Expression of human T lymphotropic virus type 1 (HTLV-1) tax/rex gene in fresh bronchoalveolar lavage cells of HTLV-1-infected individuals

ANK Therapeutic Prospects and Usefulness of PD-L1 and NK Activity as Biomarkers for Predicting Treatment Efficacy Revealed from the Treatment Course of Patients with HTLV-1-Associated Bronchioloalveolar Disease

Adult T-cell leukemia/lymphoma (ATL) is a peripheral T-cell neoplasm with poor prognosis that can present as HTLV-1-associated bronchioloalveolar disease (HABA). Chemotherapy is recommended for ATL; however, it is not very effective against all types of ATL. Furthermore, there are no effective treatments for smoldering HABA-associated ATL. We present a case in which amplified natural killer cell (ANK) therapy was effective in a woman in her early 80s who was previously diagnosed with ATL-related smoldering HABA and presented with dyspnea and productive cough on exertion. The symptoms were suppressed for approximately 10 months after the first treatment, but then gradually worsened. About a year later, a second treatment was followed by mild side effects. Suppression of ATL cell proliferation by repeated doses of ANK therapy appears to be effective in this patient. The therapeutic effect was high even with long treatment intervals, and the efficacy and safety of repeated treatments have been demonstrated. ANK therapy is expected to be the mainstay of treatment ATL and HABA. ANK therapy has been reported to kill PD-L1 positive tumor cells and some solid tumors with excellent responses have many PD-L1-positive tumor cells. ANK therapy is thought to be effective for ATL because there are many PD-L1-positive tumor cells. Furthermore, administration of activated NK cells may increase tumor-killing activity in those patients with reduced NK activity. While future studies are needed, PD-L1 positive rate and NK activity may be biomarkers for the effectiveness of ANK therapy.

Successful treatment of smouldering Human T cell Leukemia Virus Type1 associated bronchiolitis and alveolar abnormalities with amplified natural killer therapy

In amplified natural killer (ANK) cell immunotherapy, NK cells are extracted from the patient's blood, cultured for enhancing its anticancer effects and amplified before they are returned to the body. Here, we administered ANK therapy to an 81-year-old female patient diagnosed with smouldering human T cell leukaemia virus-associated bronchioloalveolar disorder. After eight sessions of twice-weekly NK cell infusion, the bilateral diffuse granular shadows on a CT scan and the overall respiratory function improved markedly. Later, the patient received outpatient treatment without serious side effects. Thus, ANK therapy may be safe for elderly patients owing to its infrequent side effects.

Human T-Cell Leukemia Virus Type 1 Changes Leukocyte Number and Oxidative Stress in the Lung and Blood of Female BALB/c Mice

BACKGROUND

Human T-cell leukemia virus type 1(HTLV-1) infection is likely to induce nonneoplastic inflammatory pulmonary diseases. Therefore, an experimental study was conducted to evaluate the leukocytes' number alteration and oxidative stress in the lung and blood of HTLV-1-infected BALB/c mice, which could be of benefit for the recognition of HTLV-1 mechanism in the induction of pulmonary disorders.

MATERIALS AND METHODS

Twenty female BALB/c mice were divided into two groups of control and HTLV-1-infected animals. The HTLV-1-infected group was inoculated with 106 MT-2 HTLV-1-infected cells. Two months later, the infection was confirmed using real-time polymerase chain reaction, and then lung pathological changes, total and differential inflammatory cell counts in the blood and bronchoalveolar lavage fluid (BALF), along with oxidative stress biomarker levels in the BALF and lung tissue were evaluated.

RESULTS

In the HTLV-1-infected group, the peribronchitis score (P < 0.01), the number of total leukocytes, neutrophils, lymphocytes, and monocytes (P < 0.05) in the blood and BALF were increased. The number of eosinophils in the blood of the HTLV-1-infected group was higher than in the control group (P < 0.01), whereas the number of basophils of BALF was increased in the HTLV-1-infected group (P < 0.001). The lung and BALF oxidative stress results showed that the MDA level was increased, while the total thiol level and superoxide dismutase activity were decreased in the HTLV-1-infected group (P < 0.01).

