Monoclonal integration of HTLV-I proviral DNA in patients with strongyloidiasis

The relationship between strongyloidiasis and HTLV-I was investigated in Okinawa, an area where both conditions are endemic. Thirty-six patients with strongyloidiasis were seropositive for HTLV-I and suffered from several related clinical complications. Fourteen of these patients (39%) were shown to have monoclonal integration of HTLV-I proviral DNA in their blood lymphocytes, a condition designated as "smouldering" adult T-cell leukaemia (ATL). Monoclonal integration of proviral DNA correlated with an increased CD4/CD8 ratio and the presence of abnormal lymphocytes in the peripheral blood, and with a trend for greater severity of the parasitic infection. Although the immunodeficiency caused by HTLV-I could predispose to hyperinfestation by Strongyloides, it is also possible that both the parasitic and the retroviral infestations are important co-factors leading to the development of ATL.

Protective immune responses induced by secretion of a chimeric soluble protein from a recombinant Mycobacterium bovis bacillus Calmette-Guérin vector candidate vaccine for human immunodeficiency virus type 1 in small animals

A recombinant Mycobacterium bovis bacillus Calmette-Guérin (BCG) vector-based vaccine that secretes the V3 principal neutralizing epitope of human immunodeficiency virus (HIV) could induce immune response to the epitope and prevent the viral infection. By using the Japanese consensus sequence of HIV-1, we successfully constructed chimeric protein secretion vectors by selecting an appropriate insertion site of a carrier protein and established the principal neutralizing determinant (PND)-peptide secretion system in BCG. The recombinant BCG (rBCG)-inoculated guinea pigs were initially screened by delayed-type hypersensitivity (DTH) skin reactions to the PND peptide, followed by passive transfer of the DTH by the systemic route. Further, immunization of mice with the rBCG resulted in induction of cytotoxic T lymphocytes. The guinea pig immune antisera showed elevated titers to the PND peptide and neutralized HIVMN, and administration of serum IgG from the vaccinated guinea pigs was effective in completely blocking the HIV infection in thymus/liver transplanted severe combined immunodeficiency (SCID)/hu or SCID/PBL mice. In addition, the immune serum IgG was shown to neutralize primary field isolates of HIV that match the neutralizing sequence motif by a peripheral blood mononuclear cell-based virus neutralization assay. The data support the idea that the antigen-secreting rBCG system can be used as a tool for development of HIV vaccines.

A highly pathogenic simian/human immunodeficiency virus with genetic changes in cynomolgus monkey

A highly pathogenic simian/human immunodeficiency virus (SHIV), designated C2/1, was obtained by serum passages in cynomolgus monkeys of p-SHIV, an SHIV strain that contains the env gene of pathogenic human immunodeficiency virus type 1 89.6. CD4+ lymphocyte depletion was induced within 1 week of the SHIV-C2/1 infection in peripheral blood as well as in various lymphoid organs in all the animals tested, with symptoms of diarrhoea and no increase in body weight, followed by intense viraemia. Serum antibody against Env protein was detected from 4 weeks after the virus infection, while the anti-Gag antibody response was absent in the SHIV-C2/1-infected animals. In contrast, both anti-Gag and anti-Env antibody responses were present in animals infected with p-SHIV or the non-pathogenic SHIV-MN. Sequencing of the env gene of isolates of SHIV-C strains showed conserved amino acid changes in the Env C2 and V3 regions that included changes to negatively charged amino acids, in the cytoplasmic region of gp41 that included a 42 amino acid deletion, and in the Nef protein. The pathogenic SHIV-C2/1-monkey model suggests that virus-specific pathogenicity in SHIV infection may be associated with the absence of anti-Gag antibody responses in animals and may be caused by genetic changes during serum passage in vivo.

