bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification and characterization of a major cytoplasmic antigen of Candida albicans
Authors: Greenfield R A , Jones J M
Published: January 2020

In previous work (Jones, Infect, Immun. 30:78-89, 1980) a major cytoplasmic antigen of Candida albicans was identified. In both humans and experimental animals, this antigen is released from C. albicans during the course of an invasive C. albicans infection and elicits a specific antibody response. In this study, we used diethylaminoethyl cellulose chromatography and concanavalin A-Sepharose chromatography to obtain purified preparations of the major cytoplasmic antigen from crude cytoplasmic extracts of C. albicans. Column chromatography yielded a purified preparation of the major cytoplasmic antigen, which produced a single line in polyacrylamide gel electrophoresis. Using crossed immunoelectrophoresis, we detected small concentrations of contaminating antigens in the purified preparations. We found that the major antigen was a single polypeptide chain containing about 435 amino acid residues and had a molecular weight of 54,300. This antigen did not possess any of 19 common activities. Enzyme linked immunosorbent assays are being developed to detect this antigen in serum and to detect antibody against the antigen.
Enhanced immunoglobulin, A release from human colostral cells during phagocytosis
Authors: Weaver E A , Goldblum R M , Davis C P , Goldman A S
Published: January 2020

Human colostral leukocytes were investigated for their ability to release immunoglobulin A during phagocytosis of latex particles, heat-killed Candida albicans, or live Escherichia coli. Leukocytes readily phagocytosed latex or serum-opsonized candida or the E. coli. Colostral fluid was also opsonic for yeast and bacteria. Immunoglobulin release, which consisted mainly of secretory immunoglobulin A, began during the first 15 min of incubation with latex, opsonized yeast, or opsonized bacteria. Release was significantly increased from control levels by 30 or 60 min. The release of immunoglobulin A could be inhibited by incubating leukocytes at 4 degrees C. We conclude that phagocytosis and immunoglobulin A release by human colostral leukocytes are related. The data support the hypothesis that colostral leukocytes may play an active role in protecting infants from pathogenic microorganisms.
Genetics of resistance to African trypanosomes: role of the H-2 locus in determining resistance to infection with Trypanosoma rhodesiense
Authors: Levine R F , Mansfield J M
Published: January 2020

Susceptibility and resistance to Trypanosoma rhodesiense infections in inbred and H-2 congenic strains of mice were studied. Mean survival times and patterns of parasitemia were examined. C3HeB/FeJ mice were highly susceptible; CBA/J, A/J, and BALB/cByJ mice displayed an intermediate level of susceptibility; whereas C57BL/10 mice were highly resistant. H-2 congenic strains with the BL/10 background resembled the BL/10 parental type, thereby suggesting that the major histocompatibility complex does not play a major role in regulating resistance and susceptibility to infection with T. rhodesiense.
Rhesus monkeys protected against Plasmodium knowlesi malaria produce antibodies against a 65,000-MrP. knowlesi glycoprotein at the surface of infected erythrocytes
Authors: Schmidt-Ullrich R , Miller L H , Wallach D F , Lightholder J , Powers K G , Gwadz R W
Published: January 2020

Sera from 27 rhesus monkeys immunized in various ways against the H strain of Plasmodium knowlesi were analyzed by quantitative crossed immunoelectrophoresis. The reaction of the sera was compared with a reference immune serum only reactive with P. knowlesi-specific 65,000-Mr glycoprotein-immune component 13 (gp65/ic13) in membranes of infected rhesus monkey erythrocytes. Triton X-100-solubilized, 125I-labeled membranes of schizont-infected erythrocytes were used as an antigen. Sera from 9 or 10 monkeys immunized by repeated infections with P. knowlesi reacted with gp65/ic13. In 6 of 10 sera, anti-gp65/ic13 was the only antibody reacting with host cell membrane proteins. In contrast, vaccination of 15 monkeys with predominantly sexual stages or trophozoites of P. knowlesi in Freund complete adjuvant resulted in protection against blood challenges in 7 monkeys, only 2 of which contained precipitating antibody against gp65/ic13. None of the sera from monkeys not protected by infections or vaccinations contained detectable levels of precipitating antibodies against gp65/ic13. Our data indicate that gp65/ic13 acts as a prominent immunogen in vivo during natural p. knowlesi infections of rhesus monkeys. There is a positive correlation suggested between anti-gp65/ic13 antibody and protection in the monkeys analyzed. This correlation does not apply to monkeys protected against P. knowlesi malaria by vaccination, pointing to other effective immune defense mechanisms.
Immunoglobulin A antibody levels in human tears, saliva, and serum
Authors: Burns C A , Ebersole J L , Allansmith M R
Published: January 2020

The presence and level of immunoglobulin A (IgA) antibodies to the oral microorganism Streptococcus mutans were determined in human tears, parotid saliva, and serum by a modified, indirect enzyme-linked immunosorbent assay. IgA antibodies were found in the tears of all 15 subjects, although S. mutans is a nonocular bacterium. The IgA antibody levels in tears and saliva were not significantly different. This finding suggests that the level of IgA antibody activity per volume is independent of the naturally occurring site of the antigen, and that local stimulation does not cause a significant difference in the antibody level per volume of secretion between exocrine sites. Much higher levels of IgA antibody were present in serum, suggesting that after oral ingestion of antigen both the systemic and exocrine systems are stimulated. IgG antibodies to S. mutans were also found in human tears, saliva, and serum. No relationship between serum levels and tear and saliva levels was found for either IgA or IgG antibodies. Thus the antibodies in tears and saliva did not appear to have leaked from serum. We conclude that there may be remote regulation of both the ocular and the parotid IgA and IgG antibody systems.
Natural cell-mediated cytotoxicity of bovine mononuclear cells against virus-infected cells
Authors: Campos M , Rossi C R , Lawman M J
Published: January 2020

