In vivo induction of human immunodeficiency virus type 1 entry into nucleus-free cells by CD4 gene transfer to hematopoietic stem cells: a hypothetical possible strategy for therapeutic intervention

As a useful alternative to employing soluble CD4 to inhibit binding of human immunodeficiency virus type 1 (HIV-1) to target cells, the introduction of CD4-bearing erythrocyte has been proposed by two study groups (see Refs. (5,6)). Prominently, Nicolau and colleagues demonstrated that the electroinserted CD4 molecules in the membranes of erythrocytes are capable of mediating HIV-1 entry. The implications of the studies are that inactivation of the integration-dependent retrovirus by the facilitation of entry into the nucleus-free cells, referred to as 'fake host trap' or 'host cell decoy', may be a possible therapeutic approach. Here we expand this concept to include genetic modification of autologous hematopoietic stem cells and review the relevant theoretical basis. Effective application of molecular technologies to induce partial replacement of hematopoiesis may be critical for this strategy.

Minor form of trigonocephaly is an autistic skull shape? A suggestion based on homeobox gene variants and MECP2 mutations

A possible role for Hoxa1 genotype in susceptibility to autism spectrum disorders was recently proposed. Furthermore, it has been demonstrated that Rett syndrome, which is categorized into pervasive developmental disorders the same as the autism spectrum disorders are, is associated with mutations in MECP2 gene. These findings suggest that the genetic backgrounds of these behavioral conditions may involve genes which also have an important role in the development of skull, because Hoxa1 is a key gene for skull development as well as for brain development and one of the clinical characteristics of Rett syndrome is deceleration in head growth. Together with this evolving knowledge, a series of ethical arguments concerning the indication of surgical treatment in patients with minor forms of trigonocephaly with autistic behaviors and/or hyperactivity leads us to hypothesize the presence of an autism subtype which may frequently be accompanied by specific morphological skull characteristics (autistic skull shape).

Clonal expansion within CD4+ and CD8+ T cell subsets in human T lymphotropic virus type I-infected individuals

To investigate the diversity of the T cell repertoire involved in human T lymphotropic virus type I (HTLV-I) infections, peripheral blood T cell subsets were analyzed by using a PCR-based assay that permits determination of complementarity-determining region 3 (CDR3) length variation in TCR Vbeta transcripts. In two of four asymptomatic HTLV-I carriers and in four of five patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), mono- or oligoclonal expansions were detected in the CD4+ T cell subset. In one patient with adult T cell leukemia, a specific clone bearing Vbeta7 was detected in the CD4+ T cell subset. In contrast, clonal expansion was not observed in the CD4 T cell subsets of three individuals with asymptomatic HTLV-II infection or in our previous studies of a large number of uninfected individuals. Oligoclonal expansions in the CD8+ T cell subset were detected in all subjects, including the patient with adult T cell leukemia. No differences in the number of expanded clones were noted between asymptomatic carriers and in patients with HAM/TSP and there was no obvious restriction in the TCR V region usage. Direct sequencing revealed no significant bias in the CDR3 motifs utilized by the predominant clones. This report is the first direct demonstration of clonal expansions within fractionated T cell subsets (CD4+ and CD8+) in HTLV-I infections and suggests that 1) clonal expansion of CD4+ T lymphocytes likely occurs as a direct result of infection and 2) polyclonal CD8+ T cell expansion occurs frequently and independently of disease association.

Reflux of HTLV-I infected lymphocytes from the privileged compartment(s) to peripheral blood flow in patients with HTLV-I-associated myelopathy

To understand the mechanisms involved in the pathogenesis of human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), three in vivo phenomena which have been observed in the peripheral blood of patients and differing from that in asymptomatic HTLV-I carriers must be taken into consideration: (a) the presence of increased HTLV-I viral load, (b) a higher immune responsiveness against HTLV-I antigens, and (c) biased nucleotide substitutions in the HTLV-I pX region which indicate a decreased selection pressure for viral amino acid changes. We now propose a hypothesis which focuses on the in vivo dynamics of HTLV-I infected lymphocyte migration and which incorporates these features. In addition, the hypothesis assumes the existence of a deviation in immune surveillance for HTLV-I in the central nervous system (CNS) in spite of the presence of frequent specific immune effectors. We suggest that in the active phase of HAM/TSP, accompanied with or following autoaggressive interactions between infected lymphocytes and immunocompetent cells in the CNS, there is a consequential reflux of the infected lymphocytes to the peripheral blood. The reflux of infected cells would be expected to provide peripheral blood with tissue-derived HTLV-I proviruses which have been indulged and propagated in an immune-privileged site. This process would result in and account for the observed increase in viral load and the substitution bias in HTLV-I sequences in the peripheral blood.