CONCLUSION

The HTLV-1 infection seems to induce pulmonary inflammatory reactions by recruiting leukocytes as well as inducing oxidative stress in the lung tissue.

Human T-cell leukaemia virus type 1 associated pulmonary disease: clinical and pathological features of an under-recognised complication of HTLV-1 infection

The lung is one of several organs that can be affected by HTLV-1 mediated inflammation. Pulmonary inflammation associated with HTLV-1 infection involves the interstitium, airways and alveoli, resulting in several clinical entities including interstitial pneumonias, bronchiolitis and alveolitis, depending on which structures are most affected. Augmentation of the inflammatory effects of HTLV-1 infected lymphocytes by recruitment of other inflammatory cells in a positive feedback loop is likely to underlie the pathogenesis of HTLV-1 associated pulmonary disease, as has been proposed for HTLV-1 associated myelopathy. In contrast to the conclusions of early case series, HTLV-1 associated pulmonary disease can be associated with significant parenchymal damage, which may progress to bronchiectasis where this involves the airways. Based on our current understanding of HTLV-1 associated pulmonary disease, diagnostic criteria are proposed.

Effectiveness of Combined Therapy with Pirfenidone and Erythromycin for Unclassifiable Interstitial Pneumonia Induced by HTLV-1-associated Bronchioloalveolar Disorder (HABA)

Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus involved in the pathogenesis of adult T-cell leukemia (ATL) and HTVL-1-associated bronchioloalveolar disorder (HABA). The clinical and pathological findings of HABA have been characterized as either a diffuse panbronchiolitis (DPB) pattern or idiopathic interstitial pneumonia (IIP) pattern. Treatments for HABA include corticosteroids for the IIP pattern and erythromycin for the DPB pattern. We herein report a case of HABA-associated unclassifiable interstitial pneumonia that improved with combined therapy with pirfenidone and erythromycin. This is the first report on the effectiveness of combined therapy with pirfenidone and erythromycin for HABA.

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.

Human T-lymphotropic virus type I (HTLV-I)-specific CD8+ cells accumulate in the lungs of patients infected with HTLV-I with pulmonary involvement

Pulmonary involvement has been identified in human T-lymphotropic virus type I (HTLV-I) carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). However, the relationship between HTLV-I infection and lung disease is poorly understood. The occurrence of HTLV-I-specific immune responses in the lungs of patients infected with HTLV-I with pulmonary involvement was investigated. The frequency of HTLV-I-specific CD8+ cells and the amount of HTLV-I proviral DNA were determined in bronchoalveolar lavage fluid cells and peripheral blood mononuclear cells (PBMCs) from five patients with HAM/TSP and one HTLV-I carrier who had pulmonary involvement. HTLV-I-specific CD8+ cells were detected by flow cytometry using human leukocyte antigen/antigen complex multimers. The analysis of bronchoalveolar lavage fluid revealed lymphocytosis in five of six patients. HTLV-I provirus was detected in the bronchoalveolar lavage fluid cells of all patients, and the proviral load in these cells was comparable to that in PBMCs. The frequency of HTLV-I-specific CD8+ cells in the bronchoalveolar lavage fluid cells was 5.1 times higher than that in PBMCs. Immunohistochemically, clusters formed by HTLV-I-specific CD8+ cells were detected in lung tissue by in situ tetramer staining. No samples were available from patients infected with HTLV-I without lung disorders. Whether accumulation of CD8+ cells is specific to patients with pulmonary involvement remains unclear. These results indicate that HTLV-I-specific CD8+ cells accumulate and HTLV-I-infected cells exist in the lungs of patients infected with HTLV-I with pulmonary involvement.

Bronchiectasis is associated with human T-lymphotropic virus 1 infection in an Indigenous Australian population

BACKGROUND

Recent studies suggest that infection with human T-lymphotropic virus 1 (HTLV-1) might be associated with bronchiectasis among Indigenous Australians. The present study compared the clinical characteristics and outcomes of bronchiectasis in this population, according to HTLV-1 serologic status.

METHODS

We performed a retrospective cohort study of Indigenous adults with bronchiectasis and known HTLV-1 serologic status admitted to Alice Springs Hospital, central Australia, from January 2000 through December 2006.

