Expression of insulin-like growth factor (IGF)-II in human prostate, breast, bladder, and paraganglioma tumors

Insulin-like growth factors (IGFs) are potent mitogens for a variety of cancer cells in vitro. A paracrine/autocrine role of IGF-II in the growth of breast and prostate cancer cells has been suggested. Information on cell-type-specific IGF-II expression in vivo in the breast and prostate is, however, limited. Thus, cell types expressing IGF-II mRNA and protein in tumors were identified by in situ hybridization and immunohistochemistry. Of 36 prostate, 17 breast, and 10 bladder cancers, and 9 paraganglioma tissues examined, IGF-II was expressed in more than 50% of prostate, breast, and bladder tumors, and in 100% of paraganglioma tumors. Expression levels of IGF-II were highest in the paraganglioma and bladder followed by prostate and breast tumors. In all the tumors expressing IGF-II, both mRNA and protein were localized to malignant cells, expression in the stroma being minimal. Since previous studies had indicated that an incompletely processed form of 15-kDa IGF-II exhibited higher mitogenic potency than the completely processed 7.5-kDa IGF-II form, the quantity and size of IGF-II proteins expressed in these tumors were analyzed by Western immunoblotting. Greater expression of 15-kDa IGF-II relative to the 7.5-kDa IGF-II form was clearly demonstrated in all six prostate cancers and in half of the two breast and four bladder cancers examined. The results are consistent with the hypothesis that the 15-kDa form of IGF-II expressed in cancerous cells contributes to autocrine cancer cell growth in vivo.

Uptake of 99mTc(5+)-complexes in ischemic myocardial slices and their dissociable ability

AIM

To find how some technetium-complexes to deliver the active species, TcO4(3-), to the target tissue from a dissociable polynuclear Tc5+ species in preserved states in vivo.

METHODS

Effect of dissociation ability of the polynuclear Tc5+ complexes on their accumulation in ischemic myocardium was tested. Ability of dissociation as having an appropriate conformation to become biologically functional after entering the blood circulation was tested using a simple dilution method by thin layer chromatography (TLC) analysis. Various degree of ischemic myocardium slices of rat were incubated with 1/100 diluted 99mTc(5+)-succimer, 99mTc(5+)-GH and 99mTc(5+)-PPi.

RESULTS

The TLC patterns of 99mTc(5+)-GH and 99mTc(5+)-PPi showed the presence of a fast increasing of free Tc-species as dilution degree increased. The relative radioactivity of peak of free pertechnetate (Rf = 0.85-1.0) with 1:500 dilution was: 99mTc(5+)-succimer 0%, 99mTc(5+)-GH 28.1% +/- 1.3%, and 99mTc(5+)-PPi 46.0% +/- 2.9% respectively. The uptake of the myocardium after ischemia for 3 h was 99mTc(5+)-succimer 420% +/- 110% dose/g tissue, 99mTc(5+)-GH 710% +/- 180% dose/g tissue, and 99mTc(5+)-PPi 1295% +/- 390% dose/g tissue respectively.

CONCLUSION

The dissociation and myocardial uptake showed: 99mTc(5+)-succimer < 99mTc(5+)-GH < 99mTc(5+)-PPi, the uptake by the ischemic myocardium is positively correlated to their dissociation.

PU.1 is essential for p47(phox) promoter activity in myeloid cells

Expression of the phagocyte cytosolic protein p47(phox), a component of NADPH oxidase, is restricted mainly to myeloid cells. To study the cis-elements and trans-acting factors responsible for its gene expression, we have cloned and characterized the p47(phox) promoter. A predominant transcriptional start site was identified 21 nucleotides upstream of the translation initiation codon. To identify the gene promoter sequences, transient transfections of HL-60 human myeloid cells were performed with a series of 5'-deletion p47(phox)-luciferase reporter constructs that extended as far upstream as -3050 bp relative to the transcriptional start site. The -224 and -86 constructs had the strongest p47(phox) promoter activity, whereas the -46 construct showed a major reduction in activity and the -36 construct a complete loss of activity. DNase I footprint analysis identified a protected region from -37 to -53. This region containing a consensus PU.1 site bound specifically both PU.1 present in nuclear extracts from myeloid cells and PU.1 synthesized in vitro. Mutations of this site eliminated PU.1 binding and abolished the ability of the p47(phox) promoter to direct expression of the reporter gene. The p47(phox) promoter was active in all myeloid cell lines tested (HL-60, THP-1, U937, PLB-985), but not in non-myeloid cells (HeLa, HEK293). Finally, PU.1 trans-activated the p47(phox)-luciferase constructs in HeLa cells. We conclude that, similar to certain other myeloid-specific genes, p47(phox) promoter activity in myeloid cells requires PU.1.

Microwave heating in the management of postmastectomy upper limb lymphedema

The results of treating chronic lymphedema using microwave heating are described in 45 patients with postmastectomy lymphedema of the upper extremity. Forty-five patients showed a significant (p < 0.01) reduction in the amount of peripheral edema after two courses of treatment. The incidence and severity of secondary acute inflammation (erysipelas) were also sharply reduced (p < 0.01). The elasticity of the soft tissue was restored.

c-fos mRNA and FOS protein expression is induced by Ca2+ influx in GH3B6 pituitary cells

The expression of the immediate early gene c-fos was studied at the mRNA and the protein level in cells of the pituitary tumour cell line GH3B6. The induction of c-fos mRNA as detected by Northern blot analysis was stimulated by TRH and by depolarization with KCl, both leading to a rise in cytosolic free [Ca2+] ([Ca2+]i), and also by epidermal growth factor (EGF). To assess the role of the changes in [Ca2+]i in the induction of c-fos, Ca2+ was chelated in the extracellular medium with EGTA to prohibit Ca2+ influx during stimulation, or intracellular Ca2+ stores were emptied by prolonged exposure to EGTA, a treatment which abolished all [Ca2+]i changes. In the latter case, the effect of TRH on c-fos mRNA expression was almost completely abolished, whereas EGF still caused substantial c-fos induction. Full induction of c-fos mRNA by TRH required a prolonged phase of stimulated Ca2+ influx. c-fos mRNA induction by TRH and KCl was markedly inhibited by two blockers of Ca2+/calmodulin-dependent protein kinase (CaM kinase), KN-62 and calmidazolium. In contrast, KCl induction of c-fos and the effects of KN-62 on TRH induction of c-fos were not observed in a closely related pituitary line GH4C1 in which TRH exerts its effects on immediate early genes predominantly via the protein kinase C pathway. In GH3B6 cells stimulated with TRH or KCl, enhanced FOS protein levels were detected by immunofluorescence and localized in the nucleus with confocal microscopy. Analysis by immunoblotting showed that TRH induced two protein species with apparent molecular masses of 52 and 57 kDa. In GH3B6 cells stimulated with KCl or TRH, the 52 kDa species was mainly found whereas, in the GH4C1 cells, TRH predominantly stimulated the 57 kDa species. These data show that distinct signalling pathways (CaM kinase and protein kinase C) involve Ca2+ influx to induce the transcription of the early gene c-fos, and that the resulting FOS protein species may depend on the pathways involved.