Alteration of cytokine levels by fosfomycin and prednisolone in spontaneous proliferation of cultured lymphocytes from patients with HTLV-I-associated myelopathy (HAM/TSP)

Fosfomycin has recently been reported as an antibiotic with immunomodulatory activities. To evaluate the possibility of clinical administration of fosfomycin in patients with human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), the effects of this agent on the HTLV-I-induced in vitro phenomenon were studied. The influence of fosfomycin on in vitro spontaneous proliferation (SP) of peripheral blood mononuclear cells (PBMCs) from four patients with HAM/TSP was measured by thymidine incorporation into the cells, and the concentration of several cytokines in the culture supernatants was examined in three HAM/TSP patients. Enzyme-linked immunosorbent assays (ELISAs) were employed to detect the concentrations of interleukin-4 (IL-4), IL-6, IL-10, interferon-gamma (IFN-gamma), transforming growth factor-beta1 (TGF-beta1), and macrophage inflammatory protein-1alpha (MIP-1alpha). The data were compared to the changes by prednisolone which is known to regulate the HTLV-I-associated in vitro phenomenon and to have a therapeutic benefit in patients with HAM/TSP. Production of IL-6, IFN-gamma and MIP-1alpha from the spontaneously proliferating cells were demonstrated. Fosfomycin could not suppress the HTLV-I-associated SP, but had the properties to decrease the levels of TGF-beta1 and MIP-1alpha. It was also demonstrated that the concentrations of IFN-gamma and MIP-1alpha in the cultures in the presence of prednisolone were apparently decreased, suggesting a possible involvement of these cytokines in the pathogenesis of HAM/TSP. These findings support the hypothesis that fosfomycin may have immunomodulatory potentials in HTLV-I-related cellular interactions in a different manner from ordinary immunomodulatory agents.

In vitro virus propagation and high cellular responsiveness to the infected cells in patients with HTLV-I-associated myelopathy (HAM/TSP)

The reasons for the development of HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in certain infected individuals remain poorly understood, but the susceptibility should involve both viral factors and host conditions. To assess simultaneously both virus-induced activation of infected cells and the cellular response to virus producing cells, an analysis of fractionated peripheral blood lymphocytes obtained from patients with HAM/TSP (n = 15) were compared with those of asymptomatic HTLV-I carriers (n = 9) in an age-matched manner. The in vitro propagation of HTLV-I infection was evaluated as the spontaneous thymidine incorporation into CD4+ cells, and proliferative response of CD8+ cells against cultured and irradiated autologous CD4+ cells was employed to analyze the HTLV-I-induced cellular response. The comparative analysis using these two parameters demonstrated that HAM/TSP patients were characterized by the concomitance of a high inducibility of HTLV-I propagation and a high cellular responsiveness against HTLV-I as compared with asymptomatic HTLV-I carriers, suggesting the involvement of both of these factors in disease susceptibility. In addition, the coupled evaluation of these two in vitro phenomena may offer a better diagnostic hallmark for HTLV-I seropositive myelopathy cases with other known cause of myelopathy.

[HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP)]

Human T lymphotropic virus type I(HTLV-I) is associated with the nonfatal neurologic disease, HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Many clinical signs of involvement outside the central nervous system (CNS) have been described in some patients with HAM/TSP and have triggered the discovery of some HTLV-I-associated concepts in the infected individuals without signs of CNS involvement. Most of these HTLV-I-associated diseases exhibit common possible 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. This review summarizes the recent perspectives of the molecular pathogenesis of HAM/TSP and other HTLV-I-associated diseases. Furthermore, the feasible pathogenic involvement of cellular interactions between infected cells and responding immunocompetent cells in the affected tissues is emphasized (bystander auto-aggressiveness).

A kinetic comparative study on lymphocyte responses to superantigen and phytohemagglutinin: reciprocal presentation of superantigen on the surface of activated lymphocytes

The kinetics of thymidine incorporation into fractionated T lymphocytes responding to bacterial superantigens were compared to those of cells activated by phytohemagglutinin (PHA). Evident differences between the kinetics of cell proliferation induced by PHA-P and staphylococcal enterotoxin B (SEB) emerged after Day 4 of culture. PHA-P-induced proliferative responses of peripheral blood mononuclear cells (PBMCs) and fractionated cells were apparent on Day 4 because of the presence of accessory cells in the initial cell suspensions. This gradually diminished in correlation with the decline of accessory cells in the cultures. The SEB-induced cell growth (PBMCs and CD4+ cells), however, continued until Day 9 of the culture. This finding suggests the reciprocal usage of MHC class II molecules to present SEB by activated T lymphocytes for superantigen-induced T cell activation and suggests that superantigen-related immune activation may depend in part on the potential of activated T lymphocytes to mediate reciprocal cell-to-cell interactions in the presence of superantigens. The decline observed in the CD8+ cell response to SEB and toxic shock syndrome toxin-1 after Day 4 was revived by exogenous recombinant interleukin-2 (rIL-2) supplementation, suggesting that the consequent autocrine or paracrine secretion of IL-2 from the responding cells is essential for subsequent cell proliferation. SEB-induced cell proliferation was significantly suppressed by anti-CD11a (lymphocyte function-associated antigen-1; LFA-1, alpha-chain) monoclonal antibody, and the inhibitory effect was most obvious in 6-day cultured CD8+ lymphocytes. The results suggest that the lymphocyte response associated with the cell-to-cell copresentation of superantigens involves LFA-1 molecules as an accessory factor, particularly in CD8+ lymphocytes.

