Prevention of experimental colitis by parenteral administration of a pathogen-derived immunomodulatory molecule.

BACKGROUND: Filamentous haemagglutinin (FHA) of Bordetella pertussis subverts host immune responses by inhibiting interleukin (IL)12 and enhancing IL10 production by macrophages and dendritic cells, and promoting the induction of regulatory T cells. HYPOTHESIS: Injection of FHA would ameliorate disease in a T cell-dependent model of colitis via the induction of anti-inflammatory cytokines and regulatory T cells. METHODS: Colitis was induced by injection of CD4CD45RB(high) naive T cells into severe combined immunodeficient (SCID) mice. Mice were treated with four subcutaneous injections of FHA or buffer alone. RESULTS: Parenteral injection of FHA stimulated IL10 and/or transforming growth factor beta production in local and mesenteric lymph nodes and Peyer's patches of mice 2-6 h after administration. Compared with phosphate-buffered saline-treated mice, FHA-treated SCID mice had significantly (p<0.01) less weight loss, lower colon weight, less colon shrinkage and reduced inflammatory lesions. The therapeutic effect of FHA was associated with enhanced IL10 and reduced type 1 and type 2 T helper cytokine production by spleen cells. Finally, FHA also attenuated the symptoms of colitis in SCID mice transferred with CD4CD45RB(high) T cells from IL10-deficient mice. CONCLUSIONS: Our finding shows that FHA suppresses type 1 T helper and pro-inflammatory cytokines, and ameliorates disease activity in a chronic T cell-dependent model of colitis, an effect that was not dependent on IL10 production by T cells, but was associated with induction of anti-inflammatory cytokines in vivo. Having already been used as a pertussis vaccine component in children, FHA is a promising candidate for clinical testing in patients with Crohn's disease.

Immunogenicity of a three-component acellular pertussis vaccine administered at birth.

OBJECTIVE: To evaluate within the first 6 months of birth the immunogenicity of a 3-component acellular pertussis (aP) vaccine containing filamentous hemagglutinin (FHA), pertactine (PRN), and genetically detoxified pertussis toxin (PT) in infants who received a dose of vaccine at birth, in addition to the recommended schedule administered at 3, 5, and 11 months. Furthermore, we investigated the influence of maternal antibodies on aP vaccine response. METHODS: We used enzyme-linked immunosorbent assay to evaluate immunoglobulin G antibody levels in 45 infants immunized at birth and at 3, 5, and 11 months (group 1) and in 46 infants immunized at the ages of 3, 5, and 11 months (group 2). All mothers were also tested at delivery. RESULTS: At the age of 5 months the geometric mean titer of anti-PT, anti-FHA, and anti-PRN was significantly greater in group 1 (who had received 2 doses) than in group 2 (1 dose). At 6 months geometric mean titers were significantly higher in group 1 than in group 2 for anti-PRN and anti-FHA, whereas no significant differences were observed for anti-PT. CONCLUSIONS: Immunization at birth may be important for an earlier prevention of the pertussis disease in infants under 6 months, especially in Italy, where the recommended ages for aP vaccine administration are 3, 5, and 11 months.

Tumor cell motility. A novel therapeutic target in bladder carcinoma, experimental and clinical results.

Surgery, chemotherapy and radiotherapy are the current modalities of tumor management. However, in systemic disease, predicted patients' cure can be achieved in but a few tumor diseases. Based on previous basic research we have highlighted that the loss of cell-cell adhesion in association with an increased tumor cell motility is an essential feature of the malignant potential of bladder tumors. Thus, we have attempted therapeutical methods differing from hitherto existing treatments by focusing on a tumor cell function we call cell motility. Characterization of so-called anti-motility drugs was performed biochemically as well analyzed by in vitro by using in established bladder carcinoma cell lines. We evaluated the potential therapeutic benefit in a model of chemically induced bladder carcinoma followed by a phase I/II trial applying anti-motility drugs in patients which were chemotherapy-resistant and having metastatic bladder cancer. Both basic research as well as the results of first translational clinical trials confirmed, that advanced bladder carcinomas can be favorably affected by inhibition of tumor cell motility.