Long-term protection against SIV-induced disease in macaques vaccinated with a live attenuated HIV-2 vaccine

The aim of this study was to test the ability of a live attenuated human immunodeficiency virus type 2 (HIV-2) vaccine to protect cynomolgus monkeys against superinfection with a pathogenic simian immunodeficiency virus (SIVsm). This report is an update on our previously reported observation period of nine months. The new data here show that three of four monkeys vaccinated with live HIV-2 were protected against immunosuppression and SIV-induced disease during more than five years of follow-up. The quality of the immunity was permissive for infection, but monkeys that survived showed restricted viral replication in peripheral blood and lymph nodes. This study shows that it is possible to induce protection against a pathogenic heterologous primate lentivirus and to prevent disease in vaccinated monkeys even if infection is not prevented. These findings provide evidence that protection against AIDS can be achieved by immunization.

Thymic immunopathology and progression of SIVsm infection in cynomolgus monkeys

Thymuses from 22 cynomolgus monkeys infected with simian immunodeficiency virus (SIVsm) developed characteristic cortical and medullary changes including formation of B-cell follicles (8/21) and accumulation of virus immune complexes. Advanced thymic histopathology was correlated with more pronounced immunodeficiency. SIVsm provirus was detected by polymerase chain reaction (PCR) in most (16/18) thymuses and spliced viral env mRNA in 3 (3/7) thymuses with advanced histopathologic changes indicative of thymic SIVsm replication. By combined in situ hybridization (ISH) and immunohistochemistry, viral RNA was localized mainly to the follicular dendritic network, macrophages, multinucleated giant cells, and lymphocytes of the medullary regions. Latent infection by an Epstein-Barr-related herpesvirus (HVMF1) was also found by PCR and by ISH in medullary regions of three (3 of 8) thymuses with B-cell follicles, suggestive of an inductive role for B-cell proliferation in these thymuses. In a control group of HIV-2-infected nonimmunosuppressed monkeys, no comparable thymic changes were observed. Our results indicate that SIV, and probably by analogy HIV, can have direct and diverse pathogenic effects on the thymus that are important in the development of simian (human) AIDS.

Exposure of human proximal tubule cells to cytotoxic levels of CdCl2 induces the additional expression of metallothionein 1A mRNA

Humans, in contrast to animals, have a complex expression of metallothionein (MT) genes which involves many MT isoforms encoded by a family of genes containing an upper limit of 12 possible functional genes. It is unknown if these human isoforms of MT have distinct functions or if they simply represent a non-essential duplication of gene function. In the present study, MT protein and mRNA for the MT-2A, MT-1A, B, E, F, and G genes was determined for 3 isolates of human proximal tubule (HPT) cells having distinct sensitivities to cadmium. For all 3 HPT isolates, the expression of MT protein and mRNA for the MT-2A, MT-1E, MT-1F and MT-1G isoforms was similar among the isolates and demonstrated no correlation to lethality. However, each isoform mRNA was expressed at different levels when compared to one another. In contrast, the expression of MT-1A mRNA differed in expression and correlated with the differing lethalities displayed by each isolate. The finding of different profiles of mRNA expression provides evidence that the MT isoforms may have unique functions and that mRNA for the MT-1A gene could be a potential marker for heavy metal exposure and/or toxicity.

Effects of glutamate dehydrogenase, choline oxidase, and glucose-6-phosphatase on 67Ga accumulation in lysosome

AIM

To clarify the effects of the activities of hepatic enzymes in liver, hepatoma, and malignant tumor on 67Ga accumulation in lysosome.

METHODS

67Ga-citrate solution was prepared from carrier-free 67Ga-citrate solution 0.08 mol.L-1 and sodium citrate solution 0.08 mol.L-1, and was injected iv 0.4 ml to the rats. Subcellular fractions of the liver were measured for radioactivity of 67Ga by a well-type scintillation counter (Aloka JDC-701). Glutamate dehydrogenase, choline oxidase, and G-6-P activities were calculated as described by Shimizu H, Ikuta S, and Baginski E, respectivily.

RESULTS

67Ga radioactivity in normal liver lysosome (55%) was significantly higher than those in hepatoma AH 109A (32%) and Yoshida sarcoma (18%). Glutamate dehydrogenase activities were 1830 +/- s 320 U.L-1 in normal liver while 23 +/- s 6 U.L-1 in hepatoma AH 109A, and 7 +/- s 2 U.L-1 in Yoshida sarcoma. Choline oxidase activities were 46 +/- s 10 U.L-1 for normal, 25.0 +/- s 0.4 U.L-1 for hepatoma AH 109A, and 2.0 +/- s 0.4 U.L-1 for Yoshida sarcoma. G-6-P activities were 2550 +/- s 180 U.L-1 in normal, 84 +/- s 14 U.L-1 in hepatoma AH 109A, and 78 +/- s 13 U.L-1 in Yoshida sarcoma.

CONCLUSION

Lysosome of normal rat liver in which hepatic enzymes work actively played a major role in the tissue concentration of 67Ga, but the role diminishes with the neoplastic transformation into hepatoma. The lysosome of Yoshida sarcoma does not play any role in 67Ga accumulation because it does not possess any features of liver.

Induction of c-fos in pituitary cells by thyrotrophin-releasing hormone and phorbol 12-myristate 13-acetate depends upon Ca2+ influx

The role of cytosolic free Ca2+ ([Ca2+]i) in the induction of the immediate early gene c-fos by TRH or by phorbol 12-myristate 13-acetate (PMA) was studied in the clonal pituitary cell line GH4C1. It was found that c-fos mRNA levels were rapidly and transiently increased by TRH at physiological concentrations (1-100 nM). The effect of TRH was dependent on a rise in [Ca2+]i, and TRH stimulation of Ca2+ influx was essential for c-fos induction. Cell depolarization with K+, which produces a [Ca2+]i rise by soliciting Ca2+ influx via voltage-gated Ca2+ channels, was insufficient to induce c-fos. Blockade or downregulation of protein kinase C (PKC) strongly attenuated TRH stimulation of c-fos expression. Direct stimulation of PKC by PMA raised c-fos mRNA levels, but only under conditions permitting Ca2+ influx. We conclude that TRH induces c-fos mRNA by a mechanism dependent on PKC activation and on Ca2+ influx. The essential role of Ca2+ influx for PMA stimulation of c-fos mRNA suggests a novel pathway linking PKC stimulation to early gene expression.

DNA of lymphoma-associated herpesvirus (HVMF1) in SIV-infected monkeys (Macaca fascicularis) shows homologies to EBNA-1, -2 and -5 genes

We have characterized a new Epstein-Barr-virus(EBV)-like herpesvirus associated with lymphomas of SIV-infected cynomolgus (Macaca fascicularis) monkeys and propose that this virus is designated herpesvirus macaca fascicularis I (HVMFI). Genomic regions in HVMF1 of potential significance for tumor pathogenesis were analyzed by Southern blotting, PCR and sequencing, and compared with human EBV DNA. Virus from 7 SIV-associated lymphomas and one lymphoma-derived cell line were shown to share homology with the EBNA1- and EBNA2-coding regions of EBV, while some homology to EBV-LMP1 was detectable only at low-stringency hybridization. Homologous regions to the long internal repeat (IR1; BamHI W), the EBER1 and 2 and the latent origin of DNA replication (oriP) could also be demonstrated in HVMF1. These coding regions, except IR1, showed restriction-enzyme maps different from those of EBV. Sequencing of the EBNA5 homologous region of HVMF1 DNA, corresponding to exons W1 and W2, showed 65% homology to the EBV exons W1 and W2, and 80% to the whole region including the intron. Since EBNA5 has been reported to bind tumor-suppressor proteins p53 and Rb in vitro, the HVMF1 homology could be important for the lymphomagenic capacity of this monkey herpesvirus.

