Total body fluid is the factor that affects the pharmacokinetics of tolvaptan, and its efficacy, in acute worsening heart failure patients.

The optimal starting dose of tolvaptan to effectively improve fluid retention in patients with heart failure (HF) is unknown. This study explored the factors affecting the pharmacokinetics (PKs) and pharmacodynamics of tolvaptan in patients with decompensated HF. We prospectively enrolled patients who were slated to receive tolvaptan because of volume overload associated with chronic HF. Blood samples were collected to measure tolvaptan concentrations before and 4, 8, 12-15, 24, and 144 h after administration. Additionally, demographic parameters, coadministered drugs, and body fluid composition were evaluated. Multiple regression analysis to detect PK parameters for the prediction of body weight (BW) loss at day 7 after the initiation of tolvaptan treatment and PK analysis to explore the factors affecting the PKs of tolvaptan were performed. In total, 165 blood samples were obtained from 37 patients. The predictors of weight loss on day 7 were area under the curve (AUC0-∞ ) of tolvaptan. PK analysis of the data revealed a strong correlation between CL/F and Vd/F, but no correlation between CL/F and kel (r = .95 and .06, respectively). A significant correlation was observed between total body fluid and Vd/F, and this correlation remained statistically significant even after adjusting for BW (r = .49, p < .05). Fat was also significantly correlated with Vd/F before adjusting for BW, on the other the correlation disappeared after adjusting BW. The optimal dose of tolvaptan based on total body fluid levels in individual patients could result in the alleviation of fluid retention in patients with HF.

Effectiveness of a pharmaceutical instruction video for adherence to dermatopathy treatment in patients with cancer receiving the anti-epidermal growth factor receptor antibody.

BACKGROUND: Dermatopathy develops as a side effect in patients receiving anti-epidermal growth factor receptor antibody treatment. Topical moisturizers are used for the prevention and treatment of this dermatopathy. Active participation of patients in their own treatment is important for the appropriate application of topical preparations. We prepared a pharmaceutical instructional video for adhering to the topical application protocol. In this study, we investigated the effectiveness of this pharmaceutical instructional video on treatment adherence. METHODS: Study participants were patients with cancer receiving the anti-epidermal growth factor receptor antibody for the first time. A pharmacist instructed the patients on how to use the pharmaceutical instruction video. Daily topical preparation use following the video demonstration was assessed. The effectiveness of the pharmaceutical instruction video was evaluated by assessing the adherence of patients who did not use the pharmaceutical instruction video for the past 2 periods (26 months; controls 1 and 2). The incidence of side effects was compared between the two control groups and the group of patients who received the pharmaceutical instruction video. RESULTS: The amount of topical preparation consumed (median, g/day) by patients who received patient compliance instructions using the pharmaceutical instruction video was 9.8 g/day, as compared with control group 1 (4.5 g/day) and control group 2 (5.5 g/day) (p < 0.001). There was no difference in the incidence of side effects during the three periods. CONCLUSION: The use of visual instructional media for patient compliance by pharmacists may be effective in maintaining and improving treatment adherence.

Computational analysis of morphological and molecular features in gastric cancer tissues.

Biological morphologies of cells and tissues represent their physiological and pathological conditions. The importance of quantitative assessment of morphological information has been highly recognized in clinical diagnosis and therapeutic strategies. In this study, we used a supervised machine learning algorithm wndchrm to classify hematoxylin and eosin (H&E)-stained images of human gastric cancer tissues. This analysis distinguished between noncancer and cancer tissues with different histological grades. We then classified the H&E-stained images by expression levels of cancer-associated nuclear ATF7IP/MCAF1 and membranous PD-L1 proteins using immunohistochemistry of serial sections. Interestingly, classes with low and high expressions of each protein exhibited significant morphological dissimilarity in H&E images. These results indicated that morphological features in cancer tissues are correlated with expression of specific cancer-associated proteins, suggesting the usefulness of biomolecular-based morphological classification.

Loss of the integral nuclear envelope protein SUN1 induces alteration of nucleoli.

