Go Ohe

Mechanism for bone invasion of oral cancer cells mediated by interleukin-6 in vitro and in vivo

Osteoclastic bone resorption is an important step in bone invasion in several malignancies. Although interleukin (IL)‐6 accelerates osteoclastic bone resorption, it remains unclear whether IL‐6 may be involved in bone invasion of oral cancer.

Severe impairment of anti-cancer effect of lipoteichoic acid-related molecule isolated from a penicillin-killed Streptococcus pyogenes in toll-like receptor 4-deficient mice.

A lipoteichoic acid-related molecule (OK-PSA) isolated from OK-432, a penicillin-killed Streptococcus pyogenes, is a potent inducer of Th1 cytokines, and elicits anti-cancer effect in tumor-bearing mice. Toll-like receptor (TLR) 4 is a member of the recently identified toll-like receptor family of proteins that has been implicated in lipopolysaccharide-induced cell signaling. In the present study, we have examined the role of TLR4 for OK-PSA-induced Th1-cytokine production and anti-tumor effect by using C3H/HeJ mice in which TLR4 function is impaired. Although OK-PSA strikingly induced Th1 cytokines [interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-2, IL-12 and IL-18] in the splenocytes derived from control animals (C3H/HeN), OK-PSA did not induce the cytokines in the splenocytes from C3H/HeJ. Furthermore, C3H/HeJ-derived splenocytes acquired the responsiveness to OK-PSA stimulation by overexpression of TLR4 gene. Finally, OK-PSA administration significantly inhibited the tumor growth and lung metastasis of syngeneic squamous cell carcinoma cells in C3H/HeN; however, no effect of OK-PSA was observed in C3H/HeJ. These findings strongly suggest that TLR4 signaling is involved in regulating OK-PSA-induced anti-cancer immunity.

Enhancement of anti-cancer immunity by a lipoteichoic-acid-related molecule isolated from a penicillin-killed group A Streptococcus

Abstract. We isolated the lipoteichoic-acid-related molecule (OK-PSA) from OK-432, a streptococcal preparation, by affinity chromatography on CNBr-activated Sepharose-4B-bound monoclonal antibody TS-2, which neutralizes the interferon (IFN)-γ-inducing activity of OK-432. We have previously reported that OK-PSA is a potent inducer of Th1-type cytokines in human peripheral blood mononuclear cells in vitro. In this study, we conducted an animal experiment to examine whether OK-PSA exhibits an anti-tumor effect in vivo by acting as a Th1 inducer in syngeneic Meth-A tumor-bearing BALB/c mice, in which the Th2 response is genetically dominant. It was found that OK-PSA induced Th1-type cytokines [IFN-γ, tumor necrosis factor-α, interleukin (IL)-2, IL-12 and IL-18] in BALB/c mice bearing Meth-A tumor and caused a marked anti-tumor effect. Although it was suggested by an in vitro study, using spleen cells derived from the animals, that IL-18 plays the greatest role in the induction of the Th1-dominant state and tumor cell killing induced by OK-PSA, the in vivo experiments demonstrated that both IL-12 and IL-18 are essential in the anti-tumor effect exhibited by OK-PSA. These findings strongly suggest that OK-PSA is a major effector molecule of OK-432 and may be a useful immunotherapeutic agent, as a potent Th1 inducer, for cancer patients with a Th2-dominant state.

Cytokine-inducing activity and antitumor effect of a liposome-incorporated interferon-γ-inducing molecule derived from OK-432, a streptococcal preparation

An interferon-gamma (IFN-gamma)-inducing molecule (OK-PSA) has been purified from OK-432 by an affinity chromatographic technique performed on cyanogen bromide-activated Sepharose 4B-bound TS-2 monoclonal antibody, which neutralizes IFN-gamma-inducing activity of OK-432. OK-PSA has striking anti-tumor activity in vivo and in vitro. In the current study, the liposomes were used to improve the delivery of the agent (OK-PSA) to effector cells and to increase the therapeutic effect. Significantly less OK-PSA encapsulated into liposomes (Lipo-OK-PSA) than OK-PSA alone (1/100 or less of OK-PSA alone) was required to induce IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), TNF-beta, interleukin-1 beta (IL-1 beta), natural killer, and lymphokine-activated killer activities by human peripheral blood mononuclear cells and mouse spleen cells. Furthermore, higher levels of these activities were detected in peripheral blood mononuclear cells and mouse spleen cells treated with Lipo-OK-PSA than in those treated with OK-PSA. All of these activities induced by Lipo-OK-PSA were almost completely neutralized by anti-asialo-GM1 antibody and complement (p < 0.001). In in vivo experiments, Lipo-OK-PSA elicited striking anti-tumor activity on syngeneic Meth-A tumor-bearing and colon 26-bearing BALB/c mice and on salivary gland tumor-bearing nude mice far better than did OK-PSA. Furthermore, high levels of natural killer and lymphokine-activated killer activities and a significant increase in the number of cells positive for asialo-GM1, IFN-gamma, TNF-alpha, or IL-1 beta were detected in the spleen cells derived from the animals given Lipo-OK-PSA compared with those given saline. These findings clearly indicate that OK-PSA plays an important role in the anti-tumor efficiency of OK-432, and that, for the most part, liposome encapsulation of this molecule markedly accelerates its effect mediated by asialo-GM1-positive cells (mainly natural killer cells).