[Acute allograft glomerulopathy and its etiology]

Acute allograft glomerulopathy (AAG) is a distinctive glomerular lesion of renal allografts. Its clinical signs and symptoms, pathology and etiology were studied. The frequency of AAG was 57.6% in renal transplant recipients. The clinical signs and symptoms included urinary protein, cast, WBC and RBC, etc. The pathologic features were diffuse endothelial hypertrophy and necrosis accompanied by accumulation of periodic acid-schiff (PAS) positive material and mononuclear cells that resulted in obliteration of glomerular capillaries, basilar membrane proliferation and immune complexes deposition. To elucidate the pathogenesis of AAG, we diagnosed HCMV infection of renal transplantation recipients by using polymerase chain reaction (PCR) and ELISA. Circulating T cell subsets were detected with APAAP method. OR of AAG occurrence in HCMV infection group was 32.4 times as high as in non-HCMV infection one (P < 0.01). OR of AAG occurrence in CD4/CD8 < 1.5 group was 12 times as high as in CD4/CD8 > 1.5 one (P < 0.01); so AAG was strongly associated with HCMV infection and T cell subsets changes (decreased or inverted CD4/CD8 ratio) induced by HCMV.

Binding kinetics of the long-acting gonadotropin-releasing hormone (GnRH) antagonist antide to rat pituitary GnRH receptors

The GnRH antagonist Antide has been shown to produce prolonged inhibition of gonadotropin secretion in ovariectomized monkeys and other animal models. The reasons for such a long duration of action have not yet been clarified. To understand the mode of action of this new antagonist, we have performed association and dissociation binding kinetics using either crude rat pituitary homogenates as source of GnRH receptors or dispersed pituitary cells in culture. The binding characteristics of the radioiodinated Antide analog 125I-labeled[D-Tyr0] Antide to GnRH receptors in rat pituitary homogenates were comparable to those of the first generation GnRH antagonist 125I-labeled [Ac(3)Pro1,pFD-Phe2,D-Trp3,6]GnRH or the GnRH agonist 125I-labeled [D-Trp6,(N-Et)Pro9,Des,Gly10]GnRH, with an affinity constant (Ka) in the 10(10) M-1 range. The maximum binding capacity was consistently higher with the antagonist tracers than with the [125I]GnRH agonist. Both antagonists dissociated at a slower rate at 4 C (approximately 4 times) than the [125I]GnRH agonist. Incubation at 23 C of 125I-labeled [D-Tyr0] Antide previously bound at 4 C resulted in complete dissociation within 8 h after the addition of an excess amount of any of the GnRH analogs; in addition, simple dilution of the incubation medium produced spontaneous dissociation at this temperature. Using rat pituitary cells, Antide was found to inhibit the LH response to native GnRH (10(-8) M) in a dose-related manner. To test whether the binding of Antide is normally reversible at 37 C, Antide (10(-7) M) was added to the culture medium 3 days after cell plating, and the initial preincubation was resumed for 24 h. Cells were then washed twice, and dissociation was allowed to take place. Bound Antide was shown to dissociate rapidly at 37 C, as cells previously treated with Antide produced a full LH response within 24 h if challenged with native GnRH. In conclusion, the binding kinetics of 125I-labeled [D-Tyr0]Antide to GnRH receptors, which should reflect those of Antide, did not present abnormal features. Although this antagonist, similar to other GnRH antagonists, dissociated from pituitary receptors at a slower rate than GnRH analogs, rapid and spontaneous dissociation was achieved at 23 C with simple dilution, and dissociation of unmodified Antide occurred at 37 C. Taken together, our results support the concept that the long duration of action of Antide is not due to any toxic effect of Antide at the receptor site and could derive only marginally from the slow dissociation rate of this antagonist.

Effects of Panax notoginseng saponins on myocardial adenosinetriphosphatase

Effects of total Panax notoginseng saponins (PNS) and Panax notoginseng saponin monomers Rb1 and Rg1 (Rb1, Rg1) on total ATPase and Na(+)-K(+)-exchanging ATPase of guinea pig heart were studied. It was found that PNS inhibited the total myocardial ATPase, but had no significant effect on the myocardial Na(+)-K(+)-exchanging ATPase. The total ATPase was inhibited by Rg1, and more clearly by Rb1. The automaticity and contractility of isolated guinea pig atria were inhibited by Rb1. Rg1 decreased the spontaneous frequency of isolated guinea pig right atrium, but not markedly the contractility of the left atrium. These results demonstrate that Rb1 is the main ingredient in PNS.

[Analysis of patients of psoriasis coexisting with chylothorax]

Six patients diagnosed as Psoriasis with complication of chylothorax (3 of chylothorax, 3 of both chylothorax and chyloperitoneum, age from 21 to 50, male 4, female 2) were reported. All patients have a history of taking a chinese medicine named "complex Wulong powder" for treating psoriasis. All patients have not the history of trauma, operation, and the history of living in epidemic focus of filariasis. Their X-ray exam and CT exam of chest did not show lung lesion but pleural effusion. Chylothorax coexisting with psoriasis was not found in literature. This result suggests that using complex WuLong powder might be the cause of chylothorax. The mechanism was unknown.

The purified COOH-terminal domain of the insulin receptor carries activity to stimulate protein kinase activity or autophosphorylation of the beta subunit domain of insulin receptor

Our previous study using a deletion mutant indicated that the COOH-terminal (CT) domain of the insulin receptor plays important roles in both catalytic efficiency and stability of the receptor kinase (Yan et al., J. Biol. Chem., 268 [1993] 22444). In this study, we purified the CT domain of 98 amino acids from bacterial cells over-expressing the CT domain and examined its effect on insulin and IGF-I receptor protein kinases. The purified CT domain stimulated the kinase activities of purified insulin receptor-transmembrane/cytoplasmic domain (IRTMTPK) and its CT domain-deletion mutant (IRTMTPK delta CT), 3.3-fold and 2.3-fold, respectively, while it was less effective in stimulating the kinase activity of purified IGF-I receptor transmembrane/cytoplasmic domain (IGFIRTMTPK) (1.4-fold). When the effect of the CT domain on autophosphorylation was examined, a marked increase in autophosphorylation was observed only with IRTMTPK delta CT. These results suggest that the CT domain specifically interacts with the insulin receptor cytoplasmic domain, thereby activating the kinase or autophosphorylation activity.

Induction of metallothionein mRNA and protein following exposure of cultured human proximal tubule cells to cadmium

Humans have a complex expression of metallothionein (MT) genes which involves many MT isoforms encoded by a family of genes containing an upper limit of 12 possible functional genes, in contrast to most animals which have one or two functional MT genes. In the present study, human proximal tubule (HPT) cells were exposed to cadmium (Cd) to determine if these cultures might serve as a model system to study MT gene expression in the renal proximal tubule. Three independent isolates of HPT cells were shown to repeatably induce MT protein when exposed continually to a non-toxic dose of 1 microgram/ml of Cd administered as CdCl2. Accumulation of MT protein was noted within 3 h and persisted over the 16-day time course. The expression of mRNA for the MT-IIA, MT-IA, B, E, F and G genes was also assessed through 16 days of exposure to 1 microgram/ml of Cd versus control media. Of these, the mRNA for the MT-IIA, MT-IE, MT-IF and MT-IG genes were detected in the cells exposed to 1 microgram/ml of Cd. Overall, the results were supportive that the HPT cells can provide a valuable model system to study the regulation of MT gene expression as it applies to the human renal proximal tubule.

