virus type 1 (HTLV-1) worldwide, and the safety of treating this population with biologics remains poorly understood.

PATIENT CONCERNS AND DIAGNOSIS

An HTLV-1-infected 66-year-old female with HTLV-1 uveitis (HU) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Her HU had been in remission and her HAM/TSP symptoms had been managed effectively with oral steroids for years. However, she developed severe rheumatoid arthritis (RA) after failing to respond well to conventional anti-rheumatic agents.

INTERVENTIONS

She was administered two intravenous 8mg/kg doses of the biologic tocilizumab.

OUTCOMES

Subsequently, her RA symptoms resolved, but she suffered a recurrence of HU and exacerbation of HAM/TSP symptoms. When she was switched back to steroid-based treatment, HU and HAM symptoms both improved, but RA symptoms again worsened. Finally, an attempt to substitute the biologic abatacept and reduce the steroids failed when HAM/TSP symptoms again became aggravated.

LESSONS

To the best of our knowledge, this represents the first report worldwide of a biologic aggravating HTLV-1-associated conditions. This report suggests that caution is advised when using biologics to treat HTLV-1-infected patients, though further research is required to clarify the situation.

A new era of uveitis: impact of polymerase chain reaction in intraocular inflammatory diseases

Uveitis is a sight-threatening intraocular inflammatory disorder which may occur from both infectious and non-infectious or autoimmune causes. The frequency of infectious uveitis and autoimmune uveitis varies depending on countries and regions. According to a nationwide survey conducted by the Japanese Ocular Inflammation Society, infectious and non-infectious uveitis accounted for 16.4 and 50.1% of new patients, respectively while the remaining 33.5% of new uveitis cases were not classified or were idiopathic uveitis. Infectious uveitis is particularly important because it causes tissue damage to the eye and may result in blindness unless treated. However, it can be treated if the pathogenic microorganisms are identified promptly and accurately. Remarkable advancements in molecular and immunological technologies have been made in the last decade, and the diagnosis of infectious uveitis has been greatly improved by the application of molecular and immunological investigations, particularly polymerase chain reaction (PCR). PCR performed on a small amount of ocular samples provides a prompt, sensitive, and specific molecular diagnosis of pathogenic microorganisms in the eye. This technology has opened a new era in the diagnosis and treatment of uveitis, enabling physicians to establish new clinical entities of uveitis caused by infectious microorganisms, identify pathogens in the eyes of many patients with uveitis, and determine prompt diagnosis and appropriate therapy. Here we review the PCR process, new PCR tests specialized for ocular diseases, microorganisms detected by the PCR tests, diseases in the eye caused by these microorganisms, and the clinical characteristics, diagnosis, and therapy of uveitis.

Characteristics of Interleukin 2 and Interleukin 4 Dependent T Cell Lines Infected with HTLV-1 in Vitro

Human T-cell leukemia/lymphoma virus type 1 (HTLV-1) is a lymphotropic retrovirus. Cells infected with HTLV-1 in vitro, when maintained in interleukin-2 (IL-2) can be immortalized, remaining for a long time strictly dependent on IL-2 addition. In this study we have compared the effect of interleukin-4 (IL-4) and interleukin-2 on HTLV-1 infection of cord blood or normal adult mononuclear cells. The results showed that either cultures of cord blood or normal adult T cells are susceptible to HTLV-1 infection in presence of IL-4 as well as IL-2. Moreover HTLV-1 infected cells in the presence of IL-4 survived only for a limited length of time in culture, while those grown in IL-2 showed the characteristics of immortalized cell lines. Moreover the profile of cytokine production showed a different pattern in HTLV-1 infected cell lines maintained in IL-4 or IL-2. This suggests that the lymphokines differently modulate retrovirus infection in vitro.

Inflammatory manifestations of HTLV-1 and their therapeutic options

Human T lymphotropic virus type 1 (HTLV-1) is one of the most intriguing retroviruses infecting humans. Most commonly, infection remains undetected, since it does not cause obvious harm, yet in 4-9% of patients, this infection can be devastating, causing adult T-cell leukemia/lymphoma and/or HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). This review concentrates on all inflammatory aspects of HTLV-1 infection: HAM/TSP, HTLV-1 associated uveitis, HTLV-1 associated conjunctivitis, sicca syndrome and interstitial keratitis, HTLV-1 associated Sjögren's syndrome, Hashimoto's thyroiditis and Graves' disease, HTLV-1 associated pulmonary disease, infective dermatitis associated with HTLV-1, HTLV-1 associated inflammatory myositis and HTLV-1 associated arthritis. With the exception of HAM/TSP treatment, studies of these conditions are sparse and even for HAM/TSP, the level of evidence is limited. While control or elimination of infection remains a goal, most therapy beyond symptomatic management is directed at the immune response to HTLV-1.