The ability of mononuclear cells (MC) from peripheral blood of normal cattle to lyse a variety of cells was tested in a 51Cr-release microcytotoxicity assay. Several types of bovine cells infected with parainfluenza 3 virus (PI3V) were susceptible to natural cytotoxicity. Bovine cells infected with infectious bovine rhinotracheitis virus or noncytopathogenic bovine viral diarrhea virus, uninfected bovine cells, and human cell lines MOLT-3, HSB-2, K562, and U-937 were not susceptible. The period of time that target cells need to be infected with PI3V to achieve maximal cytotoxicity was determined. Target cells were infected with PI3V and MC, added 1 h later. After the addition of effector cells, significant levels of cytotoxicity were recorded at 17 h. Maximal cytotoxicity occurred 22 to 24 h postinfection. To define the optimal time that MC must be present, cells were infected with PI3V for a total of 24 h, and MC were left in contact with target cells for various time intervals. Maximal cytotoxicity was recorded when effector cells were present for 20 h, suggesting that a period of activation was needed to stimulate effector cell function. Removal of adherent mononuclear cells on Sephadex G-10 columns did not reduce the low level of cytotoxicity against uninfected target cells, but markedly reduced the level of cytotoxicity against PI3V-infected cells. The effector cell was nonphagocytic and nonadherent. These characteristics and the fact that target cell lysis was independent of genetic restriction indicate that effector cells are similar to natural killer cells described in other species.
Outer membrane mutants of Salmonella typhimurium LT2 have lipopolysaccharide-dependent resistance to the bactericidal activity of anaerobic human neutrophils
Authors: Okamura N , Spitznagel J K
Published: January 2020

The capacity of neutrophil polymorphonuclear granulocytes (PMNs) to phagocytize bacteria under anaerobic as well as aerobic conditions afforded the opportunity to compare the bactericidal activities of oxygen-independent and oxygen-dependent antimicrobial mechanisms in human PMNs challenged with Salmonella typhimurium LT2 and its lipopolysaccharide mutants (outer membrane mutants). Anaerobic human PMNs challenged with either opsonized LT2 or serum-treated zymosan failed to produce detectable superoxide anion (O2-) or to reduce nitroblue tetrazolium, although aerobic PMNs readily produced O2- in response to such challenge. Anaerobic PMNs killed these bacteria in an ordered fashion that appeared to be dependent on their lipopolysaccharide chemotype. As the carbohydrate content of the mutant lipopolysaccharide decreased, the bacteria became less resistant to the oxygen-independent bactericidal activity. The results resembled the ordered resistance to oxygen-independent killing observed with LT2 and its mutants in PMN-free systems with PMN granule proteins. Studies on the kinetics of killing showed these to be less rapid in anaerobic as compared with aerobic conditions. Opsonization increased the rate of phagocytosis, but such factors as opsonization and the rate of phagocytosis did not appear to affect intraleukocytic bactericidal capacity in that the resultant proportion of bacteria remaining viable after ingestion was similar regardless of which serum was used (normal serum, C6-deficient serum, C8-deficient serum, or no serum at all). The results are consistent with an active and substantial participation by oxygen-independent systems in the antimicrobial effects of neutrophils.
Association of type- and group-specific antigens with the cell wall of serotype III group B streptococcus
Authors: Doran T I , Mattingly S J
Published: January 2020

The type-specific antigens (TSA) of group B streptococcus (GBS) represent the primary virulence factors for these organisms, yet little is known about their relationship to the cell surface of GBS. Crude cell walls of serotype III GBS strain 110 were purified by extraction with sodium dodecyl sulfate, LiCl, and urea, which removed essentially all of the protein associated with the cell wall as determined by amino acid analysis. Only those amino acids found in peptidoglycan were present, which included alanine, lysine, and glutamate (3.5:1:1 molar ratio). In contrast, these procedures resulted in the release of only 4.6% of the wall-associated TSA, indicating that protein was not the primary means by which TSA was bound to the cell surface. Mutanolysin (20 micrograms/ml) treatment of purified cell walls resulted in the release of 95% of the wall-associated TSA. The covalent association of TSA, the group B polysaccharide, and the peptidoglycan was demonstrated by the presence of N-acetylmuramic acid, rhamnose, alanine, glutamate, and lysine in mutanolysin-extracted TSA material purified by DEAE-Sephacel anion exchange and Sepharose 4B gel chromatography. Chemical analysis of purified cell walls revealed that group B antigen and peptidoglycan comprised 37.4 and 36.5%, respectively, whereas TSA accounted for 22.1 to 24.5% of the weight of the purified walls. Of the total 283.5 mg of TSA produced per 10-liter culture of GBS strain 110, 8.4% was released into the supernatant fluid. The remainder (249 mg) comprised the cell wall antigen. As described above, 4.6% of the cell wall antigen was extractable by nonenzymatic methods, which represented 3.8% of the total TSA, whereas 87.8% of the total TSA produced appeared to be covalently attached to the cell wall.
Role of macrophage activation and interferon in the resistance of alveolar macrophages from infected mice to influenza virus
Authors: Rodgers B C , Mims C A
Published: January 2020

