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We have recently reported that the intra-tumoral injection of adrenomedullin (AM) antagonist (AMA; AM (22-52)) peptides significantly reduced the in vivo growth of a pancreatic cancer cell line in severely combined immunodeficient (SCID) mice. In the present study, we examined the effects of intra-tumoral and intra-muscular transfers of naked DNA encoding AMA on the in vivo growth of cancer cell lines. We demonstrate that these treatments induce the regression of a pancreatic cancer cell line and a breast cancer cell line inoculated in SCID mice. Furthermore, CD31-positive cells disappear completely from tumor tissues, following treatment, indicating that neo-vascularization is entirely inhibited. These results suggest that the intra-tumoral or intra-muscular transfer of naked DNA encoding AMA might be a promising alternative modality for treating human cancers.

Glutathione redox status, changes in intracellular reduced (GSH) or oxidized (GSSG) glutathione, plays a significant role in various aspects of cellular function. In this study, we examined whether intracellular glutathione redox status in human dendritic cells (DCs) regulates the polarization of Th1/Th2 balance.Human monocyte-derived DCs (MD-DCs) treated with glutathione reduced form ethyl ester (GSH-OEt) or L-buthionine-(S,R)-sulfoximine (BSO) were stimulated by lipopolysaccharide (LPS), and the levels of polarization cytokines were measured. Next, DCs matured by LPS or thymic stromal lymphopoietin (TSLP) were cocultured with allogeneic CD4(+) naive T cells and Th1/Th2 balance was evaluated by cytokine production from the primed T cells.Monocyte-derived DCs exposed to GSH-OEt and BSO had increased and decreased intracellular GSH contents, respectively. Lipopolysaccharide-induced interleukin (IL)-27 production was enhanced by GSH-OEt and suppressed by BSO, but neither GSH-OEt nor BSO affected the expression of HLA-DR, CD80, CD83, or CD86. Mature GSH-OEt-treated MD-DCs enhanced interferon (IFN)-γ production from CD4(+) T cells compared with nontreated MD-DCs, and small interfering RNA (siRNA) against IL-27 suppressed the effect of GSH-OEt on IFN-γ production. Additionally, although human myeloid DCs activated by TSLP (TSLP-DCs) prime naïve CD4(+) T cells to differentiate into Th2 cells, treatment of TSLP-DCs with GSH-OEt reduced IL-13 production and enhanced IFN-γ production by CD4(+) T cells. Interleukin-27 siRNA attenuated the inhibitory effect of GSH-OEt on Th2 polarization.Our results reveal that Th1 and Th2 responses are controlled by intracellular glutathione redox status in DCs through IL-27 production.

Five anti-Id mAb (Ab2) were prepared from a BALB/c mouse immunized with anti-carcinoembryonic Ag (CEA) mAb MA208 (Ab1) in a syngeneic system. These anti-Id mAb appear to recognize unique idiotopes at the combining site of mAb MA208, because they were specifically reactive with mAb MA208 and showed the inhibitory activity against the binding of mAb MA208 to CEA. These anti-Id mAb were divided into three groups: group 1 (M7-625), group 2 (M7-413, M7-914), and group 3 (M7-049, M7-418), according to the analysis of anti-anti-Id antibodies (Ab3) induced with each anti-Id mAb (Ab2). Anti-anti-Id mAb M7-625 antisera (Ab3) reacted with purified CEA in binding assay and in Western blot analysis, and competed with Ab1 binding to CEA. Furthermore, the binding of anti-Id mAb M7-625 (Ab2) to mAb MA208 (Ab1) was inhibited with CEA, indicating that Ab2 mimicks the structure of the epitope in CEA which was recognized with Ab1. These serologic findings suggest that anti-Id mAb M7-625 carries the internal image of the Ag. According to the amino acid sequences of CDR 1, 2, and 3 of the mAb M7-625 variable region, there exists a homology of amino acid sequences between CDR2 in the H chain (5 amino acids of 10) and CDR3 in the L chain (3 amino acids of 9) of mAb M7-625 and domain III of CEA (545-554).

