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

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)-gamma-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-gamma, tumor necrosis factor-alpha, 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.

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.

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.

Th1-cytokine induction and anti-tumor effect of 55 kDa protein isolated from Aeginetia indica L., a parasitic plant.

We have isolated a 55 kDa protein from the seed extract of Aeginetia indica L. (AIL), a parasitic plant, by affinity chromatography on an N-hydroxysuccinimide-activated Sepharose High Performance column bound with F3, a monoclonal antibody that neutralizes the cytokine-inducing and anti-tumor effect of AIL. In the present study, we examined this protein (AILb-A) for cytokine induction and anti-tumor effects by animal study, using syngeneic Meth-A tumor-bearing BALB/c mice, in which the Th2 response is genetically dominant. AILb-A administration resulted in markedly increased levels of Th1 cytokines [interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-2, IL-12 and IL-18] in the sera derived from Meth-A-bearing mice. The in vitro re-stimulation with AILb-A of splenocytes derived from AILb-A-primed mice also selectively induced Th1-type cytokines and antigen-specific killer cell activity. The neutralizing test using cytokine-specific antibodies revealed that AILb-A-induced IL-18 plays a most significant role for and killer cell-inducing activities. Furthermore, IL-12 and IL-18 induced by AILb-A inhibited specifically IL-10 and IL-4 production, respectively. Finally, we examined the anti-tumor effect of AILb-A in both Meth-A-bearing BALB/c mice and Meth-A-bearing nude mice with BALB/c background. AILb-A exhibited a striking anti-tumor effect in normal BALB/c mice inoculated with Meth-A cells. In athymic nude mice, the anti-tumor effect of AILb-A was relatively weak. These findings strongly suggested that AILb-A is a potent Th1 inducer and may be a useful immunotherapeutic agent for patients with malignant diseases.

[A case of intrathoracic extension of retroperitoneal fibrosis].

A 70-year-old man was diagnosed as having retroperitoneal fibrosis 12 years ago. The patient was admitted to our hospital with complaints of fever and left chest pain. On admission, chest radiography revealed left pleural effusion and left pleural thickening. Percutaneous pleural biopsy was performed, and the pleural tissue gave a chronic inflammatory reaction characterized by proliferation of collagen fibers and chronic inflammatory cellular infiltration. Since the retroperitoneal fibrosis had been diagnosed in similar tissue, it was considered that this condition had extended to the pleura. On administration of prednisolone, the intrathoracic lesions and clinical symptoms were improved, but the patient later died of pneumonia. Autopsy showed fibrous pleuritis and chronic fibrosing lung disease. This was an extremely rare case. Prednisolone appears to be useful in the treatment of intrathoracic extension of retroperitoneal fibrosis.

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

BACKGROUND: 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. METHODS: The pit formation assay with calf femur-derived bone slices was performed to examine the bone-resorbing activity of osteoclasts and cancer cells. The chemotaxis activity of the culture media was analyzed by the use of Boyden chamber technique. Nude mice, which were inoculated with IL-6-producing oral cancer cells into masseter, were treated with anti-IL-6 neutralizing antibody, and mandibular-bone invasion of the cells was assessed. RESULTS: BHY, a bone-invasive oral cancer cell line, but not HNT, a noninvasive cell line, produced large amounts of IL-6. In a pit formation assay, addition of conditioned medium (CM) derived from BHY but not HNT increased osteoclastic bone resorption, and the effects were inhibited by anti-IL-6 antibody. BHY-secreted IL-6 showed significant chemotaxis activity for osteoclasts. Of note, CM from the cocultivation of osteoclasts and BHY markedly enhanced the cancer cell migration, and the chemotaxis activity was significantly reduced when anti-IL-6 antibody was added into the coculture and then CM were collected, but not when the antibody was added into the CM after they were collected. Furthermore, treatment with anti-IL-6 antibody almost completely inhibited mandibular bone invasion of BHY in nude mice. CONCLUSIONS: These results strongly suggest that IL-6 secreted by oral cancer cells plays a significant role in bone invasion.