Lung macrophages from uninfected CD1 mice support the replication of influenza viruses (H1N1 and H0N1), but the cells from influenza-infected mice do not. The possible mechanisms of this resistance were investigated. Murine macrophages were "activated" in vitro with lipopolysaccharide and lymphokines, and in both cases activation was associated with resistance of cells to infection with influenza virus. Exposure of alveolar macrophages in vitro to 500 U of purified type I interferon per ml enhanced cell spreading and Fc receptor-mediated phagocytosis, suggesting macrophage activation, and protected the cells against infection with influenza virus. Alveolar macrophages were also protected by a soluble factor in the bronchoalveolar washings from influenza-infected mice. This effect was not virus specific and was abolished by anti-interferon serum.
In vitro adhesion of piliated Escherichia coli to small intestinal villous epithelial cells from rabbits and the identification of a soluble 987P pilus receptor-containing fraction
Authors: Dean E A , Isaacson R E
Published: January 2020

Type 987P-piliated Escherichia coli adhered in vitro to small intestinal villous epithelial cells and brush borders isolated from adult female rabbits, but not from infant rabbits. K99-piliated E. coli adhered to epithelial cells and brush borders from both adult and infant rabbits. 987P-negative and K99-negative E. coli as well as CFA/I-positive and CFA/I-negative E. coli failed to adhere to epithelial cells or brush borders from either adult or infant rabbits. CFA/II-positive and CFA/II-negative E. coli did not adhere to epithelial cells from infant rabbits. Pretreatment of adult rabbit brush borders with purified 987P pili inhibited adherence of piliated strain 987. Optimal adherence occurred after 15 min when brush borders and piliated strain 987 were incubated together at 25 degrees C or 37 degrees C in buffers at pH 7 to 8 containing 0.11 to 0.21 M total salts. A receptor-containing fraction that caused aggregation of piliated strain 987 was released into solution when brush borders were stored at 4 degrees C. Receptor activity (aggregation) remained in solution when centrifuged at 10,000 X g for 15 min, but was sedimented at 226,000 X g for 1 h. Receptor activity was abolished by periodate oxidation and pronase digestion.
Purification and characterization of the soluble hemagglutinin (cholera lectin)( produced by Vibrio cholerae
Authors: Finkelstein R A , Hanne L F
Published: January 2020

The soluble hemagglutinin (HA) (cholera lectin) produced by Vibrio cholerae strain CA401 was purified to apparent homogeneity by a sequence of ammonium sulfate fractionation, gel filtration, and preparative isoelectric focusing. Soluble HA activity was found to focus at three different pIs, 6.3, 5.3, and 4.7. Each of the factors migrated as a large-molecular-weight protein in sodium dodecyl sulfate-polyacrylamide gel electrophoresis under normal conditions, and each, upon heating in sodium dodecyl sulfate was found to dissociate into 32,000-molecular-weight subunits. Treating the samples with a reducing agent did not affect their mobility. Each gave a reaction of immunological identity with antiserum prepared against the others. Thus, there are apparently three distinct pH isotypes of soluble HA which exist as noncovalently associated polymers of 32,000-molecular-weight subunits. Electron microscopy of purified preparations revealed long filamentous polymers. The molecule does not stain as a glycoprotein; it is hydrophobic; it is inactivated during incubation at 25, 37, or 60 degrees C; and it has significant protease activity. The protease activity likewise focused at pH values of 6.3 and 5.3 to 4.7, and it was inhibited by antiserum against the HA. However, whereas the HA is active at 4 degrees C, the protease is not. The soluble HA is, therefore, a bifunctional molecule capable of mediating hemagglutination and proteolysis. Its amino acid composition is reported. Fab fragments of antibody against the purified HA inhibited attachment of heterologous serotype-biotype V. cholerae to infant rabbit small bowel.
Urinary virulence of Proteus mirabilis in two experimental mouse models
Authors: Peerbooms P G , Marian A , Verweij J J , MacLaren D M
Published: January 2020

Two experimental mouse models were tested for their suitability in measuring urinary virulence of Proteus mirabilis. In the first model, the kidney-infecting dose and lethal dose were measured. In the second model, the kinetics of the numbers of bacteria in the kidneys and other organs of the mouse were monitored for 13 h after injection.
Antibody responses in adult volunteers to pneumococcal polysaccharide types 19F and 19A administered singly and in combination
Authors: Penn R L , Lewin E B , Douglas R G , Schiffman G , Lee C J , Robbins J B
Published: January 2020

The immunogenicity of the two major group 19 pneumococcal polysaccharides, types 19F and 19A, was studied in human volunteers. Antibody responses after vaccination with either 50 micrograms of type 19F polysaccharide, 50 micrograms of type 19A polysaccharide, or 25 micrograms of both polysaccharides premixed in a single injection revealed that the combined vaccine was immunogenic for both types, but that the optimal immunogen for each was the homologous polysaccharide. We concluded that vaccination with type 19F polysaccharide antigen, included in the current pneumococcal vaccine, does not induce a satisfactory heteroimmunogenic response to type 19A.
Identification of galactose as the immunodominant sugar of leishmanial excreted factor and subsequent labeling with galactose oxidase and sodium boro[3H]hydride
Authors: Slutzky G M , Greenblatt C L
Published: January 2020