Background: Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute severe blistering diseases of the skin and also two of the most devastating ocular surface diseases leading to corneal damage and loss of vision. The extreme rarity of cutaneous and ocular surface reactions to drug therapies led us to suspect individual susceptibility. SJS/TEN patients in the acute stage were reported to manifest increased serum levels of Fas Ligand (FasL). Thus, we performed SNP association analysis of the FasL gene. Methods: In 76 Japanese SJS/TEN patients with ocular surface complications and 160 Japanese healthy controls, we examined four SNPs of FasL reported in the Japanese Single Nucleotide Polymorphisms (JSNP) database by sequencing. Results: The SNP rs.3830150 A/G showed a significant strong inverse association with SJS/TEN. Analysis of the genotype pattern of SNPs rs.3830150 and rs.2639614 (rs.3830150 A/A–rs.2639614 G/G) also manifested a strong inverse association with SJS/TEN. Conclusion: FasL gene polymorphisms might be associated with SJS/TEN.

Activated macrophages upregulate surface expression of common cytokine receptor gamma chains (gammac, CD132), triggering of which induces secretion of proinflammatory cytokines. Rheumatoid synovial tissues contain a number of macrophages that play a pathogenic role by secreting proinflammatory cytokines. We studied the expression of gammac in the rheumatoid synovial tissues.Cryosections of synovial tissues from patients with active rheumatoid arthritis (RA) or with osteoarthritis (OA) were stained with an anti-gammac Mab. Single-cell suspensions from the rheumatoid synovial tissues were stained with the same antibody and an anti-CD14 monoclonal antibody (Mab) for 2-color flow cytometric analysis. A soluble form of gammac in synovial fluids collected from rheumatoid or OA joints was quantitated by ELISA.Rheumatoid synovial tissues, but not the OA tissues, expressed gammac at a high level. Flow cytometric analysis showed that gammac were expressed by virtually all CD 14 positive synovial cells in RA. Synovial fluid derived from the rheumatoid joints contained a high concentration of soluble gammac.Membrane bound and soluble forms of gammac are abundant in rheumatoid joints. They might play a complex role in the pathology of RA.

Lentinan, an antitumor polysaccharide, has been assessed for its potential in vivo to augment erythroid progenitor cells and protect them from the cytotoxic effects of antitumor chemotherapeutics. Lentinan augmented the level of burst-forming units-erythroid (BFU-E) and accelerated the recovery of the reduced number of BFU-E in mice treated with 5-fluorouracil (5-FU); lentinan did not influence red blood cell counts or colony-forming unit-erythroid (CFU-E) numbers in the femoral marrow. A significant decrease in stem cell inhibitory factor (SCIF) activities in bone marrow and an increase in colony-forming unit-spleen (CFU-S) formation were observed in the lentinan-treated mice. The mechanism of augmented BFU-E formation may be partly due to augmented production of stem cells, giving rise to both CFU-GM and BFU-E. Furthermore, when lentinan administration was followed by administration of erythropoietin (Epo) in 5-FU-treated mice, increases in femoral marrow and splenic CFU-E formation and augmentation of reticulocyte counts were observed beyond the level observed in mice treated with Epo alone. These results suggest that lentinan may augment the effects of Epo on erythropoiesis in the course of anemia and the decreased erythropoiesis in cancer patients receiving chemotherapy.

