High prevalence of HTLV-I infection in Mashhad, Northeast Iran: a population-based seroepidemiology survey.

BACKGROUND: Mashhad, in the northeast of Iran has been suggested as an endemic area for human T cell lymphotropic virus type I (HTLV-I) infection since 1996. OBJECTIVES: We performed a community-based seroepidemiology study to examine the prevalence and risk factors for HTLV-I infection in the city of Mashhad. STUDY DESIGN: Between May and September 2009, overall 1678 subjects from all the 12 geographical area of Mashhad were selected randomly by multistage cluster sampling for HTLV antibody. The study population included 763 males and 915 females, with the mean age of 29.1 ± 18.5 years. 1654 serum samples were assessed for HTLV antibody using ELISA and reactive samples were confirmed by Western blot and PCR. RESULTS: The overall prevalence of HTLV-I infection in whole population was 2.12% (95% CI, 1.48-2.93) with no significant difference between males and females (p = 0.093) and the prevalence of HTLV-II seropositivity was 0.12% (95% CI, 0.02-0.44). The HTLV-I Infection was associated with age (p<0.001), marital status (p<0.001), education (p = 0.047), and history of blood transfusion (p = 0.009), surgery (p<0.001), traditional cupping (p = 0.002), and hospitalization (p = 0.004). In logistic regression analysis, age was the only variable that had a significant relation with the infection (p = 0.006, OR = 4.33). CONCLUSIONS: Our results demonstrated that Mashhad still remains an endemic area for HTLV-I infection despite routine blood screening. Thus, further strategies are needed for prevention of the virus transmission in whole population.

Effect of propolis and caffeic acid phenethyl ester (CAPE) on NFκB activation by HTLV-1 Tax.

HTLV-1 is the etiological agent of aggressive malignancy of the CD4(+) T-cells, adult T-cell leukemia (ATL), and other severe clinical disorders. The viral Tax protein is a key factor in HTLV-1 pathogenicity. A major part of Tax oncogenic potential is accounted for by its capacity of inducing the transcriptional activity of the NFκB factors, which regulate the expression of numerous cellular genes. Propolis (PE), a natural product produced by honeybees, has been used for a long time in folk medicine. One of PE active components, caffeic acid phenylethyl ester (CAPE), was well characterized and found to be a potent inhibitor of NFκB activation. Therefore, the aim of this study was to pursue the possibility of blocking Tax oncogenic effects by treatment with these natural products. Human T-cell lines were used in this study since these cells are the main targets of HTLV-1 infections. We tried to determine which step of Tax-induced NFκB activation is blocked by these products. Our results showed that both tested products substantially inhibited the activation of NFκB-dependent promoter by Tax. However, only PE could efficiently inhibit also the Tax-induced activation of SRF- and CREB-dependent promoters. Our results showed also that PE and CAPE strongly prevented both Tax binding to IκBα and its induced degradation by Tax. However, both products did not interfere in the nuclear transport of Tax or NFκB proteins.

Inhibition of immune activation by a novel nuclear factor-kappa B inhibitor in HTLV-I-associated neurologic disease.

The human T-lymphotropic virus type I (HTLV-I) causes a chronic inflammatory disorder of the central nervous system termed HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-I encodes a protein known to activate several host-signaling pathways involved in inflammation, such as the nuclear factor-κB (NF-κB). The contribution of the NF-κB pathway to the pathogenesis of HAM/TSP, however, has not been fully defined. We show evidence of canonical NF-κB activation in short-term cultures of peripheral blood mononuclear cells (PBMCs) from subjects with HAM/TSP. NF-κB activation was closely linked to HTLV-I viral protein expression. The NF-κB activation in HAM/TSP PBMCs was reversed by a novel small-molecule inhibitor that demonstrates potent and selective NF-κB antagonist activity. Inhibition of NF-κB activation led to a reduction in the expression of lymphocyte activation markers and resulted in reduced cytokine signaling in HAM/TSP PBMCs. Furthermore, NF-κB inhibition led to a reduction in spontaneous lymphoproliferation, a key ex vivo correlate of the immune activation associated with HAM/TSP. These results indicate that NF-κB activation plays a critical upstream role in the immune activation of HAM/TSP, and identify the NF-κB pathway as a potential target for immunomodulation in HAM/TSP.

[Immunopathogenesis and treatment of the myelopathy associated to the HTLV-I virus]. / Inmunopatogenesis y tratamiento de la mielopatia asociada al virus linfotropico humano de celulas T (HTLV-I).