Role of IL-22- and TNF-α-producing Th22 cells in uveitis patients with Behcet's disease

Behçet's disease is a systemic inflammatory disorder with recurrent episodes of oral ulceration, skin lesions, genital ulceration, and intraocular inflammation (uveitis). The intraocular inflammation is strictly associated with Th effector cells. IL-22 is a member of the IL-10 cytokine family that is involved in inflammatory processes. Recently, Th22 cells were identified as a Th cell population that produces IL-22 and TNF-α and are distinct from Th1, Th2, and Th17 cells. In this study, we established Th22-type T cell clones from ocular samples taken from Behçet's disease patients with active uveitis. These clones produced large amounts of IL-22 and TNF-α but not the Th1 cytokine IFN-γ and the Th17 cytokine IL-17. CD4(+) T cells from the peripheral blood of Behçet's disease patients differentiated into Th22 cells in the presence of IL-6 and TNF-α in vitro. The polarized Th22 cell lines produced large amounts of IL-22, and the polarized Th1 and Th17 cells also produced IL-22. In the presence of anti-TNF-α- and anti-IL-6-blocking Abs, Behçet's disease Th22-type T cells failed to produce IL-22. In addition, infliximab-pretreated Th22 cells and Th22-type ocular T cells produced less IL-22 and TNF-α. Moreover, IL-22-producing T cells were isolated from mice with experimental autoimmune uveitis, an animal model of Behçet's disease, and the intraocular T cells from uveitis models produced large amounts of IL-22 in the presence of retinal Ags. Our results suggest that inflammatory cytokines IL-22 and TNF-α may play a key role in the ocular immune response in Behçet's disease.

HTLV infection and the eye

PURPOSE OF REVIEW

Human T-cell lymphotropic virus (HTLV) is the first discovered retrovirus causing malignancy in human. HTLV infection affects host's ocular tolerance and causes various diseases in the eye. Here we discuss the manifestations, mechanisms, treatments, and future directions of HTLV-related ocular diseases. RECENT FININGS: Recent serological researches showed that the number of HTLV-1 carriers in metropolitan area was increasing, although seroprevalence of HTLV-1 in general population was decreased after screening serological tests in blood donors started. The most common clinical entity of uveitis was still HTLV-1 uveitis in HTLV-1 highly endemic area, but prevalence of HTLV-1 uveitis varies in different parts of the world. As for treatment of inflammation, tacrolimus and 5-azacytidine were reported to be effective for autoimmune manifestations in HTLV-1-related overlap syndrome (deratomyositis/Sjogren's syndrome) and HTLV-1-related myelodysplastic syndrome. Interleukin-2 receptor targeted therapies improved scleritis in patients with adult T-cell leukemia/lymphoma caused by HTLV-1. Basic researches identified that HTLV-1 tax and HTLV-1 basic leucine zipper factor play critical roles in the HTLV-1-related disease and are now being investigated as targeted therapies.

SUMMARY

Development of modern molecular biology makes it possible to reveal deep insights of HTLV-1-related ocular diseases. Although effective therapies based on basic researches have been reported, further endeavor is necessary to establish much more specific treatments of the ocular diseases.

Constitutive release of IFNγ and IL2 from peripheral blood mononuclear cells of rhesus macaques (Macaca mulatta) infected with simian T-lymphotropic virus type 1

Simian T-cell lymphotropic viruses (STLV), the nonhuman primate counterparts of human T-cell lymphotropic viruses (HTLV), are endemic in many populations of African and Asian monkeys and apes. Although an etiologic link between STLV1 infection and lymphoproliferative disorders such as malignant lymphomas has been suggested in some nonhuman primate species, most STLV infections are inapparent, and infected animals remain clinically healthy. The retroviral transactivator, tax, is well known to increase transcription of viral and cellular genes, resulting in altered cytokine profiles. This study compared the cytokine profiles of peripheral blood mononuclear cell (PBMC) cultures from 25 STLV1-seropositive rhesus macaques (Macaca mulatta) with those of age- and sex-matched seronegative controls. IFNγ, TNFα, IL10, and IL2 levels in unstimulated PBMC culture supernatants were measured at 24, 48, and 72 h by using enzyme immunoassays. IFNγ concentrations were found significantly higher in the supernatants of PBMC cultures of seropositive monkeys as compared with seronegative controls. In addition, although IL2 concentrations were not significantly elevated in the supernatants of PBMC cultures of all seropositive monkeys as compared with all seronegative controls, IL2 levels were increased in a subset of 5 pairs. Increased constitutive cytokine release occurred in the absence of spontaneous proliferation. The increased constitutive release of IFNγ and IL2 suggests that STLV1 alters immune functions in infected but clinically healthy rhesus macaques and further characterizes STLV1 infection of rhesus macaques as a potential model for human HTLV1 infection.

Immunological homeostasis of the eye

Uveitis is a sight-threatening disease caused by autoimmune or infection-related immune responses. Studies in experimental autoimmune uveitis and in human diseases imply that activated CD4(+) T cells, Th1 and Th17 cells, play an effector role in ocular inflammation. The eye has a unique regional immune system to protect vision-related cells and tissues from these effector T cells. The immunological balance between the pathogenic CD4(+) T cells and regional immune system in the eye contributes to the maintenance of ocular homeostasis and good vision. Current studies have demonstrated that ocular parenchymal cells at the inner surface of the blood-ocular barrier, i.e. corneal endothelial (CE) cells, iris pigment epithelial (PE) cells, ciliary body PE cells, and retinal PE cells, contribute to the regional immune system of the eye. Murine ocular resident cells directly suppress activation of bystander T cells and production of inflammatory cytokines. The ocular resident cells possess distinct properties of immunoregulation that are related to disparate anatomical location. CE cells and iris PE cells, which are located at the anterior segment of the eye and face the aqueous humor, suppress activation of T cells via cell-to-cell contact mechanisms, whereas retinal PE cells suppress the activation of T cells via soluble factors. In addition to direct immune suppression, the ocular resident cells have another unique immunosuppressive property, the induction of CD25(+)Foxp3(+) Treg cells that also suppress the activation of bystander T cells. Iris PE cells convert CD8(+) T cells into Treg cells, while retinal PE cells convert CD4(+) T cells greatly and CD8(+) T cells moderately into Treg cells. CE cells also convert both CD4(+) T cells and CD8(+) T cells into Treg cells. The immunomodulation by ocular resident cells is mediated by various soluble or membrane-bound molecules that include TGF-β TSP-1, B7-2 (CD86), CTLA-2α, PD-L1 (B7-H1), galectin 1, pigment epithelial-derived factor PEDF), GIRTL, and retinoic acid. Human retinal PE cells also possess similar immune properties to induce Treg cells. Although there are many issues to be answered, human Treg cells induced by ocular resident cells such as retinal PE cells and related immunosuppressive molecules can be applied as immune therapy for refractive autoimmune uveitis in humans in the future.

