CELLULAR AND MOLECULAR HETEROGENEITY OF H-2Kk ANTIGENS

Up to 70% of mouse spleen cells expressing H-2K^k alloantigens reacted with the monoclonal anti-H-2K^k antibody 11-4.1 in an indirect rosetting assay. When the cells that rosetted with the monoclonal antibody 11-4.1 were removed by density centrifugation, the residual unreactive cells reacted with the polyclonal anti-H-2K^k alloantiserum D23 but not with the monoclonal antibody 11-4.1 indicating the existence of two cell populations. In sequential immunoprecipitation experimens, the glycoprotein fraction of NP40 extracts from H-2K^k cells, after removal of antigens reacting with the monoclonal antibody 11-4.1 still contained structures reactive with the alloantiserum. Therefore, there are at least two antigenically distinct H-2K^k molecules which are differentially expressed on two subpopulations of spleen cells.     

sgp13OcDNA在痘苗病毒载体系统中的表达

ｇｐ１３０是一种分子量为１３０ｋＤ的细胞膜糖蛋白,是ＩＬ－６等多种细胞因子共用的信号传递分子。本研究将含ｇｐ１３０胞外区全长的可溶性片段的基因（ｓｇｐ１３０ｃＤＮＡ）构建到痘苗病毒载体中,并与野生型痘苗病毒在ＴＫ－１４３细胞中发生同源重组,用ＢｕｄＲ和Ｘ－ｇａｌ双重选择,得到带有人ｓｇｐ１３０的重组痘苗病毒（Ｖｓｇｐ１３０）。采用ＩＤＡ和ＷｅｓｔｅｒｎＢｌｏｔｉｎｇ法证实：感染Ｖｓｇｐ１３０的ＴＫ－１４３细胞上清中有较强的ｓｇｐ１３０表达,表达产物分子量为１００ｋＤ左右。     

Immunological cross-reactivity between H-2Dk product and DTIC-treated H-2d lymphoma

The experiments reported here concern the characterization by techniques of in vitro cell-mediated immunity of the antigens induced by 5-(3,3' dimethyl-1-triazine)-imidazole-4-carboxamide (DTIC) on L1210, a chemically-induced lymphoma of DBA/2 mice (H-2d). This series of experiments with the DTIC-treated L1210 tumour show the presence of an 'H-2D'-like antigen which resembles the Dk gene product/s of the H-2k haplotype.     

Ⅰ型变态反应与呼吸道合胞病毒毛细支气管炎喘鸣的关系

本文从RSV特异的IgE抗体(RSV-IgE),嗜硷粒细胞和组织胺三方面,探讨了RSV毛细支气管炎喘鸣的发病机理。实验发现,RSV毛细支气管炎患儿的鼻咽分泌液(NPS)中RSV-IgE和组织胺显著升高,外周血嗜硷粒细胞绝对数升高,对 RSV抗原敏感性高,脱颗粒阳性率高。初步证实 IgE介导Ⅰ型变态反应参与了 RSV毛细支气管炎的发病。同时发现,RSV-IgE在患儿体内持续存在,这可能是 RSV毛细支气管炎喘鸣患儿在病后数年中反复出现喘鸣的原因之一。     

Somatic H-2Kk variants reveal nonidentity of serological and cytotoxic T cell-defined Kk determinants

The relationship of serologically defined determinants to determinants recognized by cytotoxic T cells on molecules encoded by the K^k gene of the murine major histocompatibility complex (H-2) has been analyzed. For this purpose we used three somatic variants of a K^k-expressing lymphoma line lacking individual determinants of the K^k molecule, as defined by monoclonal antibodies (mAb), as target cells for K^k-specific alloreactive and K^k-restricted cytotoxic T lymphocytes (CTL) cloned by limiting dilution. Neither alloreactive nor fluorescein isothiocyanate, influenza- or Newcastle disease virus-specific K^k-restricted CTL clones were found to distinguish between variants and wild type cells, indicating that the serologically defined determinants lost by the variants were not essential for antigen recognition of CTL with these specificities. On the other hand, two of the variants lacking either one of a pair of serological determinants were discriminated from K^k wild type cells by about 40% of K^k-restricted, trinitrophenol (TNP)-specific CTL clones. The third variant, lacking both of the determinants, however, was lysed by all CTL clones to the same extent as wild type cells. From these results we conclude that the determinants restricting the TNP-specific CTL were also not identical with those defined by mAb. In experiments performed to optimize the conditions for the limiting dilution analysis we found that the specificity of the CTL stimulation was strongly dependent on the concentration of T cell growth factor (interleukin 2) in the cultures during CTL stimulation. High concentrations of IL2 resulted in a drastic increase in the frequency of CTL clones. Part of these clones, however, were found not to be specific for antigens present on the stimulator cells.     