To determine whether resistance to chemoimmunotherapy is acquired during therapy, we investigated the effects of chemotherapeutic agents and anti-tumour polysaccharide, lentinan, on the progression of Rous sarcoma virus-induced S908.D2 fibrosarcomas. The chemoimmunotherapy was effective against the parental S908.D2-bearing mice. Nearly all the mice that were treated with cyclophosphamide (CY) and lentinan achieved complete tumour regression. Only a few of the mice that achieved complete regression of the primary tumours showed a recurrence of the tumour in regional lymph nodes. S908.D2-vp.1 was established from metastatic tumours that developed in the regional lymph nodes of parental S908.D2-bearing mice during therapy. S908.D2-vp.2-or vp.3 cells were sequentially derived in a similar way from S908.D2-vp.1-or-vp.2-bearing mice respectively, in which complete tumour regression at each primary site was achieved during therapy. These lines acquired resistance to CY and lentinan and also to 5-fluorouracil (5-FU)/5'-deoxy-5-fluorouracil and lentinan. No significant difference in either the sensitivity to 5-FU or 4-deoxycyclophosphamide in vitro or in the susceptibility to immune effector cells was observed between the parental and progressed lines (S908.D2-vp1 -vp3). There was an increase in the level of prostaglandin E2 (PGE2) in the progressed lines during repeated therapy (parental, 1171 pg ml(-1); vp.1, 2199 pg ml(-1); vp.2, 5500pg ml(-1); vp3, 16187 pg ml(-1)). There was no significant increase in the production of transforming growth factor beta (TGF-beta). The amount of interleukin-2 (IL-2) produced by spleen cells isolated from the S908.D2-vp.2-bearing mice was decreased compared with the amount produced by the parental S908.D2- bearing mice. Furthermore, combination therapy with lentinan and IL-2 achieved complete tumour regression in all the mice transplanted with S908.D2 progressed tumour lines, although IL-2 alone did not show any anti-tumour effects in either the S908.D2 parental or progressed lines. The findings suggest that the reduced production of IL-2 induced an increase in the production of the PGE2 by progressed tumour lines is involved in the acquisition of resistance.

Lentinan was administered for gastric cancer in order to determine what type of changes would occur as a consequence. In an experimental study, the intraperitoneal administration of lentinan on cancerous tissues caused a marked development of reticular fibers, along with an enhanced interstitial response. Findings which support the relationship between a marked development of reticular fibers and an anti-tumor effect, were also obtained. Furthermore, lentinan was administered for human gastric cancer to evaluate whether or not an increase in interstitial response would be observed. As a result, reticular fibers developed in tumor sites with a resultant fragmentation of cancer cell nests. Many T lymphocytes infiltrated cancer sites where the lentinan was administered. These findings suggest that the intratumor administration of lentinan enhanced an interstitial response and also activated an anti-tumor immune response in the human gastric cancer tissues.

The neu oncogene product, p185neu, is a tyrosine kinase receptor with structural similarity to the epidermal growth factor (EGF) receptor. We have recently described that coexpression of EGF receptors and high levels of normal p185c-neu lead to transformation of rodent fibroblasts. Anti-EGF receptor and anti-p185neu monoclonal antibodies inhibited tumorigenic growth of these transformants implanted into nude mice. These monoclonal antibodies also suppressed focus formation of the cells transformed by the synergistic action of these receptor proteins in vitro. However, EGF enhanced focus formation and stimulated cell growth when added to cells transfected just with the EGF receptor encoding cDNA. These data suggest that receptor specific effectors may have potentially useful applications in cancer therapy for neoplasms which demonstrate increased receptor densities. In addition the data suggest novel differences in the actions of tyrosine kinases when acting alone or in concert with other receptors.

HTLV-I transformed T cells not only express a large number of interleukin-2 receptors [IL-2R/p55(Tac)], but also produce a factor named ATL-derived factor (ADF) that augments the expression of IL-2R/p55(Tac). Based on a partial N-terminal amino acid sequence, complementary DNA (cDNA) clones for human and mouse ADF were isolated and sequenced. Recombinant ADF produced by COS-7 monkey kidney cells showed IL-2R/Tac inducing activity on YT cells, which are sensitive for ADF. ADF mRNA was strongly expressed in HTLV-I(+) T cells lines, but not in inactivated cells (THP-1, unstimulated PBMC). Furthermore, in normal human peripheral blood mononuclear cells, the expression of ADF mRNA was enhanced by mitogens or phorbol myristate acetate, suggesting a possible involvement of ADF in the lymphocyte activation. Homology analysis revealed an unexpected relationship between ADF and dithiol-reducing enzyme, thioredoxin, involved in many important biological reactions such as the conversion of ribonucleotides into deoxyribonucleotides, or the stabilization of glucocorticoid receptors. The biological significance of the generation of a redox potential in lymphocyte activation, and the possible involvement of dithiol reduction in the induction of IL-2R/Tac are discussed.