RESULTS

Among 89 Indigenous adults whose HTLV-1 serologic status was confirmed, 52 (58.4%) were HTLV-1 seropositive. Differences between HTLV-1-seropositive and HTLV-1-seronegative groups were apparent in childhood presentations and adult outcomes. Among adults, an increasing number of bronchiectatic lobes (univariable odds ratio [OR], 1.51; 95% confidence interval [CI]; 1.03-2.20; P = .033) and the presence of ground-glass opacities at chest high-resolution computed tomography (univariable OR, 8.54; 95% CI, 1.04-70.03; P = .046) predicted HTLV-1 infection. Cor pumonale (HTLV-1-positive group, 10/52; HTLV-1-negative group, 1/37; P = .023) was more frequent among HTLV-1-seropositive adults, who also experienced a higher disease-specific mortality (univariable OR, 5.78; 95% CI, 1.17-26.75; P = .028). Only HTLV-1-seropositive patients were admitted specifically for the treatment of infected skin lesions, and this finding predicted death (multivariable OR, 6.77; 95% CI, 1.46-31.34; P = .014). Overall mortality was high; 34.2% of the cohort died at a median age of 42.5 years.

CONCLUSIONS

HTLV-1 infection contributes to the risk of developing bronchiectasis and worsens outcomes among Indigenous Australians.

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.

Sarcoidosis and HTLV-1 infection

An asymptomatic, homosexual, white man was found to have an abnormal chest x ray. A presumptive diagnosis of sarcoidosis was made, but pulmonary function tests and a transbronchial biopsy were normal. He then remained asymptomatic for 10 years until he developed a progressive spastic paraparesis. At this point, antibodies to human T cell lymphotropic virus type 1 (HTLV-1) were identified in the serum and cerebrospinal fluid, and the diagnosis of HTLV-1 associated myelopathy was made, the history suggesting sexual exposure to HTLV-1 many years previously. HTLV-1 is associated with a spectrum of immune related disorders, including a pulmonary sarcoid-like syndrome. Infection with this chronic proinflammatory retrovirus should be considered in the differential diagnosis of all immune disorders in at risk individuals.

Influence of human T lymphotrophic virus type I on diffuse pan-bronchiolitis

Human T lymphotrophic virus type-I (HTLV-I), a human retrovirus, infects CD4(+) lymphocytes and is thought to modify their function and a possible association with pulmonary diseases has also been suggested. However, little is known about the influence of HTLV-I on diffuse pan-bronchiolitis (DPB), a chronic inflammatory lung disease with infiltration of lymphocytes and hyperplasia of the bronchus-associated lymphoid tissue. In this study, 35 DPB patients with and without HTLV-I infection were examined. HTLV-I positive DPB patients were likely to have a larger affected area with lower FEV(1). The CD3(+)/CD25(+) lymphocyte percentage was significantly higher in the BALF of HTLV-I positive patients than in negative patients. MIP-1 alpha, IP-10 and levels in BALF were also significantly higher in HTLV-I positive patients than in negative patients. The levels of MCP-1 and IL-8 were not significantly different. In HTLV-I positive patients, the MIP-1 alpha and IP-10 levels showed a significant positive correlation with the percentage of CD3(+)/CD25 lymphocytes. BALF cells of all HTLV-I positive DPB patients showed expression of p40(tax) mRNA. We suggest that HTLV-I infection may modify DPB pathogenesis via activation of T cells. We also found that the frequency of ATL development in HTLV-I positive DPB patients was significantly higher than in all HTLV-I positive patients (OR = 8.22, 95% CI = 2.61-25.9, P < 0.01). The levels of TGF-beta in patients who developed ATL were significantly lower than in patients who did not develop ATL. Sensitivity and specificity were 80% and 85.7%, respectively (cut-off = 20 pg/ml). We also propose that these features should be taken into consideration in the treatment of DPB in HTLV-I infected individuals.