A supervised machine learning algorithm, which is qualified for image classification and analyzing similarities, is based on multiple discriminative morphological features that are automatically assembled during the learning processes. The algorithm is suitable for population-based analysis of images of biological materials that are generally complex and heterogeneous. Here we used the algorithm wndchrm to quantify the effects on nucleolar morphology of the loss of the components of nuclear envelope in a human mammary epithelial cell line. The linker of nucleoskeleton and cytoskeleton (LINC) complex, an assembly of nuclear envelope proteins comprising mainly members of the SUN and nesprin families, connects the nuclear lamina and cytoskeletal filaments. The components of the LINC complex are markedly deficient in breast cancer tissues. We found that a reduction in the levels of SUN1, SUN2, and lamin A/C led to significant changes in morphologies that were computationally classified using wndchrm with approximately 100% accuracy. In particular, depletion of SUN1 caused nucleolar hypertrophy and reduced rRNA synthesis. Further, wndchrm revealed a consistent negative correlation between SUN1 expression and the size of nucleoli in human breast cancer tissues. Our unbiased morphological quantitation strategies using wndchrm revealed an unexpected link between the components of the LINC complex and the morphologies of nucleoli that serves as an indicator of the malignant phenotype of breast cancer cells.

Computational image analysis of colony and nuclear morphology to evaluate human induced pluripotent stem cells.

Non-invasive evaluation of cell reprogramming by advanced image analysis is required to maintain the quality of cells intended for regenerative medicine. Here, we constructed living and unlabelled colony image libraries of various human induced pluripotent stem cell (iPSC) lines for supervised machine learning pattern recognition to accurately distinguish bona fide iPSCs from improperly reprogrammed cells. Furthermore, we found that image features for efficient discrimination reside in cellular components. In fact, extensive analysis of nuclear morphologies revealed dynamic and characteristic signatures, including the linear form of the promyelocytic leukaemia (PML)-defined structure in iPSCs, which was reversed to a regular sphere upon differentiation. Our data revealed that iPSCs have a markedly different overall nuclear architecture that may contribute to highly accurate discrimination based on the cell reprogramming status.

The development of a filter to enhance the efficacy and safety of excimer light (308 nm) therapy.

BACKGROUND: Excimer light (308 nm) therapy is a new ultraviolet (UV) B phototherapy for which the efficacy and resulting DNA damage are not well established. PURPOSE: To develop an effective and safe phototherapy using the excimer lamp, we studied the effects of different light cut-off filters, A and B. METHODS: Efficacy was evaluated by measuring apoptosis using fluorescence-activated cell sorting analysis. DNA damage was evaluated by measuring cyclobutane pyrimidine dimers (CPDs). Light sources, including normal wave and short wave (SW) excimer light, broad-band (BB) UVB, and narrow-band (NB) UVB, were examined using the filters. A human skin equivalent model was also examined. RESULTS: The ratio of positive apoptosis to CPD formation normalized to the mean induced by NB-UVB was 5.7 using the excimer lamp without a filter, 6.3 using the excimer lamp with the A filter, 6.4 using the SW excimer lamp without a filter, and 4.2 using the BB-UVB. The A filter reduced CPD formation induced by the normal wave and SW excimer lamp. In the human skin equivalent model, the use of filters significantly decreased the amount of CPD-positive cells. CONCLUSIONS: These findings suggest that using the A filter with the excimer lamp increases the efficacy and safety of excimer light therapy.

Induction of regulatory dendritic cells by topical application of NF-kappaB decoy oligodeoxynucleotides.

Dendritic cells (DC) have a key role in inducing an immune response, but DC in different maturation states are responsible for inducing tolerance. Topical application of nuclear factor (NF)-kappaB decoy oligodeoxynucleotides (ODN) induces antigen-specific peripheral tolerance in delayed-type hypersensitivity (DTH) to ovalbumin (OVA) by expanding CD4(+)CD25(+) regulatory T cells and by inhibiting DC migration. Herein we describe how topical NF-kappaB decoy ODN modulate DC maturation with respect to their migration, phenotype, and cytokine profiles. Topical application of NF-kappaB decoy ODN after OVA sensitization delayed the migration of Langerhans cells (LC) into draining lymph nodes, and morphologically mature LC remained in the peripheral tissue 2 days longer than in OVA-sensitized mice without application of NF-kappaB decoy ODN. During migration, NF-kappaB decoy-treated DC preferentially expressed inhibitory B7 molecules (i.e., B7-H1, B7-DC, and B7-H3) compared to OVA-sensitized DC without NF-kappaB decoy ODN, whereas co-stimulatory molecules (MHC class II, B7-1 and B7-2) were upregulated. Adoptive transfer of NF-kappaB decoy-treated DC inhibited DTH induction in prophylactic and therapeutic experiments. Inhibition of DTH by DC transfer was antigen-specific in vivo. This decoy ODN strategy might be useful for regulating immunity through DC.