Intrathecal humoral immune response in HAM/TSP in relation to HLA haplotype analysis

INTRODUCTION

In HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), we correlated human leukocyte antigen (HLA) haplotypes to the fine specificities of intrathecally synthesized IgG antibodies against HTLV-1.

PATIENTS AND METHODS

HLA haplotypes of HAM/TSP patients were determined by the standard NIH microcytotoxicity test and family HLA studies. IgG antibodies against HTLV-1 synthetic peptides in paired CSF and serum were measured by enzyme immunoassay, and intrathecal synthesis of antibodies was evaluated.

RESULTS

HAM/TSP patients with particular HLA haplotypes (A24Cw7B7DR1DQ5, A2Cw7B7DR1DQ5, A24Cw-B52DR15DQ6, A11Cw1B54DR4DQ4, and A24Cw1B54DR4DQ4) showed more frequently intrathecal synthesis of antibodies against HTLV-1 synthetic peptides, especially against HTLV-1 env gp21 synthetic peptides.

CONCLUSION

In HAM/TSP, a retrovirus-induced human chronic inflammatory disease of the CNS, this is the first report to provide evidence that the intrathecal antiviral immune response is influenced by immunogenetic factors of the HLA complex.

Choroideremia with leukoencephalopathy and arylsulfatase A pseudodeficiency

A 33-year-old male patient was admitted to our hospital because of progressive gait disturbance and involuntary movement of the neck. He showed choroideremia, distal motor neuropathy, and leukoencephalopathy on T2-weighted brain magnetic resonance imaging (MRI). Choroideremia is a rare X-linked, progressive, degenerative disease of retina and choroid. There have been some reports of choroideremia patients with neurological complications. Recent studies have assigned its genetic locus to a small segment of Xq21.3 and it encodes a protein that resembles component A of rat Rab geranyl-geranyl transferase, a protein essential for cell function. This patient did not have the reported genetic abnormalities for choroideremia. Known disorders causing leukoencephalopathy were not detected except for a partial deficiency of arylsulfatase A (17.3% of normal controls in lymphocytes and 13.7% in fibroblasts). Deficiency of arylsulfatase A activity occurs in the late infantile, juvenile, and adult forms of metachromatic leukodystrophy (MLD) which is also an inherited disorder of myelin metabolism, but because of its unstability, it occurs in normal individuals and in patients with other neurological diseases. Consequently, we suspect that this patient had partial deficiency of arylsulfatase A and choroideremia as predisposing factors for white matter degeneration.

Diversity of intrathecal antibody synthesis against HTLV-I and its relation to HTLV-I associated myelopathy

The humoral immune response against human T-cell lymphotropic virus type I (HTLV-I) in the central nervous system (CNS) compartment and in the blood was investigated by enzyme immunoassay using 16 synthetic peptides corresponding to HTLV-I core and envelope sequences. We evaluated paired samples of cerebrospinal fluid and serum from HTLV-I seropositive Japanese patients, classified as follows: HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP; n = 39), patients with spinal cord disease ascribed to either HAM/TSP or to some concomitant, HTLV-I-unrelated disease (possible HAM/TSP; n = 6) or carriers without any clinical signs of HAM/TSP (n = 15). HTLV-I-peptide-specific intrathecal antibody synthesis was found in 79% of HAM/TSP patients, but only in 20% of carriers without HAM/TSP. The group of carriers without HAM/TSP showed local synthesis for some peptides (on average 0.3 peptides per patient). In most HAM/TSP patients, however, there was a diverse intrathecal immune response to several HTLV-I synthetic peptides (on average against 3.6 peptides per HAM/TSP patient), most frequently against gag p19 100-130, env gp21 458-488, and env gp46 175-199 and 288-317. The intrathecal antibody synthesis against several HTLV-I determinants may represent a pathogenic immune response in HAM/TSP and is possibly related to the infiltration of virus-infected T-cells in the spinal cord.

Identification and characterization of a new and distinct molecular subtype of human T-cell lymphotropic virus type 2

