Lymphocyte traffic through lymph nodes during cell shutdown

Antigenic challenge of lymph nodes in sheep has marked effects on lymphocyte traffic through lymph nodes. The non-specific effects include a marked reduction in lymphocyte output in efferent lymph without a corresponding decrease in lymph flow--a phenomenon known as cell shutdown. With certain antigens there is a total disappearance of B lymphocytes during cell shutdown. The phenomenon can be reproduced in unprimed lymph nodes whenever localized complement activation occurs within the node. This also induces the release of prostaglandins, particularly PGE2. These results suggest that cell shutdown might be a two-step process involving both complement and prostaglandins. Repeated stimulation of nodes with antigen also has considerable effects on the traffic of antigen-specific lymphocytes. Antigen localized within the node can promote the selective entry into the node of T lymphocytes specific for the challenge antigen. Consequently there is a net loss from the whole animal of T cells reactive to the challenge antigen. These results are discussed in relation to lymphocyte recirculation through antigen-stimulated lymph nodes.

[Ambivalent bacteriophages of different species active on Escherichia coli K12 and Salmonella sps. strains]

A study was made of several bacteriophages (including phages U2 and LB related to T-even phages of Escherichia coli) that grow both on E. coli K12 and on some Salmonella strains. Such phages were termed ambivalent. T-even ambivalent phages (U2 and LB) are rare and have a limited number of hosts among Salmonella strains. U2 and LB are similar to canonical E. coli-specific T-even phages in morphological type and size of the phage particle and in reaction with specific anti-T4 serum. Phages U2 and LB have identical sets of structural proteins, some of which are similar in size to structural proteins of phages T2 and T4. DNA restriction patterns of phages U2 and LB differ from each other and from those of T2 and T4. Still, DNAs of all four phages have considerable homology. Unexpectedly, phages U2 and LB grown on Salmonella bungori were unstable during centrifugation in a CsCl gradient. Ambivalent bacteriophages were found in species other than T-even phages and were similar in morphotype to lambdoid and other E. coli phages. One of the ambivalent phages was highly similar to well-known Felix01, which is specific for Salmonella. Ambivalent phages can be used to develop a new set for phage typing in Salmonella. An obvious advantage is that ambivalent phages can be reproduced in the E. coli K12 laboratory strain, which does not produce active temperate phages. Consequently, the resulting typing phage preparation is devoid of an admixture of temperate phages, which are common in Salmonella. The presence of temperate phages in phage-typing preparations may cause false-positive results in identifying specific Salmonella strains isolated from the environment or salmonellosis patients. Ambivalent phages are potentially useful for phage therapy and prevention of salmonellosis in humans and animals.

The functions of the phage T4 immunity and spackle genes in genetic exclusion

Genetic exclusion is the ability of a primary infecting phage to prevent a secondary infecting phage from contributing its genetic information to the progeny. The molecular mechanism of the phenomenon is not well understood. The two genes in phage T4 mainly responsible for genetic exclusion are the immunity (imm) gene and the spackle (sp) gene. Evidence is presented that the imm gp enables the host exonuclease V to degrade superinfecting phage DNA. This appears to be accomplished by the imm gp altering gp 2/64, the presumed pilot protein, which protects the 5′ end(s) of the phage DNA. Exonuclease III is also involved in genetic exclusion but its action does not appear to depend upon theimmorspgene products. Gp sp appears to interfere with the lysozyme activity of gp 5, a component of the central base plug, postulated to aid in tail tube penetration during the injection process. A molecular model of genetic exclusion is proposed. Genesimmandspare part of a cluster of genes which also includes42, beta-glucosyltransferase, anduvsX. The genes of this cluster encode proteins apparently adapted for competition and defence at the DNA level. These genes may encode fundamental adaptive strategies found throughout nature.

[Host-dependent modifications of bacteriophage T3 expressing changes in adsorption properties (serological study)]

The ability of the bacteriophage T3 to adsorb on the host cells of Escherichia coli W1655 changes depending on the host strain in which the phage was propagated before. This phenomenon is termed "non-classical" host-controlled modification in contrast to "classical" DNA modification. We demonstrate here that T3 phages with various non-classical modifications as well as the host range mutant T3hW differ from each other in the antigenic determinants of the phage adsorption protein.

