T1 bacteriophage production in Escherichia coli

Feiner, Rose R. (Columbia University, New York, N.Y.) and Solon A. Ellison. T1 bacteriophage production in Escherichia coli. J. Bacteriol. 85:7-11. 1963.-Progeny released from complexes formed between unirradiated Escherichia coli strain Bs-1 and ultraviolet (UV)-irradiated phage T1 were equally infective for strains B and Bs-1, and were therefore not hostmodified. The capacity of Bs-1 for unirradiated or irradiated T1 is relatively insensitive to UV irradiation, as compared with that of strains B and B/r. In all three strains of E. coli, B, B/r, and Bs-1, the UV sensitivity of the capacity for phage T1 is independent of the UV sensitivity of colony-forming ability. These findings are discussed in relation to the partial genetic homology hypothesis.

Antibody formation initiated in vitro. II. Antibody synthesis in x-irradiated recipients of diffusion chambers containing nucleic acid derived from macrophages incubated with antigen

The diffusion chamber technique permitted the demonstration of specific antibody formation in x-irradiated recipients of such chambers filled with normal lymph node cells and a cell-free homogenate of macrophages which had been incubated in intro with T2 bacteriophage. The activity of the cell-free homogenate was retained in its RNA fraction isolated by means of the phenol method. No antibody formation occurred if such RNA was treated with RNAase. On sucrose gradients (5 to 20 per cent), the active RNA was found to be present in the top third layer. The question of the possible presence of antigen complexed to the RNA is discussed.

Sequences of synthesis of gamma-1 macroglobulin and gamma-2 globulin antibodies during primary and secondary responses to proteins, salmonella antigens, and phage

The nature of the antibodies produced by the rabbit during the primary and secondary responses to T(2) phage, proteins, and the O and H antigens of Salmonella typhosa has been determined. Immune sera have been fractionated by zone electrophoresis, sucrose density ultracentrifugation, and anion exchange chromatography. The resulting fractions have been assayed by phage neutralization or hemagglutination (antisera to proteins) or bacterial agglutination. In confirmation and extension of earlier work from this laboratory, the primary response to these antigens, with the exception of the O antigen of the Salmonella, included the early synthesis of 19S, gamma-1 globulin antibody, and the later synthesis of 7S, gamma-2 globulin antibody. The primary response to the O antigen consisted of the synthesis of only a macroglobulin agglutinin. The secondary response to the proteins, including the H antigen of the Salmonella, comprised the early synthesis of large amounts of the 7S gamma-2 globulin antibody to the same level attained during the primary response. The secondary response to the phage consisted in the synthesis of 7S, gamma-2 globulin antibody alone. Treatment of the macroglobulin phage-neutralizing antibody with mercaptoethanol resulted in complete loss of its neutralizing activity. A working hypothesis to explain these observations was presented. A salient feature of this hypothesis was the suggestion that different cells synthesized the two distinct molecular forms of antibody. The significance of the sequential synthesis of the two forms of antibody is not known. It was proposed that the system for synthesis of macroglobulin antibody is an auxiliary system for antibody synthesis, perhaps the first to develop phylogenetically and ontogenetically. It is felt that the present observations indicate a clear-cut qualitative distinction between the primary and secondary responses to immunization whereby these responses might be identified in various experimental situations. It is also felt that these findings with the primary and secondary responses to various antigens in the rabbit may be of widespread occurrence in nature among a variety of species.

Antibody formation. IV. Formation of rapidly and slowly sedimenting antibodies and immunological memory to bacteriophage phi-X 174

Injection of a sufficient dose of bacteriophage phiX 174 into guinea pigs results in the formation of rapidly sedimenting antibody molecules (19S), and later, slowly sedimenting molecules (7S). Above a threshold dose of antigen, the relative rate of 19S formation is maximal and dose-independent; below this dose, slower relative rates are obtained. The time for doubling the serum 19S level is as short as 6 to 8 hours, suggesting that the absolute rate of antibody formation per cell is increasing in addition to proliferation of antibody-producing cells. Synthesis of 19S after injection of 10(10) phiX virtually ceases at 10 days after which 19S antibody activity disappears from the circulation with a half-life of approximately 24 hours. A second injection of phiX on day 5 or 9 prolongs 19S synthesis, indicating that antigen not only can regulate the relative rate, but also is essential for continued synthesis of 19S. 19S synthesis is also prolonged in guinea pigs by injection of phiX with endotoxin or by 400 r whole body x-irradiation 24 hours after injection of phage into rabbits. The primary 7S response is not detected until approximately 1 week after immunization and relative rates are antigen-dependent. Primary 7S synthesis can continue for many months and leads to preparation for a secondary antibody response (immunological memory) during which only 7S is detected. In contrast, in animals that form precipitating 19S without detectable 7S, a second injection of phage 1 month later results in a second 19S response which closely resembles the first. These findings have led to the suggestion that formation of 19S does not lead to persisting immunological memory.

