The bovine lymphoid system: II. Derivation and partial characterlzation of monoclonal antibodies against bovine peripheral blood lymphocytes

We have raised monoclonal antibodies to produce reagents specific for bovine lymphocyte subpopulations. Spleen cells from mice immunized with bovine peripheral blood lymphocytes were fused with X63-Ag8 myeloma cells and eleven myeloma-hybrids which secreted antibody specific for bovine lymphocytes were doubly cloned. Five of the hybrids secreted antibodies which bound to the majority of bovine lymphocytes. Two of these antibodies were specific for polymorphic antigens. One antibody bound to B lymphocytes and serum IgM molecules. The remaining five bound to subpopulations of lymphocytes. Four monoclonal antibodies bound only to bovine cells while six also bound to lymphocytes from other bovidae. None bound to human lymphocytes. We discuss the difficulty of correlating the specificities of monoclonal antibodies to functional lymphocyte subpopulations in outbred animals where few other defined markers are available.     

Production and characterization of monoclonal antibodies to bovine beta 2-microglobulin

In an attempt to isolate monoclonal antibodies specific for bovine lymphocytes, spleen cells from mice immunized with bovine lymphocytes were fused with the mouse myeloma cell line SP-2/0. The resulting hybridoma cell lines were tested for reactivity with bovine lymphocytes, polymorphonuclear neutrophils, RBC, gamma-globulin, kappa-casein, beta-casein, alpha-S1-casein, and beta 2-microglobulin (beta 2m) and with beta 2m from rabbits, goats, and human beings. None of the clones secreted anti-bovine lymphocyte-specific antibody. However, 4 secreted monoclonal antibodies to bovine beta 2m. They also reacted with beta 2m from rabbit, goat, and human being. One monoclonal antibody also was found to be reactive with bovine immunoglobulin. Monoclonal antibodies to beta 2m could serve as a tool to (1) explore the homology of the beta 2m molecule among various species, (2) examine the relationship of beta 2 m with the constant region of the immunoglobulin molecule, (3) quantitate bovine beta 2m in various body fluids and major histocompatibility antigens on cell surfaces, (4) help characterize those antigens in cattle, and (5) be used for tissue typing of those antigens.     

新城疫病毒单克隆抗体的制备及与不同分离株的反应性

以纯化的新城疫病毒(Newcastle dis-ease virus,NDV)弱毒株La Sota为免疫原,接种6周龄~8周龄Balb/c小鼠。最后一次加强免疫后3 d,取小鼠脾细胞与骨髓瘤细胞(SP2/0)融合。以纯化的NDV建立了筛选单抗的间接ELISA,经多次检测,3次亚克隆,共获得5株NDV特异性单抗,这5株单抗与NDV不同分离株的反应性存在差异,表明部分NDV毒株抗原性发生了变异。     

抗新城疫病毒糖蛋白单克隆抗体的研制及在免疫组化中的应用

应用纯化的新城疫病毒(NDV)La Sota野毒株免疫Balb/c小鼠,最后一次免疫后3 d取小鼠脾细胞与SP2/0骨髓瘤细胞融合,经间接ELISA筛选到3株分泌抗NDV单克隆抗体的杂交瘤细胞株,对各株单克隆抗体免疫球蛋白亚类及ELISA效价进行测定.结合单克隆抗体反应结果,鉴定出抗NDV NP蛋白的单克隆抗体,利用该单克隆抗体s3e1做免疫组化试验,用rLa Sota(重组La Sota第2代毒株)免疫2日龄雏鸡,接种后第5天检测到肝脏的部分肝细胞呈阳性反应.     

Development of Monoclonal Antibodies against the cOmpT Protein of Avian Pathogenic Escherichia coli and Identification of Epitopes Recognized by Monoclonal Antibodies

