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Biomedical subjects

K Komuro

Publications and source records attributed to K Komuro.

At least 37 records · Page 2Linked to original sources

Human T-lymphotropic virus type II in Japan.

Serum specimens were assayed for human T-lymphotropic virus type II(HTLV-II) infection in 1,500 individuals known to be seropositive for HTLV-I and 30,000 blood donors in Japan. All HTLV-I-positive individuals were negative for HTLV-II. However, one of the blood donors was clearly seropositive for HTLV-II. Further, the donor was shown to be positive for HTLV-IIb. Here we report at least one case with HTLV-II in Japan and discuss the origin of the infection.

Adult↗

Ovalbumin-liposome conjugate induces IgG but not IgE antibody production.

Antibody response after immunization with surface-coupled ovalbumin (OVA) of liposomes was investigated in mice. OVA was coupled to the surface of liposome via amino groups using glutaraldehyde. OVA-liposome conjugate induced a significant anti-OVA IgG antibody production in mice. However, no IgE antibody production specific for OVA was observed. Immunization with OVA-liposome induced IgE-specific unresponsiveness even after the subsequent challenge with OVA adsorbed with with aluminium hydroxide (OVA-alum), which induces a high level of IgE antibody production. Furthermore, following the primary immunization with OVA-alum, a secondary challenge with OVA-liposome boosted anti-OVA IgG but not anti-OVA IgE antibody production. These results show the potential of the antigen-liposome conjugate for the development of a vaccine with the least allergic reaction and also for the application of immunotherapy.

Aluminum Hydroxide↗

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.

AIDS Vaccines↗

Rapid development of murine AIDS is dependent of signals provided by CD54 and CD11a.

Murine AIDS (MAIDS) is induced by infection with the replication-defective virus (BM5def) component in the LP-BM5 murine leukemia virus (MuLV) mixture. The disease is characterized by polyclonally activated CD4+ T cells and B cells. It is known that BM5def is expressed at highest levels in B lymphocytes and that B cells serve as viral antigen-presenting cells. Full and sustained activation of CD4+ T cells against a conventional Ag usually requires both TCR and costimulating signals. Among various molecules known to provide costimulatory function, the expression of CD54 (ICAM-1) and CD11a/CD18 (LFA-1) on MAIDS B cells was increased, whereas that of CD2, heat-stable Ag (CD24), CD80 (B7-1), and CD86 (B7-2) was unchanged from normal. C57BL/6 mice depleted of both CD54 and CD11a expression as a result of chronic administration of mAb had developed no MAIDS at 4 wk and 8 wk after LP-BM5 MuLV infection. In addition, the proliferative response of B cells to mitogen was well conserved, whereas MAIDS-associated increases in serum Ig levels were inhibited. Replication of BM5def was suppressed markedly in infected mice treated with the CD54 and CD11a mAbs. These results suggest that the CD54/CD11a signal transduction pathway is a critical determinant of MAIDS development, and the lack of an immune response against viral Ag is enough to suppress BM5def replication and to prevent MAIDS.

Animals↗

Laparoscopic cholecystectomy with an ultrasound surgical aspirator.

Laparoscopic cholecystectomy using an ultrasound surgical aspirator has been performed in our department since March 1991. The horn cover was altered in order to be inserted through a trocar 10 mm in diameter. The main purpose of this device is to explore Calot's triangle by fragmentation and aspiration of the fatty tissue without damaging the nerves, vessels, and cystic duct. First the serosa of the Calot's triangle is cut via electrocautery with the sharp-angle hook dissector we designed. Then the cystic duct and cystic artery are efficiently exposed by the ultrasound surgical aspirator. This procedure is perfectly adapted for laparoscopic cholecystectomy. We obtained favorable results with the ultrasound surgical aspirator in 135 cases including 40 cases with a negative gallbladder, as evaluated by endoscopic retrograde cholangiography. In conclusion, the ultrasound surgical aspirator is suitable for skeletonizing the cystic duct and cystic artery, and the procedure is perfectly safe.