Pertussis toxin-sensitive G-proteins and regulation of blood pressure in the spontaneously hypertensive rat.

1. Increased Gi-protein-mediated receptor-effector coupling in the vasculature of the spontaneously hypertensive rat (SHR) has been proposed as a contributing factor in the maintenance of elevated blood pressure. If increased Gi-protein-mediated activity plays an important role in hypertension in SHR, then inhibition of Gi-proteins by pertussis toxin would be expected to decrease blood pressure in this genetic hypertensive model. To address this hypothesis, studies were undertaken comparing the cardiovascular effects of pertussis toxin in SHR and normotensive Wistar-Kyoto (WKY) rats. 2. Spontaneously hypertensive and WKY rats were instrumented with radiotelemetry devices and blood pressure measurements were recorded in conscious rats. Following a single injection of pertussis toxin (10 micrograms/kg, i.v.), mean arterial blood pressure fell from 161 +/- 3 to 146 +/- 1 mmHg in the SHR and the effect was sustained for more than 2 weeks. In contrast, 10 micrograms/kg, i.v., pertussis toxin produced no significant effect on blood pressure in WKY rats (103 +/- 4 vs 101 +/- 5 mmHg). 3. In a separate study, SHR and WKY rats were administered 30 micrograms/kg, i.v., pertussis toxin or 150 microL/kg, i.v., saline and, 3-5 days later, rats were anaesthetized and instrumented to permit measurement of blood pressure and renal function. At this higher dose, pertussis toxin reduced blood pressure in both strains of rat, although the effect was markedly greater in SHR (approximately 40 mmHg decrease) compared with WKY rats (approximately 15 mmHg decrease). In SHR, pertussis toxin increased renal blood flow (from 5.7 +/- 0.3 to 7.5 +/- 0.8 mL/min per g kidney) and decreased renal vascular resistance (from 31 +/- 2 to 19 +/- 2 mmHg/mL per min per g kidney). In WKY rats, pertussis toxin had no significant effect on renal parameters. 4. Results from these studies indicate that a pertussis toxin-sensitive Gi-protein-mediated pathway contributes to the maintenance of hypertension and elevated renal vascular tone in the SHR.

Effect of pertussis toxin on baclofen- and diphenhydramine-induced amnesia.

The effect of pretreatment with pertussis toxin at the doses of 0.25 and 0.50 microg per mouse ICV on the amnesic effect produced by baclofen (0.1 4 mg kg(-1) i.p.), diphenhydramine (15-30 mg kg(-1) i.p.) and scopolamine (0.5-5 mg kg(-1) i.p.) was investigated in the mouse passive avoidance test. Ten days after a single injection of pertussis toxin, baclofen (2 4 mg kg(-1) i.p.) amnesia was prevented. By contrast, pertussis toxin had no effect on diphenhydramine- and scopolamine-induced amnesia. Pretreatment with pertussis toxin at both doses used did not impair motor coordination of the mice, as revealed by the rota-rod test. The present results indicate that the activation of pertussis toxin-sensitive G-proteins represents an important transduction step in memory impairment induced by GABA(B) (gamma-aminobutyric acid B) agonists, but not by antihistaminic and antimuscarinic drugs.

Native, but not genetically inactivated, pertussis toxin protects mice against experimental allergic encephalomyelitis.