HTLV-1 uveitis

Human T cell lymphotropic virus type 1 (HTLV-1) is the first retrovirus described as a causative agent of human disease. Following adult T cell leukemia/lymphoma and HLTV-1-associated myelopathy/tropical spastic paraparesis, HTLV-1 uveitis (HU) has been established as a distinct clinical entity caused by HTLV-1 based on seroepidemiological, clinical, and virological studies. HU is one of the most common causes of uveitis in endemic areas of Japan and can be a problematic clinical entity all over the world. HU occurs with a sudden onset of floaters and foggy vision, and is classified as an intermediate uveitis. Analysis of infiltrating cells in eyes with HU revealed that the majority of infiltrating cells were CD3(+) T cells, but not malignant cells or leukemic cells based on their T cell receptor usage. HTLV-1 proviral DNA, HTLV-1 protein, and viral particles were detected from infiltrating cells in eyes with HU. HTLV-1-infected CD4(+) T cell clones established from infiltrating cells in eyes with HU produced large amounts of various inflammatory cytokines, such as IL-1, IL-6, IL-8, TNF-α, and interferon-γ. Taken together, HU is considered to be caused by inflammatory cytokines produced by HTLV-1-infected CD4(+) T cells that significantly accumulate in eyes; therefore, topical and/or oral corticosteroid treatment is effective to treat intraocular inflammation in patients with HU. Further investigation is needed to establish a specific treatment for HU.

Successful treatment of HTLV-1-related overlap syndrome using tacrolimus

A 56-year-old HTLV-I-positive woman, initially diagnosed as having Sjögren's syndrome, presented with muscle weakness, myalgia, face erythema and leg edema. Based on the presence of various autoantibodies, the diagnosis of overlap syndrome (dermatomyositis/Sjögren's syndrome) was made. Treatment with high-dose corticosteroid plus cyclosporine improved her symptoms. However, three months after the start of these treatments, exacerbation of myositis occurred. A muscle biopsy revealed prominent perivascular accumulation of mononuclear cells with perifascicular atrophy, which were consistent with dermatomyositis. Tacrolimus, which was substituted for cyclosporine led to marked improvement of the myositis symptoms.

HTLV-1 in rural Guinea-Bissau: prevalence, incidence and a continued association with HIV between 1990 and 2007

Background

HTLV-1 is endemic in Guinea-Bissau, and the highest prevalence in the adult population (5.2%) was observed in a rural area, Caió, in 1990. HIV-1 and HIV-2 are both prevalent in this area as well. Cross-sectional associations have been reported for HTLV-1 with HIV infection, but the trends in prevalence of HTLV-1 and HIV associations are largely unknown, especially in Sub Saharan Africa. In the current study, data from three cross-sectional community surveys performed in 1990, 1997 and 2007, were used to assess changes in HTLV-1 prevalence, incidence and its associations with HIV-1 and HIV-2 and potential risk factors.

Results

HTLV-1 prevalence was 5.2% in 1990, 5.9% in 1997 and 4.6% in 2007. Prevalence was higher among women than men in all 3 surveys and increased with age. The Odds Ratio (OR) of being infected with HTLV-1 was significantly higher for HIV positive subjects in all surveys after adjustment for potential confounding factors. The risk of HTLV-1 infection was higher in subjects with an HTLV-1 positive mother versus an uninfected mother (OR 4.6, CI 2.6-8.0). The HTLV-1 incidence was stable between 1990-1997 (Incidence Rate (IR) 1.8/1,000 pyo) and 1997-2007 (IR 1.6/1,000 pyo) (Incidence Rate Ratio (IRR) 0.9, CI 0.4-1.7). The incidence of HTLV-1 among HIV-positive individuals was higher compared to HIV negative individuals (IRR 2.5, CI 1.0-6.2), while the HIV incidence did not differ by HTLV-1 status (IRR 1.2, CI 0.5-2.7).

Conclusions

To our knowledge, this is the largest community based study that has reported on HTLV-1 prevalence and associations with HIV. HTLV-1 is endemic in this rural community in West Africa with a stable incidence and a high prevalence. The prevalence increases with age and is higher in women than men. HTLV-1 infection is associated with HIV infection, and longitudinal data indicate HIV infection may be a risk factor for acquiring HTLV-1, but not vice versa. Mother to child transmission is likely to contribute to the epidemic.

