Peripheral blood mononuclear cells from patients with bronchial asthma show impaired innate immune responses to rhinovirus in vitro.

BACKGROUND: Asthmatic patients have a higher susceptibility to rhinovirus (RV) infection, and impaired IFN-ß and IFN-λ production has been demonstrated in bronchial epithelial cells from asthmatic adults upon exposure to RV. However, the mechanisms underlying the increased susceptibility of asthmatic patients to RV infection remain poorly understood. The present study aimed to elucidate the characteristics of the immune responses of asthmatic patients' peripheral blood mononuclear cells (PBMCs) to RV exposure. METHODS: PBMCs obtained from 3 different age groups (2-6 years: young-children group; 7-19 years: youth group; ≥20 years: adult group) of asthmatic patients and nonasthmatic control subjects were stimulated with RV-14 for 72 h. Healthy adults with a history of childhood asthma were also enrolled. The concentrations of IFN-α, IL-6, TNF-α, IL-10, and soluble Fas ligand (sFasL) in the culture supernatants were measured by ELISA. RESULTS: When compared with age-matched control subjects, IFN-α production was significantly lower in the asthmatic youth group. IL-6, TNF-α, IL-10, and sFasL productions were significantly lower in both the asthmatic youth group and the adult group. Such impaired responses were not found in healthy adults with a history of childhood asthma. No significantly different responses were found between the asthmatics and controls in the young-children group, whereas young asthmatic children with persistent wheeze during a 2-year follow-up showed significantly lower IL-10 production than those without wheeze. CONCLUSIONS: These results imply the involvement of impaired production of both IFN-α and inflammatory cytokines seen in asthmatic patients' PBMCs upon exposure to RV in the higher susceptibility of those patients to RV infection.

[EIA-IgG antibody measles prevention level estimated from measles neutralizing, particle agglutination and hemagglutination-inhibition antibody titer].

Measles hemagglutination inhibition (HI) antibody titer, widely used in clinical practice to simply and easily determine the measles immunity level has, in recent years, been increasingly replaced by measles IgG-antibody titer determined by enzyme-immunoassay (EIA). HI antibody titer appears to reflect this protective level, because HI measures the antibody against H protein required for the measles virus to adhere to host cells. EIA-IgG antibody titer does not correlate with the protective level, similar to particle agglutination (PA) titer, because EIA measures different antibodies, including those unrelated to measles protection. After determining HI, PA, neutralizing test (NT) results, and EIA-IgG antibody titer for individual specimens, we compared EIA-IgG antibody titer obtained using an EIA-Kit (Denka Seiken) to HI, PA, and NT titer with the following results: (1) Subjects with EIA-IgG titer of > or = 12.0 may be protected against measles: (2) Subjects with EIA-IgG titer of 4.0 to 8.0 appear to be protected insufficiently requiring a booster dose against measles: (3) Subjects with EIA-IgG titer of 8.0 to 12.0 may benefit from booster vaccination.

[Gelatin particle agglutination (PA) antibody: comparison to neutralizing antibody (NT) and hemagglutination inhibition (HI) antibody and relationship to IgG avidity].

Changes in gelatin particle agglutination (PA), hemagglutination inhibition (HI), and neutralization (NT) antibodies were compared using sera from 124 individuals collected between 3 weeks and 10 years after measles vaccination, and the relationship between these changes and IgG avidity was studied. PA, HI, and NT antibodies peaked 4-5 months after vaccination. The rate of increase in mean antibody titer from 0-1 months after vaccination to peak levels was 1.7-fold for NT, 1.5-fold for HI, and 7.4-fold for PA antibodies. Peak mean antibody titer was 2(11.8) for PA, 2(6.7) for NT and 2(6.7) for HI antibodies. After peaking PA antibodies changed in parallel with NT and HI antibody titers, and correlated strongly with both antibodies (r = 0.801 and 0.840). In contrast, NT and HI antibodies were consistent throughout the period. IgG avidity increased for 4-5 months following vaccination, peaking at 45%, and remaining constant at 40-50% for the next 10 years. PA antibody is strongly influenced by IgG avidity, unlike NT and HI antibodies. Due to the effects of IgG avidity, PA antibodies increase more significantly than NT and HI antibodies as IgG antibodies mature following vaccination, resulting in a weak correlation between PA and NT or HI antibodies. Following the increase in IgG avidity to maturation, PA antibodies correlated strongly with NT and HI antibodies. PA assay detected IgM antibodies against measles virus more efficiently than the NT test. The PA assay thus differs from conventional, commonly used NT and HI assays. PA assay is simple and rapid, making it very useful for detecting measles antibodies provided that its unique features are taken into accounts.

