Glucocorticoids transform CD40-triggering of dendritic cells into an alternative activation pathway resulting in antigen-presenting cells that secrete IL-10

Dendritic cell (DC) activation through CD40-CD40 ligand interactions is a key regulatory step for the development of protective T-cell immunity and also plays an important role in the initiation of T-cell responses involved in autoimmune diseases and allograft rejection. In contrast to previous reports, we show that the immunosuppressive drug dexamethasone (DEX) redirects rather than simply blocks this DC activation process. We found that DCs triggered through CD40 in the presence of DEX were unable to acquire high levels of costimulatory, adhesion, and major histocompatibility complex class I and II molecules and failed to express the maturation marker CD83, whereas antigen uptake was not affected. Moreover, DEX strikingly modified the CD40-activated DC cytokine secretion profile by suppressing the production of the proinflammatory cytokine interleukin (IL)-12 and potentiating the secretion of the anti-inflammatory cytokine IL-10. Accordingly, DEX-exposed CD40-triggered DCs displayed a decreased T-cell allostimulatory potential and a dramatically impaired ability to activate cloned CD4(+) T helper 1 (Th1) cells. Moreover, interaction between Th1 cells and these DCs rendered the T cells hyporesponsive to further antigen-specific restimulation. Collectively, our results demonstrate that DEX profoundly modulates CD40-dependent DC activation and suggest that the resulting alternatively activated DCs can be exploited for suppression of unwanted T-cell responses in vivo.

Adenoviruses activate human dendritic cells without polarization toward a T-helper type 1-inducing subset

Human monocyte-derived dendritic cells (DC) infected with recombinant adenoviruses (rAd) are promising candidate vaccines for inducing protective immunity against pathogens and tumors. However, since some viruses are known to negatively affect DC function, it is important to investigate the interactions between rAd and DC. We now show that infection by rAd enhances the immunostimulatory capacity of immature human monocyte-derived DC through the upregulation of the costimulatory molecules CD80, CD86, and CD40 and the major histocompatibility complex class I and II molecules. Although rAd infection fails to induce the secretion of interleukin-12 (IL-12) and only marginally induces the expression of the DC maturation marker CD83, it acts in synergy with CD40 triggering in rendering DC fully mature. rAd-infected DC triggered through CD40 produce more IL-12 and are more efficient in eliciting T-helper type 1 responses than DC activated by CD40 triggering only. rAd lacking one or more of the early regions, E1, E2A, E3, and E4, which play an important role in virus-host cell interactions are equally capable of DC activation. Efficient DC infection requires a high multiplicity of infection (>1,000), a fact which can be attributed to the absence of the coxsackievirus and adenovirus receptor on this cell type. Despite the poor ability of DC to be infected by rAd, which may be improved by targeting rAd to alternative DC surface molecules, DC infected with all currently tested rAd constitute potent immunostimulators. Our study provides new insights into the interactions between two highly promising vaccine components, rAd and DC, and indicates that their combination into one vaccine may be very advantageous for the stimulation of T-cell immunity.

A pilot study of increasing dose intensity of epirubicin and ifosfamide in patients with small cell lung cancer by using recombinant granulocyte colony-stimulating factor

The aim of this prospective study was to investigate the feasibility of increasing the dose intensity of chemotherapy in patients with small cell lung cancer (SCLC) by using recombinant human granulocyte colony-stimulating factor (r-metHuG-CSF). Seventeen previously untreated patients (11 male, 6 female) were treated with ifosfamide (5.0 g/m2) and epirubicin (80 mg/m2) in two successive cohorts. Eight patients received chemotherapy every 2 weeks and r-metHuG-CSF 5 microg/kg given subcutaneously daily for 10 days (cohort A), and nine patients received chemotherapy at 10-day intervals with r-metHuG-CSF 5 microg/kg subcutaneously given daily for 7 days (cohort B). The relative dose intensity compared with the conventional 3-weekly regimen was 1.5 and 2.1 for cohorts A and B, respectively. Neutropenia-associated fever complicated two and five treatment courses in cohorts A and B, respectively. There were five episodes of grade 3/4 thrombocytopenia. There were no treatment delays in cohort A and one cycle was delayed in cohort B. One patient from each cohort was withdrawn due to toxicity. Grade 3/4 non-haematological toxicity, other than alopecia, was not observed. This study confirms that it is feasible to increase the relative dose intensity of ifosfamide and epirubicin in patients with SCLC to 2.1 by using r-metHuG-CSF and shortening the interval between treatment cycles.