Protective effect of nasal immunization of influenza virus hemagglutinin with recombinant cholera toxin B subunit as a mucosal adjuvant in mice.

To develop an efficient nasal influenza vaccine, influenza A and B virus HA with rCTB as a mucosal adjuvant were administered to mice intranasally. Serum anti-HA IgG and IgA antibody responses for both HA vaccines were significantly increased in the presence of rCTB. Higher HI and neutralizing antibody titers and higher mucosal IgA antibody responses in the respiratory tract were detected when rCTB was added than without rCTB. When mice were immunized with HA vaccine with or without rCTB and challenged by intranasal administration of mouse-adapted pathogenic influenza A virus, all mice immunized with HA plus rCTB survived for seven days without any inflammatory changes in the lungs, while not all the mice immunized with HA without rCTB survived, and all of them had lung consolidations. These results demonstrate that intranasal co-administration of rCTB as a mucosal adjuvant with influenza virus HA is necessary not only for the induction of systemic and mucosal HA antibodies, but also for the protection of mice from morbidity and mortality resulting from virus infection.

Narrowband ultraviolet B radiation suppresses contact hypersensitivity.

BACKGROUND/PURPOSE: A main mechanism responsible for the efficacy of narrowband ultraviolet (UV)B is thought to be the induction of apoptosis in pathogenetically relevant cells. Narrowband UVB therapy, however, generally induces a relatively long remission period. Recently, evidence that UVB radiation induces regulatory T (Treg) cells was reported. Based on these findings, we examined whether narrowband UVB suppresses contact hypersensitivity (CHS) by inducing Treg cells. METHODS: The shaved abdomens of C3H/HeN mice were irradiated with broadband or narrowband UVB. CHS was defined as an ear-swelling response. To examine whether tolerance can be induced by adoptive transfer, lymph node cells from UVB-irradiated mice were injected into naïve mice before sensitization and CHS challenge. RESULTS: Narrowband UVB exposure dose dependently suppressed CHS. Significant suppression was observed at doses between 1000 and 3000 mJ/cm(2) (P<0.05). The suppressive effect achieved with 1000 mJ/cm(2) narrowband UVB was very similar to the effect achieved with 100 mJ/cm(2) broadband UVB. The suppressive effects on CHS were transferred to naïve mice by the injection of lymph node cells from tolerant mice. CONCLUSION: Narrowband UVB induced local and systemic suppression of CHS. In addition, narrowband UVB induces tolerance to CHS and the suppressive effects were transferable to naïve mice.

Expression and identification of a new splice variant of neuroglycan C, a transmembrane chondroitin sulfate proteoglycan, in the human brain.

Neuroglycan C (NGC) is a transmembrane chondroitin sulfate proteoglycan with an EGF module. We studied the expression of NGC in the human brain, mainly in the hippocampus, and confirmed some observations by conducting experiments using rat brain. In humans, NGC mRNA was expressed exclusively in the brain, especially in the immature brain. The telencephalon, including the hippocampus and neocortex, showed strong mRNA expression. NGC was immunolocalized to neuropils in the hippocampus and neocortex of the adult rat. RT-PCR experiments showed that four splice variants (NGC-I, -II, -III, and -IV) were expressed in the adult human hippocampus. By Western blotting, the expression as proteins of all splice variants except NGC-II was confirmed in the adult rat hippocampus. NGC-IV, which was first found in the present study, had the shortest cytoplasmic domain among the four variants. NGC-IV mRNA was expressed by neurons, but not by astrocytes, in culture prepared from the fetal rat hippocampus, suggesting that NGC-IV plays a role specific to neurons. In addition, the human NGC gene, which is registered as CSPG5, comprised six exons and was approximately 19 kb in size. In exon 2, a single nucleotide polymorphism resulting in Val188Gly in the NGC ectodomain was observed.

Expression of Escherichia coli heat-labile enterotoxin B subunit (LTB) in Saccharomyces cerevisiae.