Molecular studies have demonstrated the existence of at least two major subtypes of human T-cell lymphotropic virus type 2 (HTLV-2), designated HTLV-2a and HTLV-2b. To further investigate the heterogeneity of this family of viruses, we have characterized the HTLV-2 subtypes present in several urban areas in Brazil. DNAs from peripheral blood mononuclear cells of a large number of infected individuals, the majority of whom were intravenous drug abusers, were analyzed by using PCR with restriction fragment length polymorphism and nucleotide sequencing analysis. Restriction fragment length polymorphism analysis of the env region suggested that all individuals were infected with the HTLV-2a subtype, and this was confirmed by nucleotide sequence analysis. In contrast, nucleotide sequence analysis of the long terminal repeat demonstrated that although the viruses were more related to the HTLV-2a than to the HTLV-2b subtype, they clustered in a distinct phylogenetic group, suggesting that they may represent a new and distinct molecular subtype of HTLV-2. This conclusion was supported by nucleotide sequence analysis of the pX region, which demonstrated that the Tax proteins of the Brazilian viruses differed from that of prototype HTLV-2a isolates but were more similar to that of HTLV-2b in that they would be expected to have an additional 25 amino acids at the carboxy terminus. In transient expression assays, the extended Tax protein of the prototype HTLV-2a subtype. The studies suggest that the Brazilian viruses analyzed in this study, while being phylogenetically related to the prototypic HTLV-2a seen in North America, are phenotypically more related to HTLV-2b and can be justifiably classified as a new molecular subtype, which has been tentatively designated HTLV-2c.

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.

Differential effect of TGF-beta 1 on the in vitro activation of HTLV-I and the proliferative response of CD8+ T lymphocytes in patients with HTLV-I-associated myelopathy (HAM/TSP)

While considerable information is available on the pathogenesis of human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), fundamental questions remain unanswered. In particular the clinicopathological uniformity of the disorder among patients remains poorly understood. The potential role of TGF-beta as a preferential immune regulator in the CNS and the functional heterogeneity of TGF-beta has led us to assess the possible involvement of this cytokine in the pathogenic process. To investigate this, the modulatory effects of TGF-beta 1 on HTLV-I-induced in vitro phenomena were evaluated using fractionated lymphocytes from patients with HAM/TSP. It could be shown that the proliferative response of CD8+ cells against cultured and irradiated autologous CD4+ cells possessing HTLV-I antigens was significantly inhibited by TGF-beta 1. However, the in vitro activation of HTLV-I, which was evaluated by spontaneous proliferation of CD4+ cells, was unaffected by TGF-beta 1. The induction of intracytoplasmic HTLV-I antigens in cultured CD4+ cells was facilitated by TGF-beta 1 in a dose-dependent manner. These findings suggest that TGF-beta may have a critical role in localized viral activation within the CNS in patients with HAM/TSP.

Anti-viral and immunomodulatory effects of interferon-alpha on cultured lymphocytes from patients with human T lymphotropic virus type I-associated myelopathy (HAM/TSP)

In contrast to therapeutic benefits of interferon-alpha (IFN-alpha) in patients with human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), little is known about the mechanisms underlying its clinical efficacy. To investigate the anti-viral and/or immunomodulatory properties of IFN-alpha in HTLV-I infection, the effects of IFN-alpha on HTLV-I-induced in vitro phenomena were evaluated. In vitro activation of HTLV-I in fractionated CD4+ T lymphocyte-rich cells (CD4+ cells) could be demonstrated by increased thymidine incorporation into the cells, detection of proviral HTLV-I and viral RNA, and by assays of reverse transcriptase activities in culture supernatants. T cell immune responses were evaluated by thymidine incorporation into CD8+ T lymphocyte-rich cells (CD8+ cells) responding to cultured and irradiated autologous CD4+ cells possessing HTLV-I antigens. It could be shown that IFN-alpha suppressed both the in vitro activation of HTLV-I and the CD8+ cell response. Moreover, 1 day supplementation of IFN-alpha as a pretreatment was sufficient for the induction of these properties. These findings, together with the clinical efficacy of IFN-alpha administration in patients with HAM/TSP, support the view that viral activation and T cell responses are critical components in the pathogenic processes involved in HAM/TSP.

Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP): recent perspectives

Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a well-defined clinicopathological entity, and approximately 1,900 patients with HAM/TSP have been reported in the world. Improved polymerase chain reaction (PCR)-based in situ techniques have allowed a better appreciation of the cellular localization of the virus activation in infected patients, and there is accumulating evidence that HAM/TSP is characterized by a distributional bias of viral activation between the blood flow and central nervous system (CNS). This review summarizes the current status of our understanding of HAM/TSP, and emphasizes the possible pathogenic involvement of cellular interactions between infected cells and responding immunocompetent cells in the CNS of patients with HAM/TSP. In addition, the notable systemic manifestations with or without myelopathy in HTLV-I-infected individuals are described.