Discovery of MC-02,331, a new cephalosporin exhibiting potent activity against methicillin-resistant Staphylococcus aureus

A systematic approach toward building activity against methicillin-resistant staphylococci into the cephalosporin class of beta-lactam antibiotics is described. Initial work focused on finding the optimal linkage between the cephem nucleus and a biphenyl pharmacophore, which established that a thio linkage afforded potent activity in vitro. Efforts to optimize this activity by altering substitution on the pharmacophore afforded iodophenylthio analog MC-02,002, which although highly potent against MRSA, was also highly bound to serum proteins. Further work to decrease serum protein binding showed that replacement of the iodo substituent by the positively-charged isothiouronium group afforded potent activity and reduced serum binding, but insufficient aqueous solubility. Solubility was enhanced by incorporation of a second positively-charged group into the 7-acyl substituent. Such derivatives (MC-02,171 and MC-02,306) lacked sufficient stability to staphylococcal beta-lactamase enzymes. The second positive charge was incorporated into the cephem 3-substituent in order to utilize the beta-lactamase-stable aminothiazolyl(oximino)acetyl class of 7-substituents. These efforts culminated with the discovery of bis(isothiouroniummethyl)phenylthio analog MC-02,331, whose profile is acceptable with respect to potency against MRSA, serum binding, aqueous solubility, and beta-lactamase stability.

p53 as a target for cancer vaccines: recombinant canarypox virus vectors expressing p53 protect mice against lethal tumor cell challenge

The p53 protein is an attractive target for immunotherapy, because mutations in the p53 gene are the most common genetic alterations found in human tumors. These mutations result in high levels of p53 protein in the tumor cell, whereas the expression level of wild-type p53 in nonmalignant tissue is usually much lower. Several canarypox virus recombinants expressing human or murine p53 in wild-type or mutant form were constructed. Immunization with these viruses protected BALB/c mice from a challenge with an isogenic and highly tumorigenic mouse fibroblast tumor cell line expressing high levels of mutant p53. The tumor protection was equally effective regardless of whether wild-type or mutant p53 was used for the immunization, indicating that the immunologic response was not dependent on any particular p53 mutation and that immunization with this live virus vaccine works effectively against mutant p53 protein expressed in a tumor cell. In tumors escaping immunologic rejection, the expression of the p53 protein was commonly down-regulated.

Effects of an exon 5 variant of the estrogen receptor in MCF-7 breast cancer cells

The estrogen receptor gene gives rise to variant mRNAs, generated by alternative mRNA splicing, as well as the full-length mRNA containing eight coding exons. It has been postulated that one of these, the exon 5 variant, may be important in the development of hormone-independent and anti-estrogen-resistant breast cancer since it has the potential to encode a truncated receptor that retains the N-terminal activation domain AF-1, but lacks the hormone-binding domain. We have expressed the variant using an inducible promoter in estrogen receptor-positive MCF-7 cells and analyzed the effect of the variant protein on gene expression and cell growth. Inducible expression was validated using a specific antiserum that recognized a novel epitope on the exon 5 variant. The variant was able to stimulate transcription of a reporter gene in transiently transfected chicken embryo fibroblasts in the absence of hormone but showed weak constitutive activity when it was stably expressed in MCF-7 cells. The variant had no effect on the expression of the estrogen target genes, pS2, and the progesterone receptor. Finally, we analyzed whether the proliferation of MCF-7 cells was altered by the expression of the exon 5 variant and found that the stimulatory effects of estrogen and growth inhibitory effects of tamoxifen and ICI 182780 were unchanged. We therefore conclude that expression of the variant alone is not sufficient to give rise to hormone independence or tamoxifen resistance of breast cancers.

