Nationwide and long-term molecular epidemiologic studies of mumps viruses that circulated in Japan between 1986 and 2017

In Japan, major mumps outbreaks still occur every 4–5 years because of low mumps vaccine coverage (30–40%) owing to the voluntary immunization program. Herein, to prepare for a regular immunization program, we aimed to reveal the nationwide and long-term molecular epidemiological trends of the mumps virus (MuV) in Japan. Additionally, we performed whole-genome sequencing (WGS) using next-generation sequencing to assess results from conventional genotyping using MuV sequences of the small-hydrophobic (SH) gene. We analyzed 1,064 SH gene sequences from mumps clinical samples and MuV isolates collected from 25 prefectures from 1986 to 2017. The results showed that six genotypes, namely B (110), F (1), G (900), H (3), J (41), and L (9) were identified, and the dominant genotypes changed every decade in Japan since the 1980s. Genotype G has been exclusively circulating since the early 2000s. Seven clades were identified for genotype G using SH sequence-based classification. To verify the results, we performed WGS on 77 representative isolates of genotype G using NGS and phylogenetically analyzed them. Five clades were identified with high bootstrap values and designated as Japanese clade (JPC)-1, -2, -3, -4, -5. JPC-1 and -3 accounted for over 80% of the total genotype G isolates (68.3 and 13.8%, respectively). Of these, JPC-2 and -5, were newly identified clades in Japan through this study. This is the first report describing the nationwide and long-term molecular epidemiology of MuV in Japan. The results provide information about Japanese domestic genotypes, which is essential for evaluating the mumps elimination progress in Japan after the forthcoming introduction of the mumps vaccine into Japan’s regular immunization program. Furthermore, the study shows that WGS analysis using NGS is more accurate than results obtained from conventional SH sequence-based classification and is a powerful tool for accurate molecular epidemiology studies.

Antiviral Activity of CD437 Against Mumps Virus

Many efforts have been dedicated to the discovery of antiviral drug candidates against the mumps virus (MuV); however, no specific drug has yet been approved. The development of efficient screening methods is a key factor for the discovery of antiviral candidates. In this study, we evaluated a screening method using an Aequorea coerulescens green fluorescent protein-expressing MuV infectious molecular clone. The application of this system to screen for active compounds against MuV replication revealed that CD437, a retinoid acid receptor agonist, has anti-MuV activity. The point of antiviral action was a late step(s) in the MuV life cycle. The replication of other paramyxoviruses was also inhibited by CD437. The induction of retinoic acid-inducible gene (RIG)-I expression is a reported mechanism for the antiviral activity of retinoids, but our results indicated that CD437 did not stimulate RIG-I expression. Indeed, we observed antiviral activity despite the absence of RIG-I, suggesting that CD437 antiviral activity does not require RIG-I induction.

Seroprevalence of mumps before the introduction of mumps-containing vaccine in Lao PDR: results from a nationwide cross-sectional population-based survey

OBJECTIVE

Mumps-containing vaccine is currently not a component of the national immunization schedule in Lao People's Democratic Republic (PDR). Mumps itself is not a notifiable disease in the country and the seroprevalence of anti-mumps immunoglobulin G (IgG) in the general population is unknown. In this study, anti-mumps IgG was measured in 2058 blood samples to evaluate population immunity in the country.

RESULTS

The seroprevalence of anti-mumps IgG showed a gradual increase with increasing age, starting at 10.6% (95% CI 7.4-13.7) in participants aged 1-2 years, and almost plateaued at about 75% in individuals older than 11-12 years, though it still tended toward a small increase up to 89.6% (95% CI 86.6-92.6) in participants aged 40 years or older. Compared with the results of previous studies, this increase with increasing age is less marked and the plateau of anti-mumps seroprevalence is lower. We attribute this result mainly to the lower population density in Lao PDR.

Molecular Epidemiological Study of Mumps Epidemics of 2015 in Okinawa, Japan

Although major mumps epidemics occurred every 4-5 years in Okinawa Prefecture in Japan, no laboratory diagnoses were conducted. A mumps epidemic started in Okinawa in October 2014, and we collected clinical samples from 31 patients in 4 areas (Hokubu, Nanbu, Miyako, and Yaeyama) from July to December 2015, for virus isolation and RT-PCR, whose positive ratios were 52% and 87%, respectively. Phylogenetic analyses showed that all isolates were classified into genotype G, and with one exception, consisted of 2 subgenotypes, Ge (55.6%) and Gw (40.7%), which have been prominent in Japan recently. One isolate was classified in another lineage, which was detected in Japan for the first time, and was similar to a Hong Kong isolate from 2014. Remarkably, the geographic distributions of the 2 major lineages were separated. The Ge viruses were isolated from the main island of Okinawa and the Yaeyama Islands, whereas the Gw isolates were mainly detected from the Miyako Islands. These results suggest that the Ge and Gw mumps viruses mainly caused the mumps epidemics of 2015 in Okinawa, and that they spread independently in separate regions. This is the first report describing the molecular epidemiology of mumps epidemics in Okinawa Prefecture.

