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

An Overview of Human T-Lymphotropic Virus Type 1 Lung Injury

Previous studies have demonstrated the development of pulmonary impairment in individuals infected with human T-lymphotropic virus type 1 (HTLV-1). Complications, such as alveolitis and bronchiectasis, were found in individuals who developed tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP-HAM) due to chronic inflammation. These patients exhibited increased levels of lymphocytes (CD4+ and CD25+), cytokines (IL-2, IL-12, and IFN-γ), inflammatory chemokines (MIP-1α and IP-10), and cell adhesion molecules (ICAM-1) in the bronchoalveolar lavage fluid, with the result of chronic inflammation and lung injury. The main lesions observed at Chest high-resolution computed tomography were centrilobular nodules, parenchymal bands, lung cysts, bronchiectasis, ground-glass opacity, mosaic attenuation, and pleural thickening. It can lead to progressive changes in pulmonary function with the development of restrictive and obstructive diseases. Recent studies suggest a causal relationship between HTLV-1 and pulmonary diseases, with intensification of lesions and progressive decrease in pulmonary function. This summary updates a previous publication and addresses the general lack of knowledge regarding the relationship between TSP-HAM and pulmonary disease, providing direction for future work and the management of these individuals.

Virus infection induced pulmonary fibrosis

Pulmonary fibrosis is the end stage of a broad range of heterogeneous interstitial lung diseases and more than 200 factors contribute to it. In recent years, the relationship between virus infection and pulmonary fibrosis is getting more and more attention, especially after the outbreak of SARS-CoV-2 in 2019, however, the mechanisms underlying the virus-induced pulmonary fibrosis are not fully understood. Here, we review the relationship between pulmonary fibrosis and several viruses such as Human T-cell leukemia virus (HTLV), Human immunodeficiency virus (HIV), Cytomegalovirus (CMV), Epstein–Barr virus (EBV), Murine γ-herpesvirus 68 (MHV-68), Influenza virus, Avian influenza virus, Middle East Respiratory Syndrome (MERS)-CoV, Severe acute respiratory syndrome (SARS)-CoV and SARS-CoV-2 as well as the mechanisms underlying the virus infection induced pulmonary fibrosis. This may shed new light on the potential targets for anti-fibrotic therapy to treat pulmonary fibrosis induced by viruses including SARS-CoV-2.

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.

Human T Lymphotropic Virus and Pulmonary Diseases

Human T lymphotropic virus type 1 (HTLV-1) is the etiological agent of HTLV-1-associated myelopathy, and adult T cell lymphoma/leukemia (ATL/L). Pulmonary complications such as alveolitis and bronchiectasis were found in individuals who develop TSP/HAM due to chronic inflammation. These individuals showed image anomalies in CT scans and changes in pulmonary function parameters distinctive of pulmonary disease. Furthermore, infected individuals have a greater susceptibility to pulmonary tuberculosis either due to changes in the innate immune response, in asymptomatic carriers, or to an opportunistic disease linked to immunodepression, in individuals who develop ATL/L. This summary addresses the general lack of knowledge regarding the relationship between HTLV-1 and pulmonary diseases and provides direction for future work.

CT Chest and pulmonary functional changes in patients with HTLV-associated myelopathy in the Eastern Brazilian Amazon

The aim of this study was to compare computed tomography (CT) scans of chest and lung function among patients with Human T-Lymphotropic Virus Type 1 (HTLV) with and without HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). In this cross-sectional study performed between January 2013 and June 2016, we included 48 patients with HAM/TSP (19 women and 11 men) and without HAM/TSP (12 women and 6 men). We compared CT findings and lung functions of these groups. Patients who had HAM/TSP had abnormal CT findings (P = 0.000), including more frequent bronchiectasis (P = 0.049), parenchymal bands (P = 0.007), interlobular septal thickening (P = 0.035), and pleural thickening (P = 0.009). In addition, neither patients with HAM/TSP (9/30; 30%) nor the controls (0/18; 0%) had obstructive or restrictive lung disease (P = 0.009). HTLV diagnosis should be considered in all patients with abnormal CT findings in whom no other cause is apparent. It is important to remember that lung disease increases the rates of morbidity and mortality in developing countries.