To development monoclonal antibodies against cOmpT of avian pathogenic Escherichia coli (APEC), the recombinant cOmpT of APEC origin expression plasmid pET-28a-compT was employed, and cOmpT protein with a molecular weight about 36 kD in the form of inclusion bodies was obtained after induction with IPTG, and then renatured by urea gradient dialysis. BALB/c mice were immunized with the purified cOmpT. An indirect enzyme-linked immunosorbent assay (iELISA) was developed, the optimal coating concentration of the antigen was 0.625 μg·mL^-1 and the optimal serum dilution was 1:6 400. After the fourth immunization, the spleen of immunized mice was collected for cell fusion, three monoclonal hybridomas that can secrete antibody specific to cOmpT were obtained after multiple screenings, named 1G8, 2C3 and 2G3 respectively. And all of their immunoglobulin subclasses were IgG2b. The titers of monoclonal antibodies in the cell culture supernatant were 1:200, 1:3 200 and 1:3 200 determined by iELISA, respectively. All three monoclonal antibodies were confirmed to react with cOmpT in Western blot, without cross reaction with other tested bacteria. The antigenic epitopes recognized by the three monoclonal antibodies were identified by using a series of E. coli strains harboring expression plasmids recombined with truncated fragments from compT gene. The results revealed that the antigenic epitope required for reactivity with the 1G8 was ⁸³DQDWMDS⁸⁹, and ⁹⁰SNPGTW⁹⁵, ¹⁹⁷TFKYSGW²⁰³were recognized by 2C3 and 2G3, respectively. In this study, three monoclonal antibodies against cOmpT were successfully developed and the antigenic epitopes recognized by the antibodies were identified. The cOmpT specific monoclonal antibodies obtained in this study are potentially useful tools for both the functional study of cOmpT and the development of APEC epitope vaccines.     

禽致病性大肠杆菌cOmpT单克隆抗体的研制及其识别抗原表位的鉴定

旨在制备禽致病性大肠杆菌（APEC）染色体编码外膜蛋白（cOmpT）的特异性单克隆抗体，本研究利用实验室已构建的APEC cOmpT重组表达质粒pET-28a-compT，经IPTG诱导表达后，获得以包涵体形式存在的约36 ku的重组蛋白cOmpT，利用尿素浓度梯度透析复性获得纯化蛋白cOmpT，并以此免疫BALB/c小鼠。建立间接ELISA检测方法，最适抗原包被浓度为0.625 μg·mL^-1，最适血清稀释度为1：6 400。4次免疫后取小鼠脾进行细胞融合，采用有限稀释法多轮筛选后得到3株能稳定分泌针对cOmpT蛋白的单克隆抗体，分别命名为1G8、2C3和2G3，均为IgG2b亚类。3株杂交瘤细胞上清ELISA抗体效价分别为1：200、1：3 200和1：3 200。Western blot结果显示，3株单抗均能与cOmpT发生特异性反应，而不与其他受检菌发生交叉反应。运用原核表达系统对compT基因进行截短表达，对单克隆抗体针对的cOmpT抗原表位进行鉴定，结果显示单抗1G8、2C3和2G3识别的抗原表位分别是⁸³DQDWMDS⁸⁹、⁹⁰SNPGTW⁹⁵和¹⁹⁷TFKYSGW²⁰³。本研究成功制备了3株抗cOmpT蛋白的单克隆抗体，并对其识别的抗原表位进行了鉴定，为cOmpT蛋白功能研究和APEC新型表位疫苗研发奠定了基础。     

猪RNA聚合酶Ⅱ单克隆抗体的制备与应用

旨在制备猪RNA聚合酶Ⅱ的单克隆抗体并进行初步应用。本研究采用生物信息方法预测免疫原，将其化学合成后免疫5只4~8周龄Bal b/c雌性小鼠，对免疫后呈现阳性的小鼠进行细胞融合试验，取其脾细胞与骨髓瘤细胞进行融合并获得能稳定分泌抗RNA PolⅡ的杂交瘤细胞。鉴定结果显示，RNA PolⅡ单克隆抗体的重链为IgG 2A型，轻链为Kappa型。利用间接ELISA方法对杂交瘤细胞进行筛选和亚克隆，获得了8株稳定分泌RNA PolⅡ单克隆抗体的杂交瘤细胞株。将其初步应用到染色质免疫共沉淀（ChIP-seq）技术，并与商业化抗体的富集性进行比较，结果表明，本研究得到的单克隆抗体富集性更强。本研究获得的猪RNA PolⅡ单克隆抗体可为表观遗传学的研究提供理论基础，并且提供重要的生物学材料。     

