Characterization of DNA fragments encoding fimbriae of the uropathogenic Escherichia coli strain KS71

Recombinant plasmids were constructed that expressed the KS71A, KS71B and KS71C fimbrial antigens of the pyelonephritogenic Escherichia coli strain KS71 (O4:K12) in E. coli HB101. The KS71C-encoding genes were located on a 6.4 kb HindIII-XhoI fragment obtained from the recombinant cosmid pKTH145 that expresses this antigen. Spontaneous KS71C-mutants were isolated that contained a 0.8 kb insert in a specific restriction fragment of KS71C-encoding recombinant plasmids. The KS71B-encoding segment was located on a 11.5 kb deletable DNA fragment of recombinant cosmid pKTH144. A DNA fragment encoding the KS71A fimbria was obtained on a 12 kb EcoRI fragment of the recombinant cosmid expressing this antigen in E. coli HB101 and closely resembled the KS71B-encoding fragment. In the recombinant cosmid, the KS71B-expressing region was flanked by homologous DNA segments. A similar stretch of DNA was found close to the KS71A-expressing DNA region.     

Tumor antigens: Biological activity of components of soluble antigens of MTV-induced mammary tumors

Summary Antigens (AMMT) of MTV-induced mammary tumors of BALB/cfC3H CRGL mice were solubilized by treatment of homogenates of the tumor with 1 M perchloric acid. The soluble antigens exhibited biological activity by their ability to induce DNA synthesis in spleen cells of mice bearing syngeneic transplants of the tumor. AMMT-induced DNA synthesis, however, was abrogated by serum from tumor-bearing mice. AMMT neutralized complement-dependent rabbit anti-ML(r) antibody activity and intracytoplasmic fixed cell immunofluorescent activity of the same antibodies. One component of AMMT has an electrophoretic mobility pattern identical to that of ML(r) antigen. Thus, AMMT may share antigenicity with MTV-specific antigens.     

Tumorigenesis by human herpesvirus 8 vGPCR is accelerated by human immunodeficiency virus type 1 Tat

Human herpesvirus 8 (HHV-8), also called Kaposi's sarcoma (KS) herpesvirus, can cause KS but is inefficient. Untreated human immunodeficiency virus type 1 (HIV-1) coinfection is a powerful risk factor. The HHV-8 chemokine receptor, vGPCR (ORF74), activates NF-kappaB and NF-AT, and their levels of activation are synergistically increased by HIV-1 Tat. Transgenic vGPCR mice develop KS-like tumors. A cell line derived from one such tumor expresses vGPCR and forms tumors in nude mice. Here we show that transfection of DNA encoding HIV-1 tat (but not a transactivation-defective mutant) into these tumor cells increases NF-kappaB and NF-AT activation levels and accelerates tumor formation. Tumorigenesis was also accelerated when Tat DNA was transfected into normal cells and the transfected cells were mixed with the tumor cells and injected into a single site. Tumorigenesis was also increased when the two cell types were injected at separate sites, suggesting that tumorigenesis is accelerated by Tat through soluble factors.     

颗粒化重组戊型肝炎病毒衣壳蛋白及其抗原性与免疫原性

过去的研究发现大肠杆菌表达的戊型肝炎病毒（HEV）衣壳蛋白ORF2的aa394-606片段NE2可以形成同源多聚体,并具有良好的免疫保护性,但纯化后的免疫原性较弱。这里表达了3个NE2蛋白的N端延伸突变体,发现对应于ORF2 aa368_606的重组蛋白HEV239在体外可以形成颗粒性抗原。HEV 239抗原颗粒与戊肝患者血清反应性良好,对中和性单克隆抗体8C11的反应性与NE2抗原相当,而对另一中和性单克隆抗体8H3的反应性较NE2抗原有显著提高,表明HEV 239抗原颗粒具有比NE2更好的抗原性。纯化后的HEV 239抗原颗粒直径约为15～30nm。铝佐剂吸附的HEV 239免疫Balb/c小鼠的半数有效剂量（ED50）在0.08～0.25μg之间,而同样以铝佐剂吸附的NE2抗原60μg剂量免疫的抗体阳转率仅25%,表明HEV 239抗原颗粒具有更好的免疫原性。     