Soluble form of Fas and Fas ligand in serum and bronchoalveolar lavage fluid of individuals infected with human T-lymphotropic virus type 1

Human T-lymphotropic virus type 1 (HTLV-1) carriers are known to develop pulmonary complications characterized by T-lymphocytic alveolitis. The aim of this study was to determine the profile and role of soluble Fas (sFas) and sFas ligand (sFasL) in the lung of asymptomatic HTLV-1 carriers. We measured sFas and sFasL levels in serum and bronchoalveolar lavage fluid (BALF) of 16 seropositive asymptomatic HTLV-1 carriers and 32 healthy subjects. The serum levels of both sFas and sFasL were significantly higher in HTLV-1 carriers than in the control. In BALF, the percentage of lymphocytes and CD4 positive T-cells, and the levels of sFasL were also significantly higher in asymptomatic carriers than the control, but there were no significant differences in sFas levels between the two groups. There was a significant correlation between BALF sFasL levels and serum sFasL levels and percentage of CD4 positive T-cells in BALF. Our results suggest that the increased levels of sFasL in the lung of asymptomatic HTLV-1 carriers are associated with accumulation of CD4 positive T-cells, and that resistance to apoptosis in HTLV-1 infected T-cells and overproduction of sFasL could contribute to T-lymphocytic alveolitis by down-regulating Fas-FasL mediated apoptosis.

Clinical similarities and differences between human T-cell lymphotropic virus type 1-associated bronchiolitis and diffuse panbronchiolitis

STUDY OBJECTIVES

Human T-cell lymphotropic virus type 1 (HTLV-1)-associated bronchiolitis and diffuse panbronchiolitis might overlap. We examined whether these conditions can be differentiated by comparing their clinical features and the effect of long-term macrolide treatment.

PATIENTS AND METHODS

Fifty-eight Japanese patients, including 15 with HTLV-1-associated bronchiolitis and 43 with diffuse panbronchiolitis. Both conditions were clinically compared using the clinical criteria for diffuse panbronchiolitis, including findings from CT scans and BAL fluid testing. Pulmonary function, blood gas levels, and cold hemagglutinin (CHA) levels were assessed before and after long-term treatment with macrolides. Interleukin-2 receptor (IL-2R) expression in T cells obtained from the BAL fluid of patients with HTLV-1-associated bronchiolitis or diffuse panbronchiolitis was analyzed by flow cytometry.

RESULTS

Clinical, laboratory, radiologic, and bacterial features were strikingly similar in both groups, except for the fact that patients with HTLV-1-associated bronchiolitis had a higher ratio of IL-2R-positive cells in the BAL fluid. The histopathologic features were also similar. Long-term treatment with macrolides improved PaO(2), FEV(1), and CHA in patients with HTLV-1-associated bronchiolitis to a lesser extent than in those with diffuse panbronchiolitis, and PaO(2) and FEV(1) in the group of patients with HTLV-1-associated bronchiolitis who had high IL-2R levels did not respond after therapy.

CONCLUSIONS

These findings showed that the clinicopathologic features of the two conditions are quite similar, suggesting that diffuse panbronchiolitis is a chronic pulmonary manifestation of HTLV-1 infection. However, HTLV-1-associated bronchiolitis might be associated with conditions that are distinct from those of diffuse panbronchiolitis based on the different responses to macrolide treatment and the difference in the number of activated T cells bearing IL-2R in the lungs.

High expression of p40(tax) and pro-inflammatory cytokines and chemokines in the lungs of human T-lymphotropic virus type 1-related bronchopulmonary disorders

STUDY OBJECTIVE

Human T-lymphotropic virus type 1 (HTLV-1) is closely associated with the development of certain pulmonary diseases, such as bronchiolitis, although the pathologic mechanism remains unclear. To elucidate the pathogenesis of HTLV-1-associated bronchopulmonary disorders, we analyzed the relationship between expression of p40(tax), a regulatory component of HTLV-1 that stimulates various host genes, and synthesis of pro-inflammatory cytokines and chemokines by cells in BAL fluid (BALF) obtained from HTLV-1-infected patients.

DESIGN

Reverse transcription-polymerase chain reaction was used to compare the expression of p40(tax) and pro-inflammatory cytokines and chemokines messenger RNA (mRNA) in BALF of 10 HTLV-1 carriers and 7 healthy subjects. We also studied the correlation between these parameters and the proportion of lymphocytes in BALF.

