Cloning and identification of measles virus receptor gene from marmoset cells

The measles virus (MV) strains with mutated hemagglutinin gene (ha) lost the capacity to infect its sensitive host cells (Vero cells), but it may infect the marmoset B-lymphoblastoid cell line B95a. From above, we can presume that there is a novel cellular receptor for those measles virus strains on B95a cell s. Using the yeast two-hybrid system, we screened and cloned a novel gene--bip (B-lympho- blastoid interaction protein of marmoset) from B95a cell cDNA library, which encoded a protein interacting with measles virus hemagglutinin protein (Ha). The bip cDNA was 1540 base pairs in length and contained a unique open rea ding frame (ORF) of 1011 base pairs encoding a transmembrane protein of 337 amino acid residues. The primary structure of amino acids residue is predicted that the Bip comprised a hydrophobic transmembrane domain and a hydrophobic leader region. The researches about the deletion mutants showed that the deletion of tran smembrane domain in Bip did not affect the interaction between Bip and Ha protei ns. Expression of bip in measles virus non-permissive cell line--CHO (Chinese hamster ovary) cells was performed to prove that CHO/Bip can be infected by meas les virus and then turned to the MV permissive cells. We concluded that the bip gene is a novel measles virus receptor gene in marmoset B-lymphoblastoid cells.     

猪瘟弱毒苗注射奶犊牛的E玫瑰花环试验

本实验用E玫瑰花环试验检测奶犊牛的细胞免疫状况,实验组8头奶犊牛注射疫苗前的E玫瑰花环率平均为20%,注射疫苗后第45天E玫瑰花环率平均为26%,而对照组5头犊牛E玫瑰花环率平均为22%,数据显示注射疫苗后比注射疫苗前上升了6%,比对照组上升了4%.实验结果表明犊奶牛注射猪瘟弱毒苗后能够引起细胞免疫的提高.     

Short-latency drinking and increased Na appetite after intracerebral microinjections of NGF in rats

NERVE GROWTH FACTOR (NGF) is a polypeptide trophic factor for peripheral sympathetic and sensory neurones(1,2). Apparent NGF(3-5) and NGF receptors(6,7) have also been identified in the brain, and intracerebral administration of NGF in the adult rat produces marked biochemical(8) and morphologica(9,10) changes in brain tissue. These findings, taken together with the observations that central injections of NGF facilitate behavioural recovery from brain damage(11,12), indicate that this polypeptide may have an important role in brain function. It has been observed that rats given intraventricular injections of up to 2.3 microg NGF drink copiously (M.E.L. and G. Guroff, unpublished observations). Perkins et al.(13) reported that diencephalic application of crystalline NGF (1-15 microg) resulted in an intense polydipsia. The present report confirms the observations of M.E.L. and Guroff, and extends the findings of Perkins et al.(13) by using solutions of NGF instead of crystals. It also describes for the first time a second phenomenon produced by intracranial administration of NGF, namely an intense appetite for aversive concentrations of sodium solutions.     

Molecular cloning and nucleotide sequence of the attenuated hog cholera virus Lapinized Chinese strain

The genomic sequence of the attenuated hog cholera virus Lapinized Chinese strain (HCLV) was determined from overlapping cDNA clones. The viral RNA of HCLV stain comprised 12 310 nucleotide (nt) including 374 nt and 239 nt at the 5′ and 3′-noncoding region, respectively. The complete genome sequence contained one large open reading frame which encoded an amino acid sequence of 3 898 residues with a calculated molecular weight of 437×10³. Although there were mostly only small differences between the sequence of the HCLV strain and the published sequences of strains ALD, GPE⁻, Alfort and Brescia, there was one notable insertion of 12 nucleotides, TTTTCTTTTTTC in the 3′ non-coding region of HCLV strain. Supported by the National Pandeng Project, Genbank accession number AF091507 Wang Jiafu: born in 1972, Ph. D.     

Important amino acid in the hemagglutinin glycoprotein of measles virus (MV) that governs hemadsorption

Two strains of measles virus IMA and SMD that were isolated using B95a cell line show hemadsorption negative. After adaptation to Vero cells, these strains gain the ability to agglutinate AGM-RBC and show hemadsorption positive. Sequence analysis of these two kinds of virus reveals that the two strains all have a Ser (HAD negative) to Gly (HAD positive) mutation at position 546 in the H protein. Site-directed mutagenesis and expression in COS cells were used to confirm that the mutation Ser→Gly is responsible for hemadsorption alteration. Then the monoclonal antibody against CD46 was used to identify that this mutation also governs the binding function of MV H protein to CD46 receptor. The data provide a new important amino acid of MV H protein that governs the hemadsorption and binding to CD46 receptor.