Enhancement of humoral immune responses against viral vaccines by a non-pyrogenic 6-O-acylmuramyldipeptide and synthetic low toxicity analogues of lipid A

6-O-Acyl derivatives of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) and synthetic, low toxicity lipid-A analogues were examined for their ability to enhance the potency of current viral vaccines. 6-O-(2-Tetradecylhexadecanoyl)-MDP (B30-MDP) in non-irritative vehicles such as physiological saline, phosphate-buffered saline (PBS), squalene-PBS emulsion, Intralipid or liposomes, significantly stimulated the primary and secondary antibody production of guinea-pigs against influenza split or subunit vaccine and inactivated the hepatitis B virus surface (HBs) antigen. Mice seemed less responsive to the adjuvanticity of B30-MDP than guinea-pigs. Two low toxicity lipid A analogues, acylated beta(1-6)-D-glucosamine disaccharide bisphosphates (which do not have amide-bound or ester-bound 3-acyloxyacyl groups unlike fully toxic Escherichia coli-type lipid A), caused significantly enhanced antibody responses, primary or secondary, when administered to mice by incorporation into liposomes with inactivated HBs antigen.

Somnogenic activities of synthetic lipid A

Bacterial infections and various immune response modifiers, including endotoxin and its lipid A moiety, alter sleep duration. The purpose of this study is to amplify our understanding of lipid A structure-somnogenic-pyrogenic activity relationships. Four synthetic disaccharide analogs of lipid A (LA-15-PP, LA-15-PH, LA-16-PH, and LA-18-PP) and a biosynthetic monosaccharide analog of lipid A (lipid X) were tested in rabbits for their effects on slow-wave sleep, rapid-eye-movement sleep, electroencephalographic slow-wave (0.5- to 4.0-Hz) amplitudes, and brain-colonic temperatures. Substances were injected intravenously and intracerebroventricularly. Compound LA-15-PP was the most potent; it significantly increased slow-wave sleep, delta electroencephalographic amplitudes, and brain-colonic temperatures while reducing rapid-eye-movement sleep. Compound LA-15-PH (monophosphoryl analog of LA-15-PP) induced effects similar to those of LA-15-PP, although the responses were weaker. Compound LA-18-PP induced increases in slow-wave sleep and delta amplitudes only after high doses, whereas compound LA-16-PH was devoid of these activities at the doses tested. Intracerebroventricular, but not intravenous, injections of lipid X induced small but significant increases in both slow-wave sleep and rapid-eye-movement sleep without affecting delta amplitudes or brain-colonic temperatures. These data suggest that the somnogenic actions of these lipid A analogs depend on the acylation or phosphorylation pattern and backbone structures of the molecules. Their soporific activities parallel their relative behaviors in other biological assays.

Structural requirements of lipid A for endotoxicity and other biological activities

For the past ten years, several groups were engaged in synthetic studies of lipid A, namely the lipid portion of bacterial lipopolysaccharides (LPS) that has been assumed to be the bioactive center of LPS, but has not been unanimously approved. Among them, Shiba, Kusumoto, and colleagues, Osaka, Japan have synthesized most energetically and successfully a variety of counterparts of lipid As, biosynthetic lipid A precursors, and their analogs. The endotoxic and related bioactivities of these synthetic compounds were studied by Japanese and German groups, including ours. In 1985, one of the compounds, having an acylation and phosphorylation pattern in beta(1-6)-D-glucosamine disaccharide which was proposed for Escherichia coli F515 lipid A was found to be exhibit full endotoxic and related bioactivities identical to those of the bacterial product. The study was extended by synthesis and examination of bioactivities of variously acylated D-glucosamine di- and monosaccharide phosphates, which correspond to structural components of lipid As, and their analogs or derivatives. Thus, structural requirements have been fairly well elucidated. In this article, first we will review the progress of synthetic and biological studies, with particular emphasis on chemical structure--bioactivities relationships of lipid As, and then we will discuss possible usefulness of some less or nontoxic lipid A-related synthetic compounds in clinical and preventive medicine.

