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Biomedical subjects

A Adachi

Publications and source records attributed to A Adachi.

At least 109 records · Page 6Linked to original sources
PubMed1998

Simian T cell leukemia virus type I-induced malignant adult T cell leukemia-like disease in a naturally infected African green monkey: implication of CD8+ T cell leukemia.

Spontaneous T cell leukemia was found in an African green monkey (Cercopithecus aethiops, AGM) naturally infected with simian T cell leukemia virus type I (STLV-I). The hematological features and the evidence for monoclonal integration of provirus DNA in the leukemic cells revealed that the leukemia was an ATL-like disease. The expression of surface markers on the leukemic cells indicated that they were defined as an activated CD8+ T cell subset. Together with the finding that seven in vitro spontaneously STLV-I-transformed cell lines were CD4-CD8+, it is likely that CD8+ T cells are transformed by STLV-I in AGMs, in contrast with human ATL. Finally, we assessed characteristics of the CD8 chains on these transformed cells. The result indicated that the leukemic cells expressed only the alpha chains but not the beta chains. However, in the case of in vitro-transformed cell lines the expression pattern of the CD8 chains varied in individual monkeys. Thus, STLV-I may preferentially transform CD8+ (both alphaalpha+ and alphabeta+) T cells in AGMs.

Adult↗
PubMed1998

Inhibition of HIV replication by capsid mutant C6b.

A Gag capsid mutant of human immunodeficiency virus type 1 (HIV-1) designated C6b was biologically and biochemically characterized with respect to its ability to suppress the replication of wild-type (wt) HIV. The C6b efficiently interfered with the replication of wt HIV-1 in the cleavage of Gag precursor, and also in the early replication process before or during viral DNA synthesis after viral penetration. The C6b Gag appeared to be unable to form chimeric multimers with HIV-2 Gag and failed to inhibit the replication of wt HIV-2.

Blotting, Southern↗
PubMed1998

Rapid formation of the immune complexes on solid phase in the immune complex transfer enzyme immunoassays for HIV-1 p24 antigen and antibody IgGs to HIV-1.

In order to perform the immune complex transfer enzyme immunoassays for HIV-1 p24 antigen and antibody IgGs to HIV-1 p17, reverse transcriptase and gp41 antigens as rapidly as possible, methods for rapid formation of the immune complexes on solid phase are described. HIV-1 p24 antigen was reacted with monoclonal anti-p24 Fab'-beta-D-galactosidase conjugate at a high concentration and subsequently with polystyrene beads coated successively with affinity-purified (anti-2,4-dinitrophenyl group) IgG and 2,4-dinitrophenyl-biotinyl bovine serum albumin-affinity-purified anti-p24 Fab' conjugate. Antibody IgGs to HIV-1 were reacted with polystyrene beads coated successively with affinity-purified (anti-2,4-dinitrophenyl group) IgG and 2,4-dinitrophenyl-HIV-1 antigen conjugates and subsequently with HIV-1 antigen-beta-D-galactosidase conjugates. The periods of time used for the formation of the immune complexes comprising the three components on the polystyrene beads (15-30 min) were much shorter than those used in the previous immune complex transfer enzyme immunoassays (90-300 min), and the sensitivities of the present and previous immune complex transfer enzyme immunoassays were similar. The detection limit of the HIV-1 p24 antigen by the present and previous methods were similar (3 to 10 zmol/assay).

Adult↗
PubMed1998

Mapping the genetic determinants of human immunodeficiency virus type 2 for cell tropism and replication efficiency.

Two distinct infectious molecular clones of human immunodeficiency type 2 (HIV-2) were analyzed for their biological properties in six cell lines. Fourteen chimeric and ten mutant viruses were constructed from these two viral genomes to localize the genetic determinants responsible for the phenotypes. Growth property of the viruses in the cell lines, together with the biochemical data, showed that a major determinant for the viral tropism resides in the env gene. In addition, in some cell lines, the accessory genes vif and nef affected the efficiency of virus replication. Thus, like HIV-1, mutations in the auxiliary and env genes of HIV-2 contributed much to the differences in virological characteristics.

Base Sequence↗
PubMed1998

Induction of apoptosis in HEp-2 cells by infection with herpes simplex virus type 2.