Patterns of Epstein-Barr virus latent and replicative gene expression in Epstein-Barr virus B cell lymphoproliferative disorders after organ transplantation

B cell lymphoproliferative disorders arising in organ transplant recipients (B cell posttransplant lymphoproliferative disorders [PTLD]) are generally associated with EBV. In previous reports, B cell PTLD were shown to express the full pattern of EBV latent genes, as in vitro-established lymphoblastoid cell lines. Although viral linear DNA was detected in 40% of lymphoproliferative disorders from immunocompromised hosts, immunophenotypic studies failed to detect late EBV replicative antigens. The aim of this study was to investigate the relationship of EBV latent gene expression in B cell PTLD to morphology, clonality, and immunophenotype, and to examine the replicative state of EBV in malignant cells. For this purpose, 9 cases of EBV-related B cell PTLD were analyzed. Immunoglobulin gene rearrangements were detected by Southern blot analysis. The presence of EBV was assessed by Southern blot and by in situ hybridization. B cell differentiation antigens, adhesion and activation molecules, and EBV latent and replicative gene expression were studied using immunohistochemistry techniques. We demonstrated that EBV-related B cell PTLD exhibited varying patterns of latent viral gene expression. Higher levels of adhesion molecules were detected in latent membrane protein 1 (LMP1) or LMP1 plus EBV nuclear antigen 2 (EBNA2)-positive tumors than in LMP1 and EBNA2-negative tumors. In contrast, there was no relationship between CD21 and CD23 expression and latent EBV phenotype. Activation of the EBV replicative cycle was highlighted by BamHI Z left frame 1 expression in 5 of 9 cases. Less frequent expression of late viral proteins suggested that the initiation of the EBV lytic cycle might not always lead to virions production.

Regulation of estradiol 17 beta-hydroxysteroid dehydrogenase expression and activity by retinoic acid in T47D breast cancer cells

Estradiol 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) mediates the interconversion of estrone and estradiol in endocrine-responsive tissues such as the breast. The control of 17 beta HSD expression by all-trans-retinoic acid (RA) in T47D breast cancer cells was examined using a specific 17 beta HSD complementary DNA probe. Two main 17 beta HSD messenger RNA (mRNA) transcripts of 2.2 and 1.3 kilobases (kb) were detected, of which only the 1.3-kb mRNA was regulated. RA increased expression of the 17 beta HSD 1.3-kb mRNA in a dose- and time-dependent manner, and the increased expression of this mRNA by RA was inhibited by a 10-fold excess of a RA antagonist Ro 41-5253. Insulin-like-growth factor-I, interleukin-1, and estradiol, previously shown to increase 17 beta HSD activity in breast cancer cells, had little effect on 17 beta HSD gene expression. To relate the effect of increased 17 beta HSD 1.3-kb mRNA expression to 17 beta HSD activity, the conversion of estrone to estradiol (reductive) and that of estradiol to estrone (oxidative) were measured in intact T47D cell monolayers. Whereas RA increased 17 beta HSD reductive activity, it had no effect on oxidative activity. The addition of excess NAD increased 17 beta HSD oxidative activity in control and RA-treated cells, but the addition of NADH had no effect on 17 beta HSD reductive activity. These results suggest that the increased expression of the 17 beta HSD 1.3-kb mRNA induced by RA is associated with an increase in 17 beta HSD reductive activity, but that endogenous cofactor levels may determine the direction in which this enzyme acts in T47D cells.