INTRODUCTION: Human T-cell lymphotropic virus type-I (HTLV-I) causes tropical spastic paraparesis/HTLV-I associated myelopathy (TSP/HAM). Immunopathogenesis and available treatments for TSP/HAM are reviewed. DEVELOPMENT: At least 20 million people are infected worldwide and 0.3-4% will develop TSP/HAM. Incidence in endemic areas is around 2 cases/ 100,000 inhabitants and year. The 50% of TSP/HAM patients suffer from clinical progression during their first ten years. Progression is associated with high proviral load and ager than 50 years at onset. HTLV-I proviral DNA and m-RNA load are significantly raised in TSP/HAM patients compared to asymptomatic carriers. This antigenic load activates T cells CD8+ specific for Tax-protein, which up-regulate pro-inflammatory cytokines. Corticoids, plasma-exchange, intravenous immunoglobulins, danazol, pentoxifilline, green-tea polyphenols, lactobacillus fermented milk, zidovudine, lamivudine, monoclonal antibodies (daclizumab), interferon, and valproic acid have been used in open trials in a small number of patients. Nevertheless, their clinical efficacy is limited. Interferon alpha and beta-1a have cytostatic properties and may cause a reduction in HTLV-I proviral load. CONCLUSIONS: High HTLV-I proviral load and an exaggerated pro-inflammatory cellular response are involved in the pathogenesis of TSP/HAM. No therapy has been conclusively shown to alter long-term disability associated with TSP/HAM. Multicentric clinical trials are necessary to assess long-term efficacy of interferon in TSP/HAM.

Microencapsulation of a synthetic peptide epitope for HTLV-1 in biodegradable poly(D,L-lactide-co-glycolide) microspheres using a novel encapsulation technique.

A novel procedure has been developed for the encapsulation of peptide antigens in poly(lactide-co-glycolide) (PLGA) microspheres, which employs trifluoro-acetic acid (TFA) as a carrier solvent for both the polymer and antigen. The antigen/polymer solution is emulsified in mineral oil containing sorbitan trioleate (Span 85) as an emulsifier and a low level of cottonseed oil to extract the TFA. Fluoresceinisothiocyanate-labelled bovine serum albumin (FITC-BSA) was used as a model antigen to characterize the microencapsulation. Microspheres were of the desired size (<10 microm) for targeting to antigen-presenting cells, and released the model antigen slowly after an initial burst release (11%) in PBS/0.02% Tween 80 at 37 degrees C. Subsequently, a potential peptide vaccine, designated MVFMF2, for the human T-lymphotropic virus type 1 (HTLV-1 ) was encapsulated at 4.7% loading using the novel oil-in-oil method. In vivo immune responses were examined in rabbits immunized with (i) encapsulated MVFMF2 together with encapsulated adjuvant (N-acetyl-glucosamine-3yl-acetyl-L-alanyl-D-isoglutamine, nor-MDP, (ii) encapsulated MVFMF2 without adjuvant, and (iii) free peptide with adjuvant. Inoculation of the encapsulated peptide produced an antibody response similar to that of the free peptide emulsified in adjuvant. Moreover, the elevated immune response elicited by the encapsulated peptide was observed without multiple booster immunizations and irrespective of whether an adjuvant was used. Additionally, the antibodies raised against both free and encapsulated MVFMF2 had similar affinities, as judged by competitive enzyme-linked immunosorbant assay (ELISA), indicating that the encapsulated peptide retained a significant fraction of its epitopes. Hence, these results demonstrate that peptide vaccines can be encapsulated in PLGA microspheres using a common carrier solvent for both the peptide and polymer, which produces a desirable immune response in the absence of an adjuvant.

On the etiology of tropical spastic paraparesis and human T-cell lymphotropic virus-I-associated myelopathy.

The purpose of this review is to present some concepts on the etiology of tropical spastic paraparesis or human T-cell lymphotropic virus-I (HTLV-I)-associated myelopathy (TSP/HAM). The large number of syndromes that have been associated with HTLV-I (60 to date), the existence of TSP/HAM cases associated with other retroviruses (human immunodeficiency virus-2 [HIV-2], HTLV-II), the existence of many TSPs without HTLV-I, and the evidence of clear epidemiologic contradictions in TSP/HAM indicate that the etiopathogenesis of TSP/HAM is not yet clear. Tropical spastic paraparesis/HAM affects patients of all human ethnic groups, but usually in well localized and relatively isolated geographic regions where HTLV-I has been endemic for a long time. Environmental factors and geographic locations appear to be critical factors. Because the neuropathology of TSP/HAM suggests a toxometabolic, rather than a viral cause, it is proposed that an intoxication similar to neurolathyrism could account for some of TSP/HAM cases, mainly in tropical and subtropical countries. If this were the case, HTLV-I could be a cofactor or act as a bystander. it is possible that co-infection with another agent is necessary to produce TSP/HAM and most of the syndromes associated with HTLV-I.

A prospective study of the risk of transfusion-acquired viral infections.