Cross-Neutralization between Human and African Bat Mumps Viruses

Recently, a new paramyxovirus closely related to human mumps virus (MuV) was detected in bats. We generated recombinant MuVs carrying either or both of the fusion and hemagglutinin-neuraminidase bat virus glycoproteins. These viruses showed replication kinetics similar to human MuV in cultured cells and were neutralized efficiently by serum from healthy humans.

Vaccinia Virus LC16m8∆ as a Vaccine Vector for Clinical Applications

The LC16m8 strain of vaccinia virus, the active ingredient in the Japanese smallpox vaccine, was derived from the Lister/Elstree strain. LC16m8 is replication-competent and has been administered to over 100,000 infants and 3,000 adults with no serious adverse reactions. Despite this outstanding safety profile, the occurrence of spontaneously-generated large plaque-forming virulent LC16m8 revertants following passage in cell culture is a major drawback. We identified the gene responsible for the reversion and deleted the gene (B5R) from LC16m8 to derive LC16m8Δ. LC16m8∆ is non-pathogenic in immunodeficient severe combined immunodeficiency (SCID) mice, genetically-stable and does not reverse to a large-plaque phenotype upon passage in cell culture, even under conditions in which most LC16m8 populations are replaced by revertants. Moreover, LC16m8∆ is >500-fold more effective than the non-replicating vaccinia virus (VV), Modified Vaccinia Ankara (MVA), at inducing murine immune responses against pathogenic VV. LC16m8∆, which expresses the SIV gag gene, also induced anti-Gag CD8⁺ T-cells more efficiently than MVA and another non-replicating VV, Dairen I minute-pock variants (DIs). Moreover, LC16m8∆ expressing HIV-1 Env in combination with a Sendai virus vector induced the production of anti-Env antibodies and CD8⁺ T-cells. Thus, the safety and efficacy of LC16m8∆ mean that it represents an outstanding platform for the development of human vaccine vectors.

MicroRNA regulation of glycoprotein B5R in oncolytic vaccinia virus reduces viral pathogenicity without impairing its antitumor efficacy

Vaccinia virus, once widely used for smallpox vaccine, has recently been engineered and used as an oncolytic virus for cancer virotherapy. Their replication has been restricted to tumors by disrupting viral genes and complementing them with products that are found specifically in tumor cells. Here, we show that microRNA (miRNA) regulation also enables tumor-specific viral replication by altering the expression of a targeted viral gene. Since the deletion of viral glycoprotein B5R not only decreases viral pathogenicity but also impairs the oncolytic activity of vaccinia virus, we used miRNA-based gene regulation to suppress B5R expression through let-7a, a miRNA that is downregulated in many tumors. The expression of B5R and the replication of miRNA-regulated vaccinia virus (MRVV) with target sequences complementary to let-7a in the 3'-untranslated region (UTR) of the B5R gene depended on the endogenous expression level of let-7a in the infected cells. Intratumoral administration of MRVV in mice with human cancer xenografts that expressed low levels of let-7a resulted in tumor-specific viral replication and significant tumor regression without side effects, which were observed in the control virus. These results demonstrate that miRNA-based gene regulation is a potentially novel and versatile platform for engineering vaccinia viruses for cancer virotherapy.

Prior immunization with severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) nucleocapsid protein causes severe pneumonia in mice infected with SARS-CoV

The details of the mechanism by which severe acute respiratory syndrome-associated coronavirus (SARS-CoV) causes severe pneumonia are unclear. We investigated the immune responses and pathologies of SARS-CoV-infected BALB/c mice that were immunized intradermally with recombinant vaccinia virus (VV) that expressed either the SARS-CoV spike (S) protein (LC16m8rVV-S) or simultaneously all the structural proteins, including the nucleocapsid (N), membrane (M), envelope (E), and S proteins (LC16m8rVV-NMES) 7-8 wk before intranasal SARS-CoV infection. The LC16m8rVV-NMES-immunized group exhibited as severe pneumonia as the control groups, although LC16m8rVV-NMES significantly decreased the pulmonary SARS-CoV titer to the same extent as LC16m8rVV-S. To identify the cause of the exacerbated pneumonia, BALB/c mice were immunized with recombinant VV that expressed the individual structural proteins of SARS-CoV (LC16mOrVV-N, -M, -E, -S) with or without LC16mOrVV-S (i.e., LC16mOrVV-N, LC16mOrVV-M, LC16mOrVV-E, or LC16mOrVV-S alone or LC16mOrVV-N + LC16mOrVV-S, LC16mOrVV-M + LC16mOrVV-S, or LC16mOrVV-E + LC16mOrVV-S), and infected with SARS-CoV more than 4 wk later. Both LC16mOrVV-N-immunized mice and LC16mOrVV-N + LC16mOrVV-S-immunized mice exhibited severe pneumonia. Furthermore, LC16mOrVV-N-immunized mice upon infection exhibited significant up-regulation of both Th1 (IFN-gamma, IL-2) and Th2 (IL-4, IL-5) cytokines and down-regulation of anti-inflammatory cytokines (IL-10, TGF-beta), resulting in robust infiltration of neutrophils, eosinophils, and lymphocytes into the lung, as well as thickening of the alveolar epithelium. These results suggest that an excessive host immune response against the nucleocapsid protein of SARS-CoV is involved in severe pneumonia caused by SARS-CoV infection. These findings increase our understanding of the pathogenesis of SARS.

