Major glycoprotein antigens that induce antibodies in AIDS patients are encoded by HTLV-III

Antibodies from the serum of patients with the acquired immune deficiency syndrome (AIDS) or with the AIDS-related complex and from the serum of seropositive healthy homosexuals, recognize two major glycoproteins in cells infected with human T-cell lymphotropic virus type III (HTLV III). These glycoproteins, gp160 and gp120, are encoded by the 2.5-kilobase open reading frame located in the 3' end of the HTLV-III genome, as determined by amino terminus sequence analysis of the radiolabeled forms of these proteins. It is hypothesized that gp160 and gp120 represent the major species of virus-encoded envelope gene products for HTLV-III.     

Antiserum to a synthetic peptide recognizes the HTLV-III envelope glycoprotein

In a study performed to determine which regions of the human T-cell lymphotrophic virus type III (HTLV-III) may represent vaccine candidates to prevent the acquired immune deficiency syndrome (AIDS), a synthetic peptide corresponding to amino acid sequence 735 to 752 of the precursor envelope glycoprotein of HTLV-III was used to immunize rabbits. The resulting rabbit antiserum to the synthetic peptide specifically recognized the precursor envelope glycoprotein (gp160) of HTLV-III. Human sera positive for antibody to HTLV-III reacted with this peptide. These findings indicate that synthetic peptides can be used to induce an immune response directed against a native envelope glycoprotein epitope of HTLV-III. The data are discussed in terms of using synthetic peptides to identify antigenic determinants involved in the induction of protective immunity and possibly as vaccine candidates against the etiologic agent of AIDS.     

Structure of 3' terminal region of type II human T lymphotropic virus: evidence for new coding region

The sequence of the 3' terminus of the human T lymphotropic virus type II (HTLV-II) was determined and compared to the corresponding sequence of HTLV-I. The 1557-nucleotide-long sequence can be divided into a 5' region that is not conserved between the two viruses, and a 3', 1011-nucleotide-long region that is highly conserved and that corresponds precisely with a long open reading frame for both HTLV-I and -II. The proteins that could be encoded by these open reading frames have a molecular weight of about 38,000 and are closely related in primary amino acid sequence. The genomic structure in the 3' region of HTLV was found to be similar to that of bovine leukemia virus.     

Antigens encoded by the 3'-terminal region of human T-cell leukemia virus: evidence for a functional gene

Antibodies in sera from patients with adult T-cell leukemia-lymphoma or from healthy carriers of type I human T-cell leukemia virus (HTLV) recognize an antigen of approximately 42 kilodaltons (p42) in cell lines infected with HTLV-I. Radiolabel sequence analysis of cyanogen bromide fragments of p42 led to the conclusion that this antigen is encoded in part by LOR, a conserved portion of the "X" region that is flanked by the envelope gene and the 3' long terminal repeat of HTLV-I. It is possible that this novel product mediates the unique transformation properties of the HTLV family.     

Second conserved domain of gp120 is important for HIV infectivity and antibody neutralization

Rabbit antisera were raised against three overlapping synthetic peptides with sequence homology to the second conserved domain of the external envelope glycoprotein (gp120) of the human immunodeficiency virus (HIV). All of the antisera immunoprecipitated the envelope glycoprotein. In particular, an antiserum directed against amino acids 254 to 274 of env was efficient in neutralizing three different isolates of HIV in vitro, without affecting the binding of the virus to CD4-positive cells. Therefore, this conserved region of gp120 appears to be critical in a postbinding event during virus penetration and may represent a target for antibody neutralization of HIV. These findings may be applicable in the design of a vaccine for the acquired immunodeficiency syndrome.     