乙型脑炎重组痘苗病毒J3免疫性的研究

用含有日本脑炎病毒（ＪＥＶ）结构蛋白ＰｒＭ、Ｅ和非结构蛋白ＮＳ１、ＮＳ２Ａ基因的重组痘苗病毒Ｊ３免疫家兔，能较快地诱生抗ＪＥＶ抗体，其滴度可随免疫次数的增加和免疫时间的延长而增高。此抗血清可被动保护不同毒株ＪＥＶ的致死性攻击，该保护作用与其中抗体和血凝抑制抗体有关。     

HERPES SIMPLEX VIRUS INFECTION AND APOPTOSIS

Consequences of human herpes simplex virus (HSV) infection include the induction of apoptosis and the concomitant synthesis of proteins which act to block this process from killing the infected cell. Recent data has clarified our current understanding of the mechanisms of induction and prevention of apoptosis by HSV. These findings emphasize the fact that modulation of apoptosis by HSV during infection is a multicomponent phenomenon. We review recent evidence showing how this important human pathogen modulates the fundamental cell death process.     

VARIABLE EXPRESSION AND IMMUNOGENICITY OF AN H-2K-CODED ALLOANTIGEN ON MURINE TUMOURS

The K region of the H-2 major histocompatibility complex (MHC) of mice of H-2K^k haplotype codes for two distinct alloantigens. One of these alloantigens, designated k-common, is expressed by C3HfB/HeN mice (C3Hf). The other alloantigen, designated k-unique, is not expressed by C3Hf mice. The H-2 haplotype of C3Hf mice has been classified as kv1 and the variant antigen distinguishing this strain from mice of H-2K^k haplotype has been designated kv1-unique. Several transplacentally-induced lung tumours of C3Hf mice express the k-unique, rather than the expected kv1-unique, antigen. The immunogenicity of the k-unique antigen on C3Hf-derived lung tumours varies with different tumours. In particular, the capacity of the k-unique antigen to induce radioresistant immunity in C3Hf mice appears to be lost on long term cultured tumour cells even though the tumour remains susceptible to in vivo immune responses directed against the k-unique antigen. Alterations in expression and in immunogenicity of unique H-2-coded antigens may dictate the nature and efficacy of immune surveillance of autochthanous tumours.     

感染登革病毒Ⅱ型后白纹伊蚊氨基酸动态的研究

为研究感染登革病毒Ⅱ型 (DV2 )后白纹伊蚊氨基酸的动态变化 ,采用DV2经胸注射白纹伊蚊。分别测定感染后 5天 ,10天 ,2 0天白纹伊蚊氨基酸含量 ,并与未感染DV2相应龄期蚊虫氨基酸含量对比。结果显示DV2感染后 5天 :天门冬氨酸、谷氨酸、丙氨酸和精氨酸含量较对照组有明显升高 ,其余氨基酸变化不显著。DV2感染后 10天、 2 0天所有氨基酸含量的变化均不显著。本研究提示DV2可使感染初期白纹伊蚊的少数几种氨基酸含量升高。随着感染时间延长 ,DV2对白纹伊蚊氨基酸含量影响不大。白纹伊蚊可能通过自身内在调节机制维持其体内氨基酸的稳态     

大鼠全脑缺血再灌后海马区bcl—2和Bax表达的检测

目的：检测ｂｃｌ－２和Ｂａｘ在大鼠嵛脑缺血再灌后海马区的表达。方法：用原位杂交组织化学检测ｂｃｌ－２ｍＲＮＡ,用免疫组织化学检测Ｂａｘ蛋白。结果：ｂｃｌ－２主要在海马ＣＡ３区表达,再灌８小时出现,２４小时阳性达到高峰,７２小时明显下降;Ｂａｘ则主要主要在ＣＡ１区表达,再灌８小时出现,２４小时阳性信号达到高峰,和,ＣＡ１２、ＣＡＳ４、ＤＧ区也有表达,但变化不明显,高倍镜下可见紫蓝色的阳性信号和棕黄色     