Increased expression of HBZ and Foxp3 mRNA in bronchoalveolar lavage cells taken from human T-lymphotropic virus type 1-associated lung disorder patients

OBJECTIVE

Human T-lymphotropic virus type 1 (HTLV-I) causes adult T-cell leukemia/lymphoma (ATLL), and is associated with chronic inflammatory diseases, including inflammatory pulmonary diseases. HTLV-I bZIP factor (HBZ), which is expressed in all adult T-cell leukemia cells, plays a critical role in the development of lymphoma and systemic inflammation. HTLV-I is harbored by CD4(+) T cells that express forkhead box P3 (Foxp3), and HBZ interacts with Foxp3. This study investigated the chest computed tomography (CT) findings and expression of HBZ and Foxp3 in the bronchoalveolar lavage (BAL) cells from patients with HTLV-I-associated lung disorders.

METHODS

CT scans obtained from 37 patients (10 men and 27 women, aged 37-77 years) with HTLV-I-associated lung disorders were retrospectively evaluated. The expression levels of HBZ and Foxp3 mRNA in BAL cells and the levels of inflammatory cytokines in the BAL fluid (BALF) from patients were compared with those in control subjects.

RESULTS

CT scans frequently revealed a diffuse panbronchiolitis (DPB)-like pattern, along with a nonspecific interstitial pneumonia (NSIP) pattern. An analysis of the BALF revealed lymphocytosis and increased expression of HBZ mRNA in patients with HTLV-I-associated lung disorders. The expression of Foxp3 mRNA positively correlated with the percentages of lymphocytes present in the BALF. The inflammatory cytokine and IL-10 levels were significantly increased in the BALF from patients with HTLV-I-associated lung disorders.

CONCLUSION

The NSIP pattern may be a manifestation of pulmonary involvement in HTLV-I-infected patients, as is the DPB-like pattern. HBZ and Foxp3 likely have a role in the development of lung inflammation.

Interleukin-1 alpha produced by human T-cell leukaemia virus type I-infected T cells induces intercellular adhesion molecule-1 expression on lung epithelial cells

The pathogenic mechanism of human T-cell leukaemia virus type I (HTLV-I)-related pulmonary disease, which involves overexpression of intercellular adhesion molecule-1 (ICAM-1) in lung epithelial cells, was investigated. The supernatant of HTLV-I-infected Tax(+) MT-2 and C5/MJ cells induced ICAM-1 expression on A549 cells, a human tumour cell line with the properties of alveolar epithelial cells. Neutralization of ICAM-1 partially inhibited HTLV-I-infected T-cell adhesion to A549 cells. Analysis of the ICAM-1 promoter showed that the nuclear factor-kappa B-binding site was important for supernatant-induced ICAM-1 expression. Induction of interleukin (IL)-1 alpha (IL-1α) expression in MT-2 and C5/MJ cells was observed compared with uninfected controls and HTLV-I-infected Tax-negative cell lines. The significance of IL-1α as a soluble messenger was supported by blocking the biological activities of MT-2 supernatant with an IL-1α-neutralizing mAb. Moreover, Tax and IL-1α expression was demonstrated in the bronchoalveolar lavage cells of patients with HTLV-I-related pulmonary disease. Immunohistochemistry confirmed ICAM-1 and IL-1α expression in lung epithelial cells and lymphocytes of patients with HTLV-I-related pulmonary diseases, and in a transgenic mouse model of Tax expression. These results suggest that IL-1α produced by HTLV-I-infected Tax(+) T cells is crucial for ICAM-1 expression in lung epithelial cells and subsequent adhesion of lymphocytes in HTLV-I-related pulmonary diseases.

Human T-cell leukemia virus type I infects human lung epithelial cells and induces gene expression of cytokines, chemokines and cell adhesion molecules

Background

Human T-cell leukemia virus type I (HTLV-I) is associated with pulmonary diseases, characterized by bronchoalveolar lymphocytosis, which correlates with HTLV-I proviral DNA in carriers. HTLV-I Tax seems to be involved in the development of such pulmonary diseases through the local production of inflammatory cytokines and chemokines in T cells. However, little is known about induction of these genes by HTLV-I infection in lung epithelial cells.

Results

We tested infection of lung epithelial cells by HTLV-I by coculture studies in which A549 alveolar and NCI-H292 tracheal epithelial cell lines were cocultured with MT-2, an HTLV-I-infected T-cell line. Changes in the expression of several cellular genes were assessed by reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay and flow cytometry. Coculture with MT-2 cells resulted in infection of lung epithelial cells as confirmed by detection of proviral DNA, HTLV-I Tax expression and HTLV-I p19 in the latter cells. Infection was associated with induction of mRNA expression of various cytokines, chemokines and cell adhesion molecule. NF-κB and AP-1 were also activated in HTLV-I-infected lung epithelial cells. In vivo studies showed Tax protein in lung epithelial cells of mice bearing Tax and patients with HTLV-I-related pulmonary diseases.