Physicochemical studies on the reaction between formaldehyde and DNA

The reaction between formaldehyde and phage T7 DNA has been studied by optical absorbance and sedimentation measurements. Through the course of denaturation, OD(200) and s(20, w) rise; after the attainment of full hyperchromicity the s(20, w) falls sharply, suggesting a decrease in molecular weight. Conditions in which formaldehyde causes cross-linking are defined. Some experimental applications of the denaturation technique are given. Evidence which suggests that preformed single-strand interruptions may exist in phage DNA is briefly discussed.

The adsorption of bacteriophage phi-X174 to its host

The adsorption of purified varphiX174 to E. coli C and to E. coli C cell walls was investigated. Adsorption was measured by assaying for unadsorbed plaque formers. The amount of irreversible and reversible adsorption depends upon pH and divalent ion concentration. Maximum irreversible adsorption occurs in 0.1 M CaCl(2) at 36 degrees C. There is no detectable reversible adsorption at conditions of pH and CaCl(2) concentration optimum for irreversible adsorption. Under these optimum conditions, diffusion is not the rate-limiting factor, and the encounter efficiency appears to be low. The rate constant is 1.0 x 10(-10) ml/sec. Phages adsorbed irreversibly to live cells cause infection and to the isolated cell walls apparently cause release of DNA. There is a specific varphiX174 receptor site on the mucocomplex portion of the cell wall.

Temperature and the reproduction of lambda-phage mutants

Groman, Neal B. (University of Washington, Seattle). Temperature and the reproduction of two lambda-phage mutants. J. Bacteriol. 84:438-445. 1962.-A comparative study of phage lambda, and mutants lambdatem and lambda11(2), was made, with particular emphasis on the effect of elevated temperature (44 C) on phage reproduction. Phage lambdatem was selected at 44 C and lambda11(2) was isolated from the late-lysing fraction of bacteria at 37 C. All three phages are similar in their host range, immunity pattern, and in the rate of inactivation of free phage by anti-lambda antibody and heat. Differences were observed in their plaque size and in their relative plating efficiency at 37 and 44 C. One-step growth curve studies showed that phages lambda and lambdatem are similar in the time intracellular phage appears and in their rate of maturation at 37 C. These time and rate parameters were unchanged at 44 C. Both lambda and lambdatem exhibited a reduced latent period at 44 C. However, the latent period of lambdatem was longer than that of lambda at both 37 and 44 C, and its relative 44 C/37 C yield was about 40% while that of lambda is about 3%. Phage lambdatem may be characterized as a lambda mutant with an altered latent period. Phage lambda11(2) was similar to lambda and lambdatem at 37 C, but at 44 C behaved quite differently. The time of appearance of intracellular phage was delayed, compared to 37 C, and the rate of maturation was slower. Phage production at 44 C was about 16% that at 37 C. On further investigation, it was observed that induced Escherichia coli K-12 (lambda11(2)) failed to lyse at 44 C, although it did lyse at 37 C. Lysis inhibition was imposed almost immediately by transferring cells from 37 C to 44 C at any time during the reproductive cycle, including the lytic phase. The behavior of lambda11(2) at 44 C disposed of the possibility that the lytic step was the only step in the phage cycle sensitive to variations in temperature. However, it appeared that the lytic step was a consistant target for its action.

Some observations on the role of coliphages in the number of Escherichia coli in oxidation ponds

No evidence was found to support the view that coliphages as such play an important role in reducing the number of E. coli in sewage water when it is treated in oxidation ponds. Coliphages seem to have greater powers of survival than E. coli in oxidation ponds.