HTLV-I-associated myelopathy: analysis of 213 patients based on clinical features and laboratory findings

We studied the clinical features and laboratory findings in 213 patients with HTLV-I-associated myelopathy/tropical spastic paraparesis as diagnosed in Kagoshima University Hospital. Some aspects of clinical features in HTLV-I-associated myelopathy/tropical spastic paraparesis were characterized by mode of HTLV-I transmission and age of onset. The patients with onset after 15 years old and no history of blood transfusion before the onset of the disease (151 patients, group I) showed a shorter interval between the time of disease onset and that of inability to walk. The patients with onset before 15 years old and without history of blood transfusion (21 patients, group II) had short stature and slow progression of the disease. The interval time and the progression of the disease in patients with history of blood transfusion before onset of disease (41 patients, group III) were in between those of the above two groups. Patients whose ages of onset were older than 61 years old showed a faster progression than those with younger onset regardless of the mode of HTLV-I transmission. HTLV-I-associated myelopathy/tropical spastic paraparesis patients often also showed other organ disorders such as leukoencephalopathy (69%), abnormal findings on chest X-ray (50%), Sjögren syndrome (25%) and arthropathy (17%). The patients with low anti-HTLV-I antibody titers in the cerebrospinal fluid (2X-8X by PA method) had an older age of onset on average, milder clinical symptoms and lesser increase of neopterin in the cerebrospinal fluid than those in the high titer subgroup whose titers were higher than 1024X in cerebrospinal fluid regardless of the mode of HTLV-I transmission. We speculate that the clinical course of HTLV-I-associated myelopathy/tropical spastic paraparesis mainly shows a slow progression which consists of an initial progressive phase (probably an inflammatory phase) and a latter chronic phase, although some patients showed acute/subacute onset and rapid progression.

Apoptosis of T lymphocytes in the spinal cord lesions in HTLV-I-associated myelopathy: a possible mechanism to control viral infection in the central nervous system

Immunocytochemical staining of spinal cords from five autopsied patients with HAM/TSP was performed using the monoclonal antibody TIA-1, a marker of cytotoxic T lymphocytes (CTL). Many TIA-1+, CD8+ cells are distributed in active inflammatory lesions. The number of TIA-1+ cells is related to the amount of HTLV-I proviral DNA in situ. The protein TIA-1 has been associated with the induction of apoptosis in target cells. In active inflammatory lesions, we found cells undergoing apoptosis, most of them identified as helper-inducer CD45RO T lymphocytes, which were consistent with in vivo cellular tropism of HTLV-I in patients with HAM/TSP. These findings suggest that CTL-induced apoptosis of T lymphocytes may be one of the possible mechanisms which eliminate HTLV-I-infected cells from the central nervous system. In addition, many T lymphocytes in the inflammatory lesions expressed bcl-2 oncoprotein, suggesting that infiltrated T lymphocytes may be resistant to apoptosis. Expression of bcl-2 oncoprotein may explain the longstanding inflammatory process in the central nervous system of HAM/TSP.

HTLV-I proviral DNA amount correlates with infiltrating CD4+ lymphocytes in the spinal cord from patients with HTLV-I-associated myelopathy

A quantitative method utilizing polymerase chain reaction was employed to evaluate the amount of human T-cell leukemia virus type I (HTLV-I) proviral DNA in the affected spinal cords from patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Central nervous system (CNS) tissues were obtained at post-mortem from five patients with HAM/TSP, who vary in the duration of illness from 2.5-10 years, and one patient with adult T-cell leukemia (ATL), who had leukemic cell infiltration in the CNS. The presence of HTLV-I pX and pol sequences in the CNS tissues were demonstrated in all patients examined. In HAM/TSP, the proviral DNA quantified in the thoracic cord was 0.002-2 copies per 100 tissue cells, and that in the peripheral blood mononuclear cells (PBMC) was 2-8 copies per 100 PBMC. The proviral DNA amount in the thoracic cord of the patient with ATL was 0.4 copies per 100 tissue cells. An apparent propensity for the amount of integrated HTLV-I in the thoracic cord to decrease with the disease duration in patients with HAM/TSP was observed. The decline in HTLV-I proviral DNA amount in the thoracic cord lesions was paralleled with the alteration of proportion of CD4+ T lymphocytes in patients with HAM/TSP. These findings suggest that preferential virus reservoir may be infiltrating CD4+ T lymphocytes in the spinal cord lesions of patients with HAM/TSP, and HTLV-I infection in the CNS of patients is declining with the disease duration in spite of the chronic course of neurological manifestations at least in some patients with HAM/TSP.

An autoaggressive process against bystander tissues in HTLV-I-infected individuals: a possible pathomechanism of HAM/TSP

Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a well-defined clinico-pathological entity in which the virus infection and the host immune responses are involved in the pathomechanism. It is generally agreed that the virus infection precedes the development of HAM/TSP and the infection is persistent during the course of disease. However, what plays the key role for the development of HAM/TSP remains to be elucidated. In this article, we emphasise the importance of the unique nature of HTLV-I-infected cells, which may have a potential ability to produce viral antigens outside of the blood flow, and we also review a variety of evidences supporting the following proposal. In our hypothesis, the supply of infected T cells from blood flow to central nervous system (CNS) is primary for the development of CNS lesions. Both anatomically determined hemodynamic conditions and adhesion molecule-mediated interactions between circulating infected T cells and endothelial cells may contribute to the localization of the main lesions. Following an induction of the HTLV-I antigens on the surface of infected T cells in CNS compartment, expansion of the responses of immunocompetent T cells against the viral proteins may result in CNS tissue damage which may be mediated by released cytokines. This is the first attempt to implicate a bystander damage mechanism in a human disease as an essential pathomechanism.