Immunogenicity of newly constructed attenuated vaccinia strain LC16m8Delta that expresses SIV Gag protein

We developed the method to efficiently construct recombinant vaccinia viruses based on LC16m8Delta strain that can replicate in mammalian cells but is still safe in human. Immunization in a prime-boost strategy using DNA and LC16m8Delta expressing SIV Gag elicited 7-30-fold more IFN-gamma-producing T cells in mice than that using DNA and non-replicating vaccinia DIs recombinant strain. As the previous study on the DNA-prime and recombinant DIs-boost anti-SIV vaccine showed protective efficacy in the macaque model [Someya K, Ami Y, Nakasone T, Izumi Y, Matsuo K, Horibata S, et al. Induction of positive cellular and humoral responses by a prime-boost vaccine encoded with simian immunodeficiency virus gag/pol. J Immunol 2006;176(3):1784-95], LC16m8Delta would have potential as a better recombinant viral vector for HIV vaccine.

SARS-CoV spike protein-expressing recombinant vaccinia virus efficiently induces neutralizing antibodies in rabbits pre-immunized with vaccinia virus

A vaccine for severe acute respiratory syndrome (SARS) is being intensively pursued against its re-emergence. We generated a SARS coronavirus (SARS-CoV) spike protein-expressing recombinant vaccinia virus (RVV-S) using highly attenuated strain LC16m8. Intradermal administration of RVV-S into rabbits induced neutralizing (NT) antibodies against SARS-CoV 1 week after administration and the NT titer reached 1:1000 after boost immunization with RVV-S. Significantly, NT antibodies against SARS-CoV were induced by administration of RVV-S to rabbits that had been pre-immunized with LC16m8. RVV-S can induce NT antibodies against SARS-CoV despite the presence of NT antibodies against VV. These results suggest that RVV-S may be a powerful SARS vaccine, including in patients previously immunized with the smallpox vaccine.

Rescue system for measles virus from cloned cDNA driven by vaccinia virus Lister vaccine strain

A rescue system for measles virus from cloned cDNA was established using CHO/hSLAM cells (Chinese hamster ovary cells expressing a measles virus receptor, signaling lymphocyte activation molecule), LO-T7-1 virus (the Lister vaccine strain of vaccinia virus expressing the T7 RNA polymerase under the control of the early/late p7.5 promoter), and caspase inhibitor. LO-T7-1 drove efficiently the T7 promoter in CHO/hSLAM cells. Rescue efficiency with LO-T7-1 was not as high as that with the vTF7-3 strain based on a neurovirulent vaccinia virus, but was increased by using a caspase inhibitor to block apoptosis of CHO/hSLAM cells induced by LO-T7-1. These modifications resulted in a measles virus rescue efficiency that was even higher than that of previous systems. This safer and more efficient system will facilitate further the genetic manipulation of measles virus in basic research and virus vector development.

Development and biological properties of a new live attenuated mumps vaccine

To develop a new live attenuated mumps vaccine, a wild mumps Y7 strain isolated from a patient who developed mild parotitis was treated with nitrosoguanidine and ultraviolet, followed by selection of a temperature-sensitive clone. The selected clone, Y125, showed stable temperature-sensitivity in Vero cells. Intraspinal inoculation of marmosets with the Y125 produced only minimal histopathological changes, while intracerebral inoculation of neonatal rats revealed that the Y125 did not cause hydrocephalus. Both these effects of the Y125 were similar to those of the non-neurovirulent Jeryl Lynn strain. Furthermore, subcutaneous inoculation of the Y125 induced high levels of neutralizing antibodies in all Cercopithecus monkeys examined. Although the safety and immunogenicity should be confirmed in further field trials in humans, the present results indicate that the Y125 could be a promising vaccine candidate.