Quintuple deglycosylation mutant of simian immunodeficiency virus SIVmac239 in rhesus macaques: robust primary replication, tightly contained chronic infection, and elicitation of potent immunity against the parental wild-type strain

We previously generated a mutant of simian immunodeficiency virus (SIV) lacking 5 of a total of 22 N-glycans in its external envelope protein gp120 with no impairment in viral replication capability and infectivity in tissue culture cells. Here, we infected rhesus macaques with this mutant and found that it also replicated robustly in the acute phase but was tightly, though not completely, contained in the chronic phase. Thus, a critical requirement for the N-glycans for the full extent of chronic infection was demonstrated. No evidence indicating reversion to a wild type was obtained during the observation period of more than 40 weeks. Monkeys infected with the mutant were found to tolerate a challenge infection with wild-type SIV very well. Analyses of host responses following challenge revealed no neutralizing antibodies against the challenge virus but strong secondary responses of cytotoxic T lymphocytes against multiple antigens, including Gag-Pol, Nef, and Env. Thus, the quintuple deglycosylation mutant appeared to represent a novel class of SIV live attenuated vaccine.

A Novel Endoglycoceramidase Hydrolyzes Oligogalactosylceramides to Produce Galactooligosaccharides and Ceramides

Enzymes capable of hydrolyzing the beta-glycosidic linkage between oligosaccharides and ceramides in various glycosphingolipids has been found in microorganisms and invertebrates and designated endoglycoceramidase (EC 3.2.1.123) or ceramide glycanase. Here we report the molecular cloning, characterization, and homology modeling of a novel endoglycoceramidase that hydrolyzes oligogalactosylceramides to produce galactooligosaccharides and ceramides. The novel enzyme was purified from a culture supernatant of Rhodococcus equi, and the gene encoding 488 deduced amino acids was cloned using peptide sequences of the purified enzyme. Eight residues essential for the catalytic reaction in microbial and animal endoglycoceramidases were all conserved in the deduced amino acid sequence of the novel enzyme. Homology modeling of the enzyme using endocellulase E1 as a template revealed that the enzyme displays a (beta/alpha)8 barrel structure in which Glu234 at the end of beta-strand 4 and Glu341 at the end of beta-strand 7 could function as an acid/base catalyst and a nucleophile, respectively. Site-directed mutagenesis of these glutamates resulted in a complete loss of the activity without a change in their CD spectra. The recombinant enzyme hydrolyzed the beta-galactosidic linkage between oligosaccharides and ceramides of 6-gala series glycosphingolipids that were completely resistant to hydrolysis by the enzymes reported so far. In contrast, the novel enzyme did not hydrolyze ganglio-, globo-, or lactoseries glycosphingolipids. The enzyme is therefore systematically named "oligogalactosyl-N-acylsphingosine 1,1'-beta-galactohydrolase" or tentatively designated "endogalactosylceramidase."

Coping strategies and risk of cardiovascular disease incidence and mortality: the Japan Public Health Center-based prospective Study

AIMS

Coping strategies may be significantly associated with health outcomes. This is the first study to investigate the association between baseline coping strategies and cardiovascular disease (CVD) incidence and mortality in a general population cohort.

METHODS AND RESULTS

The Japan Public Health Center-based prospective Study asked questions on coping in its third follow-up survey (2000-04). Analyses on CVD incidence and mortality included 57 017 subjects aged 50-79 without a history of CVD and who provided complete answers on approach- and avoidance-oriented coping behaviours and strategies. Cox regression models, adjusted for confounders, were used to determine hazard ratios (HRs) according to coping style. Mean follow-up time was 7.9 years for incidence and 8.0 years for mortality.The premorbid use of an approach-oriented coping strategy was inversely associated with incidence of stroke (HR = 0.85; 95% CI, 0.73-1.00) and CVD mortality (HR = 0.74; 95% CI, 0.55-0.99). Stroke subtype analyses revealed an inverse association between the approach-oriented coping strategy and incidence of ischaemic stroke (HR = 0.79; 95% CI, 0.64-0.98) and a positive association between the combined coping strategy and incidence of intra-parenchymal haemorrhage (HR = 2.03; 95% CI, 1.01-4.10). Utilizing an avoidance coping strategy was associated with increased mortality from ischaemic heart disease (IHD) only in hypertensive individuals (HR = 3.46; 95% CI, 1.07-11.18). The coping behaviours fantasizing and positive reappraisal were associated with increased risk of CVD incidence (HR = 1.24; 95% CI, 1.03-1.50) and reduced risk of IHD mortality (HR = 0.63; 95% CI, 0.40-0.99), respectively.

CONCLUSION

An approach-oriented coping strategy, i.e. proactively dealing with sources of stress, may be associated with significantly reduced stroke incidence and CVD mortality in a Japanese population-based cohort.