人疱疹病毒8型KS330基因片段的检出与Kaposi肉瘤的关系

HHV-8 sequences were recently identified in 100% of the amplifiable samples from AIDS patients with Kaposi's sarcoma(KS)and in 15% of the non-KS tissue samples from AIDS patients, so there is a strong correlation of Kaposi's sarcoma with HHV-8. Serum and DNA samples from a clinically diagnosed Kaposi's sarcoma Chinese patient were tested. HHV-8 antibody was tested positive by IFA and HIV-I antibody was negative by Western blot. The KS330 PCR product was found both in peripheral blood mononuclear cells and in KS tumor cells from this Chinese patient. This supports the hypothesis that Kaposi's sarcoma results from infection of HHV-8.     

Characterization of monoclonal antibodies raised against the latent nuclear antigen of human herpesvirus 8

Human herpesvirus 8 (HHV-8; also designated Kaposi's sarcoma-associated herpesvirus) is the likely etiological agent of Kaposi's sarcoma (KS). HHV-8 encodes a latent nuclear antigen (LNA) which is the product of the viral gene orf 73. LNA is recognized by most infected patient sera and is the basis of current immunofluorescence assays used in epidemiological studies of HHV-8 infection. Here we describe the characterization of four monoclonal antibodies raised to the C-terminal third of LNA-glutathione S-transferase fusion proteins. These monoclonal antibodies recognized discrete linear epitopes within the C terminus and repetitive region of LNA, detected antigen in primary effusion lymphoma (PEL) cells, and precipitated a 220- to 230-kDa protein doublet corresponding to LNA from HHV-8-infected PEL cell lines. In situ immunocytochemistry of KS lesions with these antibodies show that LNA is extensively expressed in KS spindle cells.     

Alpha interferon inhibits human herpesvirus 8 (HHV-8) reactivation in primary effusion lymphoma cells and reduces HHV-8 load in cultured peripheral blood mononuclear cells

Infection by human herpesvirus 8 (HHV-8) is associated with the development of Kaposi's sarcoma (KS). Since regression of KS can be achieved by treatment of the patients with alpha interferon (IFN-alpha), we analyzed the effects of IFN-alpha or anti-IFN-alpha antibodies (Ab) on HHV-8 latently infected primary effusion lymphoma-derived cell lines (BCBL-1 and BC-1) and on peripheral blood mononuclear cells (PBMC) from patients with all forms of KS and from at-risk subjects. IFN-alpha inhibited in a dose-dependent manner the amplification of HHV-8 DNA in BCBL-1 cells induced to lytic infection with tetradecanoyl phorbol acetate (TPA). This effect was associated with the inhibition of the expression of HHV-8 nut-1 and kaposin genes that are induced early and several hours, respectively, after TPA treatment. In addition, IFN-alpha inhibited virus production and/or release from BCBL-1 cells. Inhibition of nut-1 and kaposin genes by IFN-alpha was also observed in BC-1 cells induced with n-butyrate. Conversely, the addition of anti-IFN-alpha Ab to TPA-induced BCBL-1 cells resulted in a larger number of mature enveloped particles and in a more extensive cytopathic effect due to the neutralization of the endogenous IFN produced by these cells. IFN was also produced by cultured PBMC from HHV-8-infected individuals, and this was associated with a loss of viral DNA during culture. However, the addition of anti-IFN-alpha Ab or anti-type I IFN receptor Ab promoted the maintenance of HHV-8 DNA in these cells that was associated with the detection of the latency-associated kaposin RNA. Finally, the addition of IFN-alpha reduced the HHV-8 load in PBMC. Thus, IFN-alpha appears to have inhibitory effects on HHV-8 persistent infection of PBMC. These results suggest that, in addition to inhibiting the expression of angiogenic factors that are key to KS development, IFN-alpha may induce KS regression by reducing the HHV-8 load and/or inhibiting virus reactivation.     