Sedimentation rate as a measure of molecular weight of DNA

Zone centrifugation of mixtures of two labeled DNA's at low concentrations in density gradients of sucrose permits accurate measurement of relative sedimentation rates. The individual rates are constant during the run. Measurements with DNA's from phages T2, T5, and lambda conform to the relation D(2)/D(1) = (M(2)/M(1))(0.35), where D and M refer to distances sedimented and molecular weights of the DNA pair. The results show that high molecular weight DNA's sediment artificially fast in the optical centrifuge, owing to a hitherto unknown effect of molecular interactions. The molecular weight of lambda DNA is 31 million, measured either from sedimentation rate or from tests of fragility under shear.

Properties of a bacteriophage derived from Escherichia coli K235

A temperate bacteriophage was isolated from the colicinogenic strain of Escherichia coli K235 and characterized. This phage, termed PK, is related to P2 virus morphologically, serologically, and, possibly, genetically and it bears no relationship to the T-even phages. It was also demonstrated that PK virus and colicine K differ both in their host range and in their immunological specificity, and that PK prophage does not induce the colicinogenesis in its host bacterium. It was concluded that the formation of colicine K. and PK phage in E. coli K235 are controlled by different genetic determinants.

GLUCOSYLATED NUCLEOTIDE SEQUENCES FROM T-EVEN BACTERIOPHAGE DEOXYRIBONUCLEIC ACIDS

1. The frequencies of various pyrimidine nucleotide sequences in phage-T2VG111 DNA and phage-T6 DNA have been measured. The hydroxymethylcytosine nucleotides that bear glucosyl groups in phage-T2VG111 DNA and gentiobiosyl groups in phage-T6 DNA are not randomly distributed. 2. Sequences in which two or three hydroxymethylcytosine nucleotides are terminated at both ends by purine nucleotides bear only one sugar substituent and this is attached to the first hydroxymethylcytosine when the sequences are written in the conventional notation; i.e. with the 5'-phosphate before and the 3'-phosphate after each nucleoside residue. This resembles the distribution of glucosyl residues previously found in the corresponding sequences from phage-T2 DNA. Sequences in which one hydroxymethylcytosine nucleotide is attached through the 3'-position to a purine nucleotide are more fully glucosylated in phage-T2VG111 DNA and phage-T6 DNA than in the DNA of phage T2. 3. Pyrimidine sequences from the DNA of phage T6(S) have been found to contain glucosyl but not gentiobiosyl residues. The relative amounts of the sequences isolated indicate that the distribution of the glucosyl residues in this DNA resembles that of the gentiobiosyl groups in phage-T6 DNA. 4. It is suggested that the distributions of glycosyl substituents in these T-even-phage deoxyribonucleic acids reflect the specificity requirements of the alpha-glucosyltransferases induced by the different phages. The results obtained with the DNA of phage T6(S) suggest that this phage induces the usual phage-T6 alpha-glucosyltransferase but not the phage-T6 beta-glucosyltransferase.

THE EFFECT OF TEMPERATURE ON THE FORMATION OF T1 AND T2R BACTERIOPHAGE

A very rapid variation of yield of T1 and T2r bacteriophage in E. coli at slightly higher than normal temperatures has been observed. T1 phage will develop at 41.2 degrees C but not at 41.7 degrees C. By infecting cells grown on lactose and, therefore, induced to contain beta galactosidase, a technique which indicates when cells have become leaky was worked out. This method shows that at elevated temperatures the enzymatic attack on the cell wall continues to go at a faster rate, while completion of the phage goes more slowly. Thermal constants are given for the processes. Cells at higher temperature, grown on P(32) medium develop incomplete particles capable of combining with phage antibody. This suggests that the process affected by the early leakiness of the cells is the completion of the virus protein coat. Supplementing the medium with casamino acids, phosphate, and ATP causes the "rescue" of phage particles by aiding the formation of the coat. This can be achieved several minutes after the cells have become leaky and may form a useful system for the study of phage development in the presence of analogs.

FINE STRUCTURE OF THE BACTERIOPHAGE ATTACHMENT PROCESS

Cota-Robles, E. H. (University of California, Riverside) and M. D. Coffman. Fine structure of the bacteriophage attachment process. J. Bacteriol. 86:266-273. 1963.-Electron microscopic examination of cells of Escherichia coli infected with coliphage T(2) suggested that the tail spikes of the virus attach to the cell wall. This is followed by a local disorganization of the cell wall and contraction of the virus tail resulting in the approximation of the virus to the cell. Ejection of the viral contents is followed by a retraction of the attached viral ghost from the infected cell. The bacterial cells reveal a fibrillar nuclear structure which in some cases surrounds material that appears to be of cytoplasmic origin.