The role of COOH-terminal and acidic domains in the activity and stability of human insulin receptor protein tyrosine kinase studied by purified deletion mutants of the beta subunit domain

We have previously expressed the human insulin receptor beta subunit domain containing transmembrane and cytoplasmic domains (IRTMTPK) in insect cells, and showed that the purified IRTMTPK was highly active (Li, S. L., Yan, P.-F., Pax, I. B., and Fujita-Yamaguchi, Y. (1992) Biochemistry 31, 12455-12462). To investigate the role of COOH-terminal and acidic domains of the insulin receptor kinase, we have expressed deletion mutants IRTMTPK delta CT (delta 76 amino acids) and IRTMTPK delta Acid (delta 19 amino acids). Both enzymes were purified by a one-step method using the same immunoaffinity column as used for IRTMTPK. While Km and Vmax for prephosphorylated IRTMTPK and delta Acid mutant enzyme determined using poly(Glu, Tyr)(4:1) were similar, catalytic efficiency of the delta CT mutant enzyme was significantly lower than those of IRTMTPK and delta Acid mutant enzyme as judged by Km and Vmax. Experiments for thermostability and susceptibility to proteases revealed that Tm of delta CT mutant enzyme was 3.5 degrees C lower than that of IRTMTPK enzyme (= 33.3 degrees C) and that delta CT mutant enzyme was digested by either trypsin or Lys-C into a 28,000 core domain much faster than IRTMTPK. Activation of delta CT mutant enzyme by polylysine was less significant than that of IRTMTPK and delta Acid mutant enzyme, approximately 4-versus approximately 17-fold. These studies suggested that the COOH-terminal domain plays important roles in both catalytic efficiency and stability of the insulin receptor kinase, and that the acidic domain by itself is not responsible for kinase activation by polylysine.

Expression of Epstein-Barr-virus-related nuclear antigens and B-cell markers in lymphomas of SIV-immunosuppressed monkeys

Simian-immunodeficiency-virus(SIV)-infected cynomolgus monkeys develop B-cell lymphomas in approximately one third of the cases. We have now studied the expression of cynomolgus-Epstein-Barr-virus(cyno-EBV) nuclear antigens in 13 cyno-EBV-carrying SIVsm-associated monkey lymphomas and established cell lines from 3 of these tumors. Immunoblots of cell lysates were probed with polyspecific and monospecific reagents directed against human EB-virus EBNAI-6, and against the membrane protein LMPI. An EBNA2-cross-reacting protein was demonstrated in 8 lymphoma tissues (8/13) and in the 3 cell lines derived from the tumors. All tumors expressed a polypeptide with 50 to 55 kDa molecular weight, which cross-reacted with some antibodies to EBNAI. Absorption experiments with normal monkey tissue showed that this polypeptide was specific for the cyno-EBV-carrying lymphoma cells. Equivalents of EBNA3-6 and LMPI could not be detected. Immunophenotypical characterization showed that the monkey lymphomas were similar to human HIV-associated B-cell lymphomas. Malignant B-cell lymphomas in experimentally SIVsm-infected cynomolgus monkeys can be a model for EBV-associated lymphomagenesis in immunodeficiency states.

Two new monoclonal antibodies against the alpha subunit of the human insulin-like growth factor-I receptor

Recently, we have reported three monoclonal antibodies (mAbs) against purified human placental insulin-like growth factor (IGF)-I receptors. These antibodies, in contrast to the well-studied mAb alpha IR-3, stimulate binding of IGF-I and IGF-II to the receptor and DNA synthesis as well [Xiong, et al., Proc. Natl. Acad. Sci. U.S.A. 1992(89), 5356]. Here we describe two additional mAbs, 1H7 and 2C8, against the IGF-I receptor that have characteristics different from either alpha IR-3 or our previously reported mAbs. Both 1H7 and 2C8 bind to the alpha subunit of the IGF-I receptor as determined by immunoblotting. MAb 1H7 inhibited the binding of IGF-I and IGF-II to the IGF-I receptor while 2C8 had no effect on the binding of either ligand to the receptor. When their effects on DNA synthesis were examined using NIH 3T3 cells expressing human IGF-I receptors, 1H7 inhibited basal and IGF-I- or IGF-II-stimulated DNA synthesis whereas 2C8 stimulated basal DNA synthesis but provided no synergism in the presence of IGF-I or IGF-II.

State of p53, Rb and DCC tumor suppressor genes in human oral cancer cell lines

The tumor suppressor genes p53, Rb, and DCC were studied in five human oral cancer cell lines (FaDu, SCC-4, HEp-2, 1483, and OEC-M1) and in primary normal human oral keratinocytes (NHOK). All tested cancer lines had similar amount of p53 messages to normal cells, but the cancer lines FaDu and SCC-4 contained significantly higher p53 protein levels than did the normal counterpart. Sequencing p53 cDNA for these cancer cells showed point mutations: In the FaDu cell line, a mutation of CGG to CTG occurred at codon 248; and in the SCC-4 cell line, a mutation of CCC to TCC occurred at codon 151. The HEp-2 and 1483 cancer lines translated very low levels of p53 protein compared to the normal counterpart. Sequencing of p53 cDNA for HEp-2 and 1483 lines showed no mutations. Southern and Northern analyses revealed that these cell lines harbored HPV-18 DNA and expressed the viral E6/E7 protein. The OEC-M1 line showed different restriction fragment length polymorphism for the p53 gene compared with other cells, and did not express p53. All oral cancer cell lines except the OEC-M1 cells expressed both phosphorylated and hypophosphorylated Rb proteins. Further, the OEC-M1 line expressed smaller sized hypophosphorylated Rb proteins compared with normal cells. Unlike the other cancer lines, the HEp-2 and OEC-M1 lines also did not contain DCC mRNAs. These data indicate that "high risk" HPV infections and mutations of p53, Rb, and DCC genes are frequently found in oral cancer cells and may be associated with oral cancer.

Immunohistochemical distribution of leucocyte antigens in lymphoid tissues of cynomolgus monkeys (Macaca fascicularis)

Crossreactivity of antibodies to human leucocyte antigens with lymphoid tissues of cynomolgus monkeys was studied by immunohistochemistry and immunoblotting. Of a total of 54 clusters of differentiation (CD) antigens, 39 were expressed essentially with the same immunostaining patterns in the monkey as in human lymphoid tissues. By immunoblotting L26 (CD20) detected a 35 Kd molecule in the monkey lymph node. Our observations indicated that most of the CD antigens are expressed and can be studied in lymphoid tissues of cynomolgus monkeys.

[Clinical and experimental studies on membranous pulp-capping agent with Chinese medicinal herbs]

A membranous pulp-capping agent of Chinese medicinal herbs was made by ourselves prescription, and was filled in capsules for medication. Direct pulp-capping and pulpotomy were performed on 102 permanent teeth. During the observation period of more than one year, the successful rate was 82.4%. Under light microscope, the artificial exposed sites of normal sheep teeth were fully sealed after capping for 45 days. There were calcification under the exposed sites. The inner lines were preparative dentins. Experiments on dogs' teeth revealed that the pulps were normal after two month's direct pulp-capping, and the new dentins appeared. The bacteria culture test was made before and after the pulp-capping agent was used on ten deep carious teeth. It revealed that the bacteria all converted negative after medication of two weeks. Clinical and experimental studies indicated that the pulp-capping agent is valuable in clinical treatment.