Although herpes simplex virus type 1 (HSV-1) does not induce apoptosis in infected HEp-2 cells, herpes simplex virus type 2 (HSV-2) did induce apoptosis in a small but significant fraction of the same cells. Apoptosis was not observed in Vero or HeLa cells infected with HSV-2. In addition, HSV-2 infection in the presence of cycloheximide induced extensive apoptosis of HEp-2 or HeLa cells.

Animals↗
PubMed1998

Gag-Pol region determines the tropism of SIVagm for human cells.

Simian immunodeficiency virus isolated from African green monkeys (SIVagm) does not grow in many of human cell lines such as CEM x 174, H9, and MT-4, but could replicate in some human cell lines. Sequence of SIVagm responsible for its narrow host range was determined by making and monitoring growth potential of chimeric clones between SIVagm and human immunodeficiency virus type 1 (HIV-1). The results obtained indicated that the gag-pol region determines the observed narrow host range. By monitoring virus DNA synthesis and progeny virion production, the defect(s) of SIVagm in the replication in the restricted cells was demonstrated to be located at early phase.

Animals↗
PubMed1998

Complete inhibition of SIVmac replication by its capsid mutants.

Mutations were introduced into a genomic region encoding the C-terminal portion of Gag capsid protein of pathogenic simian immunodeficiency virus (SIVmac239). All the mutants generated were defective for virion production and were non-infectious for monkey cells. They all efficiently suppressed the replication of wild type SIVmac in monkey cells. These results were in good agreement with those obtained for human immunodeficiency virus type 1, showing the importance of SIV/monkey model system for studies on Gag.

Animals↗
PubMed1998

Effects of a bite-raising splint on the duration of the chewing cycle and the EMG activities of masticatory muscles during chewing in freely moving rabbits.

Metal bite-raising splints of 0.5 mm thickness were attached to the upper molar teeth on both sides of the jaw in rabbits. The effects of these splints on masticatory behaviour during the chewing of soft food (bread) by freely moving rabbits were investigated. We recorded electromyograms (EMGs) of the masseter and digastric muscles. The animals exhibited prolongation of the chewing cycle, decreased EMG activity of the masseter muscle and increased EMG activity of the digastric muscle during chewing after introduction of the bite-raising splints. The effects of the splints on the activities of masticatory muscles were abolished by bilateral sectioning of the maxillary and inferior alveolar nerves. It seems likely that afferents from oral sensory receptors were responsible for the changes in masticatory behaviour after the introduction of the occlusal splint.

Animals↗
PubMed1998

Further characterization of the 5'-flanking promoter region of the human beta1-adrenergic receptor gene.

Further characterization of the 5'-flanking promoter region of the human beta1-adrenergic receptor (AR) gene was attempted. The transcription initiation sites, determined by the primer extension and the rapid amplification of the 5'-cDNA end, are multiple in a spanning about 30 nucleotides (-289 to -261 relative to the translation start site). There exist inverted CCAAT boxes, multiple binding sites for transcription factor Sp1 and AP-2 nearby transcription initiation sites, however, this region lacks a typical TATA box. In order to localize the regulatory region for the basal transcription of the human beta1-AR gene, a variety of 5'-flanking sequence/chloramphenicol acetyltransferase reporter gene fusion constructs was prepared and transiently expressed in HeLa cells. Functional analyses reveal negatively (-3813 to -2925 and -1772 to -796) as well as positively (-2925 to -1772) regulatory regions, in addition to the region (-796 to -87) being necessary for the basic expression of the human beta1-AR gene.

Amino Acid Sequence↗
PubMed1998

Enhancement of human immunodeficiency virus type 1 infectivity by Nef is producer cell-dependent.

The growth kinetics of wild-type and nef mutant viruses of human immunodeficiency virus type 1 were comparatively analysed in several human CD4+ cell lines. Delayed replication of nef mutant virus was observed in all cell lines examined. To determine the stage in the virus replication cycle that is affected by Nef, a single-round replication assay was performed. Initially, the expression of marker genes in transfected cells was examined in order to study the role of Nef in the late phase of infection. The results obtained indicated that Nef is dispensable during the transcription to virion production stage. Next, the effect of Nef on the early phase was investigated with a single-round infection. It was demonstrated that Nef is required in the early phase of the virus replication cycle, from virion adsorption to integration. Finally, the infectivity of virus stocks prepared from four cell lines was determined. The relative infectivity of the nef mutant from the four cell lines differed. Taken together, we conclude that Nef acts via modulation of viral particles to enhance virus infectivity in a cell-dependent manner.