Antigens on HTLV-infected cells recognized by leukemia and AIDS sera are related to HTLV viral glycoprotein

Cross-reactive antigens of molecular size of 61,000 to 68,000 daltons are found on the surface of human cells infected by human T-cell leukemia-lymphoma virus (HTLV). They are recognized by antibodies from patients with adult T-cell leukemias and lymphomas, from healthy carriers of HTLV, and from patients with the acquired immunodeficiency syndrome (AIDS). The latter finding has been one of the major reasons for suggesting an association of HTLV with AIDS. However, whether these antigens are of cellular or viral origin has not been clear. These antigens have now been shown to be associated with the presence of viral proteins in the cells, and a cross-reactive glycoprotein of molecular size of 46,000 daltons has been found to be a consistent structural part of viruses purified from several HTLV-producer cell lines. The findings thus suggest a viral (HTLV) origin of these antigens.     

Functional regions of the envelope glycoprotein of human immunodeficiency virus type 1

The envelope of the human immunodeficiency virus type 1 (HIV-1) plays a central role in the process of virus entry into the host cell and in the cytopathicity of the virus for lymphocytes bearing the CD4 molecule. Mutations that affect the ability of the envelope glycoprotein to form syncytia in CD4+ cells can be divided into five groups: those that decrease the binding of the envelope protein to the CD4 molecule, those that prevent a post-binding fusion reaction, those that disrupt the anchorage of the envelope glycoprotein in the membrane, those that affect the association of the two subunits of the envelope glycoprotein, and those that affect post-translational proteolytic processing of the envelope precursor protein. These findings provide a functional model of the HIV envelope glycoprotein.     

鸭瘟病毒ZJ2016强毒株部分基因序列的测定与分析

2016年,浙江省一鸭场发生疑似鸭瘟病例,经鉴定,病鸭感染鸭瘟病毒,命名为ZJ2016病毒株。实验应用二代基因测序方法对该病毒核酸进行全基因测序,鉴定分析鸭瘟病毒ZJ2016株抗原与毒力相关基因序列特征。对测序病毒主要囊膜糖蛋白基因gB、gC、gG、gH、gI、gK、gL、gM、gN与致病力基因LORF11、UL2、UL12、UL41、UL47、US10进行核酸与氨基酸序列分析,并与已发表毒株序列及疫苗株(VAC株、clone-03株)序列比较。结果显示,与疫苗免疫保护抗原相关的ZJ2016株囊膜糖蛋白序列与疫苗毒株序列相比未发生明显的变异,而ZJ2016株的LORF11、UL2、UL12、UL41、UL47、US10基因结构及同源性与疫苗株氨基酸序列差异明显,且与中国其他分离强毒株LH2011株、CHv株、CV株同源性较高,表明该毒株具有强毒株的基因型特征。     

PRRSV陕西分离株ORF5基因克隆、序列分析及原核表达

克隆猪繁殖与呼吸综合征病毒(PRRSV)ORF5基因,并进行序列分析及原核表达。根据GenBank公布的PRRSV ORF5基因的核苷酸序列,设计并合成一对特异性引物,用RT-PCR方法扩增PRRSV陕西分离株糖基化囊膜蛋白基因ORF5,将其克隆入pGEM-T载体中,进行测序及序列分析。再设计另外1对引物扩增ORF5缺失编码N端31个氨基酸残基的基因片段,将截短的ORF5基因亚克隆入原核表达载体pET-32a中,在大肠杆菌BL21中进行原核表达。结果扩增到603 bp的PRRSV全长ORF5基因,序列分析表明,分离株与北美型代表株VR-2332和欧洲型代表株LV氨基酸同源性分别为87.8%和54.5%。因此推测陕西分离株属于北美型。SDS-PAGE可检测到大小约为38 ku的融合蛋白,主要以可溶性蛋白形式存在。West-ern-blot分析表明,重组蛋白可被PRRSV阳性血清所识别。     

