Two doses of parenterally administered split influenza virus vaccine elicited high serum IgG concentrations which effectively limited viral shedding upon challenge in mice

We have previously found that whole influenza virus vaccine induced a more rapid and stronger humoral response, particularly after the first dose of vaccine, than split virus vaccine in mice. In this study, we have evaluated the protective efficacy of whole and split influenza virus vaccines in mice using a nonlethal upper respiratory tract challenge model. We have also investigated the immunological correlates associated with no or very little viral shedding after viral challenge. Vaccination resulted in reduced viral shedding and shortened the duration of infection by at least 2 days. After one dose of vaccine, whole virus vaccine generally resulted in less viral shedding than split virus vaccine. In contrast, two doses of split virus vaccine, particularly the highest vaccine strengths of 15 and 30 microg HA, most effectively limited viral replication and these mice had high concentrations of prechallenge influenza-specific serum IgG. The vaccine formulation influenced the IgG2a/IgG1 ratio, and this IgG subclass profile was maintained upon challenge to some extent, although it did not influence the level of viral shedding. The concentration of postvaccination serum IgG showed an inverse relationship with the level of viral shedding after viral challenge. Therefore, serum IgG is an important factor in limiting viral replication in the upper respiratory tract upon challenge of an antigenically similar virus.     

Monoclonal antibodies evoked by the free oligopeptide (Gly)5 reacting specifically with peptidoglycan from staphylococci

Murine monoclonal antibodies reactive with the Staphylococcus aureus peptidoglycan (PG) epitope (Gly)5 were obtained using the synthetic oligopeptide (Gly)5 in its free form as immunogen. The selected monoclonal antibodies were of the IgM kappa isotype and reacted specifically with PG from S. aureus and Staphylococcus epidermidis, but gave no reaction with PG from Streptococcus pyogenes, Bacillus subtilis and Micrococcus lysodeikticus. Affinity chromatography showed that the antibodies were reactive with the N-terminus of the (Gly)5 peptide. These monoclonal antibodies can be used for the detection of staphylococcal PG in solution.     

Non-lethal viral challenge of influenza haemagglutinin and nucleoprotein DNA vaccinated mice results in reduced viral replication

Influenza DNA vaccines have been widely studied in experimental animal models and protection documented after lethal viral challenge. In this study, we have investigated the humoral response after a non-lethal viral challenge of mice vaccinated with plasmids encoding the influenza haemagglutinin (HA) or nucleoprotein (NP) genes. BALB/c mice were immunized intramuscularly with three doses (100 microg) of HA, NP or backbone plasmid at 3-week intervals, or alternatively infected intranasally, before being challenged with homologous virus 13 weeks later. Mice were then sacrificed at weekly intervals and the antibody-secreting cell response was examined systemically (spleen and bone marrow) and in the respiratory tract (nasal associated lymphoid tissue (NALT) and lungs). Sera were collected after each dose of vaccine and at sacrifice and analyzed by ELISA, haemagglutination inhibition and virus neutralization assays. We found that previous viral infection apparently elicits sterilizing immunity. Vaccination with HA or NP DNA significantly reduced viral replication in the nasal cavity after viral challenge, however, increases in serum antibody titres were observed after challenge. Prior to challenge, specific antibody-secreting cells were observed in the systemic compartment after HA or NP DNA vaccination but were also found in the NALT after viral challenge. In conclusion, intramuscular DNA vaccination resulted in immunological memory in the systemic compartment, which was rapidly reactivated upon viral challenge.     

Evidence for B cell participation in the in vitro and in vivo maintenance of in vivo staphylococcal enterotoxin B-induced T cell anergy

The mechanisms involved in the maintenance of staphylococcal enterotoxin B (SEB)-induced T cell anergy are poorly understood. Here, we demonstrate that CD4+ T cell anergy induced by SEB treatment is under partial B cell control. This effect is not mediated by anti-SEB antibodies or any in vitro B cell-produced suppresser factor. At day 13 after SEB immunization, T cells from B cell-deficient mice proliferate upon in vitro stimulation with SEB. These results suggest that SEB- induced T cell anergy is reversible and that B cells have an important function in anergy maintenance in CD4+ T cells, both in vivo and in vitro.      