Inhibition by low-molecular-weight sugars of precipitin line formation between a polysaccharide (EF) excreted by Leishmania tropica subsp. major, Leishmania enriettii, and rabbit antileishmanial antibodies on double gel diffusion plates revealed that galactose residues, possibly as components of lactosyl groups, were the critical immunodominant sugars mediating antibody recognition of EF. The galactose residues of the EF of L. tropica subsp. major were specifically labeled with tritium via galactose oxidase and sodium boro[3H]hydride. The radioactive EF had an apparent molecular weight of about 85,000 on sodium dodecyl sulfate-polyacrylamide gels and was precipitated by antileishmanial antibodies as well as Ricinus communis lectins I and II (galactose specific). Lectins specific for glucose-mannose residues, fucose, N-acetylglucosamine, and N-acetylgalactosamine did not precipitate the labeled EF. Treatment of [3H]EF with proteolytic (trypsin, papain, protease) or glycosidic (alpha-amylase, beta-galactosidase) enzymes had no effect on either the electrophoretic pattern of the material or on its recognition by antileishmanial antibodies or R. communis lectin. This resistance to enzyme activity suggests that EF may be a useful marker for the presence of the parasite in vivo if it can be detected in minute quantities.
Intratypic and intertypic specificity of lymphocytes involved in the recognition of herpes simplex virus glycoproteins
Authors: Carter V C , Rice P L , Tevethia S S
Published: January 2020

Cytotoxic T lymphocytes (CTL) were generated in C57BL/6 mice with herpes simplex virus type 1 (HSV-1) (strains KOS, 17, HFEM, and mP) and HSV-2 (strains 186, G, and GP6). Effector lymphocytes were tested for cytotoxicity against syngeneic HSV-1- and HSV-2-infected cells in a 5-h 51Cr release assay. HSV-1 strain HFEM was found to induce CTL efficiently only when 100-fold more virus was used as compared with HSV-1 strains KOS, 17, and mP. All HSV-1 and HSV-2 strains induced cross-reactive populations of CTL. CTL generated by HSV-1 KOS and HSV-2 186 also demonstrated cross-reactivity in an ear-swelling model for delayed-type hypersensitivity. Lymphocytes generated by all HSV-2 strains were highly efficient at lysing HSV-1-infected target cells. However, HSV-2-infected target cells were found to be less susceptible to lysis by either HSV-1 or HSV-2 CTL than were HSV-1-infected target cells. The lowered susceptibility of HSV-2-infected cells was not due to an inefficient infection of BL/6 WT-3 cells as measured by standard growth assays and infectious center assays. Varying the multiplicity of infection or the time of infection did not increase the susceptibility of HSV-2-infected target cells to lysis by CTL. Increasing the effector-to-target-cell ratio resulted in an increased lysis of both HSV-1- and HSV-2-infected target cells by CTL, but the level of HSV-2-infected target cell lysis still did not approach the level of HSV-1-infected target cell lysis. HSV-2-infected cells were as efficient as HSV-1-infected cells in the cold cell competition assay employed in reducing the lysis of 51Cr-labeled, HSV-1-infected target cells. In addition, HSV-2-infected cells were susceptible to lysis by HSV-immune serum and complement.
Natural bactericidal activity of human serum against Neisseria meningitidis isolates of different serogroups and serotypes
Authors: Craven D E , Shen K T , Frasch C E
Published: January 2020

We used a microtiter assay, standardized with serum-sensitive and serum-resistant strains of Neisseria gonorrhoeae, to determine the serum sensitivity of Neisseria meningitidis isolates of different serogroups and serotypes. Numbers of serum-resistant isolates varied among serogroups: group A = 7/8 (88%), group B = 26/50 (52%), group C = 5/8 (63%), group Y = 4/6 (67%), group W135 = 5/8 (63%), group 29E (Z') = 0/8 (0%), nongroupable isolates = 0/8 (0%). In comparison to group B isolates, group A isolates were more serum resistant (P less than 0.06), and group 29E and nongroupable isolates were more serum sensitive (P less than 0.001). Poor correlation was observed between serum sensitivity results and group-specific levels of bactericidal antibody in the normal human serum of volunteers. The frequency of serum-resistant strains among group B disease isolates (45%) was not significantly different from throat isolates of asymptomatic carriers (52%). Serotype 2 isolates of group B were no more serum resistant than were other serotypes examined. The serum sensitivity of meningococci appears to involve both capsular and noncapsular antigens and varies between serogroups. The increased serum sensitivity of nongroupable and group 29E isolates may account for the low incidence of disease caused by these organisms.
Effects of Propionibacterium acnes treatment on the course of Mycobacterium leprae infection in mice
Authors: Krahenbuhl J L , Humphres R C , Henika P C
Published: January 2020

Studies were carried out to determine the effects of treatment with killed suspensions of Propionibacterium acnes (formerly designated Corynebacterium parvum) on the course of Mycobacterium leprae infection in mice. Systemic (intravenous or intraperitoneal) treatment with P. acnes failed to significantly alter the growth of M. leprae in the mouse footpad. In contrast, injections of P. acnes directly into the infected footpad markedly inhibited the growth of the leprosy bacilli regardless of whether the local treatments were administered before infection or 3 months after infection with M. leprae. The effects of local treatment with P. acnes appeared to be bactericidal and not merely bacteriostatic. Clearance of the organism from the tissues was not enhanced by P. acnes treatment.
Experimental scrapie in golden Syrian hamsters: temporal comparison of in vitro cell-fusing activity with brain infectivity and histopathological changes
Authors: Moreau-Dubois M C , Brown P , Rohwer R G , Masters C L , Franko M , Gajdusek D C
Published: January 2020