Cloning of Thymidine Kinase Gene of Duck Plague Virus Using Degenerate PCR

The DNA of duck plague virus （DPV） thymidine kinase （TK） gene was cloned and sequenced from a vaccine virus in the study. Degenerate oligonucleotide primers for the consensus site of herpesvirus UL24, TK, and glycoprotein H（gH） gene were used in the polymerase chain reaction （PCR） to amplify DNA product with 3 741-base-pairs （bp） in size. DNA sequence analysis revealed a 1 077-base-pairs （bp） open reading frame （ORF） encoding a 358 amino acid polypeptide homologous to herpesvirus TK proteins. The predicted TK protein shared 31.2, 41.3, 35.7, 37.4, and 28.4% identity with herpes simplex virus typel, equine herpesvirus type 4, Marek＇s disease virus 2, herpesvirus turkey, and infectious laryngotracheitis virus, respectively. Comparison of the amino acid sequences of other herpesvirus TK proteins showed that these proteins were not conserved on the whole, otherwise the portion of the TK proteins corresponding to the nucleotide binding domain and the nucleoside binding site were highly conserved among herpesvirus. Comparison with the amino acid sequences of the conserved nucleotide and nucleoside binding domains of other eleven herpesvirus TK proteins to the predicted DPV peptide confirmed its identity as the DPV TK protein.     

Type-restricted neutralization of molecular clones of human immunodeficiency virus

In a study of the immunologic significance of the genetic diversity present within single isolates of human immunodeficiency virus type 1 (HIV-1), the neutralization of viruses derived from molecular clones of the HIV-1 strain HTLV-IIIB by an extensive panel of sera was compared. Sera from HIV-1-infected patients and from goats immunized with polyacrylamide gel-purified HIV-1 envelope glycoprotein (gp120), native gp120, or gp120-derived recombinant peptides, showed marked heterogeneity in neutralizing activity against these closely related viruses. The change of a single amino acid residue in gp120 may account for such "clonal restriction" of neutralizing activity.     

Light chains of mouse myeloma proteins: partial amino acid sequence

Five kappa chains in the urinary proteins of the BALB/c mouse have the same carboxyl terminal amino acid sequence; this sequence resembles that of kappa light chains in human immunoglobulins. The five chains have amino acid sequence variations at the amino- terminal. The genetic basis for the amino- terminal variations is not understood but could be due either to a mecha nism for differently translating a single genetic message or to the presence of more than one kappa- type structural cistron in the BALB/c genome.     

Uromodulin (Tamm-Horsfall glycoprotein): a renal ligand for lymphokines

The protein portion of the immunosuppressive glycoprotein uromodulin is identical to the Tamm-Horsfall urinary glycoprotein and is synthesized in the kidney. Evidence that the glycoproteins are the same is based on amino acid sequence identity, immunologic cross-reactivity, and tissue localization to the thick ascending limb of Henle's loop. Nucleic acid sequencing of clones for uromodulin isolated from a complementary DNA bank from human kidney predicts a protein 639 amino acids in length, including a 24--amino acid leader sequence and a cysteine-rich mature protein with eight potential glycosylation sites. Uromodulin and preparations of Tamm-Horsfall glycoprotein bind to recombinant murine interleukin-1 (rIL-1) and human rIL-1 alpha, rIL-1 beta, and recombinant tumor necrosis factor (rTNF). Uromodulin isolated from urine of pregnant women by lectin adherence is more immunosuppressive than material isolated by the original salt-precipitation protocol of Tamm and Horsfall. Immunohistologic studies demonstrate that rIL-1 and rTNF bind to the same area of the human kidney that binds to antiserum specific for uromodulin. Thus, uromodulin (Tamm-Horsfall glycoprotein) may function as a unique renal regulatory glycoprotein that specifically binds to and regulates the circulating activity of a number of potent cytokines, including IL-1 and TNF.     

Novel viral sequences related to human T-cell leukemia virus in T cells of a seropositive baboon

Antibodies reactive with proteins of human T-cell leukemia virus (HTLV) can be found in Old World monkeys. A T-lymphocyte cell line established from a seropositive baboon (Papio cynocephalus) was analyzed for the presence of viral DNA sequences. The provirus found in these cells was related to but distinct from HTLV subgroup I. These results add to recent evidence from human studies that HTLV represents a spectrum of infectious T-lymphotropic retroviruses that includes closely and distantly related members.     