Extraordinary high rate of HTLV type II seropositivity in intravenous drug abusers in south Vietnam

Serum specimens (n = 1899) were assayed for infections with HTLV-I, HTLV-II, and HIV-1 in seven classified groups of normal healthy controls, children, pregnant women, prostitutes, intravenous drug abusers, patients under going hemodialysis, and hemophiliacs in South and North Vietnam. Surprisingly, 125 of 954 samples from South Vietnam exhibited seropositivity for HTLV-II and 119 of these belonged to the group of IVDAs (n = 200). The remaining six positives were a healthy control, a prostitute, two children, and two patients under going hemodialysis. Two IVDAs who were seropositive for HTLV-I and 10 of 15 seropositives for HIV-1 were also positive for HTLV-II in this population. In contrast, no seropositives to any of the viruses were detected in the North Vietnamese samples (0 of 945). The HTLV-II-seropositive IVDAs exhibited increased seropositivity with age compared with HIV-1 seropositivity in the population, and there was no statistical relation between seropositivity for HTLV-II and HIV-1. The HTLV-IIs in South Vietnam IVDAs appeared, by subtype-specific peptide ELISA, to be a mixture of both subtypes a and b, with subtype a predominant. It seems possible that HTLV-II may have been introduced into this population from IVDAs from the United States during the Vietnam conflict, but in a period prior to, or early in, the introduction of HIV-1 to IVDAs.

Correlation of titer of antibody to principal neutralizing domain of HIVMN strain with disease progression in Japanese hemophiliacs seropositive for HIV type 1

With the use of the principal neutralizing determinant (PND) peptide-based ELISA to measure anti-PND antibodies that specifically bound synthetic peptides derived from HIVIIIB, HIVMN, HIVRF, HIVSC, HIVWJM-2, HIVAf1l.con, or HIVAf2.con, type-specific antibodies to the HIVMN peptide were studied in 350 serum specimens from Japanese with hemophilia A who had been injected with known unheated factor VIII concentrates until 1985 and had been infected with HIV-1 subtype B. These antibodies were not found in any of the seronegative sera of hemophiliacs, patients with autoimmune diseases, or normal healthy controls. Further, all hemophiliacs rapidly progressing to AIDS and death among the 95 hemophiliacs in a restricted Nara area had antibody titers of less than 20 and their low levels preceded the rapid progression to the disease state. In contrast, slowly progressing hemophiliacs maintained an antibody titer of more than 100 from the initial stages of viral infection and remained asymptomatic. Sequence analysis of the V3 regions of HIV-1 indicated that the hemophiliacs who maintained a high anti-PNDMN antibody level showed a conserved MN sequence. In contrast, the HIV-infected hemophiliacs with nonreactivity in the ELISA showed sequence changes in the neutralizing epitopes of HIVMN. The dynamic of the serum anti-PNDMN antibody titer appear to be a characteristic indicator of the progression of the HIV-infected status in Japanese hemophiliacs seropositive for HIV-1.

Japanese patients with chronic fatigue syndrome are negative for known retrovirus infections

Although chronic fatigue syndrome (CFS) is known to be the syndrome that begins with an acute flu-like illness that may be due to the exposure to an infectious agent, there has been no convincing evidence on the causative agents. Recently, human T-lymphotropic virus type II (HTLV-II)-like virus has been reported to be associated with the CFS by using HTLV Western blot analysis and polymerase chain reaction. However, some investigators could not detect HTLV-II by indirect immunofluorescence analysis. Lately, CFS patients have been reported in Japan. We detected all 30 tested patients with CFS were seronegative for HTLV-II, HTLV-I and HIV by specific peptide ELISA and Western blot. Further, PCR analysis was negative for HTLV-II and retrovirus was not detected by coculture method with patients' PBMC. Thus, known human retrovirus infections do not cause a CFS in Japan.