A new spontaneous mouse mutation of Hoxd13 with a polyalanine expansion and phenotype similar to human synpolydactyly

Human synpolydactyly (SPD) is an inherited congenital limb malformation caused by mutations in the HOXD13 gene. Heterozygotes are typically characterized by 3/4 finger and 4/5 toe syndactyly with associated duplicated digits; hands and feet of homozygotes are very small because of a shortening of the phalanges, metacarpal and metatarsal bones. Here we describe the phenotype and molecular basis of a spontaneous mutation of Hoxd13 in mice that provides a phenotypically and molecularly accurate model for human SPD. The new mutation, named synpolydactyly homolog (spdh), is a 21 bp in-frame duplication within a polyalanine- encoding region at the 5'-end of the Hoxd13 coding sequence. The duplication expands the stretch of alanines from 15 to 22; the same type of expansion occurs in human SPD mutations. spdh/spdh homozygotes exhibit severe malformations of all four feet, including polydactyly, syndactyly and brachydactylia. The phenotype of spdh is much more severe than that exhibited by mice with a genetically engineered, presumably null, disruption of Hoxd13. Thus spdh probably acts in a dominant-negative manner and will be valuable for examining interactions with other Hox genes and their protein products during limb development. Homozygous mice of both sexes also lack preputial glands and males do not breed; therefore, spdh/spdh mice may also be valuable in studies of reproductive physiology and behavior.      

维生素C及E联合作用对体外大鼠胚胎中脑神经细胞分化和增殖的影响

目的:观察维生素C,维生素E和维生素C 维生素E联合后对胚胎中脑神经细胞生长发育的影响。方法:实验于2006-03/04在江苏大学医学院研究中心细胞培养室完成。采用16d大鼠胚胎中脑神经细胞体外培养方法,观察不同剂量的维生素C(5,10,25,50μmol/L),维生素E(10,25,50,100μmol/L)和维生素C、维生素E联合作用(维生素C25μmol/L 维生素E50μmol/L,维生素C50μmol/L 维生素E100μmol/L),培养10d后收集细胞,并利用图像分析细胞形态的变化、蛋白质、丙二醛含量及超氧化物歧化酶活性指标。结果:①维生素C、维生素E和维生素C 维生素E联合能促进体外培养中脑神经细胞突起生长,集落数增多。②与正常对照组比较,维生素C10,25μmol/L组、维生素E10,25,50μmol/L组、维生素C25μmol/L 维生素E50μmol/L组神经细胞总蛋白相对含量明显增加。③与正常对照组比较,维生素C10,25μmol/L组、维生素E25,50μmol/L组、维生素C25μmol/L 维生素E50μmol/L组神经细胞超氧化物酶活性增加,丙二醛含量降低。④维生素C50μmol/L组、维生素E100μmol/L组和维生素C50μmol/L 维生素E100μmol/L组超氧化物酶活性低于正常对照组,丙二醛含量高于正常对照组。结论:维生素C、维生素E和维生素C 维生素E联合剂量在一定范围内能够明显提高中脑神经细胞的抗氧化能力,同时能促进胚胎中脑神经细胞分化和增殖作用。     

Psychosocial adjustment in preschool children with atopic eczema

Atopic eczema is a chronic skin disorder that is most common in early childhood, an important stage in the child's social and emotional development. The psychiatric adjustment and mother-child attachment in 30 preschool children with severe atopic eczema was compared with 20 matched controls. Patients with eczema had a significant increase in behaviour symptoms, 7/30 (23%) v 1/20 (5%); with significant excess of dependency/clinginess, 15/30 (50%) v 2/20 (10%); fearfulness, 12/30 (40%) v 2/20 (10%); and sleep difficulty, 19/30 (63%) v 9/20 (45%), but there was no significant difference between the two groups in the security of attachments, 25/29 (86%) v 14/20 (70%). Significantly fewer mothers of children with atopic eczema were in outside employment, 8/29 (27%) v 13/20 (65%), or felt supported socially, 10/29 (34%) v 13/20 (65%). Significantly more of them, 9/30 (30%) v 1/20 (5%), felt particularly stressed in relation to their parenting and less efficient in their disciplining of the affected child. In spite of this and at variance with earlier reports in the literature, they did not display negative attitudes towards their child. On the contrary mothers had a positive empathic attitude towards the child, 7/14 (50%) v 2/16 (12%). Child behaviour problems, 7/14 (50%) v 2/16 (12%), and maternal distress, 12/14 (85%) v 5/16 (31%), were significantly more common in the more severely affected children. Minor behaviour problems and parenting distress are important features of severe atopic eczema in early childhood but atopic eczema does not lead to insecurity of the mother-child attachment.     

Autoantibodies to myelin basic protein are not present in the serum and CSF of MS patients

Myelin basic protein (MBP) is one of the main constituents of the CNS myelin sheaths, and an autoimmune response directed against MBP may be crucial in the demyelination process in patients with multiple sclerosis (MS). In this study sera and cerebrospinal fluid (CSF) from 25 MS patients, 25 patients with other neurological diseases and 16 healthy controls were examined for antibodies against MBP by using radio immunoblot, western blot, radio immunoassay and enzyme-linked immunosorbant assay. No evidence for the presence of antibodies to MBP was found in sera or CSFs in either the MS patients, or in the control groups tested.