Genetically stable and fully effective smallpox vaccine strain constructed from highly attenuated vaccinia LC16m8

A highly attenuated LC16m8 (m8) smallpox vaccine has been licensed in Japan because of its extremely low neurovirulence profile, which is comparable to that of replication incompetent strains of vaccinia virus. From 1973 to 1975, m8 was administrated to >100,000 infants where it induced levels of immunity similar to that of the originating Lister strain, without any serious side effects. Recently, we observed that m8 reverts spontaneously to large plaque forming clones that possess virulence equivalent to that of LC16mO, a parental virus strain of m8. Here, we report that the B5R gene is responsible for the reversion, and that we could construct a more genetically stable virus by deleting B5R from m8. The protective immunogenicity of the vaccine candidate proved to be equivalent to that of the U.S.-licensed product Dryvax, and much superior to modified vaccinia Ankara in a mouse model. Furthermore, the vaccine strain never elicited any symptoms in severe combined immunodeficiency disease mice, even at a dose 1,000-fold greater than that used in the immune protection experiments, which is in contrast to the lethal pathogenicity induced by Dryvax inoculation of severe combined immunodeficiency disease mice. Our results suggest that this vaccine strain is a good candidate as a suitable smallpox vaccine and a vector virus, and that B5R is not essential for protective immunity against smallpox.

Neurovirulence of mumps virus: intraspinal inoculation test in marmosets

An intraspinal inoculation test of mumps virus using marmosets was performed in order to develop a neurovirulence test of mumps vaccines. In the group inoculated with non-neurovirulent Jeryl Lynn vaccine strain at 10(2.0) pfu/dose, there were only minimal histopathological changes in 3 of the 5 marmosets. In contrast, all marmosets inoculated with neurovirulent Urabe and NK-M46 vaccine strains developed extensive encephalitis and meningitis. Thus, this marmoset model, which can distinguish between non-neurovirulent and neurovirulent vaccine strains, is useful for evaluating neurovirulence of vaccine strains and elucidating the molecular pathogenesis of mumps.

Large-scale preparation of biologically active measles virus haemagglutinin expressed by attenuated vaccinia virus vectors

A procedure described here allows the efficient and rapid purification of histidine-tagged measles virus haemagglutinin that is synthesized under the control of powerful promoters (PSFJ1-10 and PSFJ2-16) of the highly attenuated vaccinia virus (VV) strain LC16mO. A single affinity chromatography step purifies recombinant haemagglutinin proteins from the lysates of cells infected with the recombinant VVs. The recovery and purity are both very high (a yield of 0.5-2.8 mg/10(8) cells and purity of >94-98%), indicating that this procedure is approximately 400 times more efficient than the conventional methods used to prepare haemagglutinin. The haemagglutinins are correctly transported to the cell surface and have haemadsorption activity. Moreover, the recombinant haemagglutinin proteins cooperate with the measles virus fusion protein to elicit cell fusion activity. In addition, the antibody titres against measles virus, as measured by enzyme-linked immunosorbent assay using the purified haemagglutinin as the capture antigen, correlated closely with neutralization test titres (R(2) = 0.84, p < 0.05), indicating the preservation of immunologically relevant antigenicity. Such recombinant haemagglutinin preparations will be useful in diagnostic tests that measure functional anti-measles immunity and investigate the biological functions and structure of the haemagglutinin.

Pathogenicity of mumps virus in the marmoset

The neurovirulence of two mumps virus strains was compared using marmosets. Marmosets were inoculated intravenously with the wild-type mumps virus Odate strain, resulting in evident meningitis in 1 of 3 marmosets at each of the weeks 3, 4, and 5 postinoculation, representing a total of 3 out of 9 marmosets. Nephritis, parotitis, pancreatitis, and tonsillitis were manifest in addition to central nervous system (CNS) sequelae. On the other hand, the Jeryl Lynn vaccine strain did not induce histopathological changes in the CNS and multiplication of the Jeryl Lynn strain was distinctly lower compared to that of the Odate strain in the marmoset. This is the first report to describe the induction of meningitis in non-human primates after peripheral inoculation of a wild-type mumps virus, presenting findings useful for the elucidation of the mechanism of infection and pathology of mumps virus in the CNS. The distinction observed between the Odate and Jeryl Lynn strains suggests the applicability of the marmoset model for the evaluation of any neurovirulence potential of vaccine strains.

Properties of tablets containing granulations of ibuprofen and an acrylic copolymer prepared by thermal processes

The objective of this study was to investigate the properties of tablets containing granulations of ibuprofen (Ibu) and Ammonio Methacrylate Copolymer, Type B (Eudragit RS PO) prepared by hot-melt processing. Tablets were compressed from granules prepared by hot-melt granulation (HMG) or direct compression (DC). For the hot-melt extrusion (HME) process, tablets were prepared by cutting the extrudate, manually. The physicochemical properties of tablets were investigated using thermal analysis, powder X-ray diffraction analysis, tablet hardness, and drug dissolution. The effect of thermal treatment of tablets on the dissolution characteristics of Ibu was also investigated. The results demonstrated that the Ibu lowered the glass transition temperature (Tg) of the Eudragit RS PO and the softened polymer functioned as a thermal binder in the granulation. Ibu was demonstrated to be an effective plasticizer for Eudragit RS PO in the thermal processes. The efficiency of the granulation process increased with increasing levels of Eudragit RS PO in the powder blend. Higher levels of Eudragit RS PO in the tablets prepared by HMG or HME resulted in a decrease in the dissolution rate of the Ibu. An increase in the amount of Ibu in the tablets prepared by HMG or DC led to a decrease in the initial dissolution rate of the Ibu. Following the thermal treatment of the Ibu tablets prepared by HMG, the dissolution rate was significantly decreased due to structural changes in the tablets that resulted from the fusion and coalescence of plasticized polymer particles, causing a reduction in tablet porosity. The Ibu tablets prepared by HME demonstrated minimal changes in their release properties following thermal treatment even at temperatures higher than the Tg of the polymer. HME was shown to be a novel method to prepare matrix tablets and stable dissolution properties were obtained when tablets were stored at 40 degrees C for 30 days.