Induction of CD95 ligand expression on T lymphocytes and B lymphocytes and its contribution to apoptosis of CD95-up-regulated CD4+ T lymphocytes in macaques by infection with a pathogenic simian/human immunodeficiency virus

Using an established SIV/HIV-C2/1-infected cynomolgus monkey model displaying stable CD4+ T cell depletion, the kinetics of apoptosis and the levels of expression of CD95 membrane-associated CD95L on lymphocytes were investigated to test the involvement of the CD95/CD95L system in CD4+ T lymphocyte loss in vivo. Rapid depletion of CD4+ T cells occurred up to 2 weeks after infection, with chronic CD4+ T lymphopenia thereafter. During the initial CD4+ T cell loss, which was accompanied by viraemia, about 90% of the peripheral CD4+ T cell subset underwent spontaneous apoptotic cell death during 24 h of culture. Increased expression of CD95 was observed on both CD4+ and CD8+ T cell subsets, with CD95 expression on CD8+ cells declining rapidly, but high CD95 expression being maintained on CD4+ cells. Since CD95L was expressed on CD8+ T cells, B cells and to a lesser extent on CD4+ T cells, this suggests that CD95-mediated apoptosis might be controlled in an autocrine/paracrine fashion.

Study of the immunogenicity of different recombinant Mengo viruses expressing HIV1 and SIV epitopes

Recombinant Mengo viruses expressing heterologous genes have proven to be safe and immunogenic in both mice and primates, and to be able to induce both humoral and cellular immune responses (Altmeyer et al., 1995, 1996). Several recombinant Mengo viruses expressing either a large region (aa 65-206) of the HIV1 nef gene product, or cytotoxic T lymphocyte (CTL) epitopic regions from the SIV Gag (aa 182-190), Nef (aa 155-178) and Pol (aa 587-601) gene products were engineered. The heterologous antigens were expressed either as fusion proteins with the Mengo virus leader (L) protein, or in cleaved form through autocatalytic cleavage by the foot-and-mouth disease virus 2A protein. Rhesus macaques and BALB/c mice inoculated with the Mengo virus SIV recombinants failed to develop CTL responses against the SIV gene products, while one of the HIV-Nef recombinants induced a weak CTL response in mice directed to an HIV1 Nef peptide spanning positions 182-198. In contrast, BALB/c mice immunized with vaccinia virus recombinants expressing HIV1 Nef developed a strong CTL response to the 182-198 peptide and also responded to a second peptide spanning positions 73-81. These results indicate that Mengo virus recombinants expressing HIV1 Nef and SIV CTL epitopes are weak immunogens. One of the fusion recombinants expressing SIV CTL epitopes failed to infect macaques even when used at high doses, while the recombinant expressing HIV1 Nef as a fusion protein failed to infect BALB/c mice. These results demonstrate that the expression of certain heterologous sequences as fusion proteins with L can result in the loss of the ability of the recombinant to infect normally susceptible animals.

Detection of HIV-Gag p24-specific antibodies in sera and saliva of HIV-1-infected adults and in sera of infants born to HIV-1-infected mothers

Secretory immunoglobulin A (IgA) is known to play an important role in the mucosal defense against a variety of pathogens. Although the role of IgA antibodies during sexual transmission of HIV is not clear, HIV-specific IgA antibodies have been detected in various mucosal secretions of HIV-infected individuals. Using a monoclonal antibody against human IgA, we established an ELISA system to detect anti-HIV p24 IgA antibodies in sera and saliva. We have analyzed the levels of anti-HIV p24 IgG and IgA antibodies in sera and saliva of 107 and 119 adults, respectively, with HIV infection at different clinical stages, and in the sera of 13 infants born to HIV-infected mothers. The level of anti-HIV p24 IgA antibodies was lower in sera and higher in saliva as compared to that of anti-HIV p24 IgG antibodies. Where the percentage of HIV-specific serum antibody-positive cases decreased with disease progression, that of saliva antibody-positive cases increased in AIDS patients. Among the 13 infants born to HIV-infected mothers, 7 infants were HIV-p24-specific serum IgA positive. These sera were negative for anti-HIV p24 secretory IgA, suggesting that some infants develop their own immune responses against HIV infection. Thus, the detection of HIV-specific IgA antibodies, especially in saliva, could be a simple and reliable test for the diagnosis of HIV infection.