Regional immunity of the eye

This article reviews molecular mechanism of intraocular inflammation in animal models and in humans, and the immunological defence system of the eye with particular attention to ocular pigment epithelium. In experimental autoimmune uveitis (EAU), T lymphocytes, particularly CD4(+) T lymphocytes, play a central role in its immunopathogenic mechanisms. In humans, activated CD4(+) T cells also play a central role in the immunopathogenic mechanisms. This notion is demonstrated in two human diseases: one is Vogt-Koyanagi-Harada disease, and the other is human T-cell leukemia virus type 1 (HTLV-1) uveitis. Activated CD4(+) T cells infiltrating the eye are harmful to vision-related cells and tissues in the eye and cause sight-threatening conditions. However, the eye has regional defence systems to protect itself from these harmful activated T cells. We focus on ocular pigment epithelium (PE) and demonstrate immunoregulatory activity of iris PE and retinal PE. Iris PE suppresses activated CD4(+) T cells by cell-to-cell contact with a crucial role played by B7-2 molecule on iris PE and CTLA4 on T cells. The actual immunosuppressive factor being membrane bound TGF-beta. In contrast, retinal PE suppresses activated CD4(+) T cells by soluble factors, such as soluble TGF-beta and thrombospondin 1. In addition to the direct T-cell suppression by ocular PE, ocular PE has the capacity to promote activated T cells to regulatory T cells and use them as a tool to amplify the immune down regulation in the eye. The molecular mechanisms of generation of T regulatory cells by iris PE and retinal PE is also discussed.

Human retinal pigment epithelium-induced CD4+CD25+ regulatory T cells suppress activation of intraocular effector T cells

Murine retinal pigment epithelial (RPE) cells suppress T-cell activation by releasing soluble inhibitory factors and promote the generation of regulatory T cells in vitro. These T cells exposed to RPE supernatants (RPE-induced Treg cells) can suppress the activation of bystander effector T cells via the production of transforming growth factor-beta (TGFbeta). In the present study, we showed that human RPE-induced Treg cells are also able to acquire regulatory function when human RPE cell lines were pretreated with recombinant TGF beta 2. These RPE-induced Treg cells produced TGF beta 1 and IL-10 but not IFN gamma, and they significantly suppressed the activation of target cell lines and intraocular T-cell clones established from patients with active uveitis. Moreover, CD4(+)CD25(+) RPE-induced Treg cells expressed CTLA-4 and Foxp3 molecules, and the CD25(+) Treg cells profoundly suppressed the T-cell activation. Thus, in vitro manipulated Treg cells acquire functions that participate in the establishment of immune tolerance in the eye.

Analysis of HLA Class I and Class II Gene Polymorphisms in Japanese Patients with Human T-Cell Lymphotropic Virus Type 1-Associated Uveitis

PURPOSE

To investigate the immunogenetic background of human T-cell lymphotropic virus type 1 (HTLV-1)-associated uveitis (HAU) that presents immune-mediated reactive changes in the uvea.

METHODS

HLA class I and class II genes were studied in 51 patients with HAU, 192 asymptomatic HTLV-1 carriers, and 266 HTLV-1-seronegative controls using a high-resolution method of HLA DNA typing. The HLA alleles of HAU were compared with those of HTLV-1 carriers and healthy controls.

RESULTS

We identified 62 distinct alleles of HLA-A, HLA-Cw, and HLA-B and 49 distinct alleles of HLA-DRB1 and HLA-DQB1 in patients with HAU, asymptomatic HTLV-1 carriers, and healthy controls. The relative frequencies of these HLA alleles did not differ among the three groups.

CONCLUSION

The results suggest that HLA class I and class II genes do not contribute to susceptibility to HAU.

Current topics in prevention of human T-cell leukemia virus type i infection: NF-kappa B inhibitors and APOBEC3

Human T-cell leukemia virus type I (HTLV-I) is the first human retrovirus and causes adult T-cell leukemia/lymphoma (ATL). Constitutive activation of nuclear factor-kappa B (NF-kappa B) in the leukemic cells is essential for their growth and survival. Thus, NF-kappa B inhibitors have been attracting attention as a potential strategy to treat ATL. Recently, the field of retrovirus research has been stimulated by the discovery of an innate host defense factor, APOBEC3, against the retroviruses. HTLV-I is relatively resistant to the antiviral effects of APOBEC3. To clarify the resistance of HTLV-I against APOBEC3 might contribute to the design of effective therapeutic approaches.

Constitutive association of MyD88 to IRAK in HTLV-I-transformed T cells

OBJECTIVE

Constitutive activation of nuclear factor (NF)-kappaB is a common feature of human T-cell leukemia virus type I (HTLV-I)-transformed T cells. Inhibition of NF-kappaB activity reduces cell growth and induces apoptosis of HTLV-I-transformed T cells, suggesting a central role of NF-kappaB in their proliferation and survival. In this study, we investigated whether MyD88, an adaptor protein of Toll-like receptor (TLR) signaling, contributes to constitutive NF-kappaB activation in HTLV-I-transformed T cells.

MATERIALS AND METHODS

Activation status of MyD88 and interleukin (IL)-1R-associated kinase 1 (IRAK1) in HTLV-I-transformed human T cells, MT2, MT4, and HUT102 was examined by using Western blot and immunoprecipitation. TLR expression was evaluated with reverse transcription polymerase chain reaction. An expression vector encoding a dominant negative MyD88 with a deletion of its death domain (MyD88dn) was transfected into MT2 cells to evaluate roles of MyD88 in spontaneous activation of cytokine gene promoters and transcription factors, proliferation, and apoptosis in HTLV-I-transformed T cells.