Transfer of SV40 temperature-sensitive early gene into human epidermal keratinocytes by the recombinant adenovirus vector

We constructed a recombinant adenovirus vector that contained the origin-defective SV40 early gene, coding temperature-sensitive T antigen. This vector transferred the SV40 early gene into human epidermal keratinocytes with high efficiency. T antigen conferred the ability of keratinocytes to grow with limited differentiation in the presence of serum and high calcium concentration at the permissive temperature (34 degrees C), although normal keratinocytes were induced to differentiate and stop growing under the same conditions. The serum/Ca++-resistant cells did not proliferate at the nonpermissive temperature (40 degrees C), indicating that they depended on T antigen for their proliferation. The temperature-sensitive T antigen dissociated from the tumor suppressor gene products, p53, at 40 degrees C. The serum/Ca++-resistant cells still had the ability to proceed to terminal differentiation when injected into SCID mice as cultured keratinocytes. However, they did not form an apparent basal layer. This indicated that the tissue remodeling process in the serum/Ca++-resistant keratinocytes was abnormal. All of these epidermoid cysts disappeared within 8 wk and no tumor developed for 6 mo. We consider that deltaE1/SVtsT is a useful tool to examine multistep carcinogenesis of human epithelial cells in vitro.

An in vivo model of human skin acute graft-versus-host disease: transplantation of cultured human epidermal cells and dermal fibroblasts with human lymphocytes into SCID mice

The ability of mixed epidermal cell-lymphocyte reactions to detect allogeneic reactivities in an in vivo model was investigated by developing an in vivo model of acute graft-versus-host disease (GVHD), using SCID mice with a C.B-17 background in which human skin structures were generated by transplantation of cultured human epidermal cells (HEC) with dermal fibroblasts (HDFC). Suspensions containing cultured HEC and HDFC from a single donor were mixed with autologous peripheral blood mononuclear cells (PBMNC) or with PBMNC from unrelated individuals, and were injected into the flanks of C.B-17-SCID mice. Ten and 21 days after injection, subcutaneous nodules generated in the mice were examined histologically and immunohistochemically. Cystic structures developing after injection of HEC and HDFC without human PBMNC showed normal epidermislike tissue. Human skin generated in SCID mice injected with HEC and HDFC with auto-PBMNC showed no graft-versus-host reaction (GVHR) histologically, whereas those mice injected with PBMNC from siblings that shared an HLA haplotype showed mild GVHR. Human skin in SCID mice injected with HEC and HDFC with histoincompatible unrelated PBMNC showed moderate to severe GVHR. The severity of GVHR paralleled the dose of unrelated PBMNC, and GVHR was prevented by peroral treatment with cyclosporine A. Immunohistochemically, inflammatory cells infiltrating human cutaneous tissue formed in the SCID mice were stained by an anti-human CD45RO antibody that reacts with human T cells but not with murine lymphocytes, and most T cells were stained by an anti-human CD8 antibody recognizing HLA class I antigens. These findings are similar to those in clinical skin graft-versus host disease (GVHD) observed in patients undergoing allogeneic bone marrow transplantation. This experimental system should be useful as an in vivo model of human skin GVHD.

Preparation and Characterization of Barium-Strontium Hydroxyapatites

Barium-strontium hydroxyapatite solid solutions with different molar ratio Ba/(Ba + Sr) were synthesized by a wet method and characterized by various means. The solid solution particles could be prepared at molar ratios ranging from 0 to 1; however, Ba2+ ions were more difficult to be incorporated into hydroxyapatite crystals compared to Sr2+ ions. With increasing Ba2+ content, the particles grew and finally turned into pure rod-shaped barium hydroxyapatite particles with a size of ca. 0.2 x 2 &mgr;m. The resulting particles were agglomerates consisted of primary fine particles except for strontium hydroxyapatite. The molar ratios (Ba + Sr)/P of all the particles were larger than the stoichiometric ratio of 1.67, suggesting that CO32- ions, OH- ions, and/or H2O molecules substitute for PO43- ions in the crystal lattices. The amount of CO2 adsorbed irreversibly on the particles increased with increasing (Ba + Sr)/P except for strontium hydroxyapatite and fitted a curve with a minimum at a cation/P ratio of ca. 1.56 as well as other HAPs.