Induction of Th1-type cytokines by lipoteichoic acid-related preparation isolated from OK-432, a penicillin-killed streptococcal agent.

We have isolated the lipoteichoic acid (LTA)-related molecule (OK-PSA) from OK-432, a streptococcal preparation, by an affinity chromatography on CNBr-activated Sepharose 4B-bound TS-2 monoclonal antibody (mAb) that neutralizes interferon (IFN)-gamma-inducing activity of OK-432. In in vitro experiments using human peripheral blood mononuclear cells (PBMC), OK-PSA induced IFN-gamma, interleukin (IL)-2, IL-12, IL-18, tumor necrosis factor (TNF)-alpha and TNF-beta that are generally called "Th1-type cytokines" both in protein and in mRNA levels. Furthermore, the neutralizing test using cytokine-specific antibodies demonstrated that IL-18 plays a most significant role for IFN-gamma- and killer cell-inducing ability of OK-PSA among the other cytokines tested. These findings clearly indicated that OK-PSA, an LTA-related molecule, is a main effective component of OK-432, and is a potent inducer of Th1-type cytokines by T cell and natural killer (NK) cell activation mediated by monocytes-derived IL-18, and that it may be a useful immunotherapeutic agent for the patients with malignancies better than original OK-432.

Purification and characterization of cytokine-inducing protein of seed extract from Aeginetia indica L., a parasitic plant.

We have isolated 55 kDa protein from the seed extract of Aeginetia indica L. (AIL), a parasitic plant, by an affinity chromatography on N-hydroxysuccinimide (NHS)-activated Sepharose High Performance column bound F3 monoclonal antibody which neutralizes cytokine-inducing and antitumor effect of AIL. In in vitro model using human peripheral blood mononuclear cells (PBMC), the 55 kDa protein (AILb-A) induced multiple cytokines, such as IFN-gamma, tumor necrosis factor (TNF)-alpha, granulocyte macrophage-colony stimulating factor (GM-CSF), IL-2, IL-6, IL-10, IL-12 and IL-18, and also accelerated killer cell activities of PBMC. When compared with a commonly used immunotherapeutic agent OK-432, AILb-A induced Th1 cytokines are greater than OK-432. Of the Th2 cytokines, the amounts of IL-6 and IL-10 induced by AILb-A were lower than those by OK-432. No significant induction of IL-4 and IL-13 was observed in AILb-A-stimulated PBMC. TNF family including TNF-alpha, TNF-beta, Fas ligand (FasL) and TNF-related apoptosis-inducing ligand (TRAIL) were suggested to be important for AILb-A-induced killing activity of PBMC by reverse transcription-polymerase chain reaction (RT-PCR) analysis. Furthermore, the neutralizing test using cytokine-specific antibodies demonstrated that IL-18 plays a most significant role for IFN-gamma- and killer cell-inducing ability of AILb-A among the cytokines tested. These findings clearly indicated that AILb-A, a 55 kDa protein of AIL, is a potent Th1 cytokine inducer and may be a useful immunotherapeutic agent for the patients with malignancies.

[Relapse of small cell carcinoma of the lung with metastasis to iris].

We reported a case of small cell carcinoma of the lung with metastasis to the iris during a stage of complete remission obtained with chemotherapy and radiation therapy. The patient was a 55-year-old man hospitalized for hoarseness and abnormal chest radiographs in August 1996. Small cell carcinoma of the lung had been diagnosed, and the stage was limited disease. Treatment consisted of 3 cycles of chemotherapy with cisplatin and etoposide, together with radiation therapy. The patient achieved complete remission and was discharged. In mid-December, he visited an eye clinic with the complaints of blurred vision and congestion in the right eye. Metastatic tumor of the iris was diagnosed. At that time, neither local recurrence of the lung cancer nor metastasis to other organs were observed. The patient was treated with cisplatin and etoposide again, resulting in a reduction of the iris tumor's size. After chemotherapy, the right eye was treated with electron irradiation, and the iris tumor and other clinical signs almost entirely disappeared. The patient retained normal vision during the clinical course.