T-even-type bacteriophages use an adhesin for recognition of cellular receptors

Protein 38 of the Escherichia coli phage T4 is thought to be required catalytically for the assembly of the long tail fibers of this phage. It is shown that this protein of phage T2 and the T-even-type phage K3 and Ox2 act differently. It was found that NH2-terminal fragments of the protein, expressed from cloned fragments of gene 38 of phage K3, bind to gene 38 amber mutants of phage T2. Such phage or T2 gene 38 amber mutants, grown on a non-permissive host, possess a complete set of six tail fibers but are non-infectious. Both types of non-infectious phage could be repaired by incubation with an extract of cells harboring a cloned gene 38 of a host range mutant of phage K3, K3hx. The repaired phages had the host range of K3hx and not of T2. Immuno-electron microscopy showed that protein 38 is located at the free ends of the long tail fibers of phages T2, K3 and Ox2. The protein serves the recognition of the cellular receptor, i.e. it acts as an adhesin.

Production and detection of coliphage T4 endonuclease V polyclonal and monoclonal antibodies using staphylococcal protein-A hybrid proteins

To facilitate the production of antibodies against endonuclease V, a pyrimidine dimer-specific DNA glycosylase produced in bacteriophage T4-infected Escherichia coli, we constructed plasmids containing protein-A-endonuclease V fusion genes under control of the E. coli tac promoter. Induction with isopropyl-beta-D-thiogalactopyranoside produced large amounts of fusion proteins, which could easily be purified on human IgG agarose columns. The affinity-purified fusion proteins were injected into rabbits and mice to produce polyclonal and monoclonal antibodies, and also used for the screening of the monoclonal antibodies. These antibodies recognized endonuclease V on immunoblots, and also inhibited the DNA-glycosylase activity in vitro. Epitope mapping of monoclonal antibodies showed that they all (6/6) recognized determinants in the C-half of endonuclease V. A convenient way to detect primary antibodies on nitrocellulose was also developed using a crude protein extract containing protein-A-beta-galactosidase fusion protein and subsequent detection with a mixture of dyes.

Defective humoral immunity in pediatric acquired immune deficiency syndrome

Specific antibody production was assessed in six young children with the acquired immune deficiency syndrome (AIDS). All patients were immunized with bacteriophage phi X 174, a T cell-dependent neoantigen. In addition, antibody responses to pneumococcal vaccine and tetanus toxoid, lymphocyte responses to mitogens, and serum immunoglobulin levels were determined. Polyclonal hypergammaglobulinemia was documented in three patients. Responses to bacteriophage phi X 174 were abnormal in all patients: primary responses were blunted, secondary responses were markedly decreased, and the class switch (IgM-IgG) was absent in five of six patients. Antibody formation to pneumococcal vaccine and tetanus toxoid was also diminished. Lymphocyte mitogenic responses to phytohemagglutinin, concanavalin A, pokeweed mitogen, and staphylococcal Cowan A were generally decreased. These findings confirm that pediatric patients with AIDS have significant abnormalities in humoral immunity. Dysfunction of both T cells and B cells plays a role in the resultant poor specific antibody production.

[Evaluation of the functional activity of peritoneal macrophages using the tetrazolium test]

The redox activity of peritoneal macrophages has been evaluated in the modified NBT test using tetranitro blue tetrazolium. This method permits the calculation of the total amount of peritoneal macrophages and the determination of their glass adherence per cent and their cytochemical activity value. The advantages of this method over the study of the phagocytic activity by means of phage T2 is shown.

Specific labeling of protein domains with antibody fragments

Monovalent antibody Fab fragments, prepared from antisera raised against two different types of crystalline arrays made of either intact, or a proteolytic fragment of bacteriophage T4 major capsid protein, gp23*, were employed to stoichiometrically label different gp23* protein domains on the outer surface of a tubular variant (i.e., "polyheads") of bacteriophage T4 capsids. Computer filtrations of both negatively stained and freeze-dried/metal-shadowed specimens permitted approximate mapping of the Fab binding sites within the capsomere of the polyheads.

[Intracellular neutralization of bacteriophage T4 by antiphagic serum]

Specific antiserum, introduced into the spheroplasts of Escherichia coli B infected with bacteriophage T4, has been shown to neutralize phage particles formed within the cells.

Immunocompetence of chimeric rabbits. I. Participation of donor-derived B lymphocytes in immunoglobulin, but not in antibody, synthesis

Stable and lasting B lymphocyte chimerism induced in newborn rabbits through the introduction of spleen or lymph node cells from adult donors matched with the recipients for major histocompatibility antigens, is characterized by an apparent immunodeficiency of donor-derived cells. However, priming of the donor with an antigen that is subsequently used to immunize the recipients results in the selective and effective participation of donor cells in the chimera's antibody response to this antigen. These findings are ascribed to limitations in the repertoire of cells from the unprimed donor that colonize the recipients. Polyclonal stimulation secondary to allogeneic effects has been suggested as an explanation for the participation of donor-derived B cells noted in occasional recipients of cells from unprimed donors matched with recipients with respect to major but not minor histocompatibility antigens, and seen more regularly in surviving recipients of unmatched or mismatched donor cells.