Heat-labile enterotoxin B subunit (LTB) of enterotoxigenic Escherichia coli (ETEC) is both a strong mucosal adjuvant and immunogen. It is a subunit vaccine candidate to be used against ETEC-induced diarrhea. It has already been expressed in several bacterial and plant systems. In order to construct yeast expressing vector for the LTB protein, the eltB gene encoding LTB was amplified from a human origin enterotoxigenic E. coli DNA by PCR. The expression plasmid pLTB83 was constructed by inserting the eltB gene into the pYES2 shuttle vector immediately downstream of the GAL1 promoter. The recombinant vector was transformed into S. cerevisiae and was then induced by galactose. The LTB protein was detected in the total soluble protein of the yeast by SDS-PAGE analysis. Quantitative ELISA showed that the maximum amount of LTB protein expressed in the yeast was approximately 1.9% of the total soluble protein. Immunoblotting analysis showed the yeast-derived LTB protein was antigenically indistinguishable from bacterial LTB protein. Since the whole-recombinant yeast has been introduced as a new vaccine formulation the expression of LTB in S. cerevisiae can offer an inexpensive yet effective strategy to protect against ETEC, especially in developing countries where it is needed most.

Oral vaccination against Helicobacter pylori with recombinant cholera toxin B-subunit.

BACKGROUND: The innocuous pure recombinant cholera toxin B-subunit (rCTB) is very attractive as a strong adjuvant for host immunization, but little is known about rCTB's gastric mucosal immunoadjuvanticity against Helicobacter pylori. The immunoadjuvanticity of rCTB against H. pylori was tested. MATERIAL AND METHODS: Mice were immunized with sonicated H. pylori and rCTB orally or intranasally and sacrificed on day 42 after immunization. Passive cutaneous anaphylaxis (PCA) test was performed to evaluate IgE-mediated anaphylaxis with serum from mice to which H. pylori-antigen with rCTB had been administered. Immunoglobulin titer specific to H. pylori in serum, lavation of the gastrointestinal tracts and feces were examined. Gastritis in vaccinated mice after a challenge was assessed with the scoring defined from grading of gastric inflammation. H. pylori proliferation after immunization was investigated by counting colony forming units (CFU) per gram of stomach tissue. RESULTS: PCA test exhibited no reactions against the serum from mice immunized with H. pylori-antigen with rCTB administered orally and intranasally. Oral and nasal coadministrations of rCTB significantly raised systemic and mucosal immunities against H. pylori and suppressed proliferation of H. pylori in gastric mucosa. The score of gastritis in mice immunized orally was significantly higher than that of mice immunized nasally due to postimmunization gastritis. Only oral administration of rCTB suppressed H. pylori proliferation as compared with intranasal administration and without rCTB. CONCLUSIONS: The present study indicated that rCTB has systemic and mucosal immunoadjuvanticities against H. pylori and that oral vaccination with rCTB might additively support antibiotic eradication.

Recombinant cholera toxin B subunit activates dendritic cells and enhances antitumor immunity.

Activation of dendritic cells (DC) is crucial for priming of cytotoxic T lymphocytes (CTL), which have a critical role in tumor immunity, and it is considered that adjuvants are necessary for activation of DC and for enhancement of cellular immunity. In this study, we examined an adjuvant capacity of recombinant cholera toxin B subunit (rCTB), which is non-toxic subunit of cholera toxin, on maturation of murine splenic DC. After the in vitro incubation of DC with rCTB, the expression of MHC class II and B7-2 on DC was upregulated and the secretion of IL-12 from DC was enhanced. In addition, larger DC with longer dendrites were observed. These data suggest that rCTB induced DC maturation. Subsequently, we examined the induction of tumor immunity by rCTB-treated DC by employing Meth A tumor cells in mice. Pretreatment with subcutaneous injection of rCTB-treated DC pulsed with Meth A tumor lysate inhibited the growth of the tumor cells depending on the number of DC. Moreover, intratumoral injection of rCTB-treated DC pulsed with tumor lysate had therapeutic effect against established Meth A tumor. Immunization with DC activated by rCTB and the tumor lysate increased number of CTL precursor recognizing Meth A tumor. The antitumor immune response was significantly inhibited in CD8+ T cell-depleted mice, although substantial antitumor effect was observed in CD4+ T cell-depleted mice. These results indicated that rCTB acts as an adjuvant to enhance antitumor immunity through DC maturation and that CD8+ T cells play a dominant role in the tumor immunity. Being considered to be safe, rCTB may be useful as an effective adjuvant to raise immunity for a tumor in clinical application.

Recombinant cholera toxin B subunit (rCTB) as a mucosal adjuvant enhances induction of diphtheria and tetanus antitoxin antibodies in mice by intranasal administration with diphtheria-pertussis-tetanus (DPT) combination vaccine.