RESULTS

Constitutive association of MyD88 with IRAK1 was observed in all three of HTLV-I-transformed T cells, but not in HTLV-I-negative T cells, such as Jurkat, HUT78, and MOLT4. MT2 cells showed expression of TLR-1, -6, and -10 mRNAs. Constitutive activation of NF-kappaB and NF-IL-6 and cytokine gene promoters, such as IL-1alpha, interferon-gamma, and tumor necrosis factor-alpha in MT2 cells was inhibited by MyD88dn expression. MyD88dn reduced proliferation and induced apoptosis of MT2 cells. HTLV-I Tax enhanced TLR expression and synergistically activated NF-kappaB with wild-type MyD88.

CONCLUSION

Our results show a novel pathway in NF-kappaB activation in HTLV-I-transformed T cells and further demonstrate a critical role of MyD88 in their dysregulated gene activation, survival, and proliferation.

Adult T-cell lymphoma mimicking Henoch-Schönlein purpura

We report a male patient with adult T-cell lymphoma, who was initially diagnosed clinically as having Henoch-Schönlein purpura (HSP) with abdominal pain and specific purpura. Adult T-cell lymphoma-like cells were minimal and abdominal lymph nodes were transiently swollen, and the symptoms were improved by supportive management. Although the clinical course was compatible with HSP, the histological examination revealed infiltration of lymphocytes rather than neutrophils. Later he developed lymphoma and was treated with chemotherapy. This rare case suggests the importance of skin biopsies to seek the underlying pathology in adult HSP.

Treatment for HTLV-I associated arthropathy: a case study and synovial tissue culture analysis

OBJECTIVE

There are few reports regarding the treatment of HTLV-I associated arthropathy (HAAP). This is a case study describing the treatment of a patient diagnosed with HAAP. We also analyzed the effects of various agents on cultured synovial tissue explants from the patient.

METHODS

Arthroscopic synovectomy of the left knee was performed. We investigated the effects of pirarubicin (THP), bestatin, betamethasone, and hyaluronic acid (HA) in synovial tissue culture to evaluate the efficacy of these medications.

RESULTS

Swelling and pain of the left knee was transiently diminished after synovectomy. However, bilateral swelling of the knees and C reactive protein (CRP) concentrations were increased. In the explant culture experiments, CD8+ cells decreased with the addition of bestatin, betamethasone, and HA. The structure of synovial cells was preserved by the addition of HA. However, the addition of THP induced fibrosis of synovial tissues, increased cells without nuclei, and diminished fascin-expressing cells.

CONCLUSION

THP inhibited, but HA preserved the structure of hypertrophic synovial cells. Scopic synovectomy effectively improved joint effusion and pain; however, the effect was transient, and additional treatment with predonisolone was required. Therefore, it is important to develop a more effective treatment for HAAP.

HTLV-I env protein acts as a major antigen in patients with HTLV-I-associated arthropathy

Our objective was to investigate the pathological mechanisms of HTLV-I (human T-cell leukemia virus type I)-associated chronic arthritis (HAAP) with respect to T-cell response to HTLV-I viral proteins. We examined T-cell clonality and the antigen recognized by T cells from the inflamed synovium of patients with HAAP by using histology, a single-strand conformation polymorphism (SSCP) analysis and T cell receptor (TCR) sequencing. The SSCP analysis showed oligoclonal expansion of T cells in the synovium, suggesting an antigen-mediated stimulation. In contrast, there was less clonal expansion in peripheral blood lymphocytes (PBL). The expression of HTLV-1 env and tax mRNA was detected in the affected synovium as well as in PBL. A number of T-cell clones in the synovium recognized HTLV-I env and tax proteins. Twenty-seven (24.9%) of 109 examined T-cell clones in the joints were HTLV-I env reactive, and 7 clones (6.4%) were HTLV-I tax reactive. Junctional sequence analysis of synovial T cells showed a lack of highly conserved amino acid motifs in the complementarity-determining region 3 (CDR3) of HTLV-I env and tax reactive T cells, suggesting that these cells recognized multiple T-cell epitopes on HTLV-I antigen. These findings suggest that HTLV-I env protein acts as a major antigen and may play a role in the development of arthropathy in patients with HAAP.

Role of Crk-associated substrate lymphocyte type in the pathophysiology of rheumatoid arthritis in tax transgenic mice and in humans

OBJECTIVE

To investigate the role of Crk-associated substrate lymphocyte type (Cas-L), a downstream signaling molecule of beta1 integrins, in the pathophysiology of rheumatoid arthritis (RA).

METHODS

We analyzed human T lymphotropic virus type I (HTLV-I) tax transgenic mice as well as samples from human RA patients. Splenocytes from tax transgenic mice were cultured on mouse endothelial cell-covered Transwell inserts, and cells migrating through the endothelial monolayer were counted. Biochemical studies were performed to analyze the protein expression and tyrosine phosphorylation of Cas-L. Immunohistochemical analysis was performed to detect Cas-L-positive cells that had infiltrated into the joints.