Gene Products, nef↗
PubMed1998

Specific distribution patterns of hCDC47 expression in cutaneous diseases.

hCDC47 is a human member of the MCM family, which has been implicated to be concerned with the regulatory machinery causing DNA to replicate once per cell cycle. In a previous paper, we described hCDC47 expression as being localized in the proliferative component of normal tissues, and showed greater expression in squamous cell skin carcinomas than in seborrheic keratosis. In the present study, we compared its expression in another type of skin tumor and various non-neoplastic cutaneous proliferative diseases. Two patterns of distribution of hCDC47-positive cells were observed. Keratoacanthomas showed a peripheral pattern in which only the cells located the basal cell layers were positive. Psoriasis vulgaris also showed this peripheral type of location, with the cells in the suprabasal layers also occasionally expressing hCDC47. Verruca vulgaris demonstrated a diffuse pattern, with positive epithelial cells distributed throughout the layers. Basal cell carcinomas also showed a similar pattern. The keratoacanthomas showed the highest hCDC47 positive cell rate (43.1%), followed by verruca vulgaris (42.5%), psoriasis vulgaris (23.4%), and basal cell carcinoma (17.3%). Our results suggest participation of hCDC47 in these proliferative disorders involving keratinocytes.

Basal Cell Carcinoma↗
PubMed1998

Comparative analysis of human and macaque monkey CD4: differences in formaldehyde lability and conformation.

Here we characterized macaque monkey CD4 by flow cytometry. The results showed that relatively lower fluorescence intensity was observed depending on the monoclonal antibodies (mAbs) used for staining; Leu-3a exhibited four-fold lower intensity than Nu-Th/i, and that formaldehyde fixation dramatically reduced fluorescence intensity of macaque CD4+ cells stained with Leu-3a but not of human cells. Nu-Th/i is therefore preferable for the analysis of macaque CD4. Pretreatment of either mAb inhibited the other mAb binding to human CD4. On the contrary, Nu-Th/i inhibited Leu-3a binding but Leu-3a poorly blocked Nu-Th/i binding to the macaque CD4. These results indicate that Leu-3a and Nu-Th/i epitopes are conserved in macaque CD4 but Leu-3a epitope is conformationally cryptic and/or fragile, resulting in the lower affinity. Amino acid sequence alignment of CD4 domain 1 shows that the substitutions outside the linear Leu-3a epitope may determine these characteristics of macaque CD4.

Amino Acid Sequence↗
PubMed1998

Suppression of HIV replication by dominant negative mutants of HIV-1 (review).

Various gag mutants of human immunodeficiency virus type 1 (HIV-1) generated in vitro were evaluated for their potentials to suppress the replication of wild-type (wt) virus. A single-round of wt virus replication in the presence of various mutant proteins was quantitatively monitored by transfection and infection experiments. Out of 38 mutants examined, 15 were demonstrated to interfere with the replication of wt HIV-1 at early and/or late viral replication phase. Some of these mutants were also effective against the replication of wt HIV-2. In this review, we focus on the mutants, which are able to act against a wide variety of HIV, and are very useful for future gene therapy against AIDS.

HIV-1↗
PubMed1998

Functional roles of HIV accessory proteins for viral replication (review).

Numerous lentiviruses, including human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) of causative agents of human AIDS as representative, have been recently isolated from various species of primates. The fundamental and most prominent feature of the viruses is the presence of a number of accessory genes in their genomes. Extensive biological and biochemical studies have demonstrated that the accessory gene products are not essential for viral replication at least in certain types of cells. Quite surprisingly, some of these accessory proteins are absolutely non-essential in any types of cells so far examined. In this brief review, our systematic genetic studies on the importance of the accessory proteins of HIV-1 and HIV-2 for viral replication are described and discussed.

Animals↗
PubMed1998

The non-env tropism of HIV/SIV (Review).