Two kinds of P-fimbrial variants of uropathogenic Escherichia coli recognizing forssman glycosphingolipid.

Various types of fimbriae on pathogenic Escherichia coli strains have been classified by their antigenicities and recognition specificities for receptors. However, the antigenicity of fimbrial proteins does not always correlate with the fimbrial recognition specificity. In this communication, the exact carbohydrate structures recognized by the fimbriae of two human uropathogenic E. coli strains, KS71 (O4) and IH11024 (O6), that have P-fimbrial antigen, were examined. Strain KS71 showed mannose-resistant (MR) hemagglutination (HA) of human blood group OP1 phenotype erythrocytes, and its HA was inhibited by blood group Pk antigen, Gal(alpha,1-4)Gal(beta,1-4)Glc-ceramide and P antigen, GalNAc(beta,1-3)Gal (alpha,1-4)Gal(beta,1-4)Glc-ceramide but not by Forssman antigen, GalNAc(alpha,1-3)GalNAc(beta,1-3)Gal(alpha,1-4)Gal (beta,1-4)Glc-ceramide, as previously described in many papers. The cells also showed MR HA of sheep erythrocytes, which was potently inhibited by Forssman, and weakly by P and Pk antigens. These phenomena could not be explained by the above P adhesin specificity. This adhesin was called Forssman-like adhesin. Strain IH11024 also caused MR HA of sheep erythrocytes but not of human erythrocytes. The HA was inhibited specifically by Forssman but neither by Pk nor P antigen. This adhesin was completely different from P adhesin and Forssman-like adhesin in recognition of the carbohydrate epitope. This adhesin, until now called a pseudotype of P fimbriae, was renamed Forssman adhesin.     

A labile antigen complex at the lymphocyte surface: the effect of the substratum on its expression

Human T lymphocytes carry a surface antigen, detectable by a monoclonal antifibronectin antibody, which appears to consist of 150 and 55 kd components as revealed by SDS-PAGE. After in vitro culture of the lymphocytes on a plastic substratum for 48 hr comparatively few cells (40 +/- 18% in separate individuals) express the antigen. In contrast, the vast majority of lymphocytes cultured on a collagen matrix for the same time period maintains surface expression of the antigen (76 +/- 14% in separate individuals). Conditioned media from lymphocytes on plastic contain substantial amounts of antigenicity detectable by the same antibody, whereas conditioned media from lymphocytes on collagen are devoid of such antigenicity. The expression at the cell surface of other T lymphocyte antigens (Leu-4, Leu-3, and OKT8) is identical during culture on plastic and collagen for 48 hr. Collagen does not activate the cells to DNA synthesis or expression of IL 2 receptors, and consequently the potentiation of antigen expression by this substratum cannot be attributed to a mitogenic effect. The composition of subsets of T lymphocytes and the viability of the cells are the same on plastic and collagen, which excludes that the substratum-dependent variations in antigenicity reflect selection or loss of antigen-bearing cells. Thus, substratum-dependent regulation of the expression at the cell surface appears to be a unique property of the 150/55 kd T cell surface antigen. Culture on collagen substrata augments the number of lymphocytes showing motile behavior two to four times compared with culture on plastic.     