Treatment of SJL mice with 400 ng Bordetella pertussis toxin (PT) either in saline or emulsified in incomplete Freund's adjuvant protected the mice against experimental autoimmune encephalomyelitis (EAE) induced 28 days later by a synthetic peptide of myelin proteolipid protein (PLP139-151) in complete Freund's adjuvant. However, treatment with a genetically inactivated pertussis toxin in which the catalytic and NAD-binding sites of the ADP-ribosyltransferase subunit were modified by site-directed mutagenesis was without effect. In vitro, lymphocyte proliferation was considerably enhanced by both the native and the inactivated toxin, at concentrations of 0.1-1 microgram/ml. However, strong inhibition of proliferation was also observed with the native toxin only, at concentrations that were two to three orders of magnitude lower than that required for the mitogenic effect (0.1-1 ng/ml). The inhibition of proliferation was detectable in the case of high-background proliferation, after stimulation with antigen (PLP139-151) or purified protein derivative of Mycobacterium tuberculosis), or with anti-CD3 monoclonal antibody, but not after stimulation with concanavalin A or phorbol esters and Ca2+ ionophore. These results suggest that the inhibitory effect of PT operates by interfering selectively with a T cell receptor-dependent signaling pathway. The biological significance of the in vitro inhibitory effect of PT was demonstrated by a considerable decrease and/or delay in the ability of lymphocytes grown with PLP139-151 and low concentrations of PT to transfer EAE to naive recipients.

A controlled trial of two acellular vaccines and one whole-cell vaccine against pertussis. Progetto Pertosse Working Group.

BACKGROUND: Concern about both safety and efficacy has made the use of whole-cell pertussis vaccines controversial. In some European countries, including Italy, the rate of vaccination against pertussis is low. METHODS: We conducted a double-blind trial in Italy in which infants were randomly assigned to vaccination at two, four, and six months of age with an acellular pertussis vaccine together with diphtheria and tetanus toxoids (DTP); a DTP vaccine containing whole-cell pertussis (manufactured by Connaught Laboratories); or diphtheria and tetanus toxoids without pertussis (DT). The acellular DTP vaccine was either one containing filamentous hemagglutinin, pertactin, and pertussis toxin inactivated with formalin and glutaraldehyde (SmithKline Beecham) or one with filamentous hemagglutinin, pertactin, and genetically detoxified pertussis toxin (Chiron Biocine). Pertussis was defined as 21 days or more of paroxysmal cough, with infection confirmed by culture or serologic testing. RESULTS: The efficacy of each vaccine, given in three doses, against pertussis was determined for 14,751 children over an average of 17 months, with cases included in the analysis if cough began 30 days or more after the completion of immunization. For both of the acellular DTP vaccines, the efficacy was 84 percent (95 percent confidence intervals, 76 to 89 percent for Biocine DTP and 76 to 90 percent for SmithKline DTP), whereas the efficacy of the whole-cell DTP vaccine was only 36 percent (95 percent confidence interval, 14 to 52 percent). The antibody responses were greater to the acellular vaccines than to the whole-cell vaccine. Local and systemic adverse events were significantly more frequent after the administration of the whole-cell vaccine. For the acellular vaccines, the frequency of adverse events was similar to that in the control (DT) group. CONCLUSIONS: The two acellular DTP vaccines we studied were safe, immunogenic, and efficacious against pertussis, whereas the efficacy of the whole-cell DTP vaccine was unexpectedly low.

A controlled trial of a two-component acellular, a five-component acellular, and a whole-cell pertussis vaccine.

BACKGROUND: Because of concern about safety and efficacy, no pertussis vaccine has been included in the vaccination program in Sweden since 1979. To provide data that might permit the reintroduction of a pertussis vaccine, we conducted a placebo-controlled trial of two acellular and one whole-cell pertussis vaccines. METHODS: After informed consent was obtained, 9829 children born in 1992 were randomly assigned to receive one of four vaccines: a two-component acellular diphtheria-tetanus-pertussis (DTP) vaccine (2566 children), a five-component acellular DTP vaccine (2587 children), a whole-cell DTP vaccine licensed in the United States (2102 children), or (as a control) a vaccine containing diphtheria and tetanus toxoids (DT) alone (2574 children). The vaccines were given at 2, 4, and 6 months of age, and the children were then followed for signs of pertussis for an additional 2 years (to a mean age of 21/2 years). RESULTS: The whole-cell vaccine was associated with significantly higher rates of protracted crying, cyanosis, fever, and local reactions than the other three vaccines. The rates of adverse events were similar for the acellular vaccines and the control DT vaccine. After three doses, the efficacy of the vaccines with respect to pertussis linked to a laboratory-confirmed case of pertussis or contact with an infected household member with paroxysmal cough for > or = 21 days was 58.9 percent for the two-component vaccine (95 percent confidence interval, 50.9 to 65.9 percent), 85.2 percent for the five-component vaccine (95 percent confidence interval, 80.6 to 88.8 percent), and 48.3 percent for the whole-cell vaccine (95 percent confidence interval, 37.0 to 57.6 percent). CONCLUSIONS: The five-component acellular pertussis vaccine we evaluated can be recommended for general use, since it has a favorable safety profile and confers sustained protection against pertussis. The two-component acellular vaccine and the whole-cell vaccine were less efficacious.