cis-Diamminedichloroplatinum and 5-fluorouracil are potent inducers of the cytokines and natural killer cell activity in vivo and in vitro

Abstract It has been reported that certain chemotherapeutic agents exhibit effects that enhance the antitumor host responses in the patients with malignant diseases. In the present study, we investigated whether cis-diamminedichloroplatinum (cisplatin) and 5-fluorouracil (5-FU) may induce cytokines and effector cells with antitumor efficacy in vivo and in vitro. The cultivation of human peripheral blood mononuclear cells (PBMC) in the presence of cisplatin (0–1.0 μg/ml) or 5-FU (0–5.0 μg/ml) resulted in the significant augmentation of natural killer (NK) and lymphokine-activated killer (LAK) cell activities as well as generation of interferon (IFN) γ, tumor necrosis factor (TNF) α, β, interleukin(IL)-1β, IL-6 and IL-12 in vitro. In addition, all of these activities were almost completely neutralized by addition of anti-asialoGM1 antibody and complement (P < 0.05). In an in vivo model, the administration of anti-asialoGM1 antibody significantly shortened the survival time extended by the treatment with cisplatin or 5-FU (P < 0.05), both on nude mice bearing salivary gland tumors and on syngeneic MethA-tumor-bearing BALB/c mice. Furthermore, high levels of NK and LAK activities and significant increases of the numbers of cells positive for asialoGM1, IFNγ, TNFα, or IL-1β were detected in the spleen cells derived from animals given cisplatin or 5-FU as compared with those given saline (P < 0.001–0.05). These findings clearly indicate that cisplatin and 5-FU are potent inducers of several types of cytokines and effector cells carrying antitumor activity mediated by asialoGM1-positive cells (mainly NK cells) for the most part, and that these abilities are closely associated with the in vivo antitumor effect of these agents.

Induction of cytokines and killer cell activities by cisplatin and 5-fluorouracil in head and neck cancer patients.

It has been suggested that certain antitumor agents stimulate antitumor immunity. In the present study, we examined whether cisplatin and 5-fluorouracil (5-FU) accelerate the antitumor host responses in head and neck cancer patients. Two groups of patients were studied, i.e. an untreated (UT) group and a treated, disease-free (TDF) group that received chemo-immunotherapy in combination with radiotherapy and operation. When peripheral blood mononuclear cells (PBMC) derived from head and neck cancer patients were treated with cisplatin or with 5-FU, interferon-γ, tumor necrosis factor (TNF)-α, TNF-β, interleukin (IL)-1β, IL-6, IL-12 and IL-18 as well as killer cell activities were significantly induced in both groups. In this case, these activities induced by cisplatin in UT showed lower levels than those in TDF, whereas the activities induced by 5-FU in the UT group demonstrated almost similar levels to those in TDF. These activities were significantly inhibited by anti-asialo-GM1 antibody. Furthermore, cytokine levels in sera and killer activities of PBMC derived from the cancer patients were significantly increased after cisplatin administration. These findings suggest that cisplatin and 5-FU increase anticancer immunity mediated by induction of cytokines and killer cell activities in patients with head and neck cancer.

Effects of low crystalline carbonate apatite on proliferation and osteoblastic differentiation of human bone marrow cells

Carbonated apatite (CO3Ap) is the inorganic component of bone. We have proposed a new method for the fabrication of CO3Ap blocks based on a dissolution-precipitation method using a synthetic precursor. The aim of this study is to examine the effects of low crystalline CO3Ap on initial cell attachment, proliferation and osteoblastic differentiation of human bone marrow cells (hBMCs) using sintered hydroxyapatite and tissue culture plates as controls. Initial cell attachment and proliferation were assessed with a MTT assay. Expression of osteoblastic markers was examined by reverse transcription-polymerase chain reaction. XRD and FT-IR results showed formation of B-type carbonate apatite with lower crystallinity. No difference was observed for initial cell attachment between HAp and CO3Ap discs. hBMSC attached more significantly on tissue culture plate than on HAp and CO3Ap discs. The number of cells on HAp was higher than that on CO3Ap until day 7, after which the number of cells was similar. hBMSC proliferated more significantly on tissue culture plate than on HAp and CO3Ap discs. In contrast, hBMCs incubated on CO3Ap demonstrated much higher expression of osteoblastic markers of differentiation, such as type I collagen, alkaline phosphatase, osteopontin and osteocalcin, than hBMCs on HAp. On the tissue culture plate, they were not any change throughout the culture period. These results demonstrated that low crystalline CO3Ap exhibit higher osteoinductivity than HAp.