Primary effusion lymphoma. A case report

BACKGROUND: Primary effusion lymphoma (PEL) is a rare type of lymphoma that presents as an effusion, seldom with evidence of a solid neoplasm elsewhere; thus, cytology is the basic diagnostic method. It usually occurs in HIV-positive males with a history of Kaposi's sarcoma (KS), and DNA sequences of human herpesvirus 8 (HHV-8) are detected by molecular analysis. The distinct morphologic, immunophenotypic, molecular and clinical characteristics render this neoplasm a new pathologic entity. CASE: A 57-year-old, HIV-positive man presented to the hospital with ascites and absence of neoplasm on radiologic investigation. Cytologic evaluation of the ascitic fluid revealed the presence of highly atypical, pleomorphic lymphoid cells. Immunocytochemistry of the lymphoma cells was positive for CD45 (leukocyte common antigen), CD30 and epithelial membrane antigen antigens and negative for panB, panT and cytokeratin antigens. DNA sequences of HHV-8 were identified by polymerase chain reaction (PCR), and DNA ploidy analysis showed aneuploidy. The patient died 5 months after the diagnosis. CONCLUSION: Conventional and ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) cytology, in combination with immunocytochemistry and PCR for HHV-8 DNA sequences, can lead to an accurate diagnosis of PEL. DNA ploidy analysis confirms the aggressive nature of this neoplasm.     

Delayed hypersensitivity to crude and partially purified murine tumor-specific transplantation antigens and alloantigens utilizing the footpad swelling assay

Antigen preparations extracted from C3H/HeJ methylcholanthrene-induced fibrosarcomas by the 3M KCl extraction procedure were assessed for tumor-specific and allospecific antigenicity. Specificity of crude tumor antigen preparations and of fractions from preparative isoelectric focusing was investigated by evocation of footpad swelling (FPS) in syngeneic mice immunized with irradiated fibrosarcoma cells. Tumor immune mice displayed delayed hypersensitivity as positive FPS responses to challenge with 3M KCl extract and with fraction (Fr) 15 (pH 5.7 to 6.0) from preparative isoelectrically focused 3M KCl extract. Crude extracts and Fr 15 exhibited immunoprotective activity in vivo. Immune mice demonstrated a specific FPS response only to crude antigen preparations of Fr 15 from immunizing tumors, not to materials from a noncross-reactive neoplasm. DBA/2J mice immunized with C3H/HeJ spleen cells displayed FPS to challenge with crude antigen preparations, but not with the tumor-specific Fr 15. Alloantigen activity, however, was detected by a positive FPS response in C3H-immune DBA mice in fractions from the pH range 5.1 to 5.5. These experiments demonstrated that the FPS assay provides the setting for detection of specific delayed hypersensitivity responses to crude and fractionated tumor antigen preparations and for delineation of tumor-specific and histocompatibility antigen activities in fractions from crude extracts.     

Neuronal cell-surface specific antigen(s) is expressed during the terminal mitosis of cells destined to become neuroblasts

By immunizing mice with cells from embryonic chick motoneuron cultures, an antiserum was produced which recognizes an antigen(s) restricted to cell surfaces of most, or all, neurons. With the use of this antiserum, the appearance of neuron-specific antigenicity in cells of the embryonic spinal cord was examined by indirect immunofluorescence microscopy. The antigen or set of antigens reacting with this antiserum was first detectable in the neural tube of chick embryos at stage 15–16 (V. Hamburger and H. L. Hamilton, 1951, J. Morphol.88, 49–92). In addition to the neuroblasts located in the mantle layer, some mitotic cells as well as some spindle-shaped cells in the germinal layer were antigen positive. Immunofluorescence microscopy combined with autoradiography revealed that none of the antigen-positive cells could be labeled with [³H]thymidine; thus they do not synthesize DNA, and none of the cells in the DNA synthetic phase expressed the antigen(s). As the neuroblasts do not synthesize DNA after they have differentiated from the germinal cells, we believe that the antigen-positive cells are differentiated elements and that the differentiation of membranes specific for neurons begins already before or during the terminal mitosis of cells which will be defined as neuroblasts.     