Identification of human T cell leukemia virus type IIb infection in the Wayu, an aboriginal population of Colombia

Human T cell leukemia virus type II (HTLV-II) is endemic in a number of native American populations and high rates of infection have also been demonstrated in intravenous drug abusers (IVDAs). Studies of virus isolates in the latter population have shown the existence of two closely related subtypes of the virus, HTLV-IIa and HTLV-IIb. To characterize the viruses present in native Americans, we analyzed by nucleotide sequence analysis the proviruses from the Wayu, an aboriginal population residing in Colombia, South America. The results showed HTLV-IIb infection in this population, and also demonstrated remarkable conservation of sequence when compared to the proviruses in IVDAs.

Benign monoclonal T cell proliferation in HTLV-I infection

A spectrum of carrier states in human T lymphotropic virus type-I (HTLV-I) infection is proposed. The suspected process of clonal selection of HTLV-I infected cells results in the spectrum of nonfatal states from polyclonal to monoclonal virus integration. This idea is based on the discovery that monoclonal proviral HTLV-I DNA was detected in the fresh peripheral blood lymphocytes from some patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a nonfatal chronic neurological disorder.

Endemic human T cell leukemia virus type II infection in southwestern US Indians involves two prototype variants of virus

Human T cell leukemia virus (HTLV) type II is endemic in certain American Indians, and high rates of infection occur in intravenous drug users (IVDUs). North American IVDUs are infected with two distinct variants, HTLV-IIa and -IIb. If IVDUs became infected as a result of interaction with members of an American Indian population, both viral forms should be demonstrable in such populations. Nucleotide sequence analysis of 630 bases of the env gene encoding the gp21 protein was done on DNA from 12 New Mexico Indians (8 Pueblo, 4 Navajo). All samples were typical subtype a or b viruses. Seven of the 8 Pueblo and 2 of 4 Navajo had subtype b; the rest had subtype a. The results are compatible with an indigenous New World origin for both subtypes of HTLV-II.

Nucleotide sequence analysis of human T cell leukemia virus, type II (HTLV-II) isolates

A study by Hall et al. (J Virol 1992;66:2456-2463; Ref. 11) has suggested the existence of two closely related molecular subtypes of HTLV-II, which were tentatively designated HTLV-IIa and HTLV-IIb. To confirm this nucleotide sequence analysis of 986 bp of the env gene region encoding the entire surface glycoprotein, gp46, and the amino terminus of the transmembrane glycoprotein, gp21, of 10 HTLV-II isolates was carried out. The results clearly established the existence of two subtypes and demonstrated a 4.3% divergence in sequence in this region. Analysis of other gene regions of the provirus, including the pol (1544 bp), gag (448 bp), and the entire LTR (743 bp) of two representative isolates of each subtype, showed a sequence divergence of 3.8 to 5.7%, with greatest divergence occurring in the LTR. In addition to single nucleotide changes, the gag regions encoding the structural protein, p19, of the HTLV-IIb isolates were also found to have a 66-bp deletion that would be expected to result in a p19 protein having a 22-amino acid deletion in the carboxy-terminus region. Attempts to exploit this to differentiate the two subtypes serologically were unsuccessful in that recombinant p19 proteins of both subtypes were found to be antigenically cross-reactive. The finding of two molecular subtypes of HTLV-II may have important implications for a better understanding of the biological and pathogenic properties of the virus, and will be useful in characterizing the viruses present in endemic foci in American Indian populations.

Synovial fluid T cells in HTLV-I positive RA

Images

Frequent clonal proliferation of human T-cell leukemia virus type 1 (HTLV-1)-infected T cells in HTLV-1-associated myelopathy (HAM-TSP)

Human T-cell leukemia virus type 1 (HTLV-1) integrates its proviruses into random sites in host chromosomal DNA. Random integration of the proviruses was observed in asymptomatic HTLV-1 carriers and patients with HTLV-1-associated myelopathy (HAM/TSP). However, clonal integration has been reported in patients with adult T-cell leukemia (ATL), including that in the smoldering, chronic, and acute states, indicating clonal expansion of infected cells. In this study, we found that about 20% of HAM/TSP patients and their seropositive family members harbored subpopulation(s) of clonally proliferated cells infected with HTLV-1, although they still maintained randomly infected cells as a major population. These clones were stable during examination periods of 4 months to 3 years. However, these carriers or HAM/TSP patients did not show any significant indication of ATL. This extremely high frequency of clonal expansion of HTLV-1-infected cells indicates that some clones of HTLV-1-infected cells have a tendency to proliferate more efficiently than the other population without malignant transformation.