Presence of multiple HIV type 1 subtypes among mothers and children in Japan

We collected blood samples from 70 HIV-1-infected pregnant women and 76 babies born to HIV-1-infected women in Japan, from 1989 to 1999. To analyze the genetic diversity of HIV-1 among mothers and children, we sequenced the C2-V3 regions of HIV-1 gp120. Phylogenetic tree analysis of these regions revealed that multiple HIV-1 subtypes, A, B, D, E, and G, were circulating among mothers and children in Japan. Thus, the genetic heterogeneity of HIV-1 among mothers and children in Japan is steadily increasing, although the number of cases remains small. Perhaps the longest term survivor, an 11-year-old child with a vertical HIV-1 subtype G infection in Japan, is one of our subjects.

Immune responses and serum levels of cytokines in adult T-cell leukemia patients and human T-cell leukemia virus type-I carriers

To find predictive parameters for development and progression of adult T-cell leukemia (ATL) in human T-cell leukemia virus type-I (HTLV-I) carriers, we investigated cellular immune responses such as mitogenic responses and natural killer activity of the peripheral blood mononuclear cells (PBMC). And serum or plasma levels of cytokines, including tumor-necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and immunosuppressive acidic protein (IAP), were also measured in patients with ATL, healthy HTLV-I carriers and healthy HTLV-I non-carriers as controls. Results are as follows: (1) increased spontaneous proliferation and decreased mitogenic responses of PBMC already existed in HTLV-I carriers; (2) IAP was significantly higher in patients with acute/lymphoma type ATL than in those with chronic/smoldering type, HTLV-I carriers and HTLV-I non-carriers. These results suggest that spontaneous proliferation or mitogenic responses and IAP may be useful parameters for the development and progression of ATL from the carriers. Since HTLV-I carriers already have various grades of immunosuppression, we should seriously try to prevent further HTLV-I transmission.

Detection of HTLV-II-seropositive blood donors in South Vietnam but not in North Vietnam

Approximately 1% (4/500) of blood donors exhibited seropositivity for HTLV-II in South Vietnam, but none (0/500) did in North Vietnam. Further, all individuals seropositive for HTLV-II were intravenous drug abusers who were seronegative for HIV-1 and HTLV-I. These findings suggest that HTLV-II infection may be specifically prevalent in drug abusers in South Vietnam.

Infection of macaques with an R5-tropic SHIV bearing a chimeric envelope carrying subtype E V3 loop among subtype B framework

To establish simian/human immunodeficiency virus (SHIV) clones bearing a chimeric envelope carrying subtype E V3 loop among subtype B envelope, four subtype E V3 sequences were substituted into SHIV(MD14), a SHIV clone bearing an envelope derived from a CXCR4 (X4)/CCR5 (R5)-dual tropic subtype B HIV-1 strain. SHIV-TH09V3, an only V3-chimera clone capable of replicating in human and macaque peripheral blood mononuclear cells (PBMCs), was propagated in pig-tailed macaque PBMCs and in cynomolgus macaque splenic mononuclear cells. The propagated virus stocks were intravenously inoculated into respective macaque species. SHIV-TH09V3 infected both macaque species as shown by plasma RNA viremia, isolated viruses from PBMCs and plasma, and antibody production against viral proteins. To assess how the substituted V3 sequence affected coreceptor usage, SHIV-TH09V3 stocks propagated in vitro and after isolation from macaques were verified for their corecepor usage by GHOST cells assay. SHIV-TH09V3 maintained R5-tropic phenotype both in vitro and after isolation from macaques, in contrast to the X4/R5-dual tropic SHIV(MD14). This indicates the substituted V3 sequence among the backbone of SHIV(MD14) governs coreceptor usage. Future study of infecting macaques with SHIV-TH09V3 and SHIV(MD14) will focus on differences of the outcome caused by the different V3 sequences in connection with coreceptor usage.

Vertical transmission of human immunodeficiency virus type 1 in Japan, 1989-1997: presence of two subtypes B and E with subtype E predominance. National Cooperative Study Investigators on Vertical Transmission of HIV-1