RESULTS

Migratory activity of splenocytes from tax transgenic mice with arthritis (ATg) was much higher than that of tax transgenic mice without arthritis (NTg) and littermate control mice. The expression of Cas-L protein and its tyrosine phosphorylation were increased in ATg mice compared with NTg and control mice, and this was accompanied by enhanced autophosphorylation of Fyn and Lck. Immunohistochemical analysis demonstrated a large number of Cas-L-positive lymphocytes migrating into the affected joints. Furthermore, in human RA, Cas-L-positive lymphocytes were shown to infiltrate to the inflammatory lesions.

CONCLUSION

These results strongly suggest that Cas-L plays an important role in the pathophysiology of RA.

Polymorphism of the Duffy erythrocyte chemokine receptor in Italian patients with Behçet's disease

This study examined the hypothesis that the polymorphism of Duffy antigen receptor for chemokines (DARC) predisposes to and/or influences the clinical manifestations of Behçet's disease. The serum levels of IL-8 and monocyte chemotactic peptide (MCP)-1, two DARC-binding chemokines, were investigated and related to this polymorphism. Twenty-eight patients with Behçet's disease and 30 healthy blood donors were included in the study. No null phenotypes were found among the patients studied, and the frequencies of the other phenotypes (Fy((a+b-)), Fy((a+b+)), and Fy((a-b+))) did not significantly differ from those found in the blood donor group or reported in the general Caucasian population. No difference was found between the single phenotypes in terms of IL-8 and MCP-1 serum levels, and no relevant association between the clinical characteristics, Behçet's disease-associated human leukocyte antigen (HLA)-B51, and single phenotypes was observed. This investigation indicates that DARC is not a genetic trait significantly associated with or predisposing to Behçet's disease, at least in Caucasian Italians. However, the role of this polymorphism in the development and in the clinical course of the disease awaits further investigation.

[Infection and disease caused by the human T cell lymphotropic viruses type I and II in Brazil]

HTLV-I/II infection is present in all regions of Brazil, but its prevalence varies according to the geographical area, being higher in Bahia, Pernambuco and Pará. It has been estimated that Brazil has the highest absolute number of infected individuals in the world. Blood donors screening and research conducted with special groups (indigenous population of Brazil, IV drug users and pregnant women) are the major sources of information about these viruses in our Country. HTLV-I causes adult T cell leukemia/lymphoma (ATLL), HTLV associated myelopathy/tropical spastic paraparesis (HAM/TSP), HTLV associated uveitis (HAU), dermatological and immunological abnormalities. HTLV-II is not consistently associated with any disease. Diagnosis is established using screening (enzymatic assays, agglutination) and confirmatory (Western blot, PCR) tests. The viruses are transmitted by blood and contaminated needles, by sexual relations and from mother to child, especially by breast feeding. Prevention efforts should focus on education of positive blood donors, infected mothers and IV drug users.

Ocular lesions in 200 patients infected by the human T-cell lymphotropic virus type 1 in martinique (French West Indies)

PURPOSE

To describe the ophthalmologic features observed in patients infected by the human T-cell lymphotropic virus, type 1 (HTLV-1) in Martinique (French West Indies).

DESIGN

Prospective consecutive observational case series.

METHODS

A complete ophthalmic examination was performed.

PATIENTS

Of 200 patients infected by HTLV-1, 77 (38.5%) were seropositive and 123 (61.5%) had HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP).

RESULTS

Uveitis was found in 29 cases (14.5%). Symptoms were mild and the uveitis had little effect on visual function. Ten cases of uveitis were discovered through a systematic examination and had no ocular symptoms. Most of the uveitis was anterior or intermediate. The lesions responded to corticosteroid therapy, but tended to recur. Keratoconjunctivitis sicca existed in 74 patients (37%), accompanied by lymphoplasmocytoid infiltration of the secondary salivary glands rated 3 or 4 on the Chisholm scale in nearly 50% of cases. Corneal alterations were observed in 20 cases (10%), and alterations in the retinal pigment epithelium in 3 cases.

CONCLUSION

The three types of ocular affections seen most frequently were uveitis, keratoconjunctivitis sicca, and interstitial keratitis. In patients with HAM/TSP, uveitis was more frequent among younger patients, patients with earlier onset of HAM/TSP, and patients with severe motor disability. Because uveitis is related to a high intrathecal production of immunoglobulin, it could represent a marker for severity of HTLV-1 infection with respect to the course of HAM/TSP. The sicca syndrome related to HTLV-1 virus differs from primary or secondary Sjögren syndrome, because it does not reveal any of the immunologic anomalies generally seen in this disease. Interstitial keratitis was more frequent among patients with HAM/TSP who had high proviral DNA levels.

Efficacy of 3'-azido 3'deoxythymidine (AZT) in preventing HTLV-1 transmission to human cord blood mononuclear cells

The present study investigated the effect of 3'-azido 3'deoxythymidine (AZT) treatment on in vitro infection of human cord blood mononuclear cells (CBMCs) exposed to HTLV-1 by cocultivation with the MT-2 cell line. Cultures of CBMCs were grown in IL-2 and were either left untreated or were treated with concentrations of AZT ranging from 0.0078 to 32 microM. HTLV-1-infected cultures were monitored at different times of culture by evaluating proliferation activity, cell growth and the presence and expression of HTLV-1 genes. Results showed that untreated cultures infected with HTLV-1 were able to grow for several weeks, while those treated with AZT at 0.03 microM or higher concentrations were limited in their growth capacity. Moreover, the addition of AZT at the moment of infection significantly inhibited cell proliferation in a dose-dependent fashion. In the presence of AZT, detection of proviral DNA and, more remarkably, viral RNA expression were clearly reduced. In addition, treatment with AZT resulted in a noticeable decrease in Tax protein expression. Using treatment with relatively low doses of AZT, effective in exerting an antiviral action, cytotoxicity on CBMCs was not observed, whereas higher doses induced apoptosis in uninfected CBMCs. These data show that CBMCs are protected by AZT against HTLV-1 transmission even at low, non-toxic doses.