In vivo cellular tropism of human T cell leukemia virus type II (HTLV-II)

To investigate the in vivo cellular tropism of human T cell leukemia virus type II (HTLV-II), subpopulations of fresh peripheral blood mononuclear cells from infected individuals were isolated and analyzed by polymerase chain reaction for the presence of provirus. In eight of nine patients, HTLV-II was detected exclusively in the CD8+ T lymphocyte population. In the remaining patient, provirus was also detected in CD4+ T lymphocytes. Provirus was not detected in B lymphocytes or monocytes of any patient. These results suggest that in vivo HTLV-II has a preferential, and perhaps in some cases, an exclusive tropism for CD8+ T lymphocytes. The findings contrast sharply with those on HTLV-I where there is a preferential tropism for CD4+ T lymphocytes. Although HTLV-II infection has not been consistently associated with any lymphoproliferative disorders, the results suggest that if these occur, they may be different from those known to be associated with HTLV-I.

High-performance liquid chromatography and post-column derivatization with diphenyl-1-pyrenylphosphine for fluorimetric determination of triacylglycerol hydroperoxides

Triacylglycerol monohydroperoxides (TG-mHPO) were selectively detected at the picomole levels after post-column reaction with diphenyl-1-pyrenylphosphine (DPPP). TG-mHPO were separated on two types of reserved-phase columns, an ODS column and a phenylated silica gel column, which were useful for determining TG-mHPO at their molecular species levels and their class levels, respectively. After the separation, DPPP solution was mixed with the eluent followed by reaction in a stainless-steel coil 20 m x 0.5 mm I.D. at 80 degrees C, then the fluorescence intensity of DPPP oxide was measured (lambda ex. 352 nm, lambda em. 380 nm). Using these systems, TG-mHPO were determined in the range 2-1000 pmol. The relative standard deviations were 2.3-2.8%.

Multiple isolates and characteristics of human T-cell leukemia virus type II

Human T-cell leukemia (or lymphotropic) virus type II (HTLV-II) was isolated from eight HTLV-seropositive patients, six of whom were also infected with human immunodeficiency virus, by cocultivation of peripheral blood mononuclear cells (PBMCs) with BJAB, a continuous B-cell line. Restriction endonuclease mapping of the proviruses demonstrated consistent differences among isolates, and two distinct physical map patterns were observed. The results suggest the existence of two closely related molecular subtypes of HTLV-II, which are tentatively designated HTLV-IIa and HTLV-IIb. This finding was supported by preliminary nucleotide sequence analysis of the env gene region encoding the transmembrane glycoprotein gp21, which showed consistent differences between the two proposed virus subtypes. Exploitation of differences in restriction endonuclease sites allowed polymerase chain reaction amplification to detect and differentiate the two subtypes in fresh PBMCs of HTLV-seropositive intravenous drug abusers (IVDAs). The results of these studies confirm that HTLV-II infection is the prominent HTLV infection in seropositive IVDAs and also show that infection with both subtypes occurs. The finding of genetic heterogeneity in the HTLV-II group of viruses may have important implications for studies on its role in human disease and will be useful in characterizing the viruses present in newly discovered endemic foci in New World indigenous populations.

Cell surface phenotype of in vitro proliferating lymphocytes in HTLV-I-associated myelopathy (HAM/TSP)

The in vitro proliferation of peripheral blood lymphocytes (PBLs) without any mitogenic stimulation is one of the hallmarks of human T lymphotropic virus type I (HTLV-I) infection. Recent evidence suggests a difference in the degree of the phenomenon between HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and asymptomatic HTLV-I carriers (AC). In this article, we demonstrated several alterations in the features of the in vitro transformed lymphocytes between patients with HAM/TSP (n = 16) and AC (n = 8). The percentages of total CD8+ and CD8+CD28+ cells were significantly increased in the in vitro proliferating T lymphocytes derived from the patients with HAM/TSP when compared to those from AC. HAM/TSP was segregated from AC by the high degree of the proliferation of CD8+CD28+ cells. The expression of HTLV-I-specific antigens on the cultured PBLs was detected only in the subjects which showed low CD8+CD28+/CD4+ ratio of the in vitro proliferating lymphocytes. These findings suggest that this phenomenon distinguishes HAM/TSP from AC, not only in quantity but also in quality.

Angiographic morphology of the posterior communicating artery and basilar in patients with ICA-PComA aneurysm

The relationships between the angiographic morphology of the posterior communicating artery (PComA) and the basilar artery (BA) and saccular aneurysms at the internal carotid artery (ICA)-PComA junction were evaluated in 23 patients with ICA-PComA aneurysm and 46 controls. No significant differences were found in the height of the basilar top, the dislocation and inner diameter of the BA, and the distance between the basilar top and the ICA-PComA junction. However, the angle between the PComA and C2 portion of the ICA was larger and the PComA straighter in ICA-PComA aneurysm patients. Tension in the PComA and mechanical damage to the divergent angle of the PComA are probably important factors in the development of ICA-PComA aneurysms.