大豆凝集素单克隆抗体的制备及鉴定

为获得分泌抗大豆凝集素(SBA)单克隆抗体的杂交瘤细胞,以纯化的SBA为抗原,免疫BALB/c小鼠,加强免疫3 d后取小鼠脾细胞与骨髓瘤细胞(SP2/0)融合,应用有限稀释法和间接ELISA 方法克隆筛选出2株分泌抗SBA单克隆抗体的杂交瘤细胞系A7、F12。细胞上清抗体效价均在1∶2×10³以上,腹水抗体效价均为1∶1×10⁶,单抗亚型鉴定结果均为IgG2b型,分子质量为189.6 ku,亲和常数为7.1×10⁷ mol/L,Western blotting结果表明,2株单抗具有较高的特异性。该McAb的制备为建立SBA定量检测方法奠定了基础。     

Ⅰ型鸭肝炎病毒VP1蛋白单克隆抗体的研制

为研制鸭肝炎病毒(Duck hepatitis virus,DHV) VP1蛋白单克隆抗体,用已鉴定的Ⅰ型DHV的全病毒免疫BALB/c小鼠,取免疫小鼠的脾细胞和骨髓瘤细胞SP2/0进行融合,并以构建的原核重组质粒pET-VP-1在大肠杆菌BL21(DE3)中表达的VP1蛋白作为筛选抗原,通过间接ELISA法对杂交瘤进行筛选,经亚克隆后获得l株针对Ⅰ型DHV VP1蛋白的特异性单克隆抗体.对该株单克隆抗体的特性鉴定发现其特异性强、中和性较好.该抗体为今后Ⅰ型鸭肝炎病毒的检测试剂盒研制提供了重要的生物制剂.     

抗κ-酪蛋白单克隆抗体的制备及其特性鉴定

To obtain the anti-kappa casein monoclonal antibody and complete the identification of the antibody characteristics. The BALB/c mice were immunized with kappa casein using foot-pad immunization. Popliteal lymph node cells from the immunized mice were fused with SP2/0 myeloma cells in the presence of PEG. Three hybridoma strains (1C4, 3G3, 3E6) which secreted the antibody specific for kappa casein were obtained．The sub-class of the antibodies were IgG1. The ascites were purified by Protein G affinity layer absorption column. The antigenic epitope of 3G3 and 3E6 were different and it was close between 1C4 and 3E6.The titer of purified ascites(1C4) was 1.28×10⁶ and the affinity constant was 2.89×10⁸ mol/L. A anti-kappa casein monoclonal antibody with good affinity had been achieved，which provided foundations for the rapid detection of casein in bovine milk samples.     

禽多杀性巴氏杆菌单克隆抗体的制备及其基本性状研究

将多杀性巴氏杆菌（Ｐ．ｍ．）Ｃ４８－１株（Ｈｅｄｄｌｅｓｔｏｎ１型；Ｃａｒｔｅｒ分型５：Ａ）灭活后全菌免疫的ＢＡＬＢ／Ｃ小鼠脾细胞与ＳＰ／０骨髓瘤细胞在ＰＥＧ１０００作用下融合。用全菌包被的间接ＥＬＩＳＡ方法检测抗体，获得了２３株能稳定分泌抗Ｐ．ｍ．１型单克隆抗体的杂交瘤细胞。杂交瘤细胞培养２个月和冻存３个月后复苏培养，均能稳定分泌特异性单克隆抗体。２３株腹水ＥＬＩＳＡ效价分别从１０－３—１０－１１，无免疫沉淀性，也无凝集性。Ｉｇ类型鉴定表明，３株属于ＩｇＭ，２０株属于ＩｇＧ。间接ＥＬＩＳＡ检测结果表明：２３株单抗只与Ｐ．ｍ．１型起反应，而不与Ｐ．ｍ．３、４、１６型起反应，也不与禽类易感的鸡白痢沙门氏菌、大肠杆菌、葡萄球菌、李氏杆菌起反应，具有型的特异性。用ＩＣ８Ｈ９腹水建立的夹心ＥＬＩＳＡ方法检定Ｐ．ｍ．１型菌株，其敏感性高，特异性强，也更为方便。     

狂犬病病毒HepFlury株P蛋白单克隆抗体的制备及间接免疫荧光检测方法的建立

本研究以原核表达的融合型的重组蛋白pET32a(+)-P(狂犬病病毒HepFlury株P蛋白)免疫6~8周龄的BALB/c小鼠,取脾细胞和SP2/0按常规杂交瘤技术进行细胞融合,经间接免疫荧光方法(IFA)筛选及对mAb进行初步鉴定。经3次亚克隆后获得1株稳定分泌表达的杂交瘤细胞株5G8。     