Insulin-induced circular membrane ruffling on rat 1 cells expressing a high number of human insulin receptors: circular ruffles caused by rapid actin reorganization exhibit high density of insulin receptors and phosphotyrosines

The early effects of insulin on morphological changes were examined using Rat1 cells expressing approximately one million human insulin receptors (Rat1HIR cells). Insulin transiently induced circular membrane ruffling on Rat1HIR cells. The circular ruffles were detected by phase microscopy as well as by fluorescence microscopy when actin was stained with rhodamine-conjugated phalloidin. The circular ruffles were also visualized by fluorescence microscopy when stained with either anti-insulin receptor monoclonal antibody, alpha IR-1, or anti-phosphotyrosine antibody, followed by fluorescein isothiocyanate-labeled second antibodies. Control Rat1 cells or Rat1HIR A/K1018 cells expressing kinase-defective insulin receptors did not show any circular ruffles when treated with insulin. These results suggest that the circular ruffles are formed by actin reorganization induced by insulin and that this process requires the protein-tyrosine kinase activity of the receptor. Detection of insulin receptors and phosphotyrosines in the circular ruffles suggests the possibility that the insulin receptors in the ruffles may be highly active and phosphorylating either the receptors themselves or proteins associated with the ruffles. These results are consistent with our previous in vitro observations that a large aggregate form of the purified insulin receptor is a highly active protein-tyrosine kinase.

Changes of T cell subsets in peripheral blood of patients with Schistosomiasis japonica and their relation to interleukin-1

T cell subsets in peripheral blood were phenotyped in 56 patients with different stages of Schistosomiasis japonica, including 17 with acute, 14 with chronic and 25 with advanced infection. The activity of interleukin-1 (IL-1) produced by peripheral blood mononuclear cells (PBMC) induced by lipopolysaccharide (LPS) in vitro was simultaneously detected in these three groups of patients. It was found that the percentages of CD3+ (total T cell), CD4+ (helper/inducer T cell) and CD8+ (suppressor/cytotoxic T cell) T cell and the level of IL-1 were significantly increased in the group of acute Schistosomiasis japonica. In the groups of chronic and advanced Schistosomiasis japonica, the proportion of CD3+ T cell, the ratio of CD3+/CD4+ and the level of IL-1 were remarkably reduced, and the percentage of CD8+ T cell was increased. The rate of CD4+ T cell was obviously decreased in cases patients with advanced Schistosomiasis japonica. The percentage of CD4+ T cell was positively correlated to the level of IL-1 in the three groups of patients. These results indicate that T cell subsets and IL-1 may play an important role in the immunoregulation of Schistosomiasis japonica.

Accessory cells and macrophages in the histopathology of SIVsm-infected cynomolgus monkeys

Thirty-three out of 39 cynomolgus monkeys (Macaca fascicularis) infected with SIVsm (strain SMM-3) developed various pathologies similar to those seen in human AIDS. Lymphadenopathy was frequently seen (72%) and was characterized by hyperplasia followed by involution of follicle/germinal centres due to follicular dendritic cell (FDC) destruction corresponding to the degree of immunodeficiency. Various organs such as the lungs, liver, central nervous system, kidneys, gastrointestinal tract, cardiovascular system and adrenals showed histopathological changes with prominent monocyte/macrophage and multinucleated giant cell formation. Eighteen (54%) monkeys presented with extranodal malignant lymphoma (ML) associated with marked CD4 decrease and destruction of follicular architecture. The high frequency of ML, giant cell disease and lymph node changes seen in the present SIV model provides an attractive system to elucidate the role of FDC and monocytes/macrophages in the pathogenesis of these conditions in common with HIV infection and human AIDS.

Human insulin receptor beta-subunit transmembrane/cytoplasmic domain expressed in a baculovirus expression system: purification, characterization, and polylysine effects on the protein tyrosine kinase activity

We have expressed, purified, and characterized the insulin receptor protein tyrosine kinase (PTK) retaining the transmembrane and downstream domains. The proteins expressed in insect cells using a baculovirus expression system were identified as membrane-bound by immunofluorescence staining and biochemical characterization. One-step purification by immunoaffinity chromatography from Triton X-100 cell extracts resulted in a approximately 360-fold increase in the specific kinase activity with a yield of approximately 50%. An appMr = approximately 60,000 protein was the major component identified by both silver staining of the purified enzyme and immunostaining of the crude extracts after separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. Using nondenaturing conditions, the molecular weight was estimated to be approximately 250,000 and approximately 500,000 by glycerol gradient centrifugation and gel permeation chromatography, respectively, suggesting that oligomers of the beta-subunit domains such as tetramers and octamers are formed. The basal PTK activity of this enzyme was much higher than those of previously reported soluble-form insulin receptor PTKs expressed in insect cells or the native receptor. Km and Vmax for two substrates, src-related peptide and poly(Glu, Tyr) (4:1), were 2.4 mM and 2.5 mumol min-1 mg-1 and 0.26 mM and 1.2 mumol min-1 mg-1, respectively. Specific activities measured under two previously reported conditions using histone H2B as a substrate were 100 or 135 nmol min-1 mg-1, in contrast to those of soluble PTKs which were reported to be 20 or 70 nmol min-1 mg-1, respectively. The purified enzyme was autophosphorylated at Tyr residues. Autophosphorylation activated the enzyme approximately 3-fold.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequential combined tumorigenic effect of HPV-16 and chemical carcinogens

We immortalized oral keratinocytes by transfection with recombinant human papillomavirus type 16 (HPV-16) DNA and established two cell lines, human oral keratinocytes-16A (HOK-16A) and -16B (HOK-16B). These cell lines were morphologically different from the normal counterpart, contained HPV-16 DNA as integrated form and expressed numerous viral genes. However, these cells proliferated only in culture medium containing low calcium (0.15 mM) and are not tumorigenic in nude mice. To test the hypothesis that tumors can be developed by sequential combined effect of human papillomavirus and chemical carcinogens in the oral cavity, these immortalized cell lines were chemically transformed by exposure to either benzo[a]pyrene or methanesulfonic acid ethyl ester. Such transformants proliferated in medium containing physiological calcium levels (1.5 mM) and demonstrated enhanced growth potential in nude mice, whereas primary human oral keratinocytes treated with these chemical carcinogens failed to show any evidence of transformation. Chemically transformed cells contained integrated, intact HPV-16 sequences and transcribed significantly higher amount of HPV-16 E6/E7 messages and transforming growth factor-alpha (TGF-alpha) compared with the immortalized oral keratinocytes. Like the HPV-immortalized cell lines, the chemically transformed oral keratinocytes contained lower levels of newly synthesized, wild-type p53 proteins compared to normal cells, and expressed wild-type c-Ha-ras. These results indicate that this in vitro system is useful for investigating the mechanisms of multistep oral carcinogenesis.