RESULTS

The expression levels of pro-inflammatory cytokines (interferon [IFN]-gamma, interleukin-2) and chemokines (monocyte chemotactic protein-1, macrophage inflammatory protein [MIP]-1alpha, IFN-gamma-inducible protein-10 [IP-10]) were significantly higher in BALF of patients than of healthy subjects. The expression of IFN-gamma and MIP-1alpha mRNA correlated with that of p40(tax). IFN-gamma and IP-10 mRNA expression correlated with the proportion of lymphocytes in BALF. The percentage of lymphocytes in BALF increased with higher expression levels of p40(tax) mRNA, although the correlation was not significant.

CONCLUSION

Our results suggested that p40(tax) seems be involved in the development of HTLV-1-associated bronchopulmonary disorders at least in part through the local production of pro-inflammatory cytokines and chemokines.

Influence of human T lymphotrophic virus type I on cryptogenic fibrosing alveolitis - HTLV-I associated fibrosing alveolitis: proposal of a new clinical entity

Human T lymphotrophic virus type-I (HTLV-I), a human retrovirus, infects CD4+ lymphocytes and is thought to modify their function; a possible association with pulmonary diseases has also been suggested. However, little is known about the influence of HTLV-I on cryptogenic fibrosing alveolitis (CFA), a chronic inflammatory interstitial lung disease of unknown aetiology. In order to clarify the influence of HTLV-I infection on CFA, 72 CFA patients with and without HTLV-I infection were examined. HTLV-I positive CFA patients were likely to have larger affected areas and to show traction bronchiectasis with honeycombing change. An imbalance of matrix metalloproteinases and tissue inhibitor of metalloproteinases were also observed in the BALF of HTLV-I positive CFA patients. CD3+/CD25+ lymphocyte percentage was significantly higher in the BALF of HTLV-I positive patients compared to negative patients. MIP-1alpha, IP-10 and sICAM levels in BALF were also significantly higher in HTLV-I positive patients than in negative patients. The levels of MCP-1 and IL-8 were not significantly different. In HTLV-I positive patients, the MIP-1alpha and IP-10 levels showed a significant positive correlation with percentage of CD3+/CD25 lymphocytes. HTLV-I positive CFA patients showed a larger lesion than negative patients and exhibited increased levels of certain cytokines that correlated with activated T cells in the BALF. We suggest that HTLV-I infection may contribute to the development of CFA via activation of T cells. We also propose that these features should be taken into consideration in the treatment of CFA in HTLV-I infected individuals.

Enhanced inhibition of lymphocyte activation by Mycobacterium avium complex in human T lymphotrophic virus type I carriers

BACKGROUND

We have previously reported that disseminated pulmonary Mycobacterium avium complex (MAC) infection is more common in human T lymphotrophic virus type I (HTLV-I) carriers than in non-carriers. However, the reason for this remains unclear. It has been shown that glycopeptidelipid (GPL), one of the lipid components of the cell envelope of MAC, is able to reduce the lymphocyte blastogenic response to mitogens. The purpose of this study was to clarify whether or not the inhibitory effect of GPL differs between HTLV-I carriers and non-carriers.

METHODS

Peripheral blood lymphocytes were obtained from 29 patients who had recovered from pulmonary MAC infection (10 of whom also had HTLV-I infection) and the lymphocyte counts and T cell subpopulations of the peripheral blood lymphocytes in HTLV-I carriers and non-carriers were compared. The inhibitory effect of GPL on the lymphocyte blastogenic response to phytohaemagglutinin (PHA) was tested in these 29 cases and in 15 healthy controls who had never suffered from MAC (seven of whom also had HTLV-I infection). All HTLV-I positive cases were carriers.

RESULTS

There was no significant difference in the numbers or subset proportions of T cells between HTLV-I carriers and non-carriers. Lymphocyte activation by PHA was significantly inhibited by GPL in MAC positive and negative HTLV-I carriers compared with MAC negative non-carriers and MAC negative healthy controls (p<0.001).

CONCLUSIONS

We suggest that MAC infection leads to strong inhibition of lymphocyte activation in HTLV-I carriers. This may account, in part, for the severity of pulmonary MAC infection in HTLV-I carriers.