Protection of mice against Brucella abortus infection by inoculation with monoclonal antibodies recognizing Brucella O-antigen

Monoclonal antibodies recognizing the O-polysaccharide portion of Brucella abortus strain 2308 provided BALB/c mice with passive protection against challenge exposure with the homologous strain. Numbers of colony-forming organisms in the spleen were reduced by IgM and IgG monoclonal antibodies. Active immunization of mice, using B abortus 2308S lipopolysaccharide, resulted in production of IgM antibody at 14 days. Clearance of organisms in the actively immunized mice after challenge exposure at 14 days was nearly identical to that in passively immunized mice. Mice either passively or actively immunized were effectively protected from 0 to 28 days. Bacterial colonization of the spleen was observed to increase in both groups of mice at 56 days and indicated that humoral responses were effective in eliminating the organism in the early stages of infection, but other immune mechanisms were necessary for protection of mice in the later stage of infection with virulent strains of B abortus.     

马立克氏病病毒抗独特型单克隆抗体的研究

应用纯化的D_(11)~4株抗马立克氏病病毒（MDV）中和性单克隆抗体（McAb_1）,以SPA-IgG法和脂质体-IgG法制成免疫原,分别免疫BALB/c小鼠,应用B淋巴细胞杂交瘤技术进行细胞融合。以两步ELISA筛选法获得了3株抗独特型单克隆抗体（McAb_2）,分别命名为1B_8、10C_1和3D_5,其Ig亚类分别为IgG_1、IgG_1和IgG_(2b),染色体数在92～102之间。在捕获阻断ELISA中,McAb_2在1:20～1:80000稀释可不同程度地阻断MDV抗原与McAb_1的结合,阻断率为2.66％～76.40％。用纯化的McAb_2制成油佐剂苗,免疫20日龄雏鸡,经3次免疫后10d采取血清,可测得不同滴度的针对MDV抗原的抗体。这提示3株McAb_2的可变区构型和与McAb_1结合的MDV抗原决定簇或其邻近结构相似,有可能用于MD抗独特型疫苗的研究。     

Monoclonal antibodies to the Sp strain of infectious pancreatic necrosis virus

Twelve hybrids secreting antibody to the Sp serotype of infectious pancreatic necrosis virus (IPNV) were isolated from the fusion of murine myeloma cells and spleen cells from mice immunized with pelleted virus. All of the monoclonal antibodies possessed the kappa (K) light chain isotype. Nine contained the mu (M), two had the gamma 2a (G2a), and one had the gamma 1 (G1) heavy chain isotype. Using an enzyme-linked immunosorbent assay (ELISA), 10 antibodies were found to be broadly reactive against partially purified representatives of the three serotypes of IPNV, the Sp, Ab, and VR-299 strains. The other two antibodies reacted with the Sp serotype alone. Characterization by immunostaining of viral polypeptides electrophoretically transferred to nitrocellulose sheets was possible only with IgG type antibodies. One of the specific monoclonal antibodies was shown to be directed against the major capsid protein while the other specific monoclonal antibody and the broadly reacting one reacted with the low molecular weight viral polypeptides.     

A bovine monoclonal antibody to oestrone/oestradiol prepared by a (murine x bovine) xbovine interspecies fusion

A heterohybridoma was produced by the fusion of sensitized peripheral blood lymphocytes (PBLs) with a previously derived heteromyeloma, generated by the fusion of bovine PBLs with murine myeloma cells. The sensitized bovine PBLs were collected from a steer immunized with an oestradiol-ovalbumin conjugate. The cell lines resulting from the fusion were screened for the production of bovine antibodies to oestradiol. A stable heterohybridoma was isolated which secreted a bovine IgG1 to oestrone/oestradiol. The use of sensitized PBLs together with heteromyeloma fusion partners has proved to be a reliable and simple way of producing monoclonal antibodies against specific haptens.     