Genotypic analysis on the ORF-K1 gene of human herpesvirus 8 from patients with Kaposi's sarcoma in Xinjiang, China

Human herpesvirus 8 (HH'V-8) is thought to be essential for the development of all forms of Kaposi's sarcoma (KS). HHV-8 DNA is present virtually in all KS tumor biopsy samples. Genes at both ends of the HHV-8 genome have been shown to vary considerably. Seve nmajor molecular subtypes of HHV-8 were defined based on the amino acid sequence of the open reading frame K1 (ORF-Kl), generally known as A, B, C, D, E, E and Z. Most strains collected worldwide were clustered into two subtypes (A and C). Here, the Kl/VRl region of HHV-8 was amplified by nested PCR in 22 (81.48%) of 27 cases from Xinjiang Uygur Autonomous Region, a province in northwest-ern China. Phylogenetic analysis on the basis of the KI/VRI amino acid sequence indicated that the majority of these KS patients were infected by subtype C HHV-8 (n = 18, including 15 belonging to the C2 group), and several by subtype A (n = 4, including 3 being the Al group). This is the fast report of subtype A HHV-g in China. Furthermore, the correlations between different forms and lesions of KS and different subtypes of HHV-8 were analyzed. The findings showed that subtype A HHV-8 resulted in significantly more frequent mucosal KS lesions than subtype C. However, there was no obvious correlation between different forms of KS and different subtypes of HHV-8.     

Impact of HIV Infection and Kaposi Sarcoma on Human Herpesvirus-8 Mucosal Replication and Dissemination in Uganda

Introduction

Kaposi sarcoma (KS) is the leading cause of cancer in Uganda and occurs in people with and without HIV. Human herpesvirus-8 (HHV-8) replication is important both in transmission of HHV-8 and progression to KS. We characterized the sites and frequency of HHV-8 detection in Ugandans with and without HIV and KS.

Methods

Participants were enrolled into one of four groups on the basis of HIV and KS status (HIV negative/KS negative, HIV positive/KS negative, HIV negative/KS positive, and HIV positive/KS positive). Participants collected oral swabs daily and clinicians collected oral swabs, anogenital swabs, and plasma samples weekly over 4 weeks. HHV-8 DNA at each site was quantified by polymerase chain reaction (PCR).

Results

78 participants collected a total of 2063 orals swabs and 358 plasma samples. Of these, 428 (21%) oral swabs and 96 (27%) plasma samples had detectable HHV-8 DNA. HHV-8 was detected more frequently in both the oropharynx of persons with KS (24 (57%) of 42 persons with KS vs. 8 (22%) of 36 persons without, p = 0.002) and the peripheral blood (30 (71%) of 42 persons with KS vs. 8 (22%) of 36 persons without, p<0.001). In a multivariate model, HHV-8 viremia was more frequent among men (IRR = 3.3, 95% CI = 1.7–6.2, p<0.001), persons with KS (IRR = 3.9, 95% CI = 1.7–9.0, p = 0.001) and persons with HIV infection (IRR = 1.7, 95% CI = 1.0–2.7, p = 0.03). Importantly, oral HHV-8 detection predicted the subsequent HHV-8 viremia. HHV-8 viremia was significantly more common when HHV-8 DNA was detected from the oropharynx during the week prior than when oral HHV-8 was not detected (RR = 3.3, 95% CI = 1.8–5.9 p<0.001). Genital HHV-8 detection was rare (9 (3%) of 272 swabs).

Conclusions

HHV-8 detection is frequent in the oropharynx and peripheral blood of Ugandans with endemic and epidemic KS. Replication at these sites is highly correlated, and viremia is increased in men and those with HIV. The high incidence of HHV-8 replication at multiple anatomic sites may be an important factor leading to and sustaining the high prevalence of KS in Uganda.     

Protective immunity against Taenia crassiceps murine cysticercosis induced by DNA vaccination with a Taenia saginata tegument antigen