In vitro and animal studies of the role of viruses in oral carcinogenesis

The linkage of herpes simplex virus (HSV) and human papillomavirus (HPV) to the development of oral cancer has been studied. In spite of the presence of viral nucleic acids in some human oral cancer specimens, HSV alone is not carcinogenic in animals: repeated viral inoculation to mouse or hamster oral mucosa fails to produce tumours or histopathological evidence of malignancy. However, HSV demonstrates co-carcinogenicity in vivo: viral inoculation significantly enhances the oncogenic capacity of chemical carcinogens in the oral cavity of mice and hamsters. Though the detailed mechanisms of HSV cocarcinogenicity are unknown, HSV promotes the chemical carcinogen-induced activation of certain cellular proto-oncogenes and inactivation of p53 tumour suppressor gene. Human papillomaviruses type 16 (HPV-16) and 18 (HPV-18) demonstrate oncogenicity by transforming normal human oral keratinocytes in vitro. While normal cells exhibit a limited life-span, cells transformed by these viruses show immortality and altered morphology in comparison with their normal counterparts. The HPV-immortalised cells contain multiple copies of intact viral genome integrated into cellular chromosomes. These cells also express several viral-specific mRNAs including viral E6/E7 mRNAs. Notably, these cells contain low levels of p53 protein and overexpressed cellular myc proto-oncogene compared to their normal counterpart; however, the immortilised cell lines are non-tumorigenic in nude mice.

Low p53 level in immortal, non-tumorigenic oral keratinocytes harboring HPV-16 DNA

The p53 protein level was determined in normal oral keratinocytes and two non-tumorigenic, immortal oral keratinocyte lines harboring human papillomavirus-16 (HPV-16)DNA. The p53 mRNA level in the immortal cells was higher than the normal counterpart, but the p53 protein level was notably lower in the immortalised cells. The half-life of p53 protein in the normal and immortal cells was < 1 h, and the p53 cDNA sequence of these cells showed no mutation. The immortal cells transcribed a high amount of E6/E7 mRNA encoded by HPV-16, but normal cells did not. These observations suggest that the immortal keratinocytes may translate normal level of wild-type p53 protein, and the low p53 level in these cells may be due to the enhanced degradation of the protein by HPV-16 E6 protein.

Long-term tolerance and efficacy of 3'-azidothymidine and 3'-fluorothymidine treatment of asymptomatic monkeys infected with simian immunodeficiency virus

Macaques chronically infected with simian immunodeficiency virus were treated with zidovudine (20 mg/kg of body weight per day for 9 weeks) or 3'-fluorothymidine (5 mg/kg of body weight per day for 9 weeks or three doses of 2 mg/kg per day for 24 days). Hematological changes in the treated animals included macrocytic anemia and leukopenia. Determination of antiviral effects in this model requires improved assay methods.

A monkey model for Epstein Barr virus-associated lymphomagenesis in human acquired immunodeficiency syndrome

High-grade malignant nonHodgkin's lymphomas--five lymphoblastic, three pleomorphic, and two immunoblastic--developed in 10/25 cynomolgus monkeys (Macaca fascicularis) followed for up to 746 d after infection with simian immunodeficiency virus, strain SIVsm. These lymphomas were shown to be associated with an Epstein-Barr (EB)-like cynomolgus B-lymphotropic herpesvirus (CBLV) by electron microscopy, by Southern blot hybridization with probes against human EBV, and by the expression of antigens corresponding to EBV-associated nuclear antigens (EBNAs) involved in human B cells transformation. Southern blot demonstration of immunoglobulin gene rearrangements and homogeneous EBV episomes indicated that all the lymphomas were CBLV-associated monoclonal B cell proliferations. Our findings suggest that these tumors correspond to the EBV-associated malignant lymphomas in acquired immunodeficiency syndrome with respect to clinical, morphological, phenotypic, and genotypic characteristics. The particular susceptibility of SIVsm immunodeficient cynomolgus monkeys for CBLV-associated lymphomagenesis appears therefore a useful model for EBV-associated lymphomas in humans.

Growth-stimulatory monoclonal antibodies against human insulin-like growth factor I receptor

Monoclonal antibodies (mAbs) against purified human placental insulin-like growth factor I (IGF-I) receptors were prepared and characterized. Three IgG mAbs were specific for the human IGF-I receptor and displayed negligible crossreactivity with the human insulin receptor. They stimulated 125I-labeled IGF-I (125I-IGF-I) or 125I-IGF-II binding to purified human placental IGF-I receptors and to IGF-I receptors expressed in NIH 3T3 cells in contrast to the well-studied mAb alpha IR-3, which inhibits 125I-IGF-I or 125I-IGF-II binding to both forms of IGF-I receptors. The mAbs introduced in this study stimulated DNA synthesis in NIH 3T3 cells expressing human IGF-I receptors approximately 1.5-fold above the basal level and the IGF-I- or IGF-II-stimulated level. In contrast, alpha IR-3 inhibited both basal and IGF-I or IGF-II-stimulated DNA synthesis by approximately 30%. Inhibition of IGF-II-stimulated DNA synthesis by alpha IR-3 was as potent as its inhibition of IGF-I-stimulated DNA synthesis, although IGF-II binding to the IGF-I receptors was not inhibited by IGF-II as potently as was IGF-I. With the purified IGF-I receptors, both inhibitory and stimulatory mAbs were shown to activate autophosphorylation of the IGF-I receptor beta subunit and to induce microaggregation of the receptors. These results suggest that conformational changes resulting from receptor dimerization in the presence of either type of mAb may affect the signal-transducing function of the IGF-I receptor differently. These additional mAbs and alpha IR-3 immunoprecipitated nearly 90% of IGF-I binding activity from Triton X-100-solubilized human placental membranes, indicating that IGF-I receptor reactive with these mAbs is the major form of the IGF-I receptor in human placenta.

Preliminary human trial of inactivated golden hamster kidney cell (GHKC) vaccine against haemorrhagic fever with renal syndrome (HFRS)

An inactivated golden hamster kidney cell culture (GHKC) vaccine against haemorrhagic fever with renal syndrome (HFRS) has been developed in recent years. A monovalent GHKC vaccine (lot 88-17) was prepared with L99 strain of the rat-type hantavirus, adapted in suckling mouse brain, cultivated in GHKC, and inactivated with 0.025% formalin, and a preliminary trial of the vaccine was carried out in a small number of human volunteers with the approval of the Ministry of Public Health, PRC, in order to identify safety and antibody response of the vaccine. Three inoculations were made on days 0, 7 and 28 respectively, by the intramuscular route with 1 ml vaccine each time for every volunteer. No obvious side effect was observed in vaccinees within 3 days after each inoculation. All 12 vaccinees (10 received three inoculations, and two received two inoculations of the vaccine) showed positive seroconversion of IgG antibody (by IFAT and ELISA) and neutralizing antibody (by enzyme focus reduction neutralization test, EFRNT), and 10 of them were still seropositive 180 and 360 days after the first inoculation. These results suggest that this vaccine would be safe for human use, and could effectively induce IgG and neutralizing antibody responses.