Cholecystectomy, Laparoscopic↗

Successful treatment of Pneumocystis carinii Pneumonia in mice with benanomicin A (ME1451).

Benanomicin A (BNM-A) has antimycotic activities via binding to mannan in the cell walls of fungi. Anti-Pneumocystis carinii activity of the agent was examined in the P. carinii-infected BALB/c nu/nu female mouse model because P. carinii also possesses mannan in the membranes. The infected mice were treated with intraperitoneal injections of six doses of BNM-A (1, 2.5, 5, 10, 30, and 100 mg/kg of body weight), 4 mg of pentamidine isethionate per kg, 100 mg of sulfamethoxazole per kg combined with 20 mg of trimethoprim per kg (co-trimoxazole), or saline for 21 days. Each dosage group consisted of 10 mice. During treatment, five mice in the control group (saline) died, whereas 8 to 10 mice in all treatment groups survived. Almost the same efficacies were obtained for the groups treated with 5 mg or more and 10 mg or more of BNM-A per kg regarding the weight and number, respectively, of cysts found in the lungs as were obtained for the groups treated with pentamidine isethionate and co-trimoxazole. Overall, a dose of 10 mg of BNM-A per kg was effective against P. carinii pneumonia infection in the mice. Thus, BNM-A is a good candidate for a novel treatment for P. carinii pneumonia as a compound with a new mechanism of action against P. carinii.

Animals↗

Gene transfer using purified retroviral integrase.

We present a new method of gene transfer into cultured cells using a purified retroviral integrase protein with liposomes. The acceleration rate of transfection by the integrase was increased by a few to ten times. The integrase target sequence containing the 3' end of LTR on the introduced plasmid was necessary for the acceleration, and the orientation of this sequence determined the level of acceleration activity. The analyses of the chromosomal DNAs of each transfectant demonstrated the integration of the introduced plasmid DNA within the integrase-target sequence.

Animals↗

Influence of H-2 class II antigens on the development of murine AIDS.

Inbred strains of mice differ markedly in their relative susceptibility to the development of lymphoproliferation and immunodeficiency, a syndrome termed mouse AIDS (MAIDS), after infection with the LP-BM5 mixture of murine leukemia viruses (MuLV). The etiologic virus in this mixture is replication defective (BM5def) and encodes only a variant gag protein. Genetic determinants of resistance and susceptibility to induction of MAIDS reside both within and outside the MHC. In strains with C57BL background genes, the MHC haplotypes associated with resistance to disease include d and a, whereas haplotypes b, s, and q are associated with sensitivity. Previous studies showed that MHC class I genes (H-2Dd, H-2Ld) mapping in the D end of H-2 and other genes mapping proximal to the D end determine resistance to MAIDS. This paper examines the nature of these non-D end MHC genes using assays of MHC recombinant and transgenic mice. We demonstrate that expression of E alpha d confers significant resistance to MAIDS, even in mice that do not express H-2Dd/H-2Ld. Unexpectedly, we found that E alpha polymorphisms can significantly influence resistance, with H-2b mice bearing E alpha d as a transgene having greater resistance to MAIDS than mice bearing an E alpha k transgene. E alpha d-mediated resistance to MAIDS was associated with decreased levels of the BM5def genome in splenic DNA, suggesting that E alpha genes exert their effect by enhancing antiviral activity.

Animals↗

Concentration of live retrovirus with a regenerated cellulose hollow fiber, BMM.