Microtubule-assembly inhibitor protein. Its distribution, localization and physicochemical properties

Microtubule-assembly inhibitor protein (MIP) is an acidic protein with Mr 33,000 which inhibits microtubule assembly in vitro [Kotani, S., Murofushi, H., Nishida, E. & Sakai, H. (1984) J. Biochem. (Tokyo) 96, 959-969]. Anti-MIP antibody was affinity-purified from rabbit anti-MIP sera raised against chemically modified MIP. MIP was localized in the nucleus in interphase culture cells as revealed by immunofluorescent light microscopy. Immunoblotting experiments showed that MIP exists in a variety of mammalian cells and tissues. Kidney appeared to be a better source of MIP than brain, the original source. Kidney MIP was isolated by the same procedure as for brain MIP and proved to be indistinguishable from brain MIP in the inhibitory activity of microtubule assembly, molecular mass, immunoreactivity, and one-dimensional peptide mapping. Physico-chemical characteristics of MIP were studied using the kidney protein. It contained 20% aspartic acid and 25% glutamic acid, accounting for its acidic nature. Hydrodynamically, MIP was a monomer with S20,w = 1.9 S and Mr = 30,000. The frictional ratio, f/fo = 1.7, indicated that MIP is not a globular molecule but has either an elongated or an expanded structure. Circular dichroic results showed a low content of alpha-helix or beta-sheet structure for MIP. Proton nuclear magnetic resonance analysis provided evidence that MIP consists mainly of very flexible structures (random-coil-like structures), but still contains a hydrophobic core structure below 60 degrees C.

Purification and characterization of kinesin from bovine adrenal medulla

Kinesin was purified from bovine adrenal medulla. The sedimentation coefficient was 8.8 S. Sedimentation equilibrium ultracentrifugation studies showed the molecular weight of kinesin to be 300,000. The calculated axial ratio was 1:16. The Stokes radius was estimated to be 8.9 nm by gel filtration. Circular dichroism showed the alpha-helix content to be about 50%. Purified kinesin preparation contained a major polypeptide with a molecular weight of 120,000 and minor ones with molecular weights of 71,000, 68,000, and 65,000. Bovine adrenal kinesin had an ATPase activity which was stimulated severalfold by microtubules to a specific activity of about 0.1 mumol/min.mg. Kinesin molecules adsorbed to a glass slide promoted the movement of microtubules on the glass surface at a rate of about 0.5 micron/s. Immunostaining of EBTr (bovine embryonic trachea fibroblast) cells and bovine adrenal chromaffin cells in interphase with an affinity-purified antibody against the major polypeptide of kinesin showed that some kinesin was located on microtubules and the rest distributed throughout the cytoplasm in a diffuse manner. EBTr cells in mitotic phase gave a staining pattern showing that kinesin was present throughout the cytoplasm with higher concentration in the region of mitotic apparatus.

Structural requirements of lipid A species in activation of clotting enzymes from the horseshoe crab, and the human complement cascade

The structure/activity relationship of lipid A, a bioactive center of endotoxic lipopolysaccharides, in the activation of the clotting enzyme cascade of a horseshoe crab amoebocyte lysate (Limulus activity) and the complement system in human serum, was examined using synthetic lipids A and related compounds. Regarding Limulus activity, a newly developed colorimetric method, which utilizes a mixture of recombined clotting factors and a chromogenic substance, was much more sensitive for detecting changes in the chemical structure of test compounds than the conventional gelation method using the amoebocyte whole lysate. (beta 1-6)-D-Glucosamine disaccharide bisphosphates, which had neither 3-hydroxyacyl nor 3-acyloxyacyl groups, and acylglucosamine phosphates, which in structure correspond or are analogous to the non-reducing or reducing moieties of lipids A and biosynthetic disaccharide lipid A precursors showed only negligible activity in the colorimetric tests, but they exhibited a distinct though much weaker gelation activity than the parent disaccharide molecules. The assay results obtained by the colorimetric Limulus test correlate better with the pyrogenicity of the test synthetic compounds than those given by the gelation method, although the dependence of pyrogenicity on chemical structure is greater. The presence of 3-hydroxyacyl groups on the bisphosphorylated (beta 1-6)-D-glucosamine disaccharide backbone is the prerequisite for effective activation of the clotting enzyme cascade of horseshoe crab amoebocyte lysate, while the presence of an adequate number (one or two) of 3-acyloxyacyl groups on the disaccharide bisphosphate backbone is needed for full pyrogenicity. Complement activation, on the other hand, showed structural requirements quite different from those for the colorimetric Limulus activity and the pyrogenicity. The disaccharide compounds that had only non-hydroxylated acyl groups, acylated glucosamine phosphates that had the structure of the non-reducing portion of lipids A and biosynthetic disaccharide precursors, which were scarcely active in the colorimetric Limulus test, caused complement activation comparable to or sometimes stronger than that of the parent disaccharide molecules. Acylglucosamine phosphates, corresponding in structure to the reducing moiety of disaccharide compounds, however, showed little activity.

Microtubule-binding domain of tau proteins

Limited chymotryptic digestion of whole tau proteins produced a fragment of Mr 14,000 (CT14), which was able to bind to microtubules reconstituted from tubulin alone in the presence of taxol. This fragment was also found to persist in microtubules when microtubules consisting of tau proteins and tubulin were digested by chymotrypsin. Analysis of amino acid composition revealed that CT14 was rich in lysine and proline residues, suggesting unique structure of microtubule-binding domain of tau proteins. Amino-terminal sequence of CT14 was determined to be Ser-Ser-Pro-Gly-Ser-Pro-Gly-Thr-Pro-Gly-Ser-Arg-Ser-Arg-X-Pro-Ser-Leu-Pr o. No heterogeneity was detected in this amino-terminal sequence of 19 residues. Five species of polypeptides consisting of tau proteins were separated from each other by gel electrophoresis and subjected to chymotryptic digestion. CT14 was produced from each of the tau polypeptides by chymotryptic digestion, indicating that all tau polypeptides have a common microtubule-binding domain.

S-100 beta positive T cell leukemia

We reported a peculiar case with T cell leukemia. The patient was a 34-year-old woman showing extensive splenomegaly and marked leukemic cell proliferation and running a rapid fatal clinical course. The leukemic cells were morphologically ordinary lymphocytes showing suppressor/cytotoxic(s/c) T cell phenotypes and containing S-100b protein. Southern blot analysis revealed rearrangement of the beta chain genes of the T cell receptor (TcR) of the leukemic cells. Because these phenotypic and morphologic features were identical with those of S-100 beta+T lymphocytes (S-100 beta +TL) in normal human peripheral blood, we regarded this case as S-100 beta +T cell leukemia. We discussed clinicopathological features of S-100 beta +T cell leukemia/lymphoma by assessing similar cases reported so far. S-100 beta +T cell leukemia/lymphoma is a new type of s/c T lymphocytic leukemia/lymphoma with aggressive features.

Isolation of rat liver microtubule-associated proteins. Evidence for a family of microtubule-associated proteins with molecular mass of around 200,000 which distribute widely among mammalian cells

Heat-stable microtubule-associated proteins (MAPs) were isolated from rat liver crude extract. The most prominent species showed a molecular mass close to that of bovine adrenal 190-kDa MAP (Kotani, S., Murofushi, H., Maekawa, S., Sato, C., and Sakai, H. (1986) Eur. J. Biochem. 156, 23-29), termed rat 190-kDa MAP. Immunological studies with antiserum against the rat 190-kDa MAP showed that this MAP exists in a variety of rat cells and tissues. The characteristics of the rat 190-kDa MAP, including molecular mass, heat stability, and distribution pattern, were very similar to those of bovine adrenal 190-kDa MAP. However, one-dimensional peptide mapping revealed considerable difference, and there is little mutual immunological cross-reactivity. We also identified in mouse neuroblastoma Neuro 2a cells a MAP of around 200 kDa which is considered to be MAP4 (Parysek, L. M., Asnes, C.F., and Olmsted, J.B. (1984) J. Cell Biol. 99, 1309-1315). MAP4 was slightly immunoreactive to both anti-(rat 190-kDa MAP) antiserum and anti-(bovine 190-kDa MAP) antiserum. Taking these results together, we conclude that mammalian tissues ubiquitously contain heat-stable MAPs of 200 kDa and that these 200-kDa MAPs should be considered as species-specific homologues.

Immunobiological activities of a porin fraction isolated from Fusobacterium nucleatum ATCC 10953

From Fusobacterium nucleatum ATCC 10953 cell envelope fraction whose inner membranes had been removed by treatment with sodium N-lauroyl sarcosinate, an outer membrane protein (37,000 Mr in a native state) was prepared by extraction with lithium dodecyl sulfate. The protein thus obtained showed distinct porin activity, namely, the ability to form hydrophilic diffusion pores by incorporation into the artificial liposome membrane. The porin fraction exhibited strong immunobiological activities in the in vitro assays: B-cell mitogenicity and polyclonal B-cell activation on murine splenocytes, stimulatory effects on guinea pig peritoneal macrophages, and enhancement of the migration of human blood monocytes. The porin fraction also exhibited immunoadjuvant activity to increase the antibody production against sheep erythrocytes in the spleen of mice that were immunized by sheep erythrocytes with porin. Although chemical analyses revealed that the test porin fraction contained a considerable amount of lipopolysaccharide (LPS) (around 12% of the fraction), the studies with LPS-nonresponding C3H/HeJ mice and on the inhibitory effects of polymyxin B strongly suggest that most of the above bioactivities are due to porin protein itself, not to coexistent LPS in the porin fraction.

Dual effect of antimitotic drugs on steroid secretion in mouse adrenocortical Y-1 tumor cells

Mouse adrenocortical Y-1 tumor cells were examined in a monolayer culture and their steroid secretion was measured. The Y-1 cells constantly released a small amount of steroids in the absence of adrenocorticotropin (ACTH). When synthetic ACTH (tetracosactide acetate) was added to the medium, an increase in the steroid secretion of approximately 5-fold was observed. The Y-1 cells also showed a typical cytoplasmic retraction in response to ACTH. Incubation of the cells with an antimitotic drug, colchicine, prior to ACTH-stimulation resulted in a 30-50% reduction in ACTH-induced steroid secretion. Under the conditions used in these experiments, viable numbers of cell and of total amount of protein per dish were not measurably changed, indicating that the condition was not lethal. Another antimitotic drug, colcemid, caused similar reactions, while lumicolchicine showed no effect. This suggests that the disruption of the microtubular system is the main cause of the inhibition. On the other hand, the ACTH-independent secretion was slightly enhanced by colchicine. The enhancement was also observed in prolonged incubation with colchicine, a condition which caused death in some of the cells.

Milk-borne transmission of human T-cell leukemia virus type I in rabbits

The mode of vertical transmission of human T-cell leukemia virus type I (HTLV-I) was investigated by foster-nursing in rabbits. Two of five rabbits born to noninfected mothers and fostered by virus-infected females seroconverted for HTLV-I after 7 weeks, whereas all seven rabbits born to virus-infected mothers and fostered by noninfected females remained seronegative for the observation period of 6 months. Culture of peripheral blood lymphocytes gave rise to an HTLV-I-carrying T-cell line from each of the two seroconverted rabbits. These findings suggest that HTLV-I is transmitted through milk from mother to offspring.

Immunohistochemical identification of Trichosporon beigelii in histologic section by immunoperoxidase method

An indirect immunoperoxidase method capable of identifying an opportunistic fungus, Trichosporon beigelii, in formalin-fixed, paraffin-embedded tissue has been developed. The authors studied autopsy materials from 19 patients with various fungal infections, including 3 patients with disseminated T. beigelii infection, 8 patients with localized or systemic candidiasis, 4 patients with invasive aspergillosis, 2 patients with pulmonary mucormycosis, and 2 patients with systemic cryptococcosis. T. beigelii could be successfully visualized in tissue sections from all three patients with this infection and a patient with systemic candidiasis who was found to have concomitant infection by T. beigelii. The capsule of Cryptococcus neoformans was also stained, indicating the presence of cross-reactive antigen between T. beigelii and C. neoformans. C. neoformans-absorbed antiserum was reactive with T. beigelii but not with other fungi, including C. neoformans.

Structural requirements of endotoxic lipopolysaccharides and bacterial cell walls in induction of interleukin-1

A variety of compounds, synthetic, semisynthetic or bacterial, which corresponds to structural components of endotoxic lipopolysaccharides (LPS) and bacterial cell wall peptidoglycans were studied for their activity to enhance interleukin-1 (IL-1) production of murine peritoneal macrophages and the ability to activate the complement cascade in fresh adult human serum. Not only bacterial LPS and cell walls or peptidoglycans but also their structural components with appropriate size and structure induced IL-1 production by macrophages and activated the human complement cascade, which may lead to the IL-1 production by monocytes/macrophages.

Antitumour effects of streptococcal lipoteichoic acids on Meth A fibrosarcoma

The antitumour effects of lipoteichoic acids (LTA) extracted from Streptococcus pyogenes were studied in comparison with other streptococcal cellular components. LTA suppressed the tumour growth of both solid- and ascites-type Meth A fibrosarcoma as did the whole cells of S. pyogenes (OK-432). No other cellular components, such as cell wall peptidoglycan, group-specific C-carbohydrate or type-specific M protein, suppressed the growth of Meth A. LTA, but not the other cellular components, induced tumour necrosis factor (TNF) in Propionibacterium acnes-primed mice. LTA had no direct killing effects on Meth A cells. These results indicate that LTA may be an important antitumour component of OK-432 and that one of the antitumour mechanisms by this streptococcal preparation is the induction of TNF.

Induction of delayed-type hypersensitivity by the T cell line specific to bacterial peptidoglycans

A T cell line specific for the chemically well-defined peptidoglycan of bacterial cell wall, disaccharide tetrapeptide, was established from Lewis rats immunized with the antigen covalently linked to the autologous rat serum albumin. The antigen specificity was examined with various analogues or derivatives of the peptidoglycan. The cell line was reactive to analogues with the COOH-terminal D-amino acid, but least reactive to those with L-amino acid as COOH terminus. Transferring of the T cell line into X-irradiated normal Lewis rats induced delayed-type hypersensitivity in an antigen specific manner.

Induction of delayed-type hypersensitivity by the T cell line specific to bacterial peptidoglycans

A T cell line specific for the chemically well-defined peptidoglycan of bacterial cell wall, disaccharide tetrapeptide, was established from Lewis rats immunized with the antigen covalently linked to the autologous rat serum albumin. The antigen specificity was examined with various analogues or derivatives of the peptidoglycan. The cell line was reactive to analogues with the COOH-terminal D-amino acid, but least reactive to those with L-amino acid as COOH terminus. Transferring of the T cell line into X-irradiated normal Lewis rats induced delayed-type hypersensitivity in an antigen specific manner.

Transmission and genetic shift of human immunodeficiency virus (HIV) in vivo

HIVYU-6 and HIVYU-7 were isolated from an acquired immune deficiency syndrome patient (MK) and his asymptomatic sexual partner (MM), respectively. YU-6 readily infected not only peripheral lymphocytes from normal individuals but also human T-cell lines such as H9, HUT-78, MOLT-4 and MT-4; YU-7, on the other hand, could not infect H9 and MT-4 cells. Furthermore, although autologous serum failed to neutralize YU-6, it was neutralized by the heterologous serum from the partner. Restriction endonuclease analysis of YU-6 demonstrated that it was a mixture of viruses. We have isolated two clones from YU-6 (YU-6-a and YU-6-b) by a plaque assay method and showed that YU-6-a had one more KpnI site than YU-6-b. It was also evident that YU-7 derived from YU-6-a, but had already shifted genetically from YU-6-a. Transmission of human immunodeficiency virus through heterosexual contact and a possible genetic shift of YU-6-a, b and YU-7 from a common progenitor virus in vivo is discussed.

Comparison of a major heat-stable microtubule-associated protein in HeLa cells and 190-kDa microtubule-associated protein in bovine adrenal cortex

A heat-stable microtubule-associated protein (MAP) with a molecular weight of 190,000, termed 190-kDa MAP, has been purified from bovine adrenal cortex (Murofushi, H. et al. (1986) J. Cell Biol. 103, 1911-1919). Immunoblotting experiments using an antibody against this MAP revealed that several kinds of culture cells derived from human tissues contain proteins with an apparent molecular weight of 180,000 reacting with the antibody. Indirect immunofluorescence microscopic observation of HeLa cells showed that the immunoreactive protein co-exists with microtubules, indicating that the protein is one of the HeLa MAPs. A heat-stable MAP with a molecular weight of 180,000, termed here HeLa 180-kDa MAP, was purified by the taxol-dependent procedure (Vallee, R.B. (1982) J. Cell Biol. 92, 435-442) and successive co-polymerization with brain tubulin. This protein was the most abundant MAP in HeLa cells, suggesting that the MAP is identical to the major HeLa MAP previously reported by Bulinski and Borisy (Bulinski, J.C. & Borisy, G.G. (1980) J. Biol. Chem. 255, 11570-11576) and Weatherbee et al. [1980) Biochemistry 19, 4116-4123). It was shown that, like bovine adrenal 190-kDa MAP, yet distinct from brain MAP2 and tau, purified HeLa 180-kDa MAP does not interact with actin filaments. This common characteristic of the two MAPs along with the same heat-stability strongly suggests that they are members of the same group of MAPs. The fact that HeLa 180-kDa MAP reacts with an antibody against bovine adrenal 190-kDa MAP means that they share common epitopes, in other words, common local amino acid sequences. However, the limited proteolytic patterns of the two MAPs with S. aureus V8 protease and chymotrypsin were distinct from each other, suggesting the presence of large differences in the overall primary structures between bovine adrenal 190-kDa MAP and HeLa 180-kDa MAP.