Role of thiol-disulfide exchange in insulin binding to its receptor

The effects of reduction by DTT, oxidation by DTNB and treatment with NEM on the thiol contents and insulin binding to its receptor in mice liver membranes were studied. Reduction with DTT leads to a parallel increase in the thiol content and the specific binding of insulin to the membrane. Scatchard analysis of the results shows little change in the number of binding sites but a twofold increase of the binding constant. Washing the membrane with bound insulin by a DTT containing buffer results in a more marked increase in the release of bound insulin than washing with buffer alone, suggesting that part of the insulin is bound to its receptor by covalent disulfide linkages through a thiol-disulfide exchange reaction and reduction with DTT leads to a marked increase in this "disulfide-linked" insulin. Treatment with DTNB or NEM of the DTT-reduced membrane seems to reverse the effect of DTT reduction, although the reaction of the untreated membrane with DTNB or NEM had little or no effect on the specific binding of insulin. It is suggested that initially, part of the thiols responsible for the exchange reaction may not be available for reaction with DTNB and reduction with DTT generates further thiols leading to increased specific binding in general and increased insulin binding to the receptor through covalent disulfide linkages in particular.

Effect of ibuprofen on the in vitro and in vivo reactivation of latent HSV-1

Prostaglandins have been suggested to play an important role in the reactivation of latent herpes simplex virus. To further understand the role of prostaglandins in the reactivation process, we investigated the effects of ibuprofen, a nonsteroidal anti-inflammatory drug with prostaglandin synthesis inhibitory activity, on the in vitro and in vivo reactivation of latent type 1 herpes simplex virus in mouse ganglia and rabbits, respectively. Ibuprofen, at a concentration of 50 or 100 microM, did not alter the titer of reactivated virus from explanted ganglia with latent virus, but, at a concentration of 200 or 500 microM, it significantly reduced the reactivated viral titer from the ganglia. Ibuprofen also directly inhibited the replication of herpes simplex virus in trigeminal ganglia and Vero cell monolayers, which indicates that the drug reduced the recovery of reactivated viral titers from explanted ganglia with latent virus by acting on the replication process rather than on the reactivation mechanism in vitro. The systemic administration of ibuprofen failed to demonstrate any significant effect on the ocular shedding of virus after attempted reactivation by 6-hydroxydopamine iontophoresis in rabbits with latent herpes simplex virus infection. This failure in vivo could be due to the short half-life and low concentration of ibuprofen at the site of reactivation and replication of latent virus. Alternatively, in the clinical setting, it is conceivable that ibuprofen may not have an effect on in vivo reactivation of latent herpes.

Malignant lymphoma associated with human AIDS and with SIV-induced immunodeficiency in macaques

Malignant lymphomas associated with human (HIV) and simian (SIV) immunodeficiency virus infections are reviewed and compared. Recent observation of a high frequency of lymphomas in a series of cynomolgus macaques, highly immunodeficient after infection with SIVsm(smm3) are described. In addition to the increased frequency in human and monkey AIDS, SIV and HIV lymphomas share several important features. Clinically and by histology they present as aggressive high-grade malignant tumors with a predilection for extranodal growth in viscera, skin, central nervous system, testis, and retroorbitally. Most malignant lymphomas are of B-cell origin. AIDS lymphomas in humans are heterogeneous with regard to Epstein-Barr virus (EBV) association. Similarly, most lymphomas in monkeys experimentally infected with SIV tested to date were shown to be associated with an EBV-like simian herpes virus. These observations point to the possibility of using SIV-immunodeficient macaques for study of EBV and other oncogenic and immunosuppressive factors in AIDS-associated lymphomagenesis.

Clinical features and predictive markers of disease progression in cynomolgus monkeys experimentally infected with simian immunodeficiency virus

OBJECTIVE

To study the pathogenicity of simian immunodeficiency virus (SIVsm) in cynomolgus monkeys in order to establish an animal model for human AIDS.

METHODS

Thirty-three cynomolgus monkeys were monitored for more than 2 years following experimental infection with SIVsm.

RESULTS

All the macaques became SIV-infected, as demonstrated by virus recovery from peripheral blood lymphocytes and by the appearance of viral antibodies. SIVsm was found to be pathogenic, killing 29 out of the 33 monkeys (88%) within 26 months. Clinically, infected monkeys developed lymphadenopathy, splenomegaly, diarrhoea, weight loss, neurological symptoms and a remarkably high incidence (39%) of malignant lymphomas. All lymphomas were high-grade malignant and of B-cell origin. Disease progression was associated with low CD4+ lymphocyte count, involution of initially hyperplastic follicular B-cell areas in lymph nodes, reappearance of viral antigen in serum, loss of anti-Gag antibodies and development of systemic giant cell disease in 55% of the monkeys.

CONCLUSIONS

There are many similarities between SIVsm-induced AIDS in cynomolgus monkeys and human AIDS with regard to clinical, virological, immunological and pathological manifestations.

Aggregation of IGF-I receptors or insulin receptors and activation of their kinase activity are simultaneously caused by the presence of polycations or K-ras basic peptides

Several groups including us reported that basic proteins and polycations activate the insulin receptor tyrosine-specific protein kinase (TPK) in vitro. However, some inconsistency has become obvious in the observations. The most intriguing was the brief description by Morrison et al. [(1989) J. Biol. Chem. 264, 9994-10001] that polylysine had no effect on the IGF-I receptor TPK despite its 84% identity to the insulin receptor TPK. In the present study, we used highly purified IGF-I and insulin receptor TPKs in an effort to solve the discrepancies noted in the recent publications and to reveal the mechanism by which polycations stimulate the receptor TPKs. We report that the IGF-I receptor TPK is stimulated by polycations and basic proteins in a manner similar to their effects on the insulin receptor TPK. When effects of polylysine and polyarginine on both receptor TPKs were closely compared, subtle qualitative differences were found: Polylysine stimulated autophosphorylation and exogenous substrate phosphorylation activities of both insulin receptor TPK and IGF-I receptor TPK similarly. In contrast, another polycation, polyarginine, affected both TPKs in a manner quite different from polylysine: Polyarginine stimulated insulin receptor autophosphorylation to a greater extent than polylysine did while it had a very small effect on the IGF-I receptor autophosphorylation as well as the exogenous substrate phosphorylation activities of the two receptor TPKs. We have further extended the studies to include the domains of natural proteins which contain a polylysine-like sequence.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in the level of IL-2, T cell subsets and the function of T suppressor cells in patients with schistosomiasis japonica

The level of interleukin-2 (IL-2) produced by peripheral blood mononuclear cells in vitro, T cell subsets and the function of T suppressor cells (Ts) in patients with schistosomiasis japonica were investigated. It was found that the level of IL-2 induced by schistosomal antigens was significantly high and positively related to the percentage of CD4+ cells. In the groups of chronic and advanced schistosomiasis japonica, the level of IL-2 induced by schistosomal antigens was markedly lower than that in the group of acute schistosomiasis japonica, but significantly higher than that in the group of normal controls. The IL-2 level was negatively related to the percentage of CD8+ T cells and the ratio of CD4+/CD8+. The level of IL-2 induced by PHA was greatly reduced in the group of advanced schistosomiasis japonica. The changes in the level of IL-2 and its relationship with T cell subsets and the function of Ts are also discussed.