Golden Syrain hamsters were inoculated intracerebrally with the hamster-adapted 263K strain of scrapie virus, and the evolution of in vitro cell fusing activity induced by brain suspensions was compared with brain infectivity titers and histological changes. Cell-fusing activity abruptly appeared 4 weeks after inoculation, 1 week before the earliest detectable histopathological changes, at an infectivity level of 7.6 log 50% lethal doses per g of brain. Cell-fusing activity was sustained throughout the remaining 4 weeks of the incubation period and the subsequent 1- to 3-week stage of clinical illness but did not increase with the logarithmic progression of infectivity, which reached a level of 11 log 50% lethal doses per g in the agonal stage of disease. Gliosis was most sensitively detected by a monoclonal antibody reacting with astrocyte intermediate filaments in an indirect immunofluorescence test, anticipating histological recognition of gliosis and spongiform change by 1 to 2 weeks. In vitro cell-fusing activity is thus one of the earliest known biological markers (apart from infectivity itself) of experimental scrapie infection.
Gamma interferon induction in human thymocytes activated by lectins and B cell lines
Authors: Reem G H , Cook L A , Henriksen D M , Vilcek J
Published: January 2020

Human thymocytes in culture synthesized small quantities of interferon (IFN) when stimulated by the lectins concanavalin A or phytohemagglutinin. IFN production by lectin-activated thymocytes was enhanced in the presence of live B lymphoblastoid cells, irradiated B lymphoblastoid cells, or the conditioned medium from B lymphoblastoid cell cultures. The IFN synthesized in mixed cultures had characteristics of IFN-gamma, whereas the IFN synthesized by B lymphoblastoid cells alone could be identified as IFN-alpha on the basis of its neutralization with specific antisera and stability at pH 2. These findings indicate that human thymocytes in culture synthesize IFN-gamma and that B lymphoblastoid cells and their products considerably stimulate IFN-gamma synthesis by lectin-activated human thymocytes in culture. This stimulation was not diminished in the presence of antibodies to IFN-alpha, indicating that IFN-alpha production by B lymphoblastoid cells was not responsible for the stimulatory effect. Removal of adherent cells from thymocyte suspensions did not abrogate IFN-gamma production.
Coxsackievirus B infection in pregnant mice and transplacental infection of the fetus
Authors: Modlin J F , Crumpacker C S
Published: January 2020

Direct instillation of coxsackievirus B1 into the gastrointestinal tracts of albino mice caused viremia in more than 85% of the animals within 1 day. In pregnant mice infected early in gestation (7 days), the geometric mean titer of virus in the blood was lower (P = 0.02) and the duration of viremia was shorter (P = 0.07) than in nonpregnant female mice, but infection of the heart, liver, and uterus did not differ on each of 5 days after infection. Although transplacental infection of the placenta or fetus or both occurred, the high spontaneous abortion rate (48%) obviated comparison of transplacental infection in these mice with mice infected later in gestation. Pregnant mice infected in the third trimester had significantly greater geometric mean titers of virus in the blood, heart, liver, and uterus, and infection persisted longer than in nonpregnant mice (P = 0.04). A very high geometric mean titer of virus was recovered from the uteri of these mice for 3 days after infection, whereas simultaneous geometric mean titers of virus in the placentas and fetuses were lower. In the majority of third trimester pregnant mice, virus was found in low titers in the fetuses at 2 and 3 days after maternal infection, and virus was not detected after day 3. We conclude that coxsackievirus B1 infection in late gestational pregnant mice is more severe than in mice at earlier gestational stages and in nonpregnant mice and that transplacental infection of the fetus occurs transiently during maternal infection. This model will prove useful in the study of perinatal enterovirus infection and in examination of the numerous factors that may influence outcome of infection of perinatally infected newborn infants.
Serum immunoglobulin A and antibody to M-associated protein in patients with acute glomerulonephritis or rheumatic fever
Authors: Potter E V , Shaughnessy M A , Poon-King T , Earle D P
Published: January 2020

Serum immunoglobulin A (IgA) was markedly increased in 80% of 50 patients with acute rheumatic fever in Trinidad in contrast to 20% of 63 patients with acute glomerulonephritis, whereas serum IgG was increased in nearly all of both groups. Since total antibody to M-associated protein (MAP) (assessed by complement fixation) is the only antibody as yet consistently found to be of higher titer in patients with acute rheumatic fever than in patients with acute glomerulonephritis in Trinidad, it was measured and the titers were related to serum levels of IgA. The titers of total antibody to MAP were greater than or equal to 40 in 58% of the rheumatic fever patients, 43% of the nephritis patients, and 8% of well school-children. However, its presence in rheumatic fever patients did not correlate directly with amounts of serum IgA present (r = 0.0507). Moreover, titers of total antibody to MAP related equally well to enzyme-linked immunosorbent assay indicated amounts of IgG antibody (r = 0.3939) and IgA antibody (r = 0.3054) to MAP in rheumatic fever patients but not in nephritis patients (r = 0.0301 for IgA antibody and 0.6909 for IgG antibody to MAP), whereas they related best to IgM antibody to MAP in the school-children (r = 0.4204).
Production and Level of Genetic Stability of an Influenza A Virus Temperature-Sensitive Mutant Containing Two Genes with
ts
Mutations
Authors: Murphy Brian R. , Markoff Lewis J. , Hosier Nanette T. , Massicot Judith G. , Chanock Robert M.
Published: January 2020