This study investigated the protective capacity of the recombinant Taenia saginata Tso18 antigen administered as a DNA vaccine in the Taenia crassiceps murine model of cysticercosis. This Tso18 DNA sequence, isolated from a T. saginata oncosphere cDNA library, has homologies with Taenia solium and Echinococcus sp. It was cloned in the pcDNA3.1 plasmid and injected once intramuscularly into mice. Compared to saline-vaccinated control mice, immunization reduced the parasite burden by 57.3-81.4%, while lower levels of non-specific protection were induced in control mice injected with the plasmid pcDNA3.1 (18.8-33.1%) or a plasmid with irrelevant construct, pcDNA3.1/3D15 (33.4-38.8%). Importantly, significant levels of protection were observed between the pcDNA3.1/Tso18 plasmid and pcDNA3.1/3D15 plasmid immunized mice. Mice immunized with pTso18 synthesized low levels of, primarily IgG1 sub-class, antibodies. These antibodies were shown to recognize a 66 kDa antigen fraction of T. crassiceps and T. solium. Splenocytes enriched in both CD4+CD8- and CD4-CD8+ T cells from these vaccinated mice proliferated in vitro when exposed to antigens from both T. solium and T. crassiceps cestodes. Immunolocalization studies revealed the Tso18 antigen in oncospheres of T. saginata and T. solium, in the adult tapeworm and in the tegument of T. solium cysticerci. The protective capacity of this antigen and its extensive distribution in different stages, species and genera of cestodes points to the potential of Tso18 antigen for the possible design of a vaccine against cestodes.     

Ty virus-like particles, DNA vaccines and Modified Vaccinia Virus Ankara; comparisons and combinations

Three types of vaccine, all expressing the same antigen from Plasmodium berghei, or a CD8+ T cell epitope from that antigen, were compared for their ability to induce CD8+ T cell responses in mice. Higher levels of lysis and numbers of IFN-gamma secreting T cells were primed with Ty virus-like particles and Modified Vaccinia Virus Ankara (MVA) than with DNA vaccines, but none of the vaccines were able to protect immunised mice from infectious challenge even after repeated doses. However, when the immune response was primed with one type of vaccine (Ty-VLPs or DNA) and boosted with another (MVA) complete protection against infection was achieved. Protection correlated with very high levels of IFN-gamma secreting T cells and lysis. This method of vaccination uses delivery systems and routes that can be used in humans and could provide a generally applicable regime for the induction of high levels of CD8+ T cells.     

Unusual type of mitochondrial DNA in mice lacking a maternally transmitted antigen

Mice that lack a maternally transmitted antigen (Mta) on the cell surface share a distinctive type of mitochondrial DNA. This is evident from restriction analyses of mitochondrial DNAs from 25 strains of mice whose antigenic state is known. One hundred sixty-eight cleavage sites have been mapped in the mitochondrial DNA of Mta- mice. Detailed maps for the 8 other types of mitochondrial DNA detected in the survey have also been prepared. The Mta- mice are estimated to differ from those expressing the antigen by 108 to 141 base substitutions at widely scattered points in the mitochondrial genome.     

Kaposi's sarcoma-like tumors in a human herpesvirus 8 ORF74 transgenic mouse

The product of human herpesvirus 8 (HHV-8) open reading frame 74 (ORF74) is related structurally and functionally to cellular chemokine receptors. ORF74 activates several cellular signaling pathways in the absence of added ligands, and NIH 3T3 cells expressing ORF74 are tumorigenic in nude mice. We have generated a line of transgenic (Tg) mice with ORF74 driven by the simian virus 40 early promoter. A minority (approximately 30%) of the Tg mice, including the founder, developed tumors resembling Kaposi's sarcoma (KS) lesions, which occurred most typically on the tail or legs. The tumors were highly vascularized, had a spindle cell component, expressed VEGF-C mRNA, and contained a majority of CD31(+) cells. CD31 and VEGF-C are typically expressed in KS. Tumors generally (but not always) occurred at single sites and most were relatively indolent, although several mice developed large visceral tumors. ORF74 was expressed in a minority of cells in the Tg tumors and in a few other tissues of mice with tumors; mice without tumors did not express detectable ORF74 in any tissues tested. Cell lines established from tumors expressed ORF74 in a majority of cells, expressed VEGF-C mRNA, and were tumorigenic in nude mice. The resultant tumors grew rapidly, metastasized, and continued to express ORF74. Cell lines established from these secondary tumors also expressed ORF74 and were tumorigenic. These data strongly suggest that ORF74 plays a role in the pathology of KS and confirm and extend previous findings on the tumorigenic potential of ORF74.