Concentration of activated T lymphocytes in extracorporeal blood circulation for plasma separation

To investigate whether the proportion of activated T lymphocytes changes in an extracorporeal blood flow, we compared paired samples collected at the inlet and outlet lines of an artificial circuit for plasma separation, using a dual-immunofluorescence flow cytometric technique. In our series of materials from patients with rheumatoid arthritis or systemic lupus erythematosus, the percentages of HLA-DR-positive cells in both CD4+ (P less than 0.01, n = 6) and CD8+ (P less than 0.05, n = 10) subsets were significantly increased in the outlet lines compared with the inlet lines, suggesting that activated T lymphocytes pass through an extracorporeal blood circuit more easily than resting T lymphocytes.

Arthritis in a human T lymphotropic virus type I (HTLV-I) carrier

The case is described of a 57 year old woman with polyarthritis fulfilling the 1987 revised criteria of the American Rheumatism Association for rheumatoid arthritis, accompanied by clinical carrier state infection of HTLV-I. Anti-HTLV-I IgM antibodies were detected by western blot analysis in her synovial fluid and serum. Atypical lymphocytes with nuclear convolutions were found in synovial fluid and synovial tissue obtained from the affected knee joint, suggesting in situ activation of HTLV-I infected lymphocytes in the affected synovial compartment. The HTLV-I antigens were detected (1.2%) in short term cultured synovial fluid lymphocytes, by indirect immunofluorescence. These findings supported the possibility that HTLV-I has a role in triggering or modifying inflammation in the synovial compartment.

[Efficacy of leukocytapheresis and low-dose prednisolone treatment in a patient with HTLV-I-associated myelopathy (HAM)]

The patient, a 66-year-old woman, was admitted because of a two year history of slowly progressive gait disturbance. A diagnosis of HTLV-I-associated myelopathy (HAM) was made on the basis of the clinical and serological criteria. Although the ordinary dose of oral prednisolone (PSL) is more than 30 mg in the treatment of HAM, we treated this patient by low-dose (5-10 mg) oral PSL administration. A series of leukocytapheresis performed before the PSL treatment halted the progression of symptoms transiently. Alterations in peripheral blood lymphocyte (PBL) subpopulations and augmented autologous proliferative response of PBLs improved concurrently with the resolution of neurological symptoms after the low-dose PSL treatment. The result suggests that some cases with HAM may respond with PSL treatment in low doses.

[Accessory use of protease-inhibiting agents for disease remission in a patient with autoimmune hemolytic anemia associated with B-CLL]

Protease inhibiting agents, which have inhibitory effects on complement system, were used to treat a patient with autoimmune hemolytic anemia (AIHA) associated with B cell chronic lymphocytic leukemia (B-CLL). Although this patient had failed to respond thoroughly to prednisolone, the additional use of protease inhibitors induced a disease remission of hemolytic anemia. The result suggests that complement components are of importance in the pathogenesis of hemolysis in AIHA, and supports the accessory use of protease inhibiting agents in autoimmune hematologic diseases associated with the complement activation and hypersplenism.

Activated T lymphocytes in cerebrospinal fluid of patients with HTLV-I-associated myelopathy (HAM/TSP)

In order to detect activated T lymphocytes in the cerebrospinal fluid (CSF) of patients with human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), we studied CSF lymphocytes in untreated patients with HAM/TSP and other neurological diseases (OND). Dual-immunofluorescence staining technique was performed using fluorescence microscopy. No significant difference in the CD4+/CD8+ ratio of CSF lymphocytes was observed between HAM/TSP patients and patients with OND. However, both CD4+ and CD8+ CSF lymphocytes of HAM/TSP patients contained higher percentages of HLA-DR-positive cells than those of patients with OND (P less than 0.05), suggesting that the activated CSF T lymphocytes were composed of both CD4+ and CD8+ subsets in patients with HAM/TSP.

Type IIa hyperlipoproteinemia masquerading as cerebrotendinous xanthomatosis

We describe an adult patient with type IIa hyperlipoproteinemia, presenting with Achilles tendon xanthomas, cataracts, dementia, ataxia, pyramidal tract signs, and peripheral neuropathy, which are commonly seen in cerebrotendinous xanthomatosis (CTX). However, the diagnosis of CTX was excluded on the basis of the cholestanol level and the normal cholestanol/cholesterol ratio in his serum and tendon. The pathomechanism for some of the clinical manifestations in type IIa hyperlipoproteinemia and CTX might be caused by a common biochemical disturbance.

In vitro modulation of lymphocyte proliferation by prednisolone and interferon-alpha in patients with HTLV-I-associated myelopathy (HAM)

One of the hallmarks of human T-lymphotropic virus type I (HTLV-I) infection is the proliferation in vitro of peripheral blood lymphocytes (PBLs) in the absence of growth factors. This phenomenon, the autologous proliferative response (APR), involves spontaneous growth of HTLV-I-infected T-cells and proliferation of T-cells in response to the infected cells. We studied the modulating effect of prednisolone (PSL) and interferon-alpha (IFN) on APR of PBLs obtained from five patients with HTLV-I-associated myelopathy (HAM). APR was significantly inhibited by PSL and IFN suggesting that APR is important in the pathogenesis of HAM.