Temperature-sensitive (
ts
) reassortant vaccine strains derived from the A/Udorn/72
ts
-1A2 donor virus were not sufficiently stable genetically in humans. We therefore sought to produce a new, more stable donor virus. We had previously identified a stable
ts
virus with a
ts
P3 gene and in the current study identified another relatively stable single-lesion
ts
virus with a
ts
mutation in the NP gene. A new
ts
reassortant virus was constructed by mating these two single mutants and by isolating three reassortant progeny, clones 20, 53, and 55, that contained both a
ts
P3 and a
ts
NP gene. These reassortant progeny possessed a 37 to 38°C shutoff temperature and were as restricted in their replication in hamster lungs as the A/Udorn/72
ts
-1A2 virus. All isolates from the lungs and nasal turbinates of hamsters were temperature sensitive. An in vitro stress test was used to determine whether the new
ts
P3
ts
NP reassortant virus would undergo loss of its
ts
phenotype after replication at semipermissive temperature. Clone 20 and 55 reassortants underwent progressive loss of their
ts
phenotype in vitro, although at a rate slightly less than that of the A/Udorn/72
ts
-1A2 virus. The level of genetic stability after replication in vivo was assessed in cyclophosphamide-treated hamsters in which virus replication continued for up to 15 days. Again, both the A/Udorn/72
ts
-1A2 and the new
ts
P3
ts
NP reassortant clone 55 manifested a progressive loss of temperature sensitivity after 7 days of replication. Clone 55 virus lost temperature sensitivity significantly less rapidly than the A/Udorn/72
ts
-1A2 virus. These results indicated that, although the new
ts
P3
ts
NP reassortant virus was more stable than the A/Udorn/72
ts
-1A2 virus, it nevertheless underwent progressive loss of temperature sensitivity after replication in vitro and in vivo. Therefore, it does not appear to be a satisfactory donor virus. This experience plus that gained earlier with other
ts
mutants of influenza A virus suggest that influenza A virus mutants that rely solely upon their
ts
phenotype for attenuation are unlikely to exhibit the phenotypic stability required of a vaccine virus. Other genetic techniques are needed to produce more stable influenza A virus strains.
Protection against group B Neisseria meningitidis disease: effect of serogroup B polysaccharide and polymyxin B on immunogenicity of serotype protein preparations
Authors: Peppler M S , Frasch C E
Published: January 2020

The inability to prepare an effective polysaccharide vaccine against group B Neisseria meningitidis was the impetus for these studies. Outer membrane protein vaccines used in our initial studies failed to induce bactericidal antibodies in humans. The particulate nature of these vaccines may have led to their clearance before effective immune stimulation. Less denaturing procedures, therefore, were developed for preparation of serotype 2 protein-containing vaccines. These procedures included isolation of naturally released outer membrane vesicles and selective removal of lipopolysaccharide from the vesicles by the nonionic detergent Brij-96. The resultant protein vaccines were evaluated with and without noncovalently complexed group B meningococcal polysaccharide or polymyxin B sulfate or both. The new vaccines were at least 10-fold more immunogenic in mice and guinea pigs than the previous vaccines when assayed for bactericidal and enzyme-linked immunosorbent assay antibodies. The protein vaccines alone protected guinea pigs from intrachamber infection, and a single 0.1-microgram injection prevented meningococcal bacteremia in mice. Addition of group B polysaccharide to the protein significantly improved the immunogenicity of the protein, and this combined vaccine showed a greater protective effect. Polymyxin B generally reduced the immunogenicity of the vaccines in both mice and guinea pigs.
Monoclonal antibodies to stages of Trypanosoma cruzi: characterization and use for antigen detection
Authors: Araujo F G , Sharma S D , Tsai V , Cox P , Remington J S
Published: January 2020

Monoclonal antibodies to the amastigote and epimastigote stages of Trypanosoma cruzi were produced and characterized by immunoglobulin class and subclass. Of the 17 monoclonal antibodies, 14 were of the immunoglobulin M (IgM) class and 2 were of the IgG2 and 1 was of the IgG1 subclass of IgG. Five of the monoclonal antibodies recognized the antigens of amastigotes only, two recognized the antigens of epimastigotes only, and ten recognized an antigen(s) common to both stages of T. cruzi. By using an immunofluorescence test with monoclonal antibodies, it was possible to visually localize amastigote- or epimastigote-specific antigens and the antigens common to both. Antigens specific for epimastigotes were noted on the flagellum or in spots over the entire body of the parasite. The antigens common to both amastigotes and epimastigotes were on one of the extremities of the amastigotes and on the region of the flagellar pouch of the epimastigotes. Four of the monoclonal antibodies were capable of detecting T. cruzi antigen in serum from mice infected with the parasite and in the supernatant of infected cell cultures, suggesting that monoclonal antibodies may be useful for antigen isolation and diagnostic methods.
Persistent Varicella-Zoster virus infection in a human rhabdomyosarcoma cell line and recovery of a plaque variant
Authors: Iltis J P , Vette J , Castellano G A , Madden D L , Sever J L
Published: January 2020