Immortalization of normal human oral keratinocytes with type 16 human papillomavirus

Primary human oral keratinocytes were transformed by transfection with recombinant human papillomavirus type 16 (HPV-16) DNA, and two transformed cell lines named human oral keratinocytes-16A and -16B (HOK-16A and HOK-16B) were established. While normal cells and cells transfected with vector only exhibited a limited lifespan, the HOK-16A and HOK-16B lines demonstrated immortality and altered morphology from their normal counterpart. The HOK-16A and HOK-16B lines contained approximately 40 and approximately 25 copies of intact HPV-16 DNA as integrated form per cell respectively, and both cell lines expressed several viral specific poly(A+) RNAs. Notably these cell lines also overexpressed cellular myc proto-oncogene in comparison with the normal counterpart. However, the immortalized cell lines were not able to produce tumors in nude mice, indicating that the cells are partially transformed. The HOK-16A and HOK-16B lines are, therefore, useful for investigating the multistep molecular events of oral carcinogenesis.

Patients treated with a monoclonal antibody (ab1) to the colorectal carcinoma antigen 17-1A develop a cellular response (DTH) to the "internal image of the antigen" (ab2)

The anti-tumor effector functions of unconjugated MAb in cancer therapy are not fully understood. Direct cytotoxic mechanisms have been demonstrated as well as induction of anti-idiotypic (ab2) and anti-anti-idiotypic (ab3) antibodies. If such a humoral response is induced, then an idiotypic cellular response would also be anticipated. Human monoclonal ab2s which mimic a tumor-associated antigen (TAA) (CO17-1A) of colorectal carcinoma (CRC) cells ("the internal image of the antigen") were produced. These ab2s were injected intradermally to patients with metastatic CRC who had been treated with the anti-colon carcinoma MAb 17-1A (ab1). Five out of 12 patients had a specific DTH (delayed-type hypersensitivity) reaction of the tuberculin type, which was proven by immunohistochemical analysis of skin biopsies. Serum ab3 was demonstrated in 4/4 tested DTH+ patients and also in 4 DTH patients. Control patients did not show any skin reactivity. Generation of an idiotypic response induced by the infused antibody (ab1) might be regarded as an active anti-tumor "vaccination". Induction of an idiotypic cellular and humoral cascade might be an important anti-tumor effector function of MAb and should be considered in future strategies for such therapy in cancer patients.

Monocyte/macrophage giant cell disease in SIV-infected cynomolgus monkeys

A non-opportunistic, generalized giant cell disease (GCD) was found in 12 out of 25 (48%) cynomologus monkeys infected with SIVsm. Most organs were affected notably the lymph nodes (LN), spleen, gut, liver, lungs and CNS. The multinucleated GC varied considerably in cell size and in the number and cytoplasmic distribution of the nuclei. Immunohistochemically most GC expressed SIV antigens and markers of mononuclear phagocytes (CD68), CD4 and also occasionally the T-cell markers CD45RO, CD43 and CD2. Monkeys with GCD had more pronounced immunosuppression with lower CD4-cell counts, more often demonstrable SIV antigen in the blood and LN and had been infected for a longer time period, as compared to monkeys without GCD. These findings show that SIV infection in cynomolgus monkeys is frequently associated with extensive formation of multinucleated GC of macrophage origin, which appears to be related to the pathogenesis of the infection and the degree of immunosuppression.

Synergism of herpes simplex virus and tobacco-specific N'-nitrosamines in cell transformation

Previous studies indicate that herpes simplex virus (HSV) enhances the carcinogenic activity of smokeless tobacco and tobacco-related chemical carcinogens in animals. Since tobacco-specific N'-nitrosamines (TSNAs) such as N'-nitrosonornicotine (NNN) and 4-(N-methyl-N'-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are major chemical carcinogens of smokeless tobacco and are known to be responsible for the development of oral cancers in smokeless tobacco users, the combined effects of TSNAs and HSV in cell transformation were investigated. Exposure of cells to NNN or NNK followed by virus infection resulted in a significant enhancement of transformation frequency when compared with that observed with chemical carcinogens or virus alone. This study suggests that TSNAs and HSV can interact together and show synergism in cell transformation.

Expression of MHC-class-I antigens in human carcinomas and sarcomas analyzed by isoelectric focusing

We analyzed the expression of class-I antigens in ex vivo human tumor cells by isoelectric focusing (IEF) the anti-class-I mAb W6/32 immunoprecipitates prepared from cell lysates. Out of 42 experiments, 27 were technically successful. The patient's blood lymphocytes were used as controls. In vitro exposure of the tumor cells to IFN gamma and TNF alpha elevated class-I antigen expression. In 11 cases, defects in MHC-class-I-antigen expression were observed. In 2 cases the antigens were detected only in the cytokine-treated tumor samples, probably due to a defect in the association between beta 2m and class-I heavy chains. Selective changes in the expression of alleles were seen in 10 cases and might involve HLA A, B and C antigens. Alterations in class-I expression as compared with the lymphocytes were observed in 9 of 13 cases in which the tumor cells were collected from metastases, and only in 2 of 14 primary tumors.

Functional characteristics of the intercellular adhesion molecule-1 (CD54) expressed on cytotoxic human blood lymphocytes

We have shown that intercellular adhesion molecule-1 (ICAM-1) (CD54) positive cells are mainly responsible for the natural cytotoxic function of human blood lymphocytes. The evidences were the inhibition of cytotoxicity by anti-ICAM-1 (LB-2) monoclonal antibodies (mAb) and the loss of lytic activity after removal of the ICAM-1+ cells. In addition, the cytotoxic potential of the separated ICAM-1- lymphocyte population after activation appeared in parallel with the expression of this molecule. The ICAM-1+ lymphocytes lysed both LFA-1 (CD11a/CD18 or Leu-CAMa) positive and negative cell lines, and pretreatment of the effectors with the LB-2 mAb also inhibited the lysis of LFA-1- targets. The results point to a yet unrecognized role of ICAM-1 on the lymphocytes. Kinetics experiments suggested that pretreatment of lymphocytes with alpha-ICAM-1 (LB-2) mAb did not inhibit the promptly established lytic interactions but influenced later events, recycling and/or recruitment of effectors. It is possible that the cytotoxic potential is regulated by contacts between the members of the lymphocyte population and that these events occur via their ICAM-1 and LFA-1. Exposure of lymphocytes to NK-sensitive targets for 16 hr elevated their cytotoxic potential. The function of activated lymphocytes was not inhibited by the LB-2 mAb.

Malignant lymphomas in cynomolgus monkeys infected with simian immunodeficiency virus

Malignant lymphomas were observed in 38% (9 of 24) of simian immunodeficiency virus (SIV)-infected cynomolgus monkeys (Macaca fascicularis) 5 to 15 months after inoculation with SIV strain SMM3. Lymphomagenesis in the SIV-infected monkeys was not related directly to the SIV-infectious dose given. All SIV-infected animals developed severe immunodeficiency. No significant difference in immunodeficiency was observed between tumor-bearing and non-tumor-bearing animals. In contrast, no lymphomas were observed in a comparable group of HIV-2-infected monkeys, which did not develop immunodeficiency; nor did the noninfected control monkeys. All 9 SIV-related tumors were high-grade B-cell lymphoblastic or pleomorphic lymphomas with extranodal, disseminated growth. Most tumors showed marked infiltration by monocytes and CD8+ T lymphocytes. Occasional tumor infiltrating cells showed immunohistochemical reaction for SIV. The cells of two tumors were established in vitro and shown to be of B-cell phenotype. The tumor cell cultures showed no reverse transcriptase activity and no evidence of virus infection by electron microscopy. Our observations indicate that SIV-induced immunodeficiency in cynomolgus monkeys also mimics HIV infection and AIDS in humans with regard to increased lymphomagenesis and type of lymphomas.