We describe monoclonal antibodies (mAbs: anti-MaG-1, TGI-1, TGI-5, and TGI-6) that block the proliferation of AML-193 cells in response to GM-CSF or IL-3 and do not affect the proliferation of AML-193 cells in response to G-CSF and IL-2-driven proliferation of Kit 225 cells. However, none of the mAbs tested had any stimulative effect on the proliferation of AML-193 cells. The mAbs (anti-MaG-1, TGI-1, -5, and -6) could inhibit the binding of [125I)GM-CSF to AML-193 cells. We were able to purify MaG-1 Ag by anti-MaG-1 affinity chromatography. Thus, the MaG-1 Ag and the Ags recognised by mAbs (TGI-1, -5, and -6) may be associated with the receptor for GM-CSF or IL-3 or a structure close to the receptor for GM-CSF or IL-3.

Many human T cell lymphotropic virus-I (HTLV-I) transformed T cells from adult T cell leukemia (ATL) patients continuously produce a humoral factor called ATL-derived factor (ADF) which induces IL-2R/Tac expression on T and NK cells. Using gel filtration, procion red Sepharose, DEAE, and reverse phase chromatography, we have purified ADF protein to homogeneity from 15 liters of serum-free culture supernatant of an HTLV-I(+) T cell line ATL-2. Purified ADF protein had the m.w. of 14,000 by SDS-PAGE and gel filtration, and its isoelectric point is around 5.0. ADF did not react with heteroantibodies against IL-1 alpha and IL-1 beta, which have also IL-2R/Tac-inducing activity on suitable target cells. Partial N-terminal amino acid sequence of ADF is different from other cytokines such as, IFN, BSF-2, and various IL whose cDNA has been cloned. Western blot analysis using rabbit antibodies against N-terminal 10mer synthetic peptide of ADF showed that IL-1 alpha and ADF are different proteins. ADF had its IL-2R/Tac-inducing activity not only on human NK-like cell line YT, but also on HTLV-I(+) T cells, such as ED. In contrast, macrophage-derived IL-1 lacked IL-2R/Tac-inducing activity on ED cells despite their IL-2R/Tac induction on YT, indicating that ADF and IL-1 have their effect via different receptors.

PGE and PGF release from peritoneal exudate cells was studied in mice after injection with two s (1–3) glucans, the antitumor active lentinan and the inactive pachyman. 4 days after injection of both polysaccharides, the spontaneous and phagocytosis-induced PGE and PGF release was markedly suppressed. However, only the immunopotentiator lentinan induced peritoneal exudate cells which exhibited a longer lasting diminished PG release. The data suggest that the T cell adjuvant lentinan may potentiate cellular immune responses by reducing synthesis of immune suppressive prostaglandins from peritoneal exudate cells.

The capacity of five antitumor polysaccharides (PS) of the β (1–3) glucan type, lentinan, pachyman, pachymaran, carboxymethylpachymaran and hydroxyethylpachyman to augment the in vitro generation of alloreactive cytotoxic T lymphocytes (CTL) in a primary murine mixed lymphocyte culture was tested in detail. All of the PS tested, each at its own optimal concentration, induced enhanced alloreactive CTL responses. Lentinan, pachymaran and hydroxyethylpachyman increased the magnitude of the in vitro CTL responses up to 28 fold. The PS tested appeared to enhance the responsiveness of alloreactive prekiller T cells rather than the immunogenicity of the stimulator cells. Kinetic experiments indicated that in vitro CTL responses could be augmented when PS were added as late as 72 hr after initiation of the cultures, suggesting that PS influences the differentiation of antigenically triggered CTL precursors into cytotoxic effector cells. PS also augmented in vitro the generation of H-2 restricted hapten-specific CTL. The results indicate that the PS tested are effective immune adjuvants of both alloreactive CTL responses and H-2 restricted CTL responses specific to foreign antigens.