The risk of transfusion-transmitted viral infections may be estimated by several methods, but only prospective studies of transfusion recipients can directly measure the incidence, with associated 95% upper confidence bound, of these infections. From 1989 through 1995, 764 recipients of allogeneic or autologous red blood cell transfusions were enrolled; 486 (64%) provided both pretransfusion and 6-month follow-up specimens. Both specimens were tested for anti-HBc, anti-HCV, anti-HTLV-I and anti-HIV, with appropriate confirmatory testing. Thirty-nine (8.0%) subjects had seroprevalent anti-HBc, 19 (3.9%) subjects had seroprevalent anti-HCV, three (0.6%) subjects had seroprevalent anti-HTLV-I/II, and one (0.2%) subject had seroprevalent anti-HIV. There were no seroconversions for any agent among the 34 patients who received only autologous blood, and no confirmed seroconversions for anti-HTLV-I or anti-HIV among all subjects. There were three seroconversions for anti-HBc (incidence 1.04 x 10(-3); 95% confidence interval (CI) 2.15 x 10(-4), 3.05 x 10(-3) per allogeneic unit transfused), and two confirmed seroconversions for HCV (incidence 6.94 x 10(-4); 95% CI 8.34 x 10(-5), 2.51 x 10(-3) per allogeneic unit transfused). One of the two anti-HCV seroconversions occurred in March 1994, after the institution of HCV EIA 2.0 screening of donated blood. Transfusion-associated seroconversions to hepatitis B and C markers were observed at low rates in the early 1990s despite testing donors for markers of both viruses, whereas seroconversions to HTLV-I or HIV were less than 1.04 x 10(3) per allogeneic unit transfused, based upon the upper 95% confidence interval of the zero incidence in this study.

Vaccination of rabbits with recombinant vaccinia virus carrying the envelope gene of human T-cell lymphotropic virus type I.

Two groups of 3 rabbits each were immunized with either recombinant vaccinia virus, WR-SFB5env, carrying the human T-cell lymphotropic virus type I (HTLV-I) env gene at the site of the hemagglutinin gene of the WR strain, or control vaccinia virus, HA-WR, lacking the functional hemagglutinin gene. All 6 rabbits responded with anti-vaccinia virus antibodies. WR-SFB5env elicited anti-HTLV-I env antibodies but no vesicular stomatitis virus (HTLV-I) pseudotype neutralizing antibodies in all 3 rabbits. After 10 weeks, the animals were challenged by transfusion of blood from an HTLV-I-infected rabbit. Two of the 3 vaccinated rabbits and all 3 control rabbits became infected with HTLV-I, as indicated by seroconversion and detection of HTLV-I proviral sequences by polymerase chain reaction. The rabbit that had been protected from initial challenge became infected with HTLV-I upon rechallenge 12 weeks after the first challenge. In view of the proven prophylactic effect of passive immunization against HTLV-I, our vaccine trial failed because WR-SFB5env was incapable of inducing neutralizing antibodies against HTLV-I in the immunized animals. It remains to be studied whether cell-mediated immunity such as antibody-dependent cellular cytotoxicity was involved in the temporary protection of I vaccinated rabbit.

Human T cell leukemia virus-I carriers and gonarthrosis. A preliminary report.

Gonarthrosis in 11 human T cell leukemia virus-1 (HTLV-I) carriers were studied for sera, synovial fluids (SF) and cerebrospinal fluids (CSF). Atypical lymphocytes similar to adult T cell leukemia cells were noticed in the SF of all the HTLV-I carriers and ranged from 19 to 1%, while those of peripheral white blood cells ranged from 3 to 0%. Anti-HTLV-I antibodies in the SF were equal to or lower than those in the sera. The CSF from 7 of them demonstrated positive titers of anti-HTLV-I antibodies, while no evidence of neurological disorders manifested. The histopathological findings of synovial membranes on hematoxylin and eosin staining method showed no statistical difference between those of gonarthrosis of HTLV-I carriers and noncarriers.

Detection of human T cell lymphotropic virus type I proviral DNA and its gene expression in synovial cells in chronic inflammatory arthropathy.

To investigate the pathogenesis of human T cell lymphotropic virus type I (HTLV-I)-associated chronic inflammatory arthropathy (HAAP), we sought to detect proviral DNA in the articular lesions. For the detection of proviral DNA, we used the polymerase chain reaction (PCR). Proviral DNA was detected not only in the peripheral blood mononuclear cells (PBMCs) and synovial fluid cells (SFCs), but also in the T lymphocyte-depleted cultured synovial cells (CSCs). These findings suggest that the infection by HTLV-I might occur in vivo in non-T cells. Furthermore, we detected HTLV-I tax1/rex1 messenger RNA in fresh synovial tissues and CSCs but not in fresh PBMCs and fresh SFCs using reverse transcription and PCR. Immunohistochemically, the CSCs from HAAP patients were also shown to express the HTLV-I antigens. These data indicate that HTLV-I in the non-T synovial cells can be transcribed and expressed. Moreover, the sequences of pXII regions in the CSCs demonstrated 97.5-99.4% homology to that in MT-2 cells, HTLV-I-infected cell line. This confirmed that the PCR-amplified bands reflect HTLV-I itself. These results suggest that this organ-specific inflammation can be attributed to non-T cell virus infection in articular lesions.