A concentrated live retrovirus is required for in vitro experiments. A cuprammonium-regenerated cellulose hollow fiber, termed BMM, originally developed for biohazardous viral removal, was used to concentrate two different retroviruses, an ecotropic murine leukemia virus (MuLV) and human immunodeficiency virus (HIV). The BMM was useful for concentrating live virus suspension 10- to 30-fold from 500-1000 ml of culture supernatant. The ecotropic MuLV concentrated by BMM was demonstrated to be viable and biologically intact by XC plaque-forming assay and reverse transcriptase assay. The concentrated MuLV reached a much higher titer in the spleen in mice than the original one. The virus concentration assessed by p24 antigen for HIV was clearly higher than that of the original culture supernatant of HIV-infected cell lines. Since BMM hollow fibers trapped viruses by the sieving mechanism but not by adsorption, the viral particles were recovered by washing and the total live virus recovery rate was high, about 50%. Furthermore 60 min sufficed to handle 1000 ml of supernatant in the case of a filtration area of 0.03 m2. These results show that the BMM provides us with a rapid, safe and efficient method for concentrating live retroviruses.

Animals↗

Synthetic oligonucleotides with certain palindromes stimulate interferon production of human peripheral blood lymphocytes in vitro.

We studied the ability of synthetic single-stranded 30-mer oligodeoxyribonucleotides (oligoDNAs) with three different kinds of hexamer palindromic sequence to induce interferon (IFN) production of human peripheral blood lymphocytes (PBL). When PBL was cultured with oligoDNA having a palindrome of AACGTT or GACGTC, IFN activity was detected by bioassay in the culture fluid after 8 h, and the amount of IFN reached the maximum after 18 h. IFN-alpha was predominantly produced, and small amounts of IFN-beta and IFN-gamma were also found. OligoDNA with the palindrome ACCGGT had no effect.

Base Sequence↗

Delayed progression of a murine retrovirus-induced acquired immunodeficiency syndrome in X-linked immunodeficient mice.

The murine acquired immunodeficiency syndrome (MAIDS) caused by defective LP-BM5 murine leukemia virus (MuLV) is a disease that shows severe immunodeficiency with abnormal lymphoproliferation, and hypergammaglobulinemia in susceptible C57BL/6 (B6) mice. To examine the cellular mechanisms of development of MAIDS, we injected LP-BM5 MuLV intraperitoneally into B6 mice bearing the X chromosome-linked immunodeficiency (xid). xid mice lack functionally mature B cells including Ly-1 B cells (also known as B-1 cells). All B6 mice died by 20 wk after LP-BM5 MuLV inoculation. In marked contrast, xid mice have continued to survive without any sign of MAIDS-related symptoms till at least 20 wk after the inoculation. The delayed progression of MAIDS in xid mice appears to depend on xid mutation, according to our experiments using both sexes of (B6.xid x B6)F1 and (B6 x B6.xid)F1 mice. Furthermore, Ly-1 B cells, enriched by a FACS, were shown to integrate the defective genome and appeared to be a major virus-infected B cell population. Our data corroborate that Ly-1 B cells play an important role in the induction and progression of MAIDS.

Animals↗

Immunological abnormalities in HIV-free haemophiliacs.

Since some haemophiliacs manifest profound immunodeficiency with no evidence of human immunodeficiency virus type 1 (HIV) infection, we measured the circulating immune complex (CIC) level in sera obtained from haemophiliacs and addressed the question of whether viral infection is associated directly or indirectly with enhanced CIC production. While more than 90% of HIV-positive individuals had a high level of CIC, around 60% of seronegative ones also showed CIC levels comparable to those of seropositive patients. These sera activated fresh complement in vitro. The patients infected with either HIV or Hepatitis C virus (HCV) or both showed higher frequency and concentration of serum CIC than those free of either pathogens. It is worth noting, however, that 64% of patients with no evidence of infection with HIV or HCV produced significant amounts of CIC. Among the infectious viruses examined, parvovirus is considered as one of the pathogens associated with CIC synthesis, since all the haemophiliacs including the HIV-free patients who had been supplied with heated coagulation factors for several years from birth carried antibodies to parvovirus B19. Strikingly, 60% of the children in this category were positive for CIC, suggesting the possible contribution of parvovirus infection to CIC formation.