The effects of interleukin-2 (IL-2) on natural killer (NK) cell activity were examined in both healthy persons and cancer patients. The NK activity of peripheral blood lymphocytes from 29 healthy donors was augmented by IL-2 treatment in all cases. However, in 14 out of 50 cancer patients NK activity was not augmented by IL-2. The rate of NK augmentation in a group of cancer patients was significantly lower than that in a healthy control group. When the cancer patients were divided into each clinical stage, NK augmentation was as follows: in stage I, 3 out of 3; in stage II, 11 out of 12; in stage III, 10 out of 18; and in stage IV, 12 out of 17. The rate of NK augmentation was significantly lower in cancer patients of stages III and IV. The rate of NK augmentation was also dependent on the performance status (PS) of cancer patients. The NK augmentation of cancer patients of PS 0 to 2 was not significantly different from that of normal controls, whereas the rate of NK augmentation was significantly lower in cancer patients of PS 3 and 4.

Recombinant IL-2 manifests both proliferation and differentiation-inducing activities in such a way as to generate secondary cytotoxic T lymphocytes (CTL) from memory CTL. IL-2 actually shows antitumor effects against syngeneic tumors, while the combination of IL-2 with chemotherapeutic agents clearly demonstrates complete regression of syngeneic tumors. In addition, the antitumor immunotherapeutic drug lentinan, augments the reactivities of pre-effector cells to IL-2, resulting in the efficient induction of antitumor effectors, CTL, NK and LAK. Combination therapy with lentinan, cyclophosphamide and IL-2 may well be documented as a new rational chemo-immunotherapy in place of adoptive LAK therapy and the infusion of large amounts of IL-2 causing frequent detrimental side effects.

Five different beta(1 leads to 3) glucans were tested for immune adjuvant activity on the in vivo induction of alloreactive murine cytotoxic T-lymphocytes (CTL). The beta(1 leads to 3) glucans, lentinan, pachyman, pachymaran, and two differently substitute hydroxyethylated pachymans strongly enhanced the in vivo generation of alloreactive CTL. The augmenting effect of i.p.-administered beta(1 leads to 3) glucans exhibited a clear dose-response relationship and was strictly dependent on the injection schedule used. Injection of high doses of beta(1 leads to 3) glucans as well as the injection during the late phase of the immune response markedly suppressed the magnitude of the lytic CTL activity induced. When the optimal conditions for enhanced CTL responses were chosen, the augmented CTL activity within spleen cells and mesenteric lymph node cells persisted for more than 25 days. Since beta(1 leads to 3) glucans are chemically defined substances without obvious toxic side effects, they may be of potential use to augment in vivo antigen-specific T-cell responses.

There are a number of immunomodulators of bacterial origin, most of which activate lymphocytes in a variety of ways (Table 1). Many bacterial cell surface components activate lymphocytes, but little is known about the ability of bacterial exotoxins to stimulate lymphocytes, probably because the extremely high cytotoxicity of typical exotoxins such as diphtheria make it technically difficult to examine their stimulatory effects on immunologically competent cells, including lymphocytes.

The chemical structure and characteristics, the antitumour activity, the antibacterial, antiviral, antifungal, antiparasitic activities, immunological properties and mode of action of immunomodulators of microbial origin, especially antitumour polysaccharide lentinan, have been discussed immunopharmacologically in comparison with pachymaran, schizophyllan, DiLuzio's yeast glucan, Coriolus preparation PS-K, Streptococcal preparation OK-432, Nocardia rubra cell wall skeleton N-CWS together with BCG and Corynebacterium parvum. Lentinan exerts its inhibitory action not only on allogeneic tumours but also on syngeneic and autologous tumours, and prevents chemical and viral carcinogenesis. The phase III randomized control study of lentinan in cancer patients with gastric and colo-rectal cancer showed the clinical efficacy of lentinan in prolonging the life span and improving host immune responses. Experimental and clinical application demonstrated the advantage of N-CWS over BCG-CWS, and a recent study on OK-432 showed similar results to those obtained with C. parvum. In future work on microbial immunomodulators, it will be essential to find a parameter of the host-tumour relationship which will indicate the protocol for application of immunomodulators, and to find a new-type of selective immunostimulant. For this purpose, exhaustive studies on lymphokines, monokines and lymphocyte tropic hormones are indispensable.