Recombinant cholera toxin B subunit (rCTB) which is produced by Bacillus brevis carrying pNU212-CTB acts as a mucosal adjuvant capable of enhancing host immune responses specific to unrelated, mucosally co-administered vaccine antigens. When mice were administered intranasally with diphtheria-pertussis-tetanus (DPT) combination vaccine consisting of diphtheria toxoid (DTd), tetanus toxoid (TTd), pertussis toxoid (PTd), and formalin-treated filamentous hemagglutinin (fFHA), the presence of rCTB elevated constantly high values of DTd- and TTd-specific serum ELISA IgG antibody titres, and protective levels of diphtheria and tetanus toxin-neutralizing antibodies but the absence of rCTB did not. Moreover, the addition of rCTB protected all mice against tetanic symptoms and deaths. DPT combination vaccine raised high levels of serum anti-PT IgG antibody titres regardless of rCTB and protected mice from Bordetella pertussis challenge. These results suggest that co-administration of rCTB as an adjuvant is necessary for induction of diphtheria and tetanus antitoxin antibodies on the occasion of intranasal administration of DPT combination vaccine.

Effects of recombinant cholera toxin b subunit (rCTB) on cellular immune responses: enhancement of delayed-type hypersensitivity following intranasal co-administration of Mycobacterium bovis-BCG with rCTB.

Recombinant cholera toxin B subunit (rCTB) is a safe and potent mucosal adjuvant. To gain insight into the mechanism underlying the adjuvant effect of rCTB, the effects of rCTB on cell-mediated immune responses of mice and guinea pigs were examined after intranasal administration of Mycobacterium bovis -bacillus Calmette-Guérin (BCG) with and without rCTB. Delayed-type hypersensitivity, for skin reactions in guinea pigs and for footpad swelling reactions in mice, to purified protein derivative (PPD) were enhanced by intranasal co-administration of BCG and rCTB, as compared to giving BCG alone to these animals. Moreover, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma production of spleen cells and antigen specific spleen cell proliferation, stimulated with PPD, were enhanced in the presence of rCTB. These results strongly suggest that rCTB enhances cellular as well as humoral immune responses.

Different susceptibility of malignant versus nonmalignant human T cells toward ultraviolet A-1 radiation-induced apoptosis.

Ultraviolet (UV) A-1 (340-400 nm) radiation is highly effective in inducing apoptosis in skin-infiltrating T cells and thereby exerts beneficial effects in patients with T cell-mediated skin diseases. In this in vitro study, we report that malignant and normal T cells differ in their susceptibility toward UVA-1 radiation-induced apoptosis. Dose-response studies revealed that malignant CD4+ T cells isolated from a patient with adult T cell leukemia and Sezary's syndrome as well as malignant T cell lines exhibited a significantly higher susceptibility toward UVA-1 radiation-induced apoptosis 4 h (early apoptosis) and 24 h (late apoptosis) after exposure than normal, CD4+ T cells. This difference was specific for UVA-1 irradiation because it was not detected when apoptosis was induced in these cells through exposure to UVB radiation or stimulation with cell-permeable ceramides. It has been shown that UVA-1 radiation-induced T cell apoptosis is initiated through the generation of singlet oxygen. This is in agreement with the present observation that stimulation of unirradiated cells with a singlet oxygen-generating system induced apoptosis in malignant cells to a greater extent than in normal cells. Moreover, downregulation of FAS surface expression in malignant T cells was associated with the inhibition of UVA-1 radiation/singlet oxygen-induced apoptosis in these cells. It was thus of great interest to learn that addition of the caspase inhibitor Z-VADfmk decreased and interferon-gamma stimulation, which is known to upregulate caspase levels including caspase-3, increased the sensitivity of T cells toward UVA-1 radiation-induced apoptosis. Furthermore, malignant T cells had significantly higher procaspase-3 levels when compared with normal cells. These studies indicate that the susceptibility of human T cells toward UVA-1 radiation-induced apoptosis is related to the availability of caspases such as caspase-3 and that strategies directed at upregulating caspase levels will increase the efficacy of UVA-1 phototherapy.

Frequent nasal administrations of recombinant cholera toxin B subunit (rCTB)-containing tetanus and diphtheria toxoid vaccines induced antigen-specific serum and mucosal immune responses in the presence of anti-rCTB antibodies.