Effects of fibroblasts of different origin on long term maintenance of xenotransplanted human epidermal keratinocytes in immunodeficient mice

We examined effects of fibroblasts of different origin on long-term maintenance of xenotransplanted human epidermal keratinocytes. A suspension of cultured epidermal cells, originating from adult human trunk skin, was injected into double mutant immunodeficient (BALB/c nu/scid) mice subcutaneously, with or without cultured fibroblastic cells of different origin. At one week after transplantation, the epidermal cells generated epidermoid cysts consisting of human epidermis-like tissue. When the epidermal cells were injected alone or together with fibroblastic cells derived from human bone marrow, muscle fascia, or murine dermis, organized epidermoid cysts regressed within 6 weeks. In contrast, when the epidermal cells were injected together with human dermal fibroblasts, generated epidermoid cysts were maintained in vivo for more than 24 weeks. Histological examination showed that the reorganized epidermis, after injection of both epidermal keratinocytes and dermal fibroblasts, retained normal structures of the original epidermis during 6 to 24 weeks after transplantation. The results indicate that human dermal fibroblasts facilitate the long-term maintenance of the reorganized epidermis after xenotransplantation of cultured human epidermal keratinocytes by supporting self renewal of the human epidermal tissue in vivo.

Immortalisation of human oesophageal epithelial cells by a recombinant SV40 adenovirus vector

We introduced the origin-defective SV40 early gene into cultured human oesophageal epithelial cells by infection of a recombinant SV40 adenovirus vector. The virus-infected cells formed colonies 3-4 weeks after infection in medium containing fetal calf serum. When the cells derived from 'serum-resistant' colonies were then maintained in the serum-free medium with a low calcium ion concentration, some of them passed the cell crisis and kept growing for over 12 months. These cells, regarded as immortalised cells, resembled the primarily cultured oesophageal epithelial cells in morphology and had some of their original characteristics. Treatment of the cells with a high calcium concentration induced phenotypic changes. These cells still responded to transforming growth factor beta. When the immortalised cells were injected into severe combined immunodeficient mice, they transiently formed epithelial cysts, although the typical differentiation pattern of the oesophageal epithelium was not observed. These cysts regressed within 2 months without development into tumours. The results indicated that human oesophageal epithelial cells were reproducibly immortalised by infection with a recombinant SV40 adenovirus vector at relatively high efficiency. The immortalised cells should be useful in studies on oesophageal carcinogenesis and in assessing the cooperative effects with other oncogene products or carcinogens.

Use of cultured human epidermal allografts for the treatment of extensive partial thickness scald burn in children

In spite of recent progress in burn treatment, the early surgical therapy of partial thickness scald burns in children is still controversial. Early tangential excisions is not easily applicable for these patients because of difficulties in determination of the burn depth and probable physiological derangement after surgery. Hypertrophic scar formation and wound contraction after meshed autografts are other limitations. For these reasons, conservative treatment, not early excision therapy, has been chosen initially for these injuries. We used cultured epidermal allografts for extensive, partial thickness scald burns, during the early post-burn period without escharectomy. Fifty to 100% of the engrafted superficial dermal burns were epithelialized within 7 days. In contrast, untreated identical wounds remained open. Repeated grafting of cultured allografts on unexcised wound granulations of dermal burns also enhanced epithelialization. Long term results showed that hypertrophic scar formation in the mixed superficial and deep dermal burns was reduced when cultured allografts were used. Allografting of the cultured epidermis without surgical excision apparently promoted the rapid regeneration of the partial thickness burns. Procedural complications did not occur. Cultured allografts should be used as an effective and safe biological dressing for partial thickness scald burns in children.

Large-scale culture system of human CD4+ helper/killer T cells for the application to adoptive tumour immunotherapy

A simple method for the rapid expansion of human CD4+ T cells with both helper and killer functions was established. CD4+ T cells separated from peripheral blood mononuclear cells using immunomagnetic beads were stimulated with immobilised OKT-3 monoclonal antibody (mAb) plus recombinant interleukin 2 (rIL-2) in 96 well culture plates. After 6 day-culture, the CD4+ T cells were restimulated by immobilised OKT-3 mAb for an additional 24 h, then inoculated into concentrated rotary-tissue culture bag and cultured for further 9 days. This procedure yielded a 3000-fold increase in cell number (about 3-5 x 10(9) per bag). Most of the cells (over 96%) continued to express CD4+ antigen and retained their capacity to produce IL-2. The activated CD4+ T cells showed marked cytotoxicity against Fc receptor positive tumour cells in the presence of OKT-3 mAb. Moreover, we succeeded in a specific targeting of the expanded CD4+ helper/killer T cells to c-erb B-2 positive tumour cells by means of anti-CD3 x anti-c-erb B-2 bispecific antibody. These results suggested that our established simple system will be available for the expansion of large number of CD4+ helper/killer T cells which may provide an efficient strategy for adoptive tumour immunotherapy.