Adolescent↗

Exocrinopathy resembling Sjögren's syndrome induced by a murine retrovirus.

BACKGROUND: Sjögren's syndrome (SS) is characterized by lymphocytic infiltration into, and destruction of exocrine glands, resulting in dryness of the mouth and eyes. The disease is considered to have an autoimmune etiology, however, its etiopathogenesis remains largely unknown. Recently, retrovirus is suggested to participate in the pathogenesis of SS, because SS-like lesions are reported in HIV infection or in human T cell leukemia virus type I infection. Moreover, human intracisternal A-type retroviral particles are reported to be detected in SS patients. During the course of our study on the histopathology of mice infected with a murine retrovirus, we happened to find SS-like exocrinopathy in those mice. EXPERIMENTAL DESIGN: Four-week-old C57BL/6 (B6) mice were injected intraperitoneally with LP-BM5 murine leukemia virus. This virus is known to induce splenomegaly, lymphadenopathy followed by lymphoid malignancy, and profound immunodeficiency in sensitive strains of mice. From 4 to 16 weeks after the virus inoculation, the infected mice were sacrificed and their submandibular and lacrimal glands were analyzed light and electron microscopically and immunohistochemically. The existence of the virus in the lesion in situ was also analyzed by the same method, and additionally by a polymerase chain reaction method. RESULTS: Periductal lymphocytic infiltration into the submandibular and lacrimal glands was observed in all the virus-infected mice at 4 weeks after the infection and progressed with time. Extraglandular lymphocytic infiltration was also observed in liver, kidney, lung, and pancreas. Immunohistochemical examination revealed that most infiltrating cells into the glands were composed of CD3+ T cells (CD4-dominant), Mac-1+ cells, and B220+ cells. The virus genome was detected in submandibular glands by immunohistochemistry or by polymerase chain reaction. In addition, retroviral particles were secreted into the lumen of exocrine ducts of submandibular glands. CONCLUSIONS: This might be an SS animal model that is induced by a certain defined retrovirus. This experimental system might provide us with valuable information for analyzing the mechanisms of how a retrovirus could induce SS.

Animals↗

High frequency of transmission of murine AIDS virus in C57BL/10 mice via mother's milk.

Maternal transmission of a murine leukemia virus (MuLV) mixture named LP-BM5 MuLV, which is knwon to induce murine AIDS (MAIDS), was investigated. Adult female C57BL/10 mice were inoculated intraperitoneally with LP-BM5 MuLV. When the virus-inoculated female mice developed splenomegaly or lymphadenopathy, they were mated with normal C57BL/10 male mice. Of 56 offspring born to MAIDS mothers, 14 appeared to develop MAIDS, as assessed by the occurrence of splenomegaly or lymphadenopathy as well as the mitogen response of spleen cells. The occurrence of MAIDS in offspring was found to be accompanied by the maternal transmission and expansion of a defective virus genome from which almost the entire pol and env regions are deleted. On the other hand, the ecotropic helper virus genome was detected in all offspring regardless of the occurrence of MAIDS. To examine the mode of maternal transmission of LP-BM5 MuLV, foster-nursing experiments were conducted. The ecotropic helper viruses were found in all normal offspring nursed by a MAIDS mother, and some of them developed MAIDS. In contrast, none of offspring born to a MAIDS mother that were nursed by an uninfected foster mother either carried the LP-BM5 MuLV or developed MAIDS. Finally, both the defective and the ecotropic helper viruses were detected in LP-BM5 MuLV-infected mother's milk. These results indicated that maternal transmission of LP-BM5 MuLV occurs with a high frequency and is mediated by mother's milk.

Animals↗

[Elevated Clq-bearing immune complexes in hemophiliacs with viral infections].