Influenza virus A/Kumamoto haemagglutinin was found to induce type I, III, and IV hypersensitivity in mice. MRL/Mp-I pr/lpr (MRL/l) mice are known to be lower responders to, and poor inducers of, interleukin-2 (IL-2). Recombinant IL-2 was found to augment the type III reaction in BALB/c mice and to suppress the reaction in MRL/I mice in vivo. Cyclophosphamide 100 mg/kg had a selective suppressive effect on the suppressor T cells responsible for type IV reaction, and subsequently the delayed type hypersensitivity (DTH) was augmented. Higher doses of cyclophosphamide suppressed both suppressor and effector T cells in DTH, and subsequently the DTH was suppressed markedly. This experimental model system employing viral haemagglutinin may provide a new screening method for the development of immunomodulators.

p185neu, the protein product of the neu gene, is a tyrosine kinase receptor with structural similarity to the epidermal growth factor (EGF) receptor. The cognate ligand for the p185neu receptor remains unknown. We have defined: 1) stage and tissue-specific expression patterns of the neu gene product in developing tissues; 2) p185neu phosphorylation and the regulation of p185neu tyrosine kinase activity by EGF. 3) Synergistic interactions of cellular rat p185neu and EGF receptor leading to cell transformation; 4) structural and functional differences of normal and oncogenic p185neu. These observations explain some features of how p185neu is involved in normal development and neoplastic transformation.

Inasmuch as human natural killer (NK) cell activity was markedly augmented by a streptococcal immunopotentiator, OK-432, both in vivo and in vitro, the mechanism in which OK-432 augmented human NK cell activity was analyzed. Culture supernatants of nonadherent lymphocytes stimulated with OK-432 significantly augmented NK cell activity. Significant activity of both interferon (IFN) (both alpha- and gamma-types) and interleukin-2 (IL-2) was detected in the culture supernatants from nonadherent lymphocytes. Concomitant treatment of supernatants with anti-IFN-alpha antiserum and pH-2 glycine-HCI buffer or the absorption of supernatants with an IL-2-dependent cell line completely abrogated the NK-augmenting activity, whereas the treatment with either one of these resulted in only partial elimination of the activity. These results indicate that OK-432 stimulates human nonadherent lymphocytes to produce IFN and IL-2 and that both factors are primarily responsible for the NK augmentation by OK-432.

Eight distinct polysaccharides (PS) of beta(1 leads to 3) glucan type were tested for their capacity to render murine peritoneal exudate cells (PEC) cytotoxic. After intraperitoneal injection of lentinan, pachymaran and HE-pachyman 3 and 4 highly cytotoxic PEC were induced. Pachyman and HE-pachyman 1 and 2 were of moderate effect, whereas CM-pachymaran and HE-pachyman 3 and 4, highly cytotoxic PEC were induced. Pachyman and HE-pachymacrophages. The induction of PEC-dependent cytotoxicity exhibited a strict dose relationship. Optimal administration of PS resulted in the induction of cytotoxicity, which persisted for more than 25 days. Surprisingly, none of the PS tested was capable of rendering normal or thioglycollate-induced PEC cytoxic under in vitro conditions. It is suggested that the capacity of PS to render in vivo macrophages cytotoxic is related to the potency of these PS to activate the alternative pathway of complement system (APC) in so far as C3b may be the essential component required to render macrophages cytotoxic.