[Immunization of healthy children with measles-mumps-rubella trivalent vaccine simultaneously given with varicella vaccine]

Trivalent vaccine, containing measles TD97, rubella TCRB-19 and mumps NK-M46 strains (MMR vaccine) was administered to a total of 116 healthy children of which 50 subjects were simultaneously injected with varicella vaccine in the opposite arm. The seroconversion rates for measles, mumps, rubella, and varicella in those who received both MMR and varicella vaccines (MMR + V group) were 100% (44/44), 91% (39/43), 100% (46/46) and 95% (39/41), respectively. And these rates were comparable to those in subjects receiving only MMR vaccine, namely 100% (64/64) for measles, 95% (57/62) for mumps, and 97% (58/60) for rubella. Fifty-eight children receiving MMR vaccine were seronegative to measles, mumps and rubella before vaccination, and 51 (88%) of them were found to be seropositive against all three viruses at 6 to 8 weeks after vaccination. Among the children injected with MMR and varicella vaccines, 36 subjects had no pre-antibodies to measles, mumps, rubella and varicella. Seroconversion in post-serum to all four viruses were found in 31 cases (86%). Clinical reactions observed in some vaccines were mild fever (17%) and exanthem (5%). There were no complications of lymphadenopathy, swelling in parotid regions, or meningitis. Our results indicate that simultaneous administration of MMR vaccine and varicella vaccine is a safe and effective method for immunizing children against these four infectious diseases.

[Immunization of healthy children with mumps-rubella bivalent live vaccine and simultaneous vaccination with mumps-rubella and varicella vaccines]

Bivalent virus vaccine, containing rubella TCRB-19 strain and mumps NK-M46 strain (MR vaccine), was administered to a total of 95 healthy children who had already received measles vaccine or had been infected with wild measles virus. The seroconversion rates for rubella and mumps viruses in subjects having no antibody to rubella or to mumps virus were 99% (75/76) and 97% (63/65), respectively, at 6-8 weeks after vaccination. The seroconversion rates for both rubella and mumps in vaccinees initially seronegative to both viruses were 95% (56/59). Immune responses after MR vaccine injection were comparable to those after administration of monovalent rubella or mumps vaccine. Clinical reactions observed in some subjects who received MR vaccine were mild fever (3.6%), exanthem (8%), lymphadenopathy (1.8%), and swelling of the parotis region (1.8%). MR vaccine could be simultaneously injected with varicella vaccine at the opposite site producing no adverse effect on immune response. Our results indicate that MR vaccine is a safe and effective vaccine, especially for children who have had wild measles or who have received measles vaccine.

Predominant recognition of human T cell leukemia virus type I (HTLV-I) pX gene products by human CD8+ cytotoxic T cells directed against HTLV-I-infected cells

We established long-term cell lines of cytotoxic T lymphocytes (CTL) specific for human T cell leukemia virus type I (HTLV-I) from peripheral blood lymphocytes (PBL) of a patient with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), an HTLV-I-carrier with Sjögren syndrome, and an asymptomatic HTLV-I-carrier, by repeated stimulation with autologous HTLV-I-infected T cells in vitro. CTL derived from the patient with HAM/TSP expressed CD8 antigen, and their function was restricted by HLA-A2. They showed cytotoxic effects predominantly against the target cells expressing HTLV-I p40tax among the autologous B cell lines infected with vaccinia recombinants containing various HTLV-I genes which served as targets. These data are consistent with the previously reported findings that fresh PBL of HAM/TSP patients contain p40tax-specific CTL activity. Furthermore, CTL derived from the patient with Sjögren syndrome without neurological involvement also demonstrated cytotoxicity predominantly to p40tax. The cytotoxicity to the target cells experimentally expressing p40tax was blocked by unlabeled HTLV-I-infected cells possessing HLA-A2. HTLV-I-specific cytotoxicity was also inhibited by unlabeled B cells bearing p40tax. Thus, HTLV-I p40tax-specific cytotoxicity is mediated by the major CTL population activated by native HTLV-I antigens in patients with HAM/TSP or Sjögren syndrome. In contrast to the CTL of these patients, CTL similarly induced from the asymptomatic HTLV-I-carrier, which were highly cytotoxic to autologous HTLV-I-infected T cells, did not show significant levels of cytotoxicity to autologous B cells expressing p40tax.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of poly(L-lysine-alt-terephthalic acid) microcapsules with fibrinogen

Interaction of poly(L-lysine-alt-terephthalic acid) microcapsules with fibrinogen was investigated by measuring the degree of microcapsule disintegration, fibrinogen adsorption to microcapsules, and the zeta potential of microcapsules as a function of fibrinogen concentration in phosphate buffer solutions of pH 7.4 at different ionic strengths. A minimum concentration was found to exist for fibrinogen to cause disintegration of the microcapsules at any ionic strength, and at this fibrinogen concentration the fibrinogen adsorption levelled off and the zeta potential exhibited an abrupt change. Increases in the ionic strength of the medium and the surface hydrophobicity of microcapsules produced an increase in the degree of microcapsule disintegration by fibrinogen. These findings were interpreted as showing that the interaction of the microcapsules with the protein is not of an ionic nature but of a hydrophobic nature.