Conclusion

Our results suggest that HTLV-I infects lung epithelial cells, with subsequent production of cytokines, chemokines and cell adhesion molecules through induction of NF-κB and AP-1. These changes can contribute to the clinical features of HTLV-I-related pulmonary diseases.

Human T-cell leukemia virus type-1 Tax oncoprotein regulates G-protein signaling

Human T-cell leukemia virus type-1 (HTLV-1) is associated with adult T-cell leukemia (ATL) and neurological syndromes. HTLV-1 encodes the oncoprotein Tax-1, which modulates viral and cellular gene expression leading to T-cell transformation. Guanine nucleotide-binding proteins (G proteins) and G protein-coupled receptors (GPCRs) constitute the largest family of membrane proteins known and are involved in the regulation of most biological functions. Here, we report an interaction between HTLV-1 Tax oncoprotein and the G-protein beta subunit. Interestingly, though the G-protein beta subunit inhibits Tax-mediated viral transcription, Tax-1 perturbs G-protein beta subcellular localization. Functional evidence for these observations was obtained using conditional Tax-1-expressing transformed T-lymphocytes, where Tax expression correlated with activation of the SDF-1/CXCR4 axis. Our data indicated that HTLV-1 developed a strategy based on the activation of the SDF-1/CXCR4 axis in the infected cell; this could have tremendous implications for new therapeutic strategies.

Contributions of E1A to mouse adenovirus type 1 pathogenesis following intranasal inoculation

We investigated the role of mouse adenovirus type 1 (MAV-1) early region 1A (E1A) protein in adenovirus respiratory infection. Intranasal (i.n.) inoculation of mice with wild type (wt) virus induced chemokine and cellular inflammatory responses in the lung. We observed similar responses in mice infected with an E1A-null mutant virus at the same dose, although the magnitude of these responses was lower. Levels of viral hexon gene expression were lower in the lung following infection with E1A-null virus than with wt virus. When input doses were adjusted so that equivalent viral loads were present following infection with varying doses of wt and E1A-null virus, we observed equivalent chemokine upregulation in the lung. Dissemination to the brain occurred following i.n. inoculation with equal doses of wt or E1A-null virus, but viral gene expression and viral loads were lower and the magnitude of chemokine responses was lower in brains of E1A-null virus-infected mice. CD4 and CD8 T cells and neutrophils were recruited to the brains of mice infected with either wt or E1A-null virus. Together, these data suggest that MAV-1 E1A makes important contributions to viral replication in the lung and the brain following i.n. inoculation. However, E1A is not essential for the induction of inflammatory responses in the lung or for viral dissemination out of the lung.

Gammaherpesvirus-Induced Lung Pathology Is Altered in the Absence of Macrophages

The purpose of this study was to examine the lung pathogenesis of murine gammaherpesvirus (MHV-68) infection in mice that lack CC chemokine receptor CCR2, an important receptor for macrophage recruitment to sites of inflammation. BALB/c and CCR2(-/-) mice were inoculated intranasally (i.n.) with MHV-68 and samples were collected during acute infection (6 dpi) and following viral clearance (12 dpi). Immunohistochemistry was used to determine which cells types responded to MHV-68 infection in the lungs. Lung pathology in infected BALB/c mice was characterized by a mixed inflammatory cell infiltrate, necrosis, and increased alveolar macrophages by 12 dpi. Immunohistochemistry showed intense positive staining for macrophages. CCR2(-/-) mice showed greater inflammation in the lungs at 12 dpi than did BALB/c mice, with more necrosis and diffuse neutrophil infiltrates in the alveoli. Immunohistochemistry demonstrated much less macrophage infiltration in the CCR2(-/-) mice than in the BALB/c mice. These studies show that CCR2 is involved in macrophage recruitment in response to MHV-68 infection and illustrates how impairments in macrophage function affect the normal inflammatory response to this viral infection.