Comparison of cytokine-inducing activity in a lipoteichoic acid-related molecule isolated from a penicillin-killed group A Streptococcus and from untreated bacteria.

We previously generated a monoclonal antibody, TS-2, that neutralizes the interferon (IFN)-gamma-inducing activity of OK-432, a penicillin-killed streptococcal preparation [J. Immunother. 13 (1993) 232]. Expression of the TS-2-binding antigen was markedly higher in the cell wall of the penicillin-treated Streptococcus pyogenes (OK-432) than in the untreated bacteria (Su-BBM). We here isolated the antigens from OK-432 and Su-BBM, designated OK-PSA and Su-PSA, respectively. OK-432 markedly induced IFN-gamma and interleukin (IL)-18 as compared with Su-BBM in human peripheral blood mononuclear cells (PBMC). Furthermore, all of the Thl-type and Th1-inducing cytokines tested [IFN-gamma, tumor necrosis factor (TNF)-alpha, IL-12 and IL-18] were secreted by OK-PSA-stimulated PBMC far better than by Su-PSA-treated PBMC. In addition, the cytolytic activities of the PBMC were accelerated by the stimulation with OK-432 or OK-PSA far better than by the stimulation with Su-BBM or Su-PSA. These findings strongly suggested that OK-PSA is a highly important molecule of OK-432 and may be a useful immunotherapeutic agent for the patients with malignant diseases as a potent Th inducer. It was also shown that penicillin treatment effectively enhances OK-PSA-induced anti-cancer immunity.

Toll-Like Receptor 4 Mediates the Antitumor Host Response Induced by a 55-Kilodalton Protein Isolated from Aeginetia indica L., a Parasitic Plant

ABSTRACT A 55-kDa protein named AILb-A, isolated from the seed extract of Aeginetia indica L., a parasitic plant, induces a Th1-type T-cell response and elicits a marked antitumor effect in tumor-bearing mice. In the present study, we examined the role of Toll-like receptors (TLRs), which have been implicated in pathogen-induced cell signaling, in AILb-A-induced immune responses. In the luciferase assay using a nuclear factor (NF)-κB-dependent reporter plasmid, AILb-A induced NF-κB activation in the cells transfected with TLR4, but not with those transfected with the TLR2 gene, in a dose-dependent manner. TLR4-mediated NF-κB activation induced by AILb-A but not by lipopolysaccharide (LPS) was also observed under serum-free conditions. In in vitro experiments using human peripheral blood mononuclear cells, AILb-A-induced cytokine production was markedly inhibited by anti-TLR4 but not by anti-CD14 antibody, while LPS-induced, TLR4-mediated cytokine production was inhibited by anti-CD14 as well as anti-TLR4 antibodies. Cytokine production, killer cell activities, maturation of dendritic cells, phosphorylation of mitogen-activated protein kinases, and nuclear translocation of interferon-regulatory factor 3 induced by AILb-A were severely impaired in TLR4-deficient but not TLR2-deficient mice. Transfection of TLR4-deficient mouse-derived macrophages with the TLR4 expression plasmid led AILb-A to induce cytokines. Finally, the antitumor effect of AILb-A was also impaired in TLR4-deficient and TLR4-mutated mice. These findings suggest that TLR4 mediates antitumor immunity induced by the plant-derived protein AILb-A.

Allergic contact dermatitis caused by titanium screws and dental implants

PATIENTS Titanium has been considered to be a non-allergenic material. However, several studies have reported cases of metal allergy caused by titanium-containing materials. We describe a 69-year-old male for whom significant pathologic findings around dental implants had never been observed. He exhibited allergic symptoms (eczema) after orthopedic surgery. The titanium screws used in the orthopedic surgery that he underwent were removed 1 year later, but the eczema remained. After removal of dental implants, the eczema disappeared completely. DISCUSSION Titanium is used not only for medical applications such as plastic surgery and/or dental implants, but also for paints, white pigments, photocatalysts, and various types of everyday goods. Most of the usage of titanium is in the form of titanium dioxide. This rapid expansion of titanium-containing products has increased percutaneous and permucosal exposure of titanium to the population. CONCLUSIONS In general, allergic risk of titanium material is smaller than that of other metal materials. However, we suggest that pre-implant patients should be asked about a history of hypersensitivity reactions to metals, and patch testing should be recommended to patients who have experienced such reactions.