大鼠额叶损伤后细胞凋亡及Bax与Bcl-2蛋白的表达变化

本研究目的为探讨大鼠额叶锐器损伤后细胞凋亡的变化规律及调控机制。通过电镜、TUNEL法及免疫组织化学染色方法检测细胞凋亡和Bax、Bcl2蛋白的表达变化,结果发现凋亡细胞在损伤后3h即可发现,24h达到高峰;伤后3hBax和Bcl2表达明显升高,Bax表达12h达到高峰,而Bcl2表达6h即达到高峰;伤后Bax/Bcl2比值上调,24h达到高峰,随后逐渐下降。结果表明大鼠额叶锐器伤后存在细胞凋亡,凋亡细胞数量的变化与伤后时程有关,Bax/Bcl2比值是决定细胞凋亡的重要因素。     

Monoclonal antibody detection of two classes of H-2Kk molecules

Studies described in this paper indicate that two anti-H-2K^k monoclonal antibodies, namely 27R9 (H-2.25) and 30R3 (H-2.5) recognize different H-2K^k molecules on the surface of lymphocytes. Initial experiments in support of this conclusion were cocapping experiments which showed mutual exclusiveness between H-2K^k molecules which bind either of the two monoclonal antibodies 27R9 (H-2.25) or 30R3 (H-2.5) whereas conventional anti-H-2K^k (H-2.23) alloantiserum binds to both types of H-2 molecules. This result was confirmed by experiments using solubilized H-2 antigen preparations to inhibit antibody binding to spleen cells. Preabsorption of the preparation with one monoclonal antibody did not remove its inhibitory activity for the other monoclonal antibody, and only partially removed its inhibitory activity for the conventional anti-H-2K^k serum. These results suggest that at least two antigenically distinct H-2K^k molecules arc controlled by the H-2K region. Subsequent blocking studies have indicated that the two different molecules are associated, to some extent, in the cell membrane. Furthermore, in ¹²⁵I-protein A radioimmunoassay.each monoclonal antibody was found to bind to only half of the estimated total number of H-2K^k molecules recognized by conventional anti-H-2K^k sera. Several interpretations for the existence of the two classes of H-2K^k molecules are discussed.     

促红细胞生成素对视网膜缺血再灌注神经元凋亡和caspase-2表达的影响

为研究促红细胞生成素(erythropoietin,EPO)预处理对视网膜缺血后caspase-2蛋白表达的影响,并探讨其对视网膜缺血保护的可能机制,我们采用升高眼内压的方法制作实验性视网膜缺血大鼠模型。将Wistar大鼠随机分为正常组、生理盐水组及EPO组。缺血前24h,生理盐水组腹腔注射生理盐水,EPO组注射重组人促红细胞生成素(rhEPO)5000U/kg。观察缺血再灌注后不同时间段生理盐水组及EPO组视网膜组织学变化、TUNEL检测及caspase-2蛋白的表达。结果发现:(1)视网膜缺血再灌注各时间段,H.E.染色EPO组大鼠视网膜内层厚度均较生理盐水组厚,且内核层细胞数多于生理盐水组(P<0.01);(2)TUNEL法凋亡细胞测定显示,正常组无阳性细胞,缺血再灌注24h,EPO组内核层的凋亡细胞比生理盐水组少(P<0.01);(3)caspase-2蛋白表达的测定显示,正常组无阳性细胞,EPO组及生理盐水组在缺血再灌注12h检测到caspase-2蛋白阳性表达,但EPO组阳性蛋白表达量比生理盐水组少(P<0.01)。以上结果提示:EPO预处理可以促进视网膜缺血再灌注后细胞的存留,减少细胞凋亡,caspase-2蛋白表达的抑制可能参与了这种保护机制。     

我国不同地域蜱类自然感染MIV-2病毒的调查

为掌握Mini Virus-2 (MIV-2)在我国的分布情况并了解其优势携带蜱种,本研究在我国云南、贵州、辽宁、黑龙江、吉林、广西省和重庆市采集游离蜱614只,采用MIV-2特异性一步法逆转录荧光定量PCR检测MIV-2感染率.结果 发现,携带MIV-2的阳性样本共67个,总阳性率10.91％.MIV-2在云南省和辽宁省的检出阳性率最高,分别为30.00％和20.83％.卵形硬蜱、长角血蜱等8个蜱种中均检测到MIV-2.     