Clinical features of human T-lymphotropic virus type 1 uveitis: a long-term follow-up

To investigate the clinical manifestations of human T-lymphotropic virus type-1 uveitis (HU), 112 HU patients who were followed up periodically for more than one year were retrospectively analyzed with respect to their ophthalmological and systemic complications. The gender ratio (female/male ratio) of the HU patients was 2.0 and the initial complications were foggy vision in 34.5%, ocular floaters in 33.3%, and blurred vision in 15.5%. As for the ocular symptoms, the majority (78.6%) of patients were classified as intermediate uveitis with vitreous inflammation. Recurrence of uveitis episodes was seen in one half of the patients (51.8%); 12 patients had more than six uveitis episodes. The interval of uveitis episodes varied from two weeks to 10 years. Nearly one half of the patients (43.8%) had ocular complications: e.g., cataract in 22 patients, persistent vitreous opacities in 17 patients, and glaucoma in 16 patients. Although the visual prognosis was essentially good, 11 patients had poor visual prognosis (<0.1). The causes of poor vision in these patients were cataract, cystoid macular edema, epiretinal membrane, and optic nerve atrophy. Of the 112 HU patients, two developed HTLV-I-associated myelopathy (TSP/HAM) after the onset of HU, while none developed adult T-cell leukemia. Sixteen HU patients had a previous history of Graves' disease and a past history of methimazole therapy, while Graves' disease was found in another HU patient only after HU onset and methimazole was not administered before the onset of HU. The present data of long-term follow-up indicate that (1) HU causes various ocular complications and its visual prognosis can be poor, (2) TSP/HAM can be induced even after the onset of HU, and (3) methimazole is not a risk factor of HU after Graves' disease.

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

To clarify the pathogenesis of human T lymphotropic virus type I (HTLV-I)-associated Sjögren's syndrome (SS), the TCR Vbeta gene usage by the infiltrating lymphocytes in the target organ was examined. The Vbeta families predominantly used in the labial salivary gland (LSG) from the HTLV-I-seropositive (HTLV-I+) SS patients were more restricted than those from the HTLV-I-seronegative (idiopathic) SS patients, and were commonly Vbeta5.2, Vbeta6, and Vbeta7. The single-strand conformation polymorphism analysis revealed that T cell clonotypes with Vbeta5.2, Vbeta6, and Vbeta7 accumulate in the LSG from the HTLV-I+ and idiopathic SS patients. Among junctional sequences of the most dominant Vbeta7 transcripts, the conserved amino acid motif (QDXG: X is any amino acid) was found in six of the five HTLV-I+ SS patients and was also detected in two of the five idiopathic SS patients. Using the probes specific to the motif, the Vbeta7 transcripts with the motif were detected in the LSG from all of the seven HTLV-I+ and five of the six idiopathic SS patients, but not from eight healthy subjects. The Vbeta7 transcripts with this motif were also detected in the HTLV-I-infected T cell lines obtained from the LSG of an HTLV-I+ SS patient. The accumulation of HTLV-I-infected T cells expressing TCR with the conserved motif was thus indicated. These T cells were commonly present in patients with idiopathic SS and are strongly suggested to most likely be involved in the pathogenesis of both HTLV-I-associated and idiopathic SS.

Human T-lymphotropic virus type I infection

Human T-cell lymphotropic virus type I (HTLV-I) is the first human retrovirus to be associated with malignant disease--namely, adult T-cell leukaemia/lymphoma. HTLV-I has also been associated with several non-malignant conditions, notably the chronic neurodegenerative disorder, HTLV-I associated myelopathy (also known as tropical spastic paraparesis), infective dermatitis of children and uveitis. More recent evidence points to disease associations not previously linked to HTLV-I. Thus, the disease spectrum of HTLV-I is not fully known. HTLV-I has a worldwide distribution with major endemic foci in the Caribbean and southern Japan. The public health importance is confirmed by the major routes of transmission, which are mother-to-child, blood transfusion, and sexual activity. Unfortunately, no vaccine is available yet and there is no proven treatment for advanced HTLV-I disease.

Genetic control and dynamics of the cellular immune response to the human T-cell leukaemia virus, HTLV-I

About 1% of people infected with the human T-cell leukaemia virus, type 1 (HTLV-I) develop a disabling chronic inflammatory disease of the central nervous system known as HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Patients with HAM/TSP have a vigorous immune response to HTLV-I, and it has been widely suggested that this immune response, particularly the HTLV-I-specific cytotoxic T-lymphocyte (CTL) response, causes the tissue damage that is seen in HAM/TSP. In this paper we summarize recent evidence that a strong CTL response to HTLV-I does in fact protect against HAM/TSP by reducing the proviral load of HTLV-I. We conclude that HTLV-I is persistently replicating at a high level, despite the relative constancy of its genome sequence. These results imply that antiretroviral drugs could reduce the risk of HAM/TSP by reducing the viral load, and that an effective anti-HTLV-I vaccine should elicit a strong CTL response to the virus. The dynamic nature of the infection also has implications for the epidemiology and the evolution of HTLV-I.