STREPTOMYCIN AS AN ANTIVIRAL AGENT: MODE OF ACTION

In host bacteria resistant to the antibiotic, streptomycin inhibits phage replication by inhibiting the process of injection. This effect is competitively reversed by certain divalent cations, polyamines, and streptidine. It is proposed that streptomycin inhibits injection by attaching to the phage DNA while it is still folded within the phage head, and in this way it prevents the unfolding which is essential for the injection process. The reversal agents probably function by displacing the antibiotic from the phage, but they also promote injection themselves.

EVOLUTION OF THE IMMUNE RESPONSE. I. THE PHYLOGENETIC DEVELOPMENT OF ADAPTIVE IMMUNOLOGIC RESPONSIVENESS IN VERTEBRATES

1. The California hagfish, Eptatretus stoutii, seems to be completely lacking in adaptive immunity: it forms no detectable circulating antibody despite intensive stimulation with a range of antigens; it does not show reactivity to old tuberculin following sensitization with BCG; and gives no evidence of homograft immunity. 2. Studies on the sea lamprey, Petromyzon marinus, have been limited to the response to bacteriophage T(2) and hemocyanin in small groups of spawning animals. They suggest that the lamprey may have a low degree of immunologic reactivity. 3. One holostean, the bowfin (Amia calva) and the guitarfish (Rhinobatos productus), an elasmobranch, showed a low level of primary response to phage and hemocyanin. The response is slow and antibody levels low. Both the bowfin and the guitarfish showed a vigorous secondary response to phage, but neither showed much enhancement of reactivity to hemocyanin in the secondary response. The bowfin formed precipitating antibody to hemocyanin, but the guitarfish did not. Both hemagglutinating and precipitating antibody to hemocyanin were also observed in the primary response of the black bass. 4. The bowfin was successfully sensitized to Ascaris antigen, and lesions of the delayed type developed after challenge at varying intervals following sensitization. 5. The horned shark (Heterodontus franciscii) regularly cleared hemocyanin from the circulation after both primary and secondary antigenic stimulation, and regularly formed hemagglutinating antibody, but not precipitating antibody, after both primary and secondary stimulation with this antigen. These animals regularly cleared bacteriophage from the circulation after both the primary and secondary stimulation with bacteriophage T(2). Significant but small amounts of antibody were produced in a few animals in the primary response, and larger amounts in the responding animals after secondary antigenic stimulation. 6. Studies by starch gel and immunoelectrophoresis show that the hagfish has no bands with mobilities of mammalian gamma globulins; that the lamprey has a single, relatively faint band of this type; and that multiple gamma bands are characteristic of the holostean, elasmobranchs, and teleosts studied. By this method of study, the bowfin appeared to have substantial amounts of gamma(2) globulin. 7. We conclude that adaptive immunity and its cellular and humoral correlates developed in the lowest vertebrates, and that a rising level of immunologic reactivity and an increasingly differentiated and complex immunologic mechanism are observed going up the phylogenetic scale from the hagfish, to the lamprey, to the elasmobranchs, to the holosteans, and finally the teleosts.

THE INHERITANCE OF THE PROTEIN AND NUCLEIC ACID CHARACTERISTICS OF T2 AND T6 BACTERIOPHAGE

A study of the immunological properties of phage strains derived from T2 x T6 crosses revealed that the majority of the progeny differ serologically from the parental viruses. Some hybrids were found to contain head membranes having the serological specificity of both T2 and T6 phages, while others contained tail sheaths of the former and the tail fibers of the latter. Since the immunological properties of all hybrids were heritable, it has been concluded that the serological specificity of the head proteins of T2 and T6 is controlled by at least two genetic determinants, and that the specificities of the fiber and sheath proteins may be governed by single genes. Furthermore it was found that nucleic acids of hybrids had similar proportions of unsubstituted, mono- and diglucosylated hydroxymethylcytosine nucleotides to the nucleic acid of either T2 or T6 phage. Since the parental and hybrid viruses having chemically similar nucleic acids contained in some instances serologically different proteins, it has also been concluded that the extent of glucosylation of the hydroxymethylcytosine component of viral nucleic acids and the immunological properties of viral proteins are independently heritable traits of T2 and T6 bacteriophages.