The effects of human rIL-6/B cell stimulatory factor 2 (hrIL-6/BSF-2) from Escherichia coli on murine Ag, SRBC-specific antibody responses were examined in vitro and in vivo. HrBSF-2 was effective in augmenting the primary and the anamnestic plaque-forming cells response to SRBC in vitro. The augmentation of the primary response was apparent when B cell-enriched spleen cells (B cells) were cultured with BSF-2 in the presence of IL-2. On the other hand, hrBSF-2 alone strongly enhanced the anamnestic response in a dose-dependent manner when spleen cells from SRBC-immunized mice were used. These effects of BSF-2 were abolished completely by anti-BSF-2 antibody, but not by normal rabbit Ig. Cell depletion experiments indicated that L3T4 (CD4)+ T cells, but not Lyt-2(CD8)+ T cells, and adherent cells (macrophages) have an important role in this BSF-2-induced augmentation of the response. In addition, kinetic studies showed that hrBSF-2 acts on B cells in the anamnestic response even when added relatively late in the culture. Finally, it was determined whether BSF-2 also could be active in modulating antibody responses in vivo. BSF-2 was shown to enhance the primary and secondary antibody responses in mice. The most apparent effect of BSF-2 was observed in the secondary response.

Proteose-peptone-induced intraperitoneal neutrophils from rats were activated in terms of tumor cytotoxicity by pretreatment with culture supernatants from a human T cell leukemia line, Jurkat (culture sup). Culture sup-treated neutrophils showed cytotoxicity against various tumor cell lines. The cytotoxicity of culture sup-treated neutrophils was dependent on the number of neutrophils and the concentration of culture sup. Cytostasis by activated neutrophils was observed very early in the assay incubation period (within 6 hr), but cytolysis first occurred at 24 hr after the start of incubation. Factor(s) in culture sup responsible for the activation of cytotoxic neutrophils were stable to temperature and pH treatments, and their molecular weight was higher than 10,000. The responsible factor(s) for activation of cytotoxic neutrophils were different from interleukin-2, serum-derived factor, and bacterial lipopolysaccharide.

The antitumor and metastasis-inhibitory activities, mode of action, and clinical application of lentinan, a strictly purified beta-1,6:beta-1,3-glucan, are reviewed. Lentinan exerts a prominent antitumor effect and prevents chemical and viral oncogenesis. The antitumor action of lentinan is host-mediated. Compared to other well-known immunostimulants, such as bacille Calmette Guérin (BCG), Corynebacterium parvum, and lipopolysaccharide (LPS), lentinan appears to represent a unique class of immunopotentiator, a T cell-oriented adjuvant. Lentinan triggers the increased production of various kinds of bioactive serum factors associated with immunity and inflammation, such as IL-1, CSF, IL-3, vascular dilation inducer, and acute-phase protein inducer, by the direct impact of macrophages or indirectly via lentinan-stimulated T cells, which results in the induction of many immunobiological changes in the host. Augmented IL-1 production amplifies the maturation of immature effector cells to mature cells capable of responding to lymphokines such as IL-2 and T cell-replacing factors. Because of this mode of action, intact T cell compartments for antitumor activity of lentinan are required. Lentinan has little toxic side effects. Excellent results were obtained in a 4 year follow-up of the randomized control study of lentinan in phase III on patients with advanced and recurrent stomach and colorectal cancer.

While the central function of the Bb fragment as C3 activating enzyme is well recognized, there are up to now no reports concerning the smaller fragment Ba. To ascertain whether Ba exhibits biological functions the following studies were performed. Factor B was purified from EDTA-plasma using a seven-step-procedure. The last step was an affinity chromatography at low ionic strength (1 mM MgCl2) on a sepharose 4B column, to which cobra venom factor was coupled. The final product was homogeneous on SDS-PAGE and showed only one precipitation line after immunoelectrophoresis using two sera: goat anti-whole guinea pig serum and goat anti-guinea pig factor B. Factor B was cleaved by immobilized cobra venom factor and D̄. Fragment Ba was recovered from the filtrate of the reaction mixture while fragment Bb was eluted by 2M NaSCN. The m.w. for B, Bb and Ba as determined by the SDS-PAGE method was 106,000, 65,000 and 53,000, respectively. Reduction did not change the picture, indicating a single chain structure.