Elevated levels of soluble adhesion molecules in sera and BAL fluid of individuals infected with human T-cell lymphotropic virus type 1

STUDY OBJECTIVE

T-lymphocytic alveolitis and increased levels of interleukin-2 receptor-alpha (CD25)-bearing T cells in the BAL fluid (BALF) of human T-cell lymphotropic virus type 1 (HTLV-1) carriers have been reported. Several chemokines and adhesion molecules may contribute to the accumulation of T lymphocytes in the lungs of HTLV-1 carriers. To clarify the correlation between adhesion molecules and HTLV-1-associated pulmonary disorders, we compared the distribution of T-lymphocyte subsets and soluble adhesion molecules, including soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble L-selectin (sL-selectin), soluble E-selectin (sE-selectin), and soluble P-selectin (sP-selectin), in BALF and peripheral blood, between HTLV-1 carriers and noninfected healthy subjects.

DESIGN

Flow cytometric analysis with monoclonal antibodies to cell-surface antigens was used to identify T-lymphocyte subsets in BALF samples from HTLV-1 carriers (n = 13) and noninfected healthy control subjects (n = 10). The levels of various soluble adhesion molecules in serum and in BALF were estimated by enzyme-linked immunosorbent assay.

RESULTS

Higher percentages of CD3+ cells, CD3-expressing human leukocyte antigen-DR antigen, and CD3+CD25+ cells were detected in the BALF of HTLV-1 carriers than in that of noninfected control subjects. The concentrations of sICAM-1, sVCAM-1, sL-selectin, SE- selectin, and sP-selectin in the sera of patients were significantly higher than those in noninfected healthy control subjects. The concentration of sICAM-1 in the BALF of patients was significantly higher than that in noninfected healthy control subjects, and the concentration of sICAM-1 correlated well with the percentage of CD3+CD25+ cells.

CONCLUSION

The concentrations of adhesion molecules in the sera of and sICAM-1 in the BALF of HTLV-1 carriers were significantly higher than those in noninfected individuals, and the concentration of sICAM-1 correlated well with the percentage of CD3+CD25+ cells in BALF. Our results suggest a possible interaction between activated T cells bearing CD25 and soluble adhesion molecules, especially sICAM-1, which may contribute to the pulmonary involvement in HTLV-1 carriers.

Up-regulation of human T lymphotropic virus type 1 (HTLV-1) tax/rex mRNA in infected lung tissues

HTLV-1 has been implicated in certain pulmonary diseases. We previously demonstrated that expression of HTLV-1 tax/rex mRNA, encoding the transcriptional transactivator Tax, was closely associated with infiltration of activated T lymphocytes into lung tissue. To explore mechanisms of tax/rex expression in the lung, tax/rex mRNA expression and proviral DNA load were compared between peripheral blood mononuclear cells (PBMC) and bronchoalveolar lavage cells (BALC) from four patients with HTLV-1-associated myelopathy (HAM/TSP) and 13 carriers with various pulmonary symptoms. Semiquantitative detection of tax/rex mRNA strongly suggested that the lung was a preferential site for its expression. Proviral DNA loads in non-HAM/TSP carriers were variable but correlated well between PBMC and BALC in each individual, and revealed no relationship with tax/rex mRNA expression. In contrast, both cell groups from four HAM/TSP patients expressed detectable tax/rex mRNA accompanied by high proviral DNA load. The ratio of tax/rex mRNA expression to proviral DNA load was higher in BALC than in PBMC in three of four carriers and in three of four HAM/TSP patients, suggesting up-regulation of tax/rex mRNA in infected lung tissue. To analyse differences in distribution of HTLV-1 quasispecies between the two tissues, phylogenetic analysis was performed for sequence sets of the proviral tax open reading frame (ORF: 1059 bp) derived from PBMC and BALC of two infected individuals. Sequences derived from the two tissues distributed similarly to branches of phylogenetic trees, and there was no evidence of selective distribution of certain quasispecies in the lung. Our results suggest the presence of tissue-specific conditions that activate viral expression in infected cells in the lung. Constitutive exposure of this tissue to foreign antigens leading to up-regulation of basal viral promoter activity is likely to be one such mechanism.