Epstein-Barr virus latent and replicative gene expression in post-transplant lymphoproliferative disorders and AIDS-related non-Hodgkin's lymphomas. French Study Group of Pathology for HIV-associated Tumors

In acquired immunodeficiency, B-cell proliferation is usually associated with Epstein-Barr virus (EBV), implying the impairment of the normal control of EBV and EBV-infected cells. It has been assumed that EBV infection is latent in lymphoproliferative disorders. In order to determine the type of latency and to investigate whether any lymphoproliferative disorders enter into the lytic cycle, we analyzed the expression of latent and replicative EBV genes in 9 post-transplant lymphoproliferative disorders (PTLD) and in 23 EBV-positive AIDS-related non-Hodgkin's lymphomas (AR-NHL). The PTLD cases were categorized into polyclonal or monoclonal polymorphic tumors and monoclonal monomorphic tumors. The AR-NHL cases included large-cell/immunoblastic (LC/IB) and Burkitt's lymphoma (BL) groups. We demonstrated that varying patterns of latent-viral-gene expression are exhibited showing the 3 forms of latency. Polymorphic PTLD and LC/IB AR-NHL frequently expressed type II or III latency, whereas monomorphic tumors and BL AR-NHL showed type I latency. It is noteworthy that 3 cases of BL AR-NHL expressed latency II form. Induction of lytic cycle highlighted by the expression of BZLF1 occurred in 55.5% of PTLD, 36% of LC/IB and 22% of BL AR-NHL. In contrast, late viral proteins indicating productive cycle were present in 22% of PTLD, 14% of LC/IB, and were absent in BL cases. These data suggest that the impairment of EBV control permits disruption of latency, but the initiation of the lytic cycle may not always lead to viral production.

A phase I study of the left-shifting agent BW12C79 plus mitomycin C and the effect on the skeletal muscle metabolism using 31P magnetic resonance spectroscopy

BW12C79 stabilizes the oxyhemoglobin molecule resulting in a reversible left-shift of the oxygen saturation curve. The activity of a number of bioreductive anticancer drugs, such as mitomycin C, may be enhanced under hypoxic conditions. Twenty-four patients with various malignancies received BW12C79 and mitomycin C. BW12C79 was administered i.v. with a loading dose (20-50 mg/kg) over 1 h followed by a maintenance infusion of 4 mg/kg/h for 5 h. Percentage modification of the oxyhemoglobin (degree of left-shift) was dose related with maximum modification of 56% and was maintained for the duration of maintenance infusion of BW12C79. Hemoglobin electrophoresis showed a fast moving band consistent with the BW12C79-oxyhemoglobin complex. Side effects at the top dose level comprised headache, nausea/vomiting, vein irritation, and myocardial ischemia. One other patient suffered from an acute encephalopathy of unknown etiology a few days following BW12C79. 31P magnetic resonance spectroscopy of exercising calf muscles showed increased breakdown of high energy phosphate stores and a greater reduction in pH. Recovery of the high energy phosphate stores after exercise was slow. These results were consistent with reduced oxygen supply due to either a left shift of the oxygen saturation curve and/or reduced muscle blood flow. BW12C79 did not interfere with the pharmacokinetics of mitomycin C. In conclusion, this phase I study demonstrates the feasibility of achieving a significant left shift in the oxygen saturation curve in cancer patients which is maintained for at least 5 h with acceptable toxicity. The maximum tolerated dose of BW12C79 was 50 mg/kg loading infusion followed by a maintenance infusion of 4 mg/kg/h. Magnetic resonance spectroscopy results were consistent with reduced supply of oxygen to exercising skeletal muscle. BW12C79 may be of potential benefit as an adjunct to bioreductive drugs in the treatment of solid tumors.

Phase I study of bryostatin 1: assessment of interleukin 6 and tumor necrosis factor alpha induction in vivo. The Cancer Research Campaign Phase I Committee

BACKGROUND

Many oncogenes have been shown to code for growth factor receptors that are involved in regulation of cell growth and proliferation and can activate transcription via protein kinase C. Bryostatin 1, a partial agonist of protein kinase C, has demonstrated potent antitumor activity in vitro and in vivo in human tumor xenografts.

PURPOSE

The aim of this phase I study was to determine the optimal dosage and toxicity profile of bryostatin 1 and its influence on cytokine release in vivo.