Effects of Bordetella pertussis toxin pretreatment on the antiarrhythmic action of ischaemic preconditioning in anaesthetized rats.

1. Bordetella pertussis toxin, which catalyses the ADP-ribosylation of certain guanine nucleotide binding proteins (G proteins), thus functionally uncoupling them from associated receptors, was examined to determine whether it modified the antiarrhythmic effect of ischaemic preconditioning in anaesthetized rats. 2. Pertussis toxin (25 micrograms kg-1, i.p., 48 h prior to heart isolation) attenuated the negative chronotropic effect of acetylcholine (ACh) in rat isolated Langendorff perfused hearts. ACh (10 microM) reduced heart rate by 4% in hearts taken from pertussis toxin-treated animals, compared to a reduction of 57% in hearts taken from animals treated only with vehicle. 3. In anaesthetized rats, ischaemic preconditioning (a single 3 min occlusion of the left main coronary artery followed by 10 min reperfusion) had a pronounced antiarrhythmic effect during a subsequent 30 min period of regional myocardial ischaemia. Compared to hearts receiving only a 30 min period of left coronary occlusion, there was a reduced mortality (67% and 0% for control and preconditioned groups, respectively; P < 0.01) and decreased incidences of ventricular tachycardia (VT) and ventricular fibrillation (VF). Pretreatment with pertussis toxin (25 micrograms kg-1, i.p., 48 h previously) did not modify the arrhythmias associated with a 30 min period of regional myocardial ischaemia, neither did it modify the reduction in mortality (from 56% to 0%; P < 0.05) associated with preconditioning. Furthermore, the decrease in total ventricular premature beat count induced by preconditioning seen in controls (from 427 +/- 130 to 95 +/- 45) was also seen in pertussis toxin-treated rats (from 252 +/- 190 to 57 +/- 25). 4. These results suggest that receptor coupling to pertussis toxin-sensitive G proteins is not necessary for the antiarrhythmic effect of ischaemic preconditioning in this model.

Development and clinical testing of an acellular pertussis vaccine containing genetically detoxified pertussis toxin.

In 1924 Ramon described the inactivation of diphtheria toxin by formaldehyde treatment. This method allowed the introduction of mass vaccination against diphtheria and tetanus and opened the way to the inactivation of viruses by chemical treatment. In this review we describe the use of genetic manipulations for the inactivation of pertussis toxin. The toxin inactivated by this new method is an antigen superior to those obtained by chemical treatment and has been used to develop a new vaccine against whooping cough.

Anti-invasive activities of experimental chemotherapeutic agents.