Development and evaluation of the TD97 measles virus vaccine

The TD97 strain vaccine virus was prepared from the Tanabe strain measles virus by low-temperature passages in primary cell cultures and ultraviolet (UV) mutagenesis. The TD97 strain exhibited the following characteristics: highly temperature sensitive, neither multiplying nor forming any plaques at 40 degrees C in Vero cells; genetically stable, maintaining high temperature sensitivity after ten successive passages in CE cells at 30 degrees C or 35 degrees C; and M proteins of this virus about 1 KD slower in mobility in SDS-PAGE than that of the Tanabe strain. The TD97 strain was further confirmed to be attenuated by an inoculation test into primate brain. In field trials, 752 healthy children were inoculated with a live virus vaccine prepared with this strain, and the following results were obtained: the seroconversion rate was 97% (517/533), and the average HI antibody titer was 2(5.2). An antibody-increasing effect was also observed in children who were initially seropositive. In children who seroconverted, the rates of fever were 15.7% (55/351) for 37.5 degrees C or higher and 4.0% (14/351) for 39 degrees C or higher. The rash rate was 7.7% (27/351), and the incidence of local reaction was 5.4% (19/351). The TD97 strain is thus considered to be suitable in use for an attenuated measles vaccine.

Effects and virulences of recombinant vaccinia viruses derived from attenuated strains that express the human T-cell leukemia virus type I envelope gene

We constructed recombinant vaccinia viruses (RVVs) that expressed human T-cell leukemia virus type I (HTLV-I) envelope glycoproteins by using attenuated vaccinia viruses (VVs) which have much lower neurovirulence than the WR strain that is extensively used as a vector. The RVV produced from the LC16mO strain, one of the attenuated VVs, elicited a high titer of anti-HTLV-I antibody in rabbits and protected them against HTLV-I infection. The env gene was inserted into the VV hemagglutinin gene. The resultant inactivation of the hemagglutinin gene led to the attenuation of VVs, but the extent of their attenuation depended on the VV strain. The propagation of LC16mO and its RVV in rabbit brain was poorer than that of LO-1, a cloned derivative of Lister strain, and its RVV, although LC16mO replicated in other organs better than did LO-1. Taken together, these results suggest that LC16mO is a good candidate as a vector for vaccination of humans.

Processing of gag precursor polyprotein of human T-cell leukemia virus type I by virus-encoded protease

The biological activity encoded in the putative protease gene (pro) of human T-cell leukemia virus type I was investigated by using a vaccinia virus expression vector. The 53-kilodalton gag precursor polyprotein was processed into the mature p19, p24, and p15 gag proteins when the gag and protease-coding sequence was expressed under the control of a vaccinia virus promoter, suggesting that the protease may be synthesized through the mechanism of ribosomal frame shifting. The processing defect of a protease mutant could be complemented by cointroduction of a wild-type construct into the cell, demonstrating that the pro gene encodes the biologically active protease molecules which are capable of processing the gag precursor polyprotein in vivo in trans. A study involving the use of a variety of mutants constructed in vitro revealed that the protease consists of a nonessential carboxy-terminal region and a part essential for its activity, including the putative catalytic residue, aspartic acid. Furthermore, a cluster of adenine residues positioned at the overlapping region between the gag and pro genes was shown to be involved in the ribosomal frameshifting event for the synthesis of protease. To mimic the formation of the 76-kilodalton gag-pro precursor polyprotein formed by ribosomal slipping, the coding frames of the gag and pro gene were adjusted. The processing of the gag-pro precursor polyprotein depended on an intact protease gene, implying that a cis-acting function of human T-cell leukemia virus type I protease may be necessary to trigger the initial cleavage event that leads to the release of protease from the precursor protein.

(+)Nortrachelogenin, a new pharmacologically active lignan from Wikstroemia indica

A new lignan, (+)-nortrachelogenin (I), and a known compound, daphnoretin were isolated from Wikstroemia indica C.A. Meyer (Thymelaeaceae). The structure of (+)-nortrachelogenin was established as 8(R)8'-4,4',8'-trihydroxy-3,3'-dimethoxylignan-olid, (9,9') on the basis of spectroscopic evidence and comparison with its enantiomer, (-)-nortrachelogenin. +-nortrachelogenin(I) showed effects on the central nervous system producing depression in rabbits.