Vaccination via a mucosal route is a very attractive means for immunization, because both local and systemic immune responses are inducible and vaccines can be administered easily and safely from infants to elderly persons. For developing widely applicable mucosal vaccines using recombinant cholera toxin B subunit (rCTB) as a safe adjuvant, we examined whether frequent nasal administrations of rCTB-containing same and different vaccines could induce antigen-specific immune responses without induction of systemic tolerance and suppression by pre-existing anti-rCTB immunity. Ten repetitive nasal administrations to mice of tetanus toxoid (TT) + rCTB or diphtheria toxoid (DT) + rCTB raised and maintained high levels of antigen- and rCTB-specific serum IgG including high levels of tetanus/diphtheria antitoxin titres and raised nasal, salivary, lung, vaginal and fecal secreted IgA, suggesting that the regimen did not induce systemic tolerance to TT/DT and rCTB. Mice successively received repetitive five doses of TT as the first antigen and subsequent five doses of DT as the second antigen, and vice versa, raised serum IgG to the second antigen at various levels including low but sufficient protective levels of antitoxin titres and induced mucosal IgA in the lungs, the vaginas and feces, but hardly in the nasal secretions and salivas. After an interval of 22 weeks between the dosage of the first and second antigens, mice induced serum IgG to the second antigen at high levels and mucosal IgA in all sites. In conclusion, anti-TT and -DT serum and mucosal antibody responses induced by repeated intranasal immunization using rCTB adjuvant lasted for a long period, and for improving the effectivity of vaccination, different rCTB-containing vaccines should be administered at appropriate intervals.

Mucosal and systemic antibody responses against an acellular pertussis vaccine in mice after intranasal co-administration with recombinant cholera toxin B subunit as an adjuvant.

To investigate the possibility of intranasal immunization with an acellular pertussis vaccine, groups of mice were administered intranasally with aluminium-non-adsorbed pertussis toxoid (PTd; 0.5 or 5 microg) and formalin-treated filamentous hemagglutinin (fFHA; 5 microg) with and without recombinant cholera toxin B subunit (rCTB; 10 microg) as a mucosal adjuvant. At a low concentration of PTd, the following things became clear: (1) earlier and higher elevation of serum anti-PTd and anti-FHA IgG antibody titres in the presence of rCTB than in its absence, (2) higher serum anti-PTd and anti-FHA IgG antibody titres than 200 and 100 ELISA units ml(-1) (EU ml(-1)) in all mice, respectively, in the presence of rCTB, which were obtained by calibration against a reference anti-pertussis mouse serum, and (3) in an intranasal challenge experiment with Bordetella pertussis, slightly more rapid elimination of the bacteria from the lungs of mice intranasally immunized in the presence of rCTB, suggesting the effectiveness of rCTB as a mucosal adjuvant. However, irrespective of rCTB and dose of PTd, mice which were immunized four times and sacrificed on day 35 developed high levels of anti-PTd serum IgG antibodies, high or moderate levels of anti-FHA serum IgG antibodies and mucosal anti-PTd IgA antibodies in the lungs; only a slight or no increase of anti-FHA mucosal IgA antibodies was observed in the lung. These facts suggested the immunogenicity and mucosal adjuvanticity of PTd, and therefore, the mucosal adjuvanticity of rCTB seemed to be inconspicuous. Moreover, the addition of rCTB induced higher anti-PTd serum IgE antibody responses than no addition of it depending on dose of PTd. These results show that dose of PTd included in an acellular pertussis vaccine had better be low as possible and the addition of rCTB may not be always necessary in case of this nasal vaccine alone unlike tetanus and diphtheria toxoids and hepatitis B virus vaccine reported before.

Effects of recombinant cholera toxin B subunit on IL-1beta production by macrophages in vitro.

Recombinant cholera toxin B subunit (rCTB) is a safe and potent mucosal adjuvant. As a clue to the mechanism of the adjuvant effect of rCTB, the profile of cytokines secreted in vitro by the mouse peritoneal macrophage (Mphi) treated with rCTB was examined. IL-1beta secretion, intracellular production, and expression of its mRNA of LPS-stimulated Mphi was greatly enhanced by treatment with rCTB. IL-1beta production in response to other microbial stimulators, such as Pansorbin, Sansorbin, insoluble peptidoglycan, and Taxol, was also potentiated by rCTB. Mphi pretreated with rCTB before 24 hr could maintain the ability to produce a high level of IL-1beta, suggesting that this ability may be involved in the adjuvant activity of rCTB on Mphi stimulation. The possibility of close association between rCTB and signal transduction of a Toll-like receptor family in Mphi is discussed.