[Correlation between measles-neutralizing antibody and HI antibody, between measles-neutralizing antibody and PA antibody among pregnant women, and protective levels of three titration types].

When measles antibody levels among pregnant women were measured with measles hemagglutinin inhibition (HI), 31% of subjects had negative HI antibody titers. When the same blood samples were tested with measles gelatin particle agglutination (PA) and neutralizing (NT), the percentages of those with negative antibody levels were 1% and 3%. We conducted the correlation between antibody titers measured by the three types of titration. Correlation between NT and HI antibody titers higher than 1:8 and that between NT and PA antibody titers were good, but 81% of subjects whose HI antibody titer was below 1:8 and all women with HI antibody of 1:8 were found to have NT antibody titer higher than 1:4. NT antibody titer higher than 1:4 was found in 95% of women having PA antibody titer of 1:256 and in 99% of those with PA antibody titer of 1:512. Based on the relationships to measles NT antibody level, the majority of subjects with HI antibody titer higher than 1:8 or PA antibody level higher than 1:512 was reasonably assumed to be protected against clinical measles. PA seemed superior to HI in finding subjects with insufficient immunity against measles, because the former detects weak immunity more efficiently than the latter.

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.

[Measles antibody followed after measles vaccination: comparison with gelatin beads agglutination (PA) antibody, hemagglutination inhibition (HI) antibody and IgG-avidity].

The immunity status of 37 cases has been tested at 6 weeks and 3.5 years after vaccination by using gelatin beads agglutination (PA), hemagglutination inhibition (HI) and avidity of specific IgG. The geometric mean titer (GMT) of HI antibody was 34.5 at 6 weeks and had fallen to 17.9 over 3.5 years. On the other hand, GMT of PA antibody was 36.5 at 6 weeks and had increased to 286.0 over 3.5 years. Also, the average of measles specific IgG avidity was 4.5% at 6 week and had increased to 45.4% over 3.5 years. The multiple regression analysis was performed in order to investigate the relationship of HI antibody and avidity to PA antibody. The significant involvement of the HI antibody and avidity to PA antibody (standardized partial regression coefficients; 0.612, 0.726) was recognized and the multiple correlation coefficient was 0.880 (p < 0.001). Hence it was strongly suggested that the increase of PA antibody with time could be dependent on that of IgG avidity.

Changes in brain monoamine levels in neonatal rats exposed to bisphenol A at low doses.

To examine whether exposure to bisphenol A (BPA) at low levels affect brain function, monoamine concentrations in hippocampus, striatum and brain stem, were investigated in neonatal male rats injected intracranially with BPA at 0-10microgkg(-1). Significant increases of serotonin (5-HT) in hippocampus, 5-HIAA and 5-HIAA/5-HT in brain stem, dopamine (DA) and DOPAC in striatum were observed at 28d after the injection on postnatal day 2. At 7d after the injection, increases in 5-HT and norepinephrine (NE) and decreases in DOPAC and 5-HIAA were observed in hippocampus. To investigate the degradation of BPA in brain, we also measured BPA concentrations of whole neonatal rat brain. Free BPA disappeared from brain tissues within 5h, even when the highest dose (1000microgkg(-1)) was injected. The present results suggest that BPA exposure at lower doses than environmentally relevant levels may have a great impact on monoamine levels in neonatal brain over 28d after its disappearance.

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.

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.