We have discussed a number of agents that affect invasion and we have grouped them according to their most probable targets. This strategy is based on the following hypothesis. Invasion is the result of cellular responses to extracellular signals. Candidate signals are components of the extracellular matrix, which are rendered inactive by the flavonoid (+)-catechin (see Section III). Signals are recognized by receptors on the plasma membrane, possibly glycoproteins, that may lose their recognition function through alteration of the oligosaccharide side chains by inhibitors of protein glycosylation (see Section IV) and possibly also by alkyllysophospholipids (see Section V). Synthetic oligopeptides reflecting sequences from cell-binding domains of extracellular matrix molecules are also effective tools for blocking specific receptors (see Section VI). GTP-binding proteins (G proteins) act as signal transducers and can be inactivated by pertussis toxin (see Section VII). An intriguing aspect of both alkyllysophospholipids and pertussis toxin is that they can either inhibit the invasion of constitutively invasive cells or induce invasion of constitutively noninvasive cells. Without doubt, cellular responses implicated in invasion are many-fold. Discussed here are cell motility and directional migration with inhibition through dipyridamole and its analogs and through microtubule inhibitors, respectively (see Section VIII). Alternative hypotheses and alternative strategies for the dissection of the invasion process do exist, and alternative cellular and molecular mechanisms of action may explain the anti-invasive activity of the agents discussed earlier. The latter are mentioned in each section. It is the authors' opinion that the possibilities for exploiting the battery of anti-invasive agents have by no means been exhausted. Introducing researchers to experiments that may lead to an understanding of the mechanisms of invasion and metastasis and to new rationales for cancer treatment has been the purpose of our review.

Characterization and clinical study on the acellular pertussis vaccine produced by a combination of column purified pertussis toxin and filamentous hemagglutinin.

Bordetella Pertussis Tohama phase I was cultured in a 300-liter fermentor using a medium containing 0.1% heptakis (2,5-0-dimethyl) beta-cyclodextrin (MeCD). Pertussis toxin (PT) and filamentous hamagglutinin (FHA) were purified using affinity and ion exchange gel column chromatographies. Endotoxin contents of these antigens (10 micrograms PN/ml) were less than 10 ngLPS/ml. PT and FHA were independently treated with formalin in the presence of amino acid and were mixed at a protein concentration ratio of 1:4, the same ratio of our commercialized acellular pertussis vaccine. PDT vaccine containing 2 micrograms PN of PT and 8 micrograms PN of FHA per milliliter was prepared. This PDT vaccine satisfied all the items of the Japanese Minimum Requirements including potency and toxicity tests. Even after this vaccine was incubated for 4 weeks at 37 degrees C, no deaths of the inoculated mice were observed after challenge with 4 mg of histamine on the 4th and 12th day of the inoculation. Compared with the conventional vaccine, this new vaccine caused less swelling in the mouse footpad test. A field trial of our two vaccines, one manufactured by the conventional method (lot No. 21A) and the other produced by the new method (lot No. KC8702), revealed that children receiving KC8702 showed almost the same anti-PT and anti-FHA antibody levels as those given 21A. Those who received KC8702 suffered from less local side effects such as redness, swelling or induration than those given 21A. Our new method for the production of acellular pertussis vaccine permits us the economical manufacturing of the vaccine with uniform quality in a closed system.

Inhibition of lymphoma invasion and liver metastasis formation by pertussis toxin.

We have examined whether pertussis toxin, an agent known to inhibit entry of normal lymphocytes into tissues, affects invasion and metastasis formation by malignant lymphoma and T-cell hybridoma cells. The toxin reduced invasion in vitro in hepatocyte cultures to 20% of control values. Inhibition was maximal after pretreatment for 2 h with approximately 100 ng/ml. The effect of pretreatment with 1 to 5 micrograms toxin/ml for 4 h persisted for at least 5 days, despite a more than 100-fold increase in cell number. The proliferation rate was not affected. Liver metastasis formation after tail vein injection of TAM2D2 T-cell hybridoma cells in syngeneic AKR mice, measured as liver weight, was reduced to 10 to 25% of controls after pretreatment of the cells for 4 h with 1 microgram pertussis toxin/ml. Metastasis to kidneys, ovaries, and lymph nodes was not, or less evidently, affected. With MB6A lymphosarcoma cells no effect was seen after treatment with 1 microgram/ml, but a significant reduction of the liver tumor burden to approximately 50% of controls was achieved by treatment with at least 5 micrograms toxin/ml. Spleen metastasis by MB6A cells was not affected. These results provide evidence for a similarity in invasion mechanisms of normal and malignant lymphoid cells, and they suggest that invasiveness is an important factor in the formation of lymphoma metastases, particularly in the liver.