Elevated expression of CCL5/RANTES in adult T-cell leukemia cells: possible transactivation of the CCL5 gene by human T-cell leukemia virus type I tax

HTLV-I is the etiologic agent of ATL and of tropical spastic paraparesis/HTLV-I-associated myelopathy. Infiltration of various tissues by circulating leukemic cells and HTLV-I-infected T cells is a characteristic of ATL and HTLV-I-associated inflammatory diseases. Chemokines play important roles in migration and tissue localization of various lymphocyte subsets. Here, we report the highly frequent expression of CCL5 (RANTES) in ATL and HTLV-I-infected T-cell lines. Among various human T-cell lines, those infected with HTLV-I selectively expressed the CCL5 gene and secreted CCL5. Furthermore, CCL5 was expressed by leukemic cells in peripheral blood and lymph nodes from patients with ATL. Inducible expression of HTLV-I transcriptional activator Tax in a human T-cell line Jurkat, up-regulated CCL5 mRNA and induced CCL5 secretion. Analysis of the CCL5 promoter revealed that this gene is activated by Tax, via the activation of NF-kappaB, whose responsive element, R(A/B), is located at positions -71 to -43 relative to the putative transcription start site. Aberrant expression of CCL5 by HTLV-I-infected T cells may impact on the pathophysiology of HTLV-I-associated diseases.

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.

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.

A kinetic analysis of immune mediators in the lungs of mice infected with vaccinia virus and comparison with intradermal infection

The early inflammatory response to a virus may be critical in restricting infection and in shaping the subsequent adaptive immune response. In this study we have examined the early inflammatory response of mice following infection with vaccinia virus (VV) strain Western Reserve (WR). Respiratory challenge of BALB/c mice with VV led to early virus replication in the lung and upper respiratory tract followed by dissemination of virus to other visceral organs and to the brain. The number of inflammatory cells, largely macrophages and T lymphocytes, recovered from bronchoalveolar lavage (BAL) fluid increased markedly during infection and coincided with the expression of CC chemokine ligands (CCL) 3, 2 and 11 and CXC chemokine ligands (CXCL) 1 and 2/3 in BAL. The peak of the inflammatory response occurred around day 10 and declined thereafter. The antiviral cytokines IFN-gamma and TNF-alpha, and the reactive nitrogen intermediate nitric oxide (NO), were also detected in BAL from VV-infected mice. A markedly different inflammatory response was observed after intradermal inoculation of WR into the ear pinnae of mice. Intradermal challenge was followed by highly localized virus replication and by a cellular influx, consisting largely of neutrophils and T lymphocytes, into the dermal compartment of the infected ear. Together these findings highlight differences in the pathogenesis and in the cellular inflammatory response to WR following intranasal and intradermal inoculation of mice.

Elevated chemokine responses are maintained in lungs after clearance of viral infection

We observed two patterns of chemokine expression in the lungs of mice infected with murine gammaherpesvirus 68: peaks of chemokine expression correlated with or occurred after the peak of viral gene expression. Chemokine expression remained elevated through 29 days postinfection.

p53 and PTEN/MMAC1/TEP1 gene therapy of human prostate PC-3 carcinoma xenograft, using transferrin-facilitated lipofection gene delivery strategy

We previously reported that supplementation of a cationic liposome with transferrin (Tf) greatly enhanced lipofection efficiency (P.-W. Cheng, Hum. Gene Ther. 1996;7:275-282). In this study, we examined the efficacy of p53 and PTEN tumor suppressor gene therapy in a mouse xenograft model of human prostate PC-3 carcinoma cells, using a vector consisting of dimyristoyloxypropyl-3-dimethylhydroxyethyl ammonium bromide (DMRIE)-cholesterol (DC) and Tf. When the volume of the tumors grown subcutaneously in athymic nude mice reached 50-60 mm(3), three intratumoral injections of the following four formulations were performed during week 1 and then during week 3: (1) saline, (2) DC + Tf + pCMVlacZ, (3) DC + Tf + pCMVPTEN, and (4) DC + Tf + pCMVp53 (standard formulation). There was no significant difference in tumor volume and survival between group 1 and group 2 animals. As compared with group 1 controls, group 3 animals had slower tumor growth during the first 3 weeks but thereafter their tumor growth rate was similar to that of the controls. By day 2 posttreatment, group 4 animals had significantly lower tumor volume relative to initial tumor volume as well as controls at the comparable time point. Also, animals treated with p53 survived longer. Treatment with DC, Tf, pCMVp53, DC + pCMVp53, or Tf + pCMVp53 had no effect on tumor volume or survival. Expression of p53 protein and apoptosis were detected in tumors treated with the standard formulation, thus associating p53 protein expression and apoptosis with efficacy. However, p53 protein was expressed in only a fraction of the tumor cells, suggesting a role for bystander effects in the efficacy of p53 gene therapy. We conclude that intratumoral gene delivery by a nonviral vector consisting of a cationic liposome and Tf can achieve efficacious p53 gene therapy of prostate cancer.