bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation Between Virulent and Avirulent Strains of
Rickettsia prowazekii
by Macrophage-Like Cell Lines
Authors: Turco Jenifer , Winkler Herbert H.
Published: January 2020

The growth of avirulent (E) and virulent (Breinl) strains of
Rickettsia prowazekii
was compared in four mouse macrophage-like cell lines (RAW264.7, J774.1, P388D1, and PU5), one human macrophage-like cell line (U937-1), and the mouse fibroblast line L929. The E and Breinl strains grew equally well in L929 cells. However, all of the mouse macrophage-like cell lines clearly differentiated between the two strains by restricting the growth of the E strain relative to that of the Breinl strain. A nonuniform response to infection was sometimes observed in which E strain rickettsiae were cleared from the majority of the infected cells, but multiplied in some of the remaining infected cells. The human line U937-1 was not very effective at differentiating the E and Breinl strains. Addition of rabbit antirickettsial antiserum to the Breinl or E strains of
R. prowazekii
immediately before infection of L929 cells caused a marked decrease in the initial infection but had no effect on the subsequent growth of the rickettsiae in the L929 cells. In contrast, addition of antiserum to Breinl or E strain rickettsiae immediately before infection of macrophage-like cell lines caused either no change or an increase in the initial infection. Most of the rickettsiae that infected the mouse macrophage-like cell lines in the presence of antiserum were destroyed in these cell lines. Thus, when the infection took place in the presence of antiserum, the mouse macrophage-like cell lines no longer differentiated between the E and Breinl strains. These data indicate that mouse macrophage-like cell lines should be a useful model system for defining the differences between the E and Breinl strains of
Rickettsia prowazekii
, differences which should lead to an understanding of the biochemical basis of virulence in this organism.
Evaluation of
Streptococcus pneumoniae
Type XIV Opsonins by Phagocytosis-Associated Chemiluminescence and a Bactericidal Assay
Authors: Gardner Susan E. , Anderson Donald C. , Webb Bette J. , Stitzel Ann E. , Edwards Morven S. , Spitzer Roger E. , Baker Carol J.
Published: January 2020

The relative roles of serum factors required for opsonization of type XIV
Streptococcus pneumoniae
were investigated by means of luminol-enhanced chemiluminescence (CL), bactericidal, and immunofluorescence assays employing adult sera containing high (>1,000 ng of antibody nitrogen per ml) or low (<200 ng of antibody nitrogen per ml) antibody concentrations as determined by radioimmunoassay. Specific antibody concentration correlated directly with both total and heat-labile CL activity (
P
< 0.005) and with the bactericidal index (
P
< 0.05) at a serum concentration of 10%. The importance of specific antibody as an opsonin was confirmed by the abolition of CL activity and immunoglobulin immunofluorescence observed after absorption of heated sera with type XIV pneumococcal cells and by the dose response in CL and bactericidal activity observed with the addition of immunoglobulin G to hypogammaglobulinemic serum. A role for the classical complement pathway in opsonization was indicated by significantly greater CL integrals for high-antibody sera than for low-antibody sera depleted of factor D and by the bactericidal activity noted for untreated, but not magnesium ethylene glycol-bis(β-aminoethyl ether)-
N,N
-tetraacetic acid-chelated low-antibody sera. The alternative pathway contributed more than half of the CL activity of both high- and low-antibody sera. However, after magnesium ethylene glycol-bis(β-aminoethyl ether)-
N,N
-tetraacetic acid chelation, only sera with high antibody concentrations or agammaglobulinemic serum reconstituted with immunoglobulin G with high specific antibody levels supported significant bactericidal activity. Therefore, type-specific antibody and complement promote opsonization of type XIV
S. pneumoniae
, and this may occur via either complement pathway. These results suggest that CL is a suitable tool to delineate serum factors and their contribution to opsonization, but results must be related to other functional assays.
Activation of Monocyte and Granulocyte Antibody-Dependent Cytotoxicity by Phorbol Myristate Acetate
Authors: Klassen David K. , Conkling Paul R. , Sagone Arthur L.
Published: January 2020

We have characterized the effects of phorbol myristate acetate (PMA) on human monocyte and neutrophil oxidative metabolism and antibody-dependent cytotoxicity toward anti-D sensitized human erythrocytes (RBC) and a human lymphoblastoid cell line (CEM). Hexose monophosphate shunt activity was measured by [1-
14
C]glucose oxidation and target lysis by
51
Cr release. PMA produced a dose-dependent stimulation of hexose monophosphate shunt activity. Neutrophils responded with higher hexose monophosphate shunt activity and at a lower PMA concentration than did monocytes. PMA increased monocyte lysis of antibody-sensitized RBC by two-thirds, but did not affect lysis of CEM targets. Neutrophils were unable to lyse either antibody-sensitized or nonsensitized RBC without the addition of PMA. When PMA was added, lysis of both targets increased markedly. Neutrophils without PMA were able to lyse a small number of both antibody-sensitized and nonsensitized CEM targets. PMA also increased neutrophil lysis of these targets. Target lysis by neutrophils from a patient with chronic granulomatous disease, cells unable to produce reactive oxygen species, was not increased by PMA. Chronic granulomatous disease monocytes, however, responded to PMA by more than doubling lysis of antibody-sensitized RBC. Hypoxia inhibited PMA augmentation of antibody-sensitized RBC lysis by neutrophils, but not by monocytes. Generation of reactive oxygen species by the xanthine-xanthine oxidase system inhibited CEM growth, but did not cause lysis, indicating that in some cases oxidative injury may be nonlytic. We suggest that PMA augments neutrophil cytotoxicity to tumor and RBC targets by stimulating reactive oxygen species-mediated lysis, but in monocytes augmentation of lysis is due to activation of a nonoxidative mechanism of lysis.
Colonization of the large bowel by Clostridium difficile in healthy infants: quantitative study
Authors: Stark P L , Lee A , Parsonage B D
Published: January 2020

Colonization of the large bowel of healthy infants by Clostridium difficile was studied. Feces were collected from five breast-fed aand five formula-fed infants throughout the first year of life, and levels of C. difficile were quantitated. Three breast-fed and five formula-fed infants were colonized for periods of between 8 and 42 weeks, and another infant harbored the organism only during week 1. Colonization of breast-fed infants commenced before or during weaning, with levels reaching 10(3) to 10(5) organisms per g of wet feces. Colonization of formula-fed infants commenced before solid foods were given, with levels of 10(3) to 10(7) organisms per g of wet feces. Isolates from eight of the babies were shown to produce cytotoxin in vitro. Single fecal specimens from 60 more children aged up to 4 years were also examined, and it was found that the carriage rate of C. difficile fell sharply after 1 year of age, although in the second year it was still higher than in adults. These findings are discussed in relation to the microbial ecology of the large bowel and the paradox that levels of C. difficile in the large bowel of healthy infants are similar to those causing pseudomembranous colitis in patients.
Depression by
Pseudomonas aeruginosa
of Two T-Cell-Mediated Responses, Anti-
Listeria
Immunity and Delayed- Type Hypersensitivity to Sheep Erythrocytes
Authors: Petit J.-C. , Richard G. , Albert B. , Daguet G.-L.
Published: January 2020

Pseudomonas aeruginosa
was studied for its effects on T-cell-mediated responses in mice, as exemplified by anti-
Listeria
immunity and delayed-type hypersensitivity to sheep erythrocytes. Immunity to
Listeