Abstract Low doses of actinomycin D (0.1 μg/ml) can enhance, markedly inhibit, or have no effect ... more Abstract Low doses of actinomycin D (0.1 μg/ml) can enhance, markedly inhibit, or have no effect on poliovirus growth: the outcome depends on the pretreatment given the cells, in particular on the properties of the serum in which they have been incubated. Preincubation of cells without serum or with certain batches of calf serum renders subsequent virus growth sensitive to actinomycin. It appears that some sera contain a specific substance that induces an actinomycin-resistant state; this substance is probably insulin, since physiological levels of insulin are shown to simulate active batches of serum. Other hormones are inactive. In sensitive cells, actinomycin prevents synthesis of viral RNA by affecting a stage of growth that occurs after penetration; this stage is a fairly late one. Cells in the actinomycin-sensitive state do not necessarily differ from actinomycin-resistant cells in microscopical appearance, rate of multiplication, rates of incorporation of radioactive leucine and uridine, and yield of virus in absence of actinomycin.
... The damage by urea culminates in 1 Present address: Department of Microbiology, John Curtin S... more ... The damage by urea culminates in 1 Present address: Department of Microbiology, John Curtin School of Medical Research, Aus tralian National University, Canberra, Australia. ... Virology 2, 665678. STAKK, GR, STEIN, WH, and MOORE, S. (1960). ...
Summary A count of specifically labelled tryptic peptides from purified poliovirus (strain Mahone... more Summary A count of specifically labelled tryptic peptides from purified poliovirus (strain Mahoney) showed that the amino acid sequence comprising its structural protein contains at least 21 and 25 uniquely placed residues of histidine and methionine, respectively. Amino acid analysis after performic acid oxidation showed a content of, respectively, 21 and 27 moles of these residues per 1000 amino acids recovered. Accordingly, poliovirus structural protein must comprise a unique sequence of about 1000 amino acids, representing about 40% of the coding potential of the poliovirus genome. The correspondence of this percentage with the proportion of the poliovirus genetic map occupied by structural protein genes (48%) suggests that the map represents a major part of the genome. A value of about 1000 amino acids, or 100 to 110000 daltons of protein, for the repeating structural unit, coupled with a total content of 6.0 to 6.4 × 106 daltons of protein in the poliovirus particle, indicates that it contains 60 such structural units and that its triangulation number = 1.
Summary A count of specifically labelled tryptic peptides from purified poliovirus (strain Mahone... more Summary A count of specifically labelled tryptic peptides from purified poliovirus (strain Mahoney) showed that the amino acid sequence comprising its structural protein contains at least 21 and 25 uniquely placed residues of histidine and methionine, respectively. Amino acid analysis after performic acid oxidation showed a content of, respectively, 21 and 27 moles of these residues per 1000 amino acids recovered. Accordingly, poliovirus structural protein must comprise a unique sequence of about 1000 amino acids, representing about 40% of the coding potential of the poliovirus genome. The correspondence of this percentage with the proportion of the poliovirus genetic map occupied by structural protein genes (48%) suggests that the map represents a major part of the genome. A value of about 1000 amino acids, or 100 to 110000 daltons of protein, for the repeating structural unit, coupled with a total content of 6.0 to 6.4 × 106 daltons of protein in the poliovirus particle, indicates that it contains 60 such structural units and that its triangulation number = 1.
When primary baby mouse skin (BMS) cultures were subcultured for 48 hours into media containing 1... more When primary baby mouse skin (BMS) cultures were subcultured for 48 hours into media containing 10(-6) to 10(-7) M colchicine or demecolcine, the number of altered cell foci appearing after 3-4 weeks' maintenance at 36 degrees C was substantially enhanced over drug-free controls. This applied whether or not the primary cultures had been irradiated with white fluorescent light. The additional presence of cytochalasin D and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) sometimes improved and sometimes partly suppressed the enhancing effect of the antitubulin drugs, and these drugs were omitted for reproducible focus enhancement. The enhancement depended on passage through DNA synthesis in presence of colchicine, which did not prevent concurrent or subsequent DNA synthesis but induced a substantial proportion (greater than 33%) to replicate in the tetraploid (4n to 8n) chromosome configuration. Another effect was to induce widespread asymmetric nuclear division, allowing the potential for chromosome loss. All these effects occurred within the first one or few cell cycles after removal of the antitubulin drugs. The results suggest that the generation of tetraploidy perhaps followed by chromosome loss may be an important factor in the rapid induction of altered cell foci. Pre-existing DNA damage is another important factor.
Algammulin is a new vaccine adjuvant comprising a stable suspension of 1-2 microns ovoids of the ... more Algammulin is a new vaccine adjuvant comprising a stable suspension of 1-2 microns ovoids of the immune stimulant gamma inulin in which alum (Alhydrogel) is embedded as a protein carrier. Adjuvanticity tests in mice with Algammulin show that the presence of gamma inulin on the alum particles has synergistically enhanced their adjuvanticity for low doses of hepatitis B surface antigen. The primary-response titres of HBsAg-specific antibody from a given low dose of alum injected as Algammulin were 3- to 5.6-fold greater than those from the same alum dose injected as free alum. This corresponds closely with more extensive previous work using keyhole limpet haemocyanin as antigen.
There has been a recent resurgence of interest into new and improved vaccine adjuvants. This inte... more There has been a recent resurgence of interest into new and improved vaccine adjuvants. This interest has been stimulated by the need for new vaccines to combat problematic pathogens such as SARS and HIV, and to counter potential bioterrorist attacks. A major bottleneck in vaccine development is the low immunogenicity of purified subunit or recombinant proteins, creating the need for safe human adjuvants with high potency. A major problem in the search for the ideal adjuvant is that adjuvants that promote cell-mediated (Th1) immunity (e.g. Freund's complete adjuvant) generally have unacceptable local or systemic toxicity that precludes their use in human vaccines. There is a need for a safe, non-toxic adjuvant that is able to stimulate both cell-mediated and humoral immunity. Inulin-derived adjuvants that principally stimulate the innate immune system through their ability to activate the alternative complement pathway have proven ability to induce both cellular and humoral immunity. With their excellent tolerability, long shelf-life, low cost and easy manufacture, they offer great potential for use in a broad range of prophylactic and therapeutic vaccines. Based on successful animal studies in a broad range of species, human trials are about to get underway to validate the use of inulin-based adjuvants in prophylactic vaccines against hepatitis B, malaria and other pathogens. If such trials are successful, then it is possible that inulin-derived adjuvants will one day replace alum as the adjuvant of choice in most human prophylactic vaccines.
Abstract Low doses of actinomycin D (0.1 μg/ml) can enhance, markedly inhibit, or have no effect ... more Abstract Low doses of actinomycin D (0.1 μg/ml) can enhance, markedly inhibit, or have no effect on poliovirus growth: the outcome depends on the pretreatment given the cells, in particular on the properties of the serum in which they have been incubated. Preincubation of cells without serum or with certain batches of calf serum renders subsequent virus growth sensitive to actinomycin. It appears that some sera contain a specific substance that induces an actinomycin-resistant state; this substance is probably insulin, since physiological levels of insulin are shown to simulate active batches of serum. Other hormones are inactive. In sensitive cells, actinomycin prevents synthesis of viral RNA by affecting a stage of growth that occurs after penetration; this stage is a fairly late one. Cells in the actinomycin-sensitive state do not necessarily differ from actinomycin-resistant cells in microscopical appearance, rate of multiplication, rates of incorporation of radioactive leucine and uridine, and yield of virus in absence of actinomycin.
... The damage by urea culminates in 1 Present address: Department of Microbiology, John Curtin S... more ... The damage by urea culminates in 1 Present address: Department of Microbiology, John Curtin School of Medical Research, Aus tralian National University, Canberra, Australia. ... Virology 2, 665678. STAKK, GR, STEIN, WH, and MOORE, S. (1960). ...
Summary A count of specifically labelled tryptic peptides from purified poliovirus (strain Mahone... more Summary A count of specifically labelled tryptic peptides from purified poliovirus (strain Mahoney) showed that the amino acid sequence comprising its structural protein contains at least 21 and 25 uniquely placed residues of histidine and methionine, respectively. Amino acid analysis after performic acid oxidation showed a content of, respectively, 21 and 27 moles of these residues per 1000 amino acids recovered. Accordingly, poliovirus structural protein must comprise a unique sequence of about 1000 amino acids, representing about 40% of the coding potential of the poliovirus genome. The correspondence of this percentage with the proportion of the poliovirus genetic map occupied by structural protein genes (48%) suggests that the map represents a major part of the genome. A value of about 1000 amino acids, or 100 to 110000 daltons of protein, for the repeating structural unit, coupled with a total content of 6.0 to 6.4 × 106 daltons of protein in the poliovirus particle, indicates that it contains 60 such structural units and that its triangulation number = 1.