Chemokine synthesis and cellular inflammatory changes in lungs of mice bearing p40tax of human T-lymphotropic virus type 1

To elucidate the pathogenic mechanisms of human T-lymphotropic virus type 1 (HTLV-1)-associated lung inflammation, we conducted a histopathological and molecular analysis study using transgenic mice bearing pX region of this virus. In these mice, accumulations of inflammatory cells consisting mainly of lymphocytes were present in peribronchiolar and perivascular areas and alveolar septa, while control littermate mice did not show such changes. In situ hybridization showed that the anatomic distribution of p40tax mRNA was similar to that of inflammatory cells, typically in peribronchiolar areas and to a lesser extent in perivascular and alveolar septa. Inflammatory cytokines, including IL-1beta, tumour necrosis factor-alpha and interferon-gamma, and several chemokines, such as monocyte chemotactic protein-1 (MCP-1), RANTES, macrophage inflammatory protein-1alpha (MIP-1alpha) and IP-10, were detected in lungs of transgenic mice but not control mice. Semiquantitative analysis using reverse transcription-polymerase chain reaction showed a significant correlation between MCP-1 mRNA expression and p40tax mRNA, but not with other chemokines. The gene expression of the above chemokines, with the exception of MIP-1alpha, correlated with the severity of histopathological changes in the lung. Considered together, our results suggested that p40tax synthesis may be involved in the development of lung lesions caused by HTLV-1 through the induction of local production of chemokines.

Green tea polyphenols induce apoptosis in vitro in peripheral blood T lymphocytes of adult T-cell leukemia patients

Green tea polyphenols (TEA) are known to exhibit antioxidative activity as well as tumor-suppressing activity. In order to examine the tumor-suppressing activity of TEA against adult T-cell leukemia (ATL), we cultivated peripheral blood T lymphocytes of ATL patients (ATL PBLs), an HTLV-I-infected T-cell line (KODV) and healthy controls (normal PBLs) for 3 days in the presence of TEA and its main constituent, epigallocatechin-3-gallate (EGCg), to measure cell proliferation and apoptosis, and to quantitate mRNAs of HTLV-I pX and beta-actin genes of the cultured cells. Growth of ATL PBLs was significantly inhibited by 9-27 microg/ml of TEA and EGCg, in contrast to minimal growth inhibition of T cells of normal PBLs. Inhibition of KODV was intermediate between ATL PBLs and normal PBLs. The ATL PBLs and KODV treated with 27 microg/ml of either TEA or EGCg induced apoptotic DNA fragmentation, producing terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells, while the normal PBLs treated with the same concentration of TEA or EGCg produced a negligibly small number of TUNEL-positive cells, in which apoptotic DNA fragmentation was not detectable. Expression of HTLV-I pX mRNA was suppressed more than 90% in ATL PBLs by treatment with 3-27 microg/ml of either TEA or EGCg, while expression of beta-actin mRNA was much less suppressed by treatment with the same concentration of TEA or EGCg. These results indicate that TEA and EGCg inhibit growth of ATL PBLs, as well as HTLV-I-infected T-cells, by suppressing HTLV-I pX gene expression and inducing apoptotic cell death.

Elevated levels of beta-chemokines in bronchoalveolar lavage fluid (BALF) of individuals infected with human T lymphotropic virus type-1 (HTLV-1)

Pulmonary complications are known to develop in HTLV-1 carriers, including T lymphocytic alveolitis, and increased IL-2 receptor alpha (CD25)-bearing T cells have been found in BALF. Several chemokines may contribute to accumulation of T lymphocytes in the lungs of HTLV-1 carriers. Here, we compared the distribution of T lymphocyte subsets and beta-chemokines, such as macrophage inflammatory peptide-1alpha (MIP-1alpha), regulated on activation normal T expressed and secreted (RANTES), and macrophage chemoattractant protein-1 (MCP-1), in BALF and peripheral blood between HTLV-1 carriers and non-infected healthy normal subjects. Flow cytometric analysis with MoAbs to cell surface antigens was used to identify T lymphocyte subsets in BALF samples from HTLV-1 carriers (n = 13) and non-infected healthy controls (n = 10). The levels of different beta-chemokines were estimated by ELISA. High percentages of CD3+ cells, CD3 expressing HLA-DR antigen and CD3+CD25+ cells were detected in BALF of HTLV-1 carriers compared with non-infected controls. The concentration of MIP-1alpha in BALF of patients was significantly higher than in non-infected healthy controls and correlated well with the percentage of CD3+CD25+ cells. The level of RANTES in BALF was also significantly high in HTLV-1 carriers, but did not correlate with the percentage of CD3+CD25+ cells. On the other hand, the level of MCP-1 in BALF of HTLV-1 carriers was not different from that of controls. Our results suggest a possible interaction between activated T cells bearing CD25 and beta-chemokines, especially MIP-1alpha, which may contribute to the pulmonary involvement in HTLV-1 carriers.