[Intercellular information transfer in the process of immunogenesis. IX. The induction of the synthesis of antiphage antibodies in lymphosarcoma cells of rats as affected by different fractions of immune nuclear RNA]

Various fractions of the immune nuclear RNA were isolated from spleens of phage T2 immunized rats. The fractions were compared for their ability to induce anti-phage T2 antibody synthesis in transplantable lymphosarcoma cells. The most active proved to be the nuclear sap RNA and its subfraction with sedimentation constant of 10 S. The 4S and 26S subfractions RNA were less stable and in some experiments failed to induce antibody synthesis.

Gene 20 product of bacteriophage T4. II. Its structural organization in prehead and bacteriophage

The location of gene 20 product of bacteriophage T4 in phage and phage percursors has been determined by immunochemical analysis of polyacrylamide gels, immunoturbidimetry and immunoelectron microscopy. The protein is present at the membrane attachment site of the prehead, a head precursor, and is accessible to the antibodies in the solution. It is present at the tail attachment site of the capsid, partially buried in the structure. In complete phage particles it is totally buried in the structure. It is in contact with the major shell proteins, gp23 and gp23*, respectively, in preheads and capsids, as revealed by partial crosslinking experiments. It forms the upper collar of the neck in necked tails. The lower collar is constructed from other gene products. On the basis of these data a structural model of the neck region of the phage has been derived. This model is consistent with a number of events in phage assembly, such as the role of gp20 in head assembly and DNA packaging, prehead detachment from the bacterial membrane and head-tail attachment. The symmetry mismatch known to occur between head and tail has been localized at the gp20-gp23* contact area.

Degrees of relatedness of T-even type E. coli phages using different or the same receptors and topology of serologically cross-reacting sites

The relatedness of a series of T-even like phages which use the Escherichia coli outer membrane protein OmpA as a receptor, and the classical phages T2, T4 and T6 has been investigated. Immunoelectron microscopy and the pattern of phage resistance in bacterial mutants revealed that: (i) phages of this morphology do not necessarily cross-react serologically; (ii) phages using different receptors may bind heterologous IgG everywhere except to the tip (comprising approximately 10% of one fiber polypeptide) of the long tail fibers; (iii) cross-reacting OmpA-specific phages may bind heterologous IgG only to the tip of these fibers: (iv) OmpA-specific phages not cross-reacting at the tip of the tail fibers use different receptor sites on the protein. Absence of cross-reactivity appears to reflect high degrees of dissimilarity. A DNA probe consisting of genes encoding the two most distal tail fiber proteins of T4 detected homologies only in DNA from phages serologically cross-reacting at this fiber. Even under conditions of low stringency, allowing the formation of stable hybrids with almost 30% base mismatch, no such homologies could be found in serologically unrelated phages. Thus, in the collection of phages examined, there are sets of very similar and very dissimilar tail fiber genes and even of such gene segments.

Specific antibodies and immunoglobulins in the oviductal fluid of the rhesus monkey

Levels of specific antibodies against model antigens, immunoglobulins G and A and also albumin, in oviductal fluid were studied in the rhesus monkey during the periovulatory period. Animals were systemically or intravaginally immunized against T4 coliphages. Attempts to induce ovulation were made with human menopausal gonadotropin (hMG) and human chorionic gonadotropin (hCG) monitored by radioimmunoassay of serum estrogen and progesterone. Collection of tubal fluid over 6 to 13 days was accomplished by surgical cannulation using a refrigerated extracorporeal collection device for each side. The results indicated the following: (1) The levels of specific antibodies against T4 coliphage and immunoglobulins (IgG, IgA) in the oviduct fluid averaged approximately one tenth of the serum values and showed a characteristic decrease and subsequent increase by a factor of 4 to 5 during and following treatment with hMG/hCG. The nadir was observed on the first or second day after hCG injection. (2) This pattern was similar in both ovulatory or nonovulatory cycles; therefore, these changes seem to be associated with the changes in serum estrogen levels. (3) There was a striking difference in serum and tubal fluid antibody levels after systemic versus after vaginal immunization by a factor of 10(3) and 10(4); however, the patterns in tubal fluid under treatment with hMG/hCG were very similar. (4) Specific antibodies in oviductal fluid and serum were mainly of the IgG class. (5) A concomitant change of total protein and albumin in oviduct fluid was also observed. The presence of sperm agglutination antibody in oviductal fluid was demonstrated in two monkeys after systemic immunization with homologous spermatozoa. The sperm antibody titers showed a similar pattern of change after hMG/hCG treatment.