Varicella-zoster virus (VZV) has been found to persistently infect the human rhabdomyosarcoma cell line A204. Infectious center assays and fluorescent antibody staining demonstrated continuous production of infectious VZV and viral antigen. The level of infection determined by fluorescent antibody staining was variable, and usually only a small percentage of the cells were capable of producing plaques in permissive fibroblasts. The extent of infection was similar in cell cultures passaged at split ratios of 1:2 or 1:10 and grown at 33 or 37 degrees C. VZV recovered from A204 cells several months after establishment of the persistent infection had markedly increased syncytia-forming activity as compared with the parental VZV grown in human diploid fibroblast cells and the three monkey kidney-derived cell lines Vero, CV-1, and MA104. The expression of this altered phenotype continued after serial passage of the cell-associated virus in human diploid fibroblast and Vero cells. Consequently, we designated the reisolated VZV as plaque variant A. The buoyant densities of VZV plaque variant A and VZV DNAs in CsCl gradients were indistinguishable.
Mycoplasma pneumoniae proteins that selectively bind to host cells
Authors: Krause D C , Baseman J B
Published: January 2020

Mycoplasma pneumoniae proteins that bind to hamster trachea epithelial cells were identified by incubating 125I-labeled, detergent-solubilized mycoplasmas with glutaraldehyde-fixed host cells. Analysis of the bound fraction by gel electrophoresis and autoradiography revealed that proteins P1, P2, and HMW3 (molecular weights, 165,000, 110,000, and 140,000, respectively), previously implicated in attachment, were among the predominant species. Unlabeled mycoplasma preparations competed with the binding of radiolabeled proteins, suggesting the involvement of a limited number of receptor sites on the host cells.
Production of the Kanagawa hemolysin by Vibrio parahaemolyticus in a synthetic medium
Authors: Cherwonogrodzky J W , Clark A G
Published: January 2020

A synthetic medium capable of supporting growth of Vibrio parahaemolyticus is described. Growth yields and generation times were comparable to growth in a complex medium, although Kanagawa hemolysin was undetectable in the synthetic medium. Upon the addition of single amino acids to this synthetic medium, only D-tryptophan induced production of the hemolysin. L-Tryptophan was found to inhibit the action of the D-stereoisomer. The response to D-tryptophan was pH dependent; the greatest hemolysin expression occurred at pH values below 6.5. The addition of 100 micrometers D-tryptophan to early-logarithmic-phase cultures caused an inhibition of growth and of substrate utilization, both of which lasted 7 h. During this time, hemolysin was produced only intracellularly. The hemolysin appeared in the supernatant only when growth recommenced. The hemolysins within the cell and in the supernatant were both inactivated by antiserum raised against the standard Kanagawa hemolysin.
Production and characterization of monoclonal antibodies to cholera toxin
Authors: Remmers E F , Colwell R R , Goldsby R A
Published: January 2020

Monoclonal antibodies against cholera toxin were produced to obtain highly specific antisera to cholera toxin. Fifteen hybridoma cell lines producing monoclonal antibodies specific for the determinants of cholera toxin were derived from the fusion of mouse myeloma cells and spleen cells from mice immunized with cholera toxin. The cell lines were stabilized, examined for specific antibody production, and immortalized by freezing cultured cells and tumor cells which had been grown subcutaneously in mice. All cell lines continued antibody secretion upon thawing. The antibodies produced by the hybridoma cell lines were characterized by determination of the class of light- and heavy-chain components and by determination of specificity for the cholera toxin subunit. All of the antibodies contained the k light chain, 4 contained the mu heavy chain, and the remaining 11 contained the gamma 1 heavy chain. Ten of the monoclonal antibodies are specific for the B subunit of cholera toxin, and three are specific for the A subunit. The remaining two appear to react with both subunits.
Canine prostatic secretions kill Trichomonas vaginalis
Authors: Krieger J N , Rein M F
Published: January 2020

The zinc content of prostatic secretions is thought to be an important nonspecific defense against urinary tract infection in men. This investigation measured killing by prostatic fluid of Trichomonas vaginalis, a common sexually transmitted pathogen, and related this activity to zinc concentration. We used a canine model which closely resembles the human male genital tract. Prostatic secretions from all dogs killed all T. vaginalis isolates. There appear to be several mechanisms for killing of trichomonads by prostatic fluid. At prostatic fluid zinc concentrations comparable to those in normal men (greater than or equal to 3.2 mM), the rate of killing of trichomonads was proportional to the zinc concentration. At intermediate zinc levels, killing occurred by both zinc-dependent and zinc-independent mechanisms. A zinc-independent mechanism was responsible for antitrichomonal activity at relatively low zinc levels (less than 1.6 mM), comparable to those in the prostatic fluid of men with chronic prostatitis. This study suggests that the variable clinical spectrum of trichomoniasis in men may result from a balance between the zinc sensitivity of the T. vaginalis strains on one side and the content of both zinc and zinc-independent factors in prostatic fluid on the other.
Interference of Salivary immunoglobulin A antibodies and other salivary fractions with adherence of Streptococcus mutans to hydroxyapatite
Authors: Gahnberg L , Olsson J , Krasse B , Carlén A
Published: January 2020