METHODS

Three successive cohorts consisting of 35 patients with various malignant tumors were treated with bryostatin 1 by intravenous infusion over 1 hour as follows: cohort A--35 micrograms/m2 (three patients) or 50 micrograms/m2 (eight patients) once every 2 weeks; cohort B--25 micrograms/m2 once a week (eight patients); and cohort C--25 micrograms/m2 once a week for 3 weeks, with no treatment during the 4th week (16 patients). Plasma levels of tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) were measured by immunoradiometric assay and by radioimmunoassay, respectively.

RESULTS

The dose-limiting toxicity was grade 3 or 4 myalgia in four of 11 patients in cohort A, in two of eight in cohort B, and in none of 16 in cohort C. Occurrence of myalgia was dose related. There was no significant myelosuppression, apart from a small and transient fall in platelet count. Six patients experienced acute but transient skin flushing, dyspnea, hypotension, and bradycardia, probably related to the bryostatin 1 vehicle. TNF-alpha and IL-6 were detected in plasma at 2 and 24 hours after treatment, respectively, and the levels were dose related (P = .02). Two patients with metastatic malignant melanoma had partial remission after three or four cycles of therapy; remission lasted 6 weeks and 10+ months, respectively.

CONCLUSIONS

The dose-limiting toxicity of bryostatin 1 was myalgia. Plasma IL-6 and TNF-alpha concentrations were increased within 24 hours of therapy. Antitumor activity against malignant melanoma was observed early in the course of treatment.

IMPLICATIONS

The recommended dosage of bryostatin 1 for phase II studies is 25 micrograms/m2 by intravenous infusion for 1 hour once a week for 3 weeks, with no treatment in the 4th week. IL-6 and TNF-alpha plasma concentrations may be useful in monitoring biological activity of bryostatin 1. Future studies should explore use of this drug with other conventional immune modulators and conventional cytotoxic drugs.

Epstein-Barr virus-latent gene expression and tumor cell phenotype in acquired immunodeficiency syndrome-related non-Hodgkin's lymphoma. Correlation of lymphoma phenotype with three distinct patterns of viral latency

We investigated 49 acquired immunodeficiency syndrome-related lymphomas (ARLs) for Epstein-Barr virus (EBV) by Southern blotting and in situ hybridization and, in positive cases, used cryostat immunohistology to compare EBV-latent gene expression (EBV encoded small RNA-1 [EBER-1], EBV nuclear antigen-2 [EBNA-2], latent membrane protein-1 [LMP-1] and host cell immunophenotype (CD11a, CD18, CD54, CD58, CD21, CD23, CD30, CD39, CDw70, immunoglobulin) patterns with those reported in other EBV infections. EBV+ immunoblast-rich/large cell ARLs (n = 22) showed three patterns of latency: broad (EBER+EBNA-2+/LMP-1+; n = 9), reminiscent of a lymphoblastoid cell line phenotype; restricted (EBER+/EBNA-2-/LMP-1-; n = 6), similar to endemic Burkitt's lymphoma; and intermediate (EBER+/EBNA-2-/LMP-1+; n = 7), a pattern rarely described in vitro but seen in certain EBV-related malignancies. EBNA-2 expression was associated with extranodal lymphomas. EBV+ Burkitt-type ARLs (n = 11) usually showed the restricted latency pattern (n = 8), but some expressed the intermediate form (n = 3). Adhesion (CD54, CD58) and activation (CD30, CD39, CDw70) molecule expression varied with morphology (immunoblast-rich/large cell versus Burkitt-type), but was not independently correlated with EBV-positivity. CD30 and LMP-1 expression were associated. ARLs show heterogeneity regarding both the presence of EBV and latency pattern. Comparison of these phenotypically distinct lymphoma groups with known forms of EBV infection provides clues to their possible pathogenesis.