鲤春病毒血症病毒Shlj1株糖蛋白空间结构及其B细胞抗原表位的预测

为预测鲤春病毒血症病毒(Spring Viremia of Carp Virus,SVCV)Shlj1株糖蛋白(Glycoprotein,G)的空间结构及B细胞抗原表位,采用RT-PCR法从接种SVCV的鲤上皮细胞悬液提取的病毒总RNA中扩增糖蛋白基因,并通过序列测定获得Shlj1株糖蛋白基因的核苷酸序列及氨基酸序列,利用Phyre2对Shlj1分离株的糖蛋白空间结构进行预测,使用DNAStar软件综合分析糖蛋白的柔性区域、亲水性、表面可能性和抗原指数参数。结果表明:获得的SVCV Shlj1株糖蛋白核苷酸序列长1527 bp,推导出其氨基酸序列为509aa;空间结构预测显示,SVCV Shlj1株糖蛋白存在一定数量的α-螺旋、β-折叠、β-转角及大量无规则卷曲结构,空间构象较规则;抗原指数及抗原表位指数分析显示,糖蛋白中存在许多抗原指数较高的区域,该区域平均抗原指数为1.025,最大值达1.250,其中5个区域(4~26、145~157、293~302、315~327、407~491氨基酸区段)可能是B细胞抗原表位的主要分布区域。本研究结果为SVCV糖蛋白表位疫苗的设计及单克隆抗体的制备奠定了理论基础。     

Expression of the art/trs protein of HIV and study of its role in viral envelope synthesis

The art/trs transactivator protein of human immunodeficiency virus (HIV) was expressed in mammalian cells as a 19-kilodalton protein that was immunoreactive with sera from HIV-infected patients. Separate plasmids encoding the art/trs protein, the tat protein, or the envelope glycoprotein gp120 were used to demonstrate that both art/trs and tat are absolutely required for the synthesis of gp120 from its cognate messenger RNA. In addition, both the tat and art/trs proteins influence the level of envelope RNA. The results suggest that art/trs and tat may be ideal targets for potential anti-HIV agents in AIDS therapy.     

Human T cell leukemia viruses use a receptor determined by human chromosome 17

Human T cell leukemia viruses (HTLV-I and HTLV-II) can infect many cell types in vitro. HTLV-I and HTLV-II use the same cell surface receptor, as shown by interference with syncytium formation and with infection by vesicular stomatitis virus (VSV) pseudotypes bearing the HTLV envelope glycoproteins. Human-mouse somatic cell hybrids were used to determine which human chromosome was required to confer susceptibility to VSV(HTLV) infection. The only human chromosome common to all susceptible cell hybrids was chromosome 17, and the receptor gene was localized to 17cen-qter. Antibodies to surface antigens known to be determined by genes on 17q did not block the HTLV receptor.     

Amino acid sequence similarity between rabies virus glycoprotein and snake venom curaremimetic neurotoxins

Evidence was presented earlier that a host-cell receptor for the highly neurotropic rabies virus might be the acetylcholine receptor. The amino acid sequence of the glycoprotein of rabies virus was compared by computer analysis with that of snake venom curaremimetic neurotoxins, potent ligands of the acetylcholine receptor. A statistically significant sequence relation was found between a segment of the rabies glycoprotein and the entire sequence of long neurotoxins. The greatest identity occurs with residues considered most important in neurotoxicity, including those interacting with the acetylcholine binding site of the acetylcholine receptor. Because of the similarity between the glycoprotein and the receptor-binding region of the neurotoxins, this region of the viral glycoprotein may function as a recognition site for the acetylcholine receptor. Direct binding of the rabies virus glycoprotein to the acetylcholine receptor could contribute to the neurotropism of this virus.