The adherence of Streptococcus mutans to hydroxyapatite was studied in the presence of salivary fractions with varying activity of naturally occurring immunoglobulin A (IgA) antibodies. Human parotid saliva from different donors was fractionated by chromatography and compared. Salivary IgA antibodies had no decisive effect on the adherence of the S. mutans strain used. High-molecular-weight salivary components from some subjects had an adherence-promoting effect, whereas fractions collected after the void volume of a Sepharose 2B column always inhibited adherence. The data indicate that the influence of unfractionated saliva on adherence is dependent on the net effect of adherence-promoting and adherence-inhibiting components. This principle has to be considered when the effect of human saliva on microbial adherence is studied.
Rates in vitro changes of gonococcal colony opacity phenotypes
Authors: Mayer L W
Published: January 2020

The rate of change of colony opacity phenotype was determined for 12 strains of Neisseria gonorrhoeae. The average rate of change was about 2 X 10(-3) per colony-forming unit per generation with a range of 0.2 X 10(-3) to 4 X 10(-3) per colony-forming unit per generation. Transition from opaque to transparent occurred at the same rate as transition from transparent to opaque. The following factors were shown to have no effect on the transition rate: (i) the state of piliation; (ii) the number of passages as a particular phenotype; (iii) alteration in the temperature, pH, or amount of oxygen in the atmosphere during growth; (iv) the addition of any of 194 compounds or mixtures to the growth media; (v) the addition of DNase or of DNA from opaque or transparent gonococci; and (vi) incubation between the opacity-transparency transition and the change resulting in the loss of piliation was seen. Some implications of the high transition rate are discussed.
Binding characteristics of wild mouse type C virus to mouse spinal cord and spleen cells
Authors: Mohan S , Pal B K
Published: January 2020

Binding characteristics of mouse spinal cord and spleen cells to naturally occurring, ecotropic (paralytogenic and lymphomagenic 1504M virus) and amphotropic (lymphomagenic 1504A virus) retroviruses of wild mice were investigated. 125I-labeled ecotropic (N-tropic) virus bound efficiently to both spinal cord and spleen cells from SWR/J mice (Fv-1n), but labeled amphotropic (N-tropic) virus bound efficiently only to spleen cells. The extent of binding of 1504M virus to the spinal cord cells was related to the time of incubation and to the amount of labeled input virus. 1504M virus bound to both glial and neuronal subpopulations of the spinal cord with almost equal efficiency. Binding of 125I-labeled 1504M virus to SWR/J mouse spinal cord cells was competitively inhibited by unlabeled homologous virus, whereas an excess of unlabeled 1504A virus inhibited only 10% of the ecotropic virus binding. Unlabeled 1504M virus almost completely inhibited the low-level binding of 125I-labeled 1504A virus to spinal cord cells. The different extent of binding of 1504M virus to spinal cord cells from different strains of mice (SWR/J, NIH Swiss, BALB/c-Jax, Lake Casitas wild, and CD-1) correlated with the susceptibility to paralysis in these strains of mice after inoculation with 1504M virus. Although the spinal cord cells of BALB/c mice contained a moderate amount of 1504M virus receptor sites, these mice were resistant to virus-induced paralysis because of their Fv-1b genotype. Our results indicate that the receptor sites for wild mouse ecotropic retrovirus are strain and organ specific and suggest that the presence of such receptors in central nervous system tissue may be a prerequisite for a successful virus infection and paralysis induction in Fv-1n mice.
Influence of the Indigenous Microbiota on Amounts of Protein, DNA, and Alkaline Phosphatase Activity Extractable from Epithelial Cells of the Small Intestines of Mice
Authors: Savage Dwayne C. , Whitt Dixie D.
Published: January 2020

Germfree mice housed in isolators under controlled environmental and nutritional conditions were associated with an intestinal microflora. These associated animals and germfree mice drawn from the same population were used in experiments in which saline extracts of cells from the small intestine were assayed for alkaline phosphatase activity and for protein and DNA content. Epithelial cells were harvested from the intestines sequentially from the villous tips to the crypts of Lieberkühn. In all preparations, germfree animals yielded from one and one-third to one and one-half times the mass (wet weight) of cells yielded by associated mice. Likewise, for all preparations, extracts of the mass of cells from germfree mice contained more protein and DNA per milliliter than did extracts from associated animals. The ratio of the amount of extractable protein or DNA per milliliter of extract to the total wet weight of the cells in milligrams was about the same, however, for preparations from germfree and associated animals. All preparations from germfree animals yielded higher total alkaline phosphatase activities than those from associated mice. When related to the amount of DNA in the cells, the enzymatic activities were slightly but not significantly higher in preparations from germfree animals, except for preparations of cells removed from the tips of the villi. When related to the amount of protein in the extracts, the enzymatic activity (i.e., specific activity) was about the same in preparations from germfree and from associated mice, except (again) for preparations of cells removed from the tips of the villi. In the latter preparations, the specific alkaline phosphatase activities and enzymatic activities calculated relative to the amount of DNA were substantially higher for germfree animals than for mice with a microflora. Individual intestinal epithelial cells from germfree and associated animals, except those close to the villous tips, contain about the same alkaline phosphatase activity. Therefore, germfree mice must yield more activity of such microvillous enzymes than do mice with a microflora, partly because enterocytes at the tips of the villi in germfree mice contain more protein with enzymatic activity than do cells in a comparable location in mice with a microflora. In addition, the small intestines of germfree mice contain more activity of enzymes such as alkaline phosphatase than do those of associated animals because the small intestines of the former animals contain more enterocytes than do those of the latter.