Induction of lymphocytic inflammatory changes in lung interstitium by human T lymphotropic virus type I

Human T lymphotropic virus type I (HTLV-I) is the etiological agent of adult T cell leukemia, and reports suggest that several other clinical conditions are associated with HTLV-I infection, including myelopathy and inflammatory pulmonary diseases. However, the clinical entity of HTLV-I-associated lung disease remains unsubstantiated more than 10 years after its description. In the present study, we conducted a histopathological analysis of lung tissues of transgenic mice that expressed gene segments of HTLV-I p40(tax) regions. The aim of the study was to examine the relationship between expression of viral components and development of lung disorders. In these mice, inflammatory changes with infiltration of lymphocytes in peribronchial and perivascular areas and in alveolar septa developed at 11 wk of age and increased in incidence during the observation period (26 wk). There was a significant correlation between the pulmonary pathological changes and the level of expression of p40(tax) mRNA in the lungs. Our results provided for the first time strong evidence of a direct relationship between HTLV-I and development of bronchopulmonary infection.

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.

Low copy numbers of human T-cell lymphotropic virus type I (HTLV-I) tax-like DNA detected in the salivary gland of seronegative patients with Sjögren's syndrome in an HTLV-I endemic area

To evaluate the hypothesis, proposed in previous reports from HTLV-I non-endemic areas, that HTLV-I is involved in a significant proportion, about a quarter, of Sjögren's syndrome patients who lack serum antibodies to the virus, we examined for the presence or absence of HTLV-I in DNA samples isolated from salivary gland tissues of 17 seronegative as well as 7 seropositive patients with Sjögren's syndrome in Nagasaki, Japan, where the virus is highly endemic. The nested two-step polymerase chain reaction (PCR), with a sensitivity capable of detecting a single DNA molecule, failed to amplify the HTLV-I tax sequence from DNA of 14 of the 17 seronegative patients. The tax was only amplifiable from the tissue DNA of the remaining three seronegative patients. The detection rate, 3/17 (18%), was, unexpectedly, less than those previously reported from the HTLV-I non-endemic areas. Moreover, in contrast to high viral loads (10(-1) to 10(-3) per cell) in the salivary gland of the seropositive patients, a semiquantitative PCR revealed that the copy number of the HTLV-I tax in the gland tissue of these seronegative patients was very low, 10(-5) per cell. This level is unlikely to be sufficient to promote an inflammatory reaction in the tissue. Our findings might argue against the involvement of "prototype" HTLV-I in the pathogenesis of Sjögren's syndrome in seronegative patients.

HAM/TSP: recent perspectives in Japan

Neurologic diseases associated with human T-cell lymphotropic virus type I (HTLV-I) infection have a clinical spectrum that includes myelopathy (HTLV-I-associated myelopathy/tropical spastic paraparesis, HAM/TSP) as the central manifestation. Many clinical signs of involvement outside the central nervous system (CNS) have been described in some patients with HAM/TSP and have triggered and advanced the discovery of some HTLV-I-associated concepts in HTLV-I-infected individuals without signs of CNS involvement. Most of these HTLV-I-associated diseases exhibit common viroimmunologic characteristics that include a distributional bias of HTLV-I activation between the blood flow and the affected lesions and accumulated cellular immune responses in the lesions. These facts suggest that the vulnerable tissue(s) in some HTLV-I-infected individuals may not be defined by an exclusive tissue specificity, but that common steps of HTLV-I-versus-host interactions may have an important role in the pathologic process(es) in these diseases. This review summarizes the recent perspectives of the clinical spectrum and the pathogenesis of HAM/TSP in Japan. Furthermore, the feasible pathogenic involvement of cellular interactions between infected cells and responding immunocompetent cells in the affected tissues is emphasized.