Specificity for tail fibers of a humoral crab factor neutralizing T2 bacteriophage

It is now becoming clear that invertebrates, animals lacking the ability to make humoral antibodies, are capable of recognizing self from non-self. In several instances this recognition is manifest in normal ("unimmunized") animals by a rapid clearance of certain foreign materials from the circulation One example of such a rapid innate reaction involves the clearance of T2 bacteriophage from the blue crab (1). Other studies have indicated that blue crab plasma contained a factor capable of neutralizing in vitro T2 bacteriophage and hence, by inference, was responsible for the in vivo clearance reaction with this virus (2). The purpose of the work undertaken here was to establish the nature of the specificity of this in vitro neutralizing factor. The strategy involved utilizing purified T2 bacteriophage tail fibers to inhibitthe neutralization of T2 bacteriophage by crab plasma.

[Serologic affinity and specificity of action of pseudotuberculosis and coli-dysentery phages]

The study of serological properties, specificity and the range of action has revealed affinity between Y. pseudotuberculosis phages (PST, 3M, Kotlyarova, 2344, 2391), some coliphages (T2, T3, T4) and Sh. dysenteriae phage (dd IV). The existence of serovar III of Y. pseudotuberculosis phages has been established; to this serovar phage PST belongs. Newly isolated 2344 and 2391 belong to serovar I. The problem of the existence of Y. pseudotuberculosis phages as an independent group is discussed.

Lymphocyte traffic through antigen-stimulated lymph nodes. I. Complement activation within lymph nodes initiates cell shutdown

Complement activation within lymph nodes has been shown to alter lymphocyte traffic through the node. Challenge of cannulated sheep lymph nodes with either immune complexes or complement activators was found to initiate the phenomenon of cell shutdown associated with antigenic challenge of lymph nodes in primed animals.

Lymphocyte traffic through antigen-stimulated lymph nodes. II. Role of Prostaglandin E2 as a mediator of cell shutdown

Prostaglandin E2 (PGE2) can mediate changes in lymphocyte traffic through lymph nodes. By measuring PGE2 levels in efferent lymph from cannulated sheep lymph nodes it was shown that increased synthesis of PGE2 always correlated with cell shutdown; infusion of PGE2 alone induced cell shutdown and inhibition of PGE2 synthesis by the node abolished cell shutdown induced by antigen.

Antigen controlled immuno diagnosis-- 'ACID test'

A test for the presence of antibodies in sera is described in which the binding of the antibody to a morphologically identifiable antigen, visualized using staphylococcal protein A-coated gold, serves as the criterion for specificity. This 'Antigen Controlled Immuno Diagnosis' (ACID test) as applied to T4 bacteriophage, vaccinia virus and Enterobacterium Yersinia has proved to be reliable and simple to carry out.

Antibody-producing cells in bovine lacteal secretions after local immunization

The indirect Jerne plaque assay was used to determine the presence of antibody-forming cells in lacteal secretions of 2 cows inoculated in the mammary gland with T4 phage. Two adjacent mammary glands of 2 nonlactating 7-months pregnant cows were inoculated by intramammary injection 4 times at 3- to 5-day intervals. The presence of plaque-forming cells (PFC) was assessed in each quarter beginning on postinoculation day 8 and at 4- to 14-day intervals thereafter. Amounts of antibodies in serum and secretions were measured by an indirect hemagglutination test. The PFC were detected in secretions from all quarters of both cows between postinoculation days 8 and 32. Concentrations of PFC fluctuated within quarters during the course of the experiment but no relationship was evident between numbers of PFC in a quarter and its inoculation status. The use of monospecific antiglobulin sera at 1 sample-collection period revealed that cells synthesizing immunoglobulin (Ig)G and IgA antibodies were predominant in lacteal secretions. Antibody amounts in serum and secretions rose after inoculation, and titers in secretions were markedly higher in most instances. Antibody-forming cells were thus demonstrated to accumulate in the mammary gland after intramammary inoculation. The presence of antibody-forming cells in non-inoculated glands may have been the result of antigen transfer among quarters, but was considered more likely to have resulted from systemic migration of antigen-stimulated cells with migration into all quarters, regardless of inoculation status. Antibodies in lacteal secretions may have accumulated through a combination of local synthesis and selective transport from the bloodstream.