Human T cell leukemia virus type-I and rheumatoid arthritis

HTLV-I is a retrovirus known as an oncogenic virus for human. This virus, initially found as a causative agent for adult T cell leukemia, has been lately focused as a causative virus for several autoimmune disorders. Here we described the characteristics of polyarthritis in HTLV-I careers, which is indistinguishable from idiopathic rheumatoid arthritis (RA). The relationship between arthritis and this virus was clearly proved by epidimiological study. Moreover, we presented transactivating gene of this virus, tax, is responsible for proliferation of synovial cells. This was proved by Tax transgenic mice, which present chronic destructive arthritis resembling human RA. Other autoimmune disorders, such as Sjögren's syndrome and uveitis, are also reviewed.

Accumulation of human T lymphotropic virus type I-infected T cells in the salivary glands of patients with human T lymphotropic virus type I-associated Sjögren's syndrome

OBJECTIVE

To clarify the involvement of human T lymphotropic virus type I (HTLV-I) in the pathogenesis of Sjogren's syndrome (SS).

METHODS

In HTLV-I-seropositive patients with SS, HTLV-I proviral DNA in the labial salivary glands (SG) was detected by polymerase chain reaction (PCR) amplification of the extracted cellular DNA, and the localization in the SG was examined by in situ PCR hybridization.

RESULTS

The cellular DNA extracted from the SG contained full HTLV-I proviral DNA, which was present in the nucleus of the infiltrating T cells, but not in either the SG epithelial cells or the acinar cells. Furthermore, the viral loads in the SG were approximately 8 times to 9 x 10(3) times higher than those in the peripheral blood mononuclear cells.

CONCLUSION

Accumulation of HTLV-I-infected T cells in the SG suggests that HTLV-I likely causes the self-reactive T cells to proliferate, which, as a result, induces SS.

Provirus load in patients with human T-cell leukemia virus type 1 uveitis correlates with precedent Graves' disease and disease activities

We previously demonstrated the increased provirus load in the peripheral blood of patients with human T-cell leukemia virus type 1 (HTLV-1) uveitis (HU). To delineate the relevance of the increased provirus load to clinical and immunologic parameters, we studied the correlation between them. Seventy-nine HU patients (24 male and 55 female) were included in the study, with their informed consent. Plasma samples and genomic DNA of the peripheral blood mononuclear cells were isolated and the provirus load was estimated by semi-quantitative polymerase chain reaction of the gag region sequence. Serum levels of anti-HTLV-1 antibodies and soluble IL-2R were determined by electrochemiluminescence immuno assay and by ELISA, respectively. Disease activities were assessed and graded 0 to 4 according to the evaluation system. Recurrence of the disease during the follow-up period was diagnosed ophthalmologically. The provirus load was significantly higher in the HU patients after Graves' disease (GD) than in those without GD (P<0.05). It correlated with disease activities assessed in terms of vitreous inflammation and interval to recurrence (both P<0.05). In the HU patients without GD, it correlated with the serum levels of soluble IL-2 receptor (P<0.01), and nearly with those of HTLV-1 antibody (P=0.063). These correlations were not found in the HU patients after GD under methimazole treatment. The results suggested a direct involvement of HTLV-1-infected cells in the pathogenesis of uveitis, and raise the possibility that hyperthyroidism may contribute to the clonal expansion of HTLV-1-infected cells.

Evidence for autoantigens of Env/Tax proteins in human T cell leukemia virus type I Env-pX transgenic mice

OBJECTIVE

To examine T cell clonotypes infiltrating into arthritic joints and to investigate whether human T cell leukemia virus type I (HTLV-I) env-pX gene products act as autoantigens in HTLV-I env-pX transgenic mice.

METHODS

Complementary DNA (cDNA) encoding the V-D-J (third complementarity-determining region [CDR3]) region of T cell receptor beta chain was amplified by Vbeta family polymerase chain reaction. T cell clonotypes were detected by a single-strand conformational polymorphism method, and sequence analysis of the CDR3 region was performed.

RESULTS

Distinct oligoclonal T cell expansion was observed in arthritic joints, and a conserved amino acid motif in the CDR3 region was found in T cells infiltrating joints. Moreover, several intraarticular T cells recognized HTLV-I Env and Tax proteins.

CONCLUSION

Our results suggest that HTLV-I Env and Tax proteins act as autoantigens that are recognized by autoreactive T cells in inflamed arthritic lesions in the HTLV-I env-pX transgenic mouse. Thus, some T cells infiltrating the joint recognize Env or Tax protein. These cells may trigger chronic arthritis in HTLV-I env-pX transgenic mice.

HTLV-1 and Adult T-Cell Leukemia/Lymphoma: A Review

Infection with the human T-lymphotropic virus type 1 (HTLV-1) has been shown to be fundamental to the etiology of Adult T-cell Leukemia/Lymphoma (ATL). The disease is endemic in specific geographic areas but is increasingly reported from non-endemic regions. With increasing number of patients with this entity, the diversity in the clinical features has become apparent. In the past treatment strategies using combination chemotherapy have been unsatisfactory, but more recent trials using adenosine analouges, interferons, and combination of interferons and AZT have shown promise. With increased understanding of the etiology and molecular basis of the disease more effective therapies can be anticipated.