In vivo production of interleukin-10 by malignant cells in AIDS lymphomas

Expression of the interleukin (IL)-10/BCRF1 gene was studied by in situ hybridization in tissue samples from acquired immunodeficiency syndrome (AIDS) lymphomas using a BCRF1 probe which also recognizes the human IL-10 sequence. Hybridization was detected in 8 out of 15 lymphomas. In contrast, the IL-10/BCRF1 gene expression was detected in only 1 out of 11 lymphomas from human immunodeficiency virus (HIV)-seronegative patients (p = 0.05). In AIDS lymphomas, the number of cells labeled with a BCRF1-specific probe was dramatically lower than that of cells labeled with the IL-10/BCRF1 probe. Thus, the IL-10 rather than the BCRF1 gene was expressed. Production of IL-10 was associated with that of IL-10 mRNA, as shown by immunodetection of the protein in numerous cells. In contrast, BCRF1-producing cells were rarely detected. Both in situ hybridization and immunochemical experiments indicated that malignant cells were involved in this IL-10 synthesis. IL-10 production in AIDS lymphomas was associated with the presence of Epstein-Barr virus (EBV) in lymphomatous cells (p = 0.02). As IL-10 is a potent growth factor for human B lymphocytes, these results suggest that IL-10 may stimulate the proliferation of malignant cells in an autocrine pathway in a number of AIDS lymphomas, and that EBV and HIV may synergistically trigger its production.

[Disclosure of protein C deficiency with pulmonary embolism followed by cardiac arrest during the recovery period]

A case of unexpected cardiac arrest occurring in a 17-year-old male patient is reported. The patient had been admitted after sustaining hand trauma. A first emergency surgical procedure was carried out, followed about three weeks later by another one. No incidents occurred during or after either of these two operations. A third procedure was required about two months after the accident (free toe graft to the thumb of the left hand). The twelve-hour operation was carried out under general anaesthesia and axillary block. The patient was given intravenous heparin (800 IU.h-1) during the procedure on the arm. The patient recovered quickly, and was extubated before his transfer to the recovery room. Fifteen minutes later, the patient's heart rate decreased to 40 b.min-1, followed by a transient cardiorespiratory arrest. The suspicion of pulmonary embolism was confirmed by pulmonary scintigraphy. Thrombolysis was carried out with 2,000 IU.kg-1.h-1 of urokinase for a 72 h period, combined with continuous heparin administration (16 to 36 x 10(3) IU.day-1). The patient recovered after one week. No thrombophlebitis was found for origin of the emboli. Biological investigations carried out both before and after 10 minutes of anoxia revealed a normal fibrinolytic system, but a deficit in protein C (62% antigen, 64% activity). Two years after the episode of pulmonary embolism, the patient, still taking acenocoumarol, remained free from any sequela. Current perioperative management of patients with a known protein C deficit is discussed.

The development of a programme of care for elderly people in Northern Ireland

This paper describes the development of a Programme of Care for elderly people in Northern Ireland. The problems of the elderly were previously identified, and a classification system was designed in key areas which allocated groups of individuals with similar needs to particular services. It was thus possible to quantify the resources required to meet the future needs of elderly people in Northern Ireland. The major implications for the Health and Social Services were then stressed on the basis of certain assumptions. Generally, resources are currently being channelled in the right direction but considerable expansion of resources is necessary in the future especially in community care. In showing one method of planning services for the elderly people and the possible results, this study also offers a methodology to assist the planning process in general.

Identification of the needs of elderly people in Northern Ireland

This paper presents the results of a survey on persons over the age of 65 in Northern Ireland. One of the aims of this research was to identify and measure the needs of the elderly population in order to develop a Programme of Care. It would seem logical that the problems of the elderly tend to increase with age. Since the population is becoming older and given the commitment to community care, this will have serious implications for the National Health and Social Services. The present survey was carried out using a questionnaire to extract details concerning the individuals' mental state, ability for self-care and household duties, mobility, accommodation, social activities, general health, strain imposed on others and current support from the statutory services. The results for each category were then presented for 5 age-groups: 65-69, 70-74, 75-79, 80-84 and 85+. Specific problems in relation to home help provision and social facilities such as day care are also discussed.