Preparation of antibodies directed to the Babesia ovata- or Theileria sergenti-parasitized erythrocytes

To investigate the surface antigens of the bovine red blood cells (RBCs) parasitized by Babesia ovata or Theileria sergenti, attempts were made to produce monoclonal antibodies (mAbs) with BALB/c mice. Comparable numbers of hybridomas producing anti-piroplasm mAbs, as well as anti-bovine RBC mAbs, were obtained from the mice immunized with B. ovata- or T. sergenti-PRBCs. However, mAbs directed to the surface of parasitized RBCs (PRBCs) were obtained only from the mice immunized with B. ovata-PRBCs, but not from those immunized with T. sergenti-PRBCs. When serum samples from the immunized mice and the infected cattle were examined, antibodies recognizing B. ovata-PRBC surface were detected in the sera against B. ovata, but analogous antibodies were undetectable in the sera against T. sergenti, despite that the sera showed substantial antibody titers to T. sergenti piroplasms. The results suggest that significant antigenic modifications occur on the surface of B. ovata-PRBCs, but not on the surface of T. sergenti-PRBCs.     

麋鹿重组朊蛋白单克隆抗体的制备及初步鉴定

为研制鹿慢性消耗性疾病(chronic wasting disease,CWD)单克隆抗体,本研究以原核表达后经纯化的麋鹿重组成熟朊蛋白(PrP^c)为免疫原免疫PrP^c基因敲除小鼠(PrP^c-null mice)。两次加强免疫后,利用淋巴细胞杂交瘤技术,取脾细胞与SP2/0骨髓瘤细胞进行细胞融合,间接ELISA方法筛选阳性杂交瘤细胞,采用3次有限稀释法实现杂交瘤细胞的亚克隆,筛选出5株能稳定分泌针对麋鹿重组成熟朊蛋白特异性单克隆杭体(McAbs)的杂交瘤细胞株5A5、3B2、6D12、5E3、1F5,其腹水ELISA效价均达到1∶10000以上。经鉴定,5株单抗均为IgG抗体,5A5、6D12、5E3株为IgG1亚类,3B2、1F5株为IgG2a亚类。Western blotting鉴定结果表明,获得的McAbs均能特异性识别麋鹿重组成熟朊蛋白和健康麋鹿脑组织匀浆中的PrP^c。本研究制备了CWD腹水McAbs,同时也为CWD的研究及其诊断方法的建立奠定了基础。     

赤羽病毒单克隆抗体的研制及鉴定

用纯化的赤羽病毒（akabane virus,AKAV）免疫Balb/c小鼠,取小鼠脾细胞和骨髓瘤细胞SP2/0融合,经间接ELISA筛选和3次有限稀释法克隆,得到2株能稳定分泌抗赤羽病毒单克隆抗体（McAb）的杂交瘤细胞株,分别命名为AKAV McAb 3A株和2C株。ELISA试验和中和试验结果表明,本研究制备的2株McAb均具有良好的特异性,为AKAV阳性,杂交瘤细胞培养上清液抗体的效价分别为1∶640和1∶320,腹水的效价分别为1∶256000和1∶128000,亲和常数（Ka）分别为1.16×10^-9和6.31×10^-8 mol/L,3A株的相对亲和力大于2 C株,具有病毒中和活性,中和效价分别为1∶64和1∶32,其IgG亚类为IgG1,轻链的亚型均为kappa型,2株细胞冻存3次复苏后仍能稳定分泌抗体,表明AKAV McAb制备成功,为赤羽病快速诊断方法的研究奠定了基础。     

用抗原免疫构建分泌兔出血症病毒抗独特型抗体的杂交瘤细胞

用纯化的兔出血症病毒（ｒａｂｂｉｔｈａｅｍｏｒｈａｇｉｃｄｉｓｅａｓｅｖｉｒｕｓ,简称,ＲＨＤＶ）免疫Ｂａｌｂ／ｃ小鼠。正如网络学说所指出的,从免疫鼠的杂交瘤细胞克隆中,不仅筛选出能分泌抗ＲＨＤＶ抗体（Ａｂ１）的细胞克隆,同时也筛选出能分泌抗ＲＨＤＶ独特型抗体（ａｎｔｉ－ｉｄｉｏｔｙｐｉｃａｎｔｉｂｏｄｉｅｓ,Ａｂ２）的杂交瘤细胞,用抗原而不用单克隆抗体（Ａｂ１）免疫,诱导产生抗独特型抗体（Ａｂ２）是一种具有广阔的应用前景的新技术