One hundred hemophilia A and 30 hemophilia B patients who had been treated with non-heated and heated factor VIII or prothrombin complex concentrates were examined by immunological tests including Clq-bearing immune complexes assay. Antibodies to human immunodeficiency virus type 1 (HIV-1), hepatitis B virus (HBV), hepatitis C virus (HCV) and human parvovirus B19 (B19) were analyzed by Western blotting, enzyme immunoassay, passive hemagglutination or radio-immunoassay. Clq-bearing immune complexes were assayed by a monoclonal anti-Clq ELISA system (Immunomedics). Seropositivity to HIV-1, HBV, HCV, and B19 was 56.9%, 87.7%, 79.2% and 100% respectively. Clq-bearing immune complexes were positive in 109 of the 130 patients (83.8%). The positivity and the levels were extremely higher than those in normal individuals. Clq-bearing immune complex levels in patient positive for HIV-1, HCV, or HBV were higher than those in the negative group (HIV: P less than 0.001, HCV: P less than 0.005, HBV: P less than 0.05). When the patients were divided into four groups according to seropositivity to HIV-1 and/or HCV, Clq-bearing immune complex levels were the highest in the group positive for both antibodies, and the lowest in the group negative for both antibodies. These results suggested that each viral infection influences the formation of immune complexes and repeated viral infection increased the level of Clq-bearing immune complexes in these patients.

Adolescent↗

Bovine albumin-like protein in commercial human albumin for clinical use.

We have demonstrated that several lots of commercial human serum albumin (HSA), prepared for clinical use by two manufacturers, reacted with anti-bovine whole serum in the double-diffusion test. The antigenic proteins were purified by affinity chromatography from these HSA lots and their chemical and immunological properties characterized. The purified proteins showed the same molecular weight as HSA and bovine serum albumin (BSA). By CNBr treatment and trypsin digestion, the purified protein produced the same fragments as BSA. Moreover, the purified protein had an amino acid composition very similar to BSA and also 30 residues identical to those of the N-terminal amino acid sequence of BSA. In addition, it was shown that heterophilic Hanganutziu-Deicher antigenicity was present in the purified protein. The protein reactive against-bovine whole serum, contained in commercial HSA, was called BSA-like protein.

Amino Acid Sequence↗

3'-Azido-3'-deoxythymidine prevents induction of murine acquired immunodeficiency syndrome in C57BL/10 mice infected with LP-BM5 murine leukemia viruses, a possible animal model for antiretroviral drug screening.

Adult C57BL/10 mice (H-2b Fv-1b) inoculated with LP-BM5 murine leukemia virus develop a disease which has many features in common with human acquired immunodeficiency syndrome (AIDS), in particular abnormal lymphoproliferation and severe immunodeficiency. In the present study, we examined the possibility that this murine AIDS (MAIDS) model would be useful for evaluating antiretrovirus drugs in vivo through the use of a well-defined antiretrovirus drug, the reverse transcriptase (RT) inhibitor (H. Mitsuya, K.J. Weinhold, P.A. Furman, M.H. St. Claire, S. Nusinoff-Lehrman, R.C. Gallo, D. Bolognesi, D.W. Barry, and S. Broder, Proc. Natl. Acad. Sci. USA 82:7096-7100, 1985) 3'-azido-3'-deoxythymidine (AZT). We evaluated the effect of AZT treatment on de novo virus infection as well as on the induction of immunodeficiency by various parameters, including RT activity in serum, splenomegaly, proliferative responses against alloantigens and mitogens, soluble-antigen-presenting cell activity, and immunoglobulin G levels in serum. Our results demonstrated that AZT treatment of C57BL/10 mice infected with LP-BM5 murine leukemia virus efficiently prevented the induction of immunodeficiency if started at the time of virus inoculation. Starting AZT treatment 1 week later provided only a partial protective effect. Starting AZT treatment 2 weeks later was associated with suppression of RT activity in serum but no prevention of immunosuppression. This MAIDS model may allow rapid and cost-effective screening for antiretrovirus drugs targeted against retroviral functions shared between human AIDS and MAIDS, such as those encoded by gag, pol, or env.

Acquired Immunodeficiency Syndrome↗