Monoclonal antibody detection of carbohydrate-defined and protein-defined H-2Kk antigens

Three different monoclonal anti-H-2K^k antibodies, 27R9, 30R3 and 11-4 were examined for the biochemical nature of the antigenic determinants they recognize. When these were compared on the basis of their sensitivity to pronase and various glycosidases, 27R9 was shown to bind to protein-defined H-2K^k antigens, while 30R3 and 11-4 bound to H-2 antigens defined by carbohydrate. From sugar inhibition studies, and treatments with specific glycosidases, d-mannose appears to be the immunodominant sugar involved in the antigenic site recognized by 30R3, while several sugars, namely sialic acid, d-mannose and α-and β-linked d-galactose would appear to be components of the antigenic site bound by 11-4. The carbohydrate determinants appear to be present on glycolipid molecules, since both the 30R3 and 11-4 antibodies could be inhibited by glycolipid extracts from spleen cells of the appropriate H-2 haplotype, as well as from several other strains of mice previously shown to be cross-reactive targets for these antibodies. This finding is supported by evidence that the molecule carrying the protein-defined antigen is distinct from that carrying the carbohydrate-defined antigens. The results are discussed in the light of current information on the nature of glycolipid Ia antigens, as well as the role of H-2 antigens in T-cell interactions.     

NK sensitivity, H-2 expression and metastatic potential: analysis of H-2Dk gene transfected fibrosarcoma cells

We have used the 3-Methylcholanthrene induced T-10 fibrosarcoma tumour cell system (H-2b xH-2k)F1 to elucidate the possible correlation between metastatic potential, expression of individual H-2 antigens and susceptibility to NK cells. Transfection of the non-metastatic and NK sensitive IC9 cells (Db+, Dk-, Kb-, Kk-) with the H-2Dk gene, altered the metastatic phenotype of the parental cells, yet had no effect on the susceptibility of these tumour cells to lysis by NK and did not elicit a specific CTL response in syngeneic hosts. Variants of the metastatic and NK resistant IE7 clone (Db+, Dk+, Kb-, Kk-), lacking H-2Dk, were selected by treatment with monoclonal anti H-2Dk antibodies and complement. These variants were sensitive to NK and poorly or non metastatic. Retransfection of 'Dk' 'loss' variants with the H-2Dk gene, resulted in the isolation of several clones expressing a wide range of metastatic phenotypes but maintained sensitivity to NK. These results indicate that the H-2D region of the MHC and or closely linked genes may be involved in the complex interrelationship between target susceptibility to NK and metastasis.     

Binding of cytotoxic T-lymphocytes to supported lipid monolayers containing trypsinized H-2Kk

H-2Kk, a transmembrane protein coded for by the mouse major histocompatibility complex, was modified by trypsinization to remove its intracellular segment and was incorporated into lipid monolayers made on an alkylated glass substrate. Cloned cytotoxic T-lymphocytes specific for H-2Kk were incubated on the monolayer. More cytotoxic T-cells bound to monolayers containing the H-2Kk fragment (tH-2Kk) than to control monolayers made without H-2Kk. Preincubation of monolayers with alloantisera against H-2Kk reduced binding of CTL to levels seen with control monolayers. This method offers the possibility of studying specific binding of cytotoxic T-cells to well-defined model membranes.     

PHYSIOLOGICAL SIGNIFICANCE OF APOPTOSIS DURING ANIMAL VIRUS INFECTION

Apoptosis has been considered to be a host defense mechanism against viral infection in multicellular organisms. This is based on the findings that apoptogenic mutants of insect viruses cannot grow because infected host cells die by apoptosis. This suggests that the apoptotic response of host cells has a deleterious effect on virus infection. Thus, apoptosis is an important host defense mechanism that is capable of inhibiting viral replication during infection. However, in vitro studies indicated that apoptosis alone does not provide the same protection against viral infection in animal cells as it does in the insect cells. Still, most animal viruses have acquired a strategy to overcome host cell apoptosis. In addition, a varying degree of necrosis usually accompanies apoptosis, suggesting a possible contribution of necrosis to the host reactions against virus. To understand the physiological significance of apoptosis during animal virus infection, we have characterized viral growth and the cellular responses against virus infection in a wide variety of virus-cell interaction systems. Mainly based on our own works, we discuss the nature of apoptosis in the animal virus infection and verify its role as a host defense mechanism against virus infection.