Summary A count of specifically labelled tryptic peptides from purified poliovirus (strain Mahone... more Summary A count of specifically labelled tryptic peptides from purified poliovirus (strain Mahoney) showed that the amino acid sequence comprising its structural protein contains at least 21 and 25 uniquely placed residues of histidine and methionine, respectively. Amino acid analysis after performic acid oxidation showed a content of, respectively, 21 and 27 moles of these residues per 1000 amino acids recovered. Accordingly, poliovirus structural protein must comprise a unique sequence of about 1000 amino acids, representing about 40% of the coding potential of the poliovirus genome. The correspondence of this percentage with the proportion of the poliovirus genetic map occupied by structural protein genes (48%) suggests that the map represents a major part of the genome. A value of about 1000 amino acids, or 100 to 110000 daltons of protein, for the repeating structural unit, coupled with a total content of 6.0 to 6.4 × 106 daltons of protein in the poliovirus particle, indicates that it contains 60 such structural units and that its triangulation number = 1.
When primary baby mouse skin (BMS) cultures were subcultured for 48 hours into media containing 1... more When primary baby mouse skin (BMS) cultures were subcultured for 48 hours into media containing 10(-6) to 10(-7) M colchicine or demecolcine, the number of altered cell foci appearing after 3-4 weeks' maintenance at 36 degrees C was substantially enhanced over drug-free controls. This applied whether or not the primary cultures had been irradiated with white fluorescent light. The additional presence of cytochalasin D and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) sometimes improved and sometimes partly suppressed the enhancing effect of the antitubulin drugs, and these drugs were omitted for reproducible focus enhancement. The enhancement depended on passage through DNA synthesis in presence of colchicine, which did not prevent concurrent or subsequent DNA synthesis but induced a substantial proportion (greater than 33%) to replicate in the tetraploid (4n to 8n) chromosome configuration. Another effect was to induce widespread asymmetric nuclear division, allowing the potential for chromosome loss. All these effects occurred within the first one or few cell cycles after removal of the antitubulin drugs. The results suggest that the generation of tetraploidy perhaps followed by chromosome loss may be an important factor in the rapid induction of altered cell foci. Pre-existing DNA damage is another important factor.
Algammulin is a new vaccine adjuvant comprising a stable suspension of 1-2 microns ovoids of the ... more Algammulin is a new vaccine adjuvant comprising a stable suspension of 1-2 microns ovoids of the immune stimulant gamma inulin in which alum (Alhydrogel) is embedded as a protein carrier. Adjuvanticity tests in mice with Algammulin show that the presence of gamma inulin on the alum particles has synergistically enhanced their adjuvanticity for low doses of hepatitis B surface antigen. The primary-response titres of HBsAg-specific antibody from a given low dose of alum injected as Algammulin were 3- to 5.6-fold greater than those from the same alum dose injected as free alum. This corresponds closely with more extensive previous work using keyhole limpet haemocyanin as antigen.
There has been a recent resurgence of interest into new and improved vaccine adjuvants. This inte... more There has been a recent resurgence of interest into new and improved vaccine adjuvants. This interest has been stimulated by the need for new vaccines to combat problematic pathogens such as SARS and HIV, and to counter potential bioterrorist attacks. A major bottleneck in vaccine development is the low immunogenicity of purified subunit or recombinant proteins, creating the need for safe human adjuvants with high potency. A major problem in the search for the ideal adjuvant is that adjuvants that promote cell-mediated (Th1) immunity (e.g. Freund's complete adjuvant) generally have unacceptable local or systemic toxicity that precludes their use in human vaccines. There is a need for a safe, non-toxic adjuvant that is able to stimulate both cell-mediated and humoral immunity. Inulin-derived adjuvants that principally stimulate the innate immune system through their ability to activate the alternative complement pathway have proven ability to induce both cellular and humoral immunity. With their excellent tolerability, long shelf-life, low cost and easy manufacture, they offer great potential for use in a broad range of prophylactic and therapeutic vaccines. Based on successful animal studies in a broad range of species, human trials are about to get underway to validate the use of inulin-based adjuvants in prophylactic vaccines against hepatitis B, malaria and other pathogens. If such trials are successful, then it is possible that inulin-derived adjuvants will one day replace alum as the adjuvant of choice in most human prophylactic vaccines.
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