Immunological methods based on antigen-coupled bacteriophages

Simple chemicals, many proteins, nucleic acids or polysaccharides can be coupled to bacteriophages without completely destroying their infectivity. The coupled phages are then sensitive to inactivation by the relevant antibodies. Thus it is possible to construct phage inactivation assays for antibodies or inactivation inhibition assays for antigens. The advantages of the bacteriophage methods include superior sensitivity and good stability of the reagents. The phage inactivation method detects preferably high-affinity antibodies, but what really matters is a high avidity. Because of the polyvalency IgM antibodies can have a high avidity associated with moderate affinity, and therefore low amounts of IgM class antibody, for instance natural antibody, are often measurable by this test. The chemical conjugation inactivates a proportion of the bacteriophages. If the antigen can be made chemically reactive (self-coupling), approximately 10% of the phage particles escape this inactivation and can serve as indicators of antibody action. When the antigen cannot be made chemically reactive, this inactivation is more complete and the phage assay is less satisfactory.

A role for clonal dominance in the maintenance of allotype suppression?

The establishment of immunological memory during the early and complete phase of allotype suppression in the young rabbit has been shown to lead to the preferential production of antibodies with the nonsuppressed allotypic specificity in response to recall injections given after spontaneous or induced release from suppression. It is suggested that this manifestation of clonal dominance, applied to stimulation by environmental antigens, may contribute to the long lasting persistence of allotype imbalance in allotype suppressed rabbits.

[Investigation of serological features and molecular heterogeneity of virion proteins of morphologically related phages]

Some interaction process peculiarites of morphologically related phate T4, DDVI and FI1 with the corresponding antiphageous sera in cross reactions of neutralisation have been investigated. Close serological relationship of phage T4 and DDVI was demonstrated. Inactivation of phage FI1 in these serological reactions showed anomalous nature and did not submit to the rules of the first step reaction. According to investigations of the protein component of virions of these phages by electrophoresis in polyacrylamide gel, phages T4 and DDVI contain twelve, FI1 and DDVI four, and T4 and FI1 two protein fractions common in molecular weight. The data obtained indicates that close serological relationship between phages T4 and DDVI is determined by the presence of common protein antigens in the absorptional apparatus of virions. Proteins of phage FI1, common with the proteins of T4 and DDVI, are obviously located in other structural components, and this determines the specific aggregation of virions in cross reactions of neutralization.

Morphology, serology and biochemical characters of phage CVX-5, isolated from a patient with colitis

Electronmicroscopic observations indicate that bacteriophage CVX-5 has an angular head with long spiral tail which is noncontractile, possibly having 2--3 tail fibres attached at the distal part of the tail. This phage is antigenically unrelated to any of the T-phages. Inhibition of phage CVX-5 multiplication by mitomycin C and incorporation of 3H-thymidine into this phage indicate that phage CVX-5 is a DNA phage.

Bacteriophage T4-coded dihydrofolate reductase: synthesis, turnover, and location of the virion protein

Dihydrofolate reductase plays a dual role in bacteriophage T4, first, as an enzyme of thymidylate metabolism, and second, as a protein component of the tail baseplate. Antibody to the purified enzyme has been used to study its synthesis and intracellular turnover. The antibody specifically precipitates one protein from T4D-infected cell extracts. This has been identified as dihydrofolate reductase, although the polypeptide molecular weight (22,000) is lower than that earlier determined for this enzyme. The protein comigrates on gels with pY, a genetically undefined protein component of the baseplate. However, it is not pY, for pY is synthesized late in infection, whereas virtually no dihydrofolate reductase synthesis occurs later than 10 min after infection at 37 degrees C. Dihydrofolate reductase, once formed, is neither degraded nor converted to proteins of higher or lower molecular weight. Thus, it is probably incorporated into virions at the same molecular weight as that of the soluble enzyme. 125I-radiolabeled antibody binds to the wedge substructure of the baseplate, and this binding is blocked by preincubation with purified T4 dihydrofolate reductase. Thus, the enzyme protein seems to be a component of the wedge.

[Host range relationship of bacteriophages T3 and T7 with Escherichia coli K 12 strains]

The closely related phages T3 and T7 exhibit different growth patterns on Escherichia coli W hosts cells (E. coli K12 derivatives). T7 grows normally while T3 does not adsorb. T3hw mutants displaying a T7-like host range were isolated and described.