The tropism of human and simian immunodeficiency viruses (HIV and SIV) determined by sequences other than env has been studied. The restriction of HIV-1 replication in monkey cells was demonstrated to be regulated by viral non-env sequence. Likewise, the gag-pol region of SIVagm (virus of the African green monkey) genome was found to be responsible for growth restriction in human cells of the virus. No viral DNA synthesis was detected in cells nonpermissive for the viruses. In addition, a number of HIV-1 gag gene mutants, which have an early defect in viral replication cycle and direct no viral DNA synthesis in some cells, exhibited a phenotype of host range mutant. Taken together, it can be concluded that the viral tropism associated with the uncoating/ reverse transcription process does exist in HIV/SIV replication. Furthermore, many of the accessory gene mutants of HIV/SIV exhibit host cell-dependent replication property. In this review, we summarize these examples of non-env tropism of HIV/SIV.

Animals↗
PubMed1998

Ultrasensitive and rapid enzyme immunoassay (thin aqueous layer immune complex transfer enzyme immunoassay) for antibody IgG to HIV-1 p17 antigen.

The immune complex transfer enzyme immunoassay for antibody IgG to HIV-1 p17 antigen was performed in two different ways (the present immunoassays I and II) within shorter periods of time than previously reported. In the present (simultaneous) immunoassay I, antibody IgG to HIV-1 p17 antigen in 10 microL of serum samples was incubated simultaneously with 2,4-dinitrophenyl-maltose binding protein-recombinant p17(rp17) fusion protein and rp17-beta-D-galactosidase conjugate in a total volume of 22 microL for 10 min to form the immune complex comprising the three components. The reaction mixture was incubated with a polystyrene bead of 6.35 mm in diameter coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG for 5 min in a styrol test tube (13.3 x 54 mm and 2.1 g) to trap the immune complex. After washing, the polystyrene bead was incubated with 30 microL of epsilonN-2,4-dinitrophenyl-L-lysine solution in a polystyrene tube (12 x 75 mm) coated with affinity-purified (antihuman IgG gamma-chain) IgG for 10 min to transfer the immune complex. In the present (sequential) immunoassay 11, a polystyrene bead of 6.35 mm in diameter coated successively with affinity-purified (anti-2,4-dinitrophenyl group) IgG and 2,4-dinitrophenyl-maltose binding protein-rp17 fusion protein was incubated in a styrol test tube (13.3 x 54 mm and 2.1 g) sequentially with antibody IgG to HIV-1 p17 antigen in 10 microL of serum samples in a total volume of 16 microL for 5 min and subsequently with rp17-beta-D-galactosidase conjugate in a volume of 10 microL for 5 and 10 min. The immune complex formed on the polystyrene bead was transferred to a polystyrene tube coated with affinity-purified (antihuman IgG gamma-chain) IgG for 5 and 10 min in the same way as in the present immunoassay I. During the incubations, the styrol test tubes containing the polystyrene beads and reaction mixtures were shaken, and the polystyrene test tubes were rotated with shaking, so that the polystyrene beads were rotated randomly, and small drops (16 to 30 microL) of the reaction mixtures evenly contacted all parts of the solid phase surfaces during the incubations, though only small parts of the solid phase surfaces were contacted at one time. The intent was to continuously mix thin aqueous layers of the reaction mixtures covering the solid phase surfaces with the rest of the reaction mixtures. (Therefore, these immunoassays were called thin aqueous layer immunoassays.) beta-D-Galactosidase activity bound to the polystyrene tubes was assayed by fluorometry for 30 and 60 min. The present immunoassays I and II, in which only 15 to 25 min were used for the immunoreactions, were as sensitive if not more so than the previous immune complex transfer enzyme immunoassay requiring 150 min for the immunoreactions. In these earlier immunoreactions, the immune complex comprising the three components formed by 30 min incubation was trapped onto two polystyrene beads (3.2 mm in diameter) coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG for 60 min, and was then transferred to two polystyrene beads (3.2 mm in diameter) coated with affinity-purified (antihuman IgG y-chain) IgG for 60 min in a total volume of 150 microL. Furthermore, the present (sequential) immunoassay 11 (and probably I) could become approximately 10 times more sensitive by assaying bound beta-D-galactosidase activity for a longer period of time (10 h), since beta-D-galactosidase activity, bound nonspecifically in the presence of serum samples from HIV-1 seronegative subjects, was considerably low.

2,4-Dinitrophenol↗