A collaborative group for studying vertical transmission of human immunodeficiency virus (HIV)-1 in pregnant women and their babies was established in Japan in 1989. Forty-two infants, including 13 HIV-1-infected, 25 uninfected and four of undetermined status and 15 control children born to HIV-1 negative mothers were diagnosed and followed from birth to 1.5 years. All strains from HIV-positive infants were either clade E (eight infants, 61.5%) or B (five infants, 38.5%) according to DNA sequencing specific for the HIV-1 C2-V3 region. The 42 mothers with HIV-1 were women with sexual-risk behavior from all regions, but were concentrated in the Kanto District. In this group of HIV-infected children, there was no significant difference between the transmissibility of their mother's clade E and B viruses. Eight (61.5%) of the 13 virus-infected babies were Japanese and five (62.5%) of the eight were positive for HIV-1 clade E. The V3 loop region of the clade E virus of the babies was conserved but approximately 60% of the sequences which showed a substitution of aspartic acid by asparagine at position 29. The results suggest that HIV-1 clade E may be predominant in vertical transmissions and are phenotypically different from HIV-1 in persons with various other risk behaviors in Japan.

Decline in the HIV-1 isolation rate in Japan: a 12-year observation

Since 1988, we have isolated HIV-1 from 614 HIV-1-infected persons (total sample=2,785) in Japan. During the past 12 years, we have found a decline in the HIV-1 isolation rate in Japan, with two identifiable turning points, 1991-1992 and 1996-1997. The two turning points correspond to shifts in anti-HIV-1 therapy. These findings suggest that HIV-1 in Japan is currently biologically well controlled, probably due to anti-HIV-1 therapy. On the other hand, this decline is inconsistent with the recent increase of genetic drug-resistant HIV-1 in Japan. Further studies are needed to clarify mechanisms that might explain the discrepancy.

Analysis of IgE turnover in non-sensitized and sensitized rats

BACKGROUND

Although the levels of immunoglobulin E (IgE) in the circulating blood are often elevated in patients with allergic diseases, such levels cannot always be considered as pathognomonic signs of allergy. The induction of allergic reactions in the tissue was inferred to be related to the amount of IgE passing through the vascular wall.

AIMS

We attempted to clarify which compartment, the intravascular or extravascular, plays an important role in the regulation of the turnover of rat IgE.

METHODS

The level of DNP-specific rat IgE in the serum was estimated by IgE-capture enzyme-linked immunosorbent assay, and the turnover of IgE was analyzed from its pharmacokinetic parameters.

RESULTS

The transfer rate constants from the central to tissue compartment (Kct) were larger than those from the tissue to central compartment (Ktc) irrespective of the sensitized state. The value of the distribution volume of the tissue compartment (Vt) was larger than that of the distribution volume of the central compartment (Vc) irrespective of the sensitized state.

CONCLUSIONS

These Findings suggest that the short half-life of rat IgE in the circulation could be attributable to the distribution of IgE from the intravascular to the extravascular compartment.

Nucleotide sequence variation of human T-lymphotropic virus type II in Vietnam

A high rate of human T-lymphotropic virus type II (HTLV-II) infection has been documented in intravenous drug abusers (IVDAs) in South Vietnam. We have investigated the molecular characteristics of the virus and have shown that one HTLV-II subtype is predominant in Ho Chi Minh City. This molecular subtype, HTLV-IIb, was identified in a number of South Vietnamese by nucleotide sequence analysis of the long terminal repeat (LTR) region. HTLV-IIa was not found. These findings suggest that HTLV-IIb is endemic in IVDAs in South Vietnam, although IVDAs in urban areas in North America are predominantly infected with HTLV-IIa.

[A case of pulmonary carcinoma presenting flow cytometrical heterogeneity of the nuclear DNA content between its primary focus and the metastatic foci]

We have experienced case involving a 63-year-old patient with a pulmonary carcinoma, who was given an enterectomy following a lobectomy, due to minimal intestinal metastasis. In this case, using flow cytometry, the cancer cell nuclear DNA content was analyzed for the primary tumor focus, the mediastinal lymph node metastatic focus, and the small intestinal metastatic focus. For the primary focus, a cancer cellular population of polyploidy with 2 ploidies of DNA content was observed, while for both the metastatic foci, only a single cancer cellular population was observed, indicating the heterogeneity of the nuclear DNA content between the primary focus and metastatic foci. These 2 metastatic foci had DNA contents completely corresponding to that for a ploidy with a high DNA content in the primary focus, suggesting a metastasis of only the above population from the primary focus. The present case apparently formed metastatic foci in other organs than the lungs but only by cancer cells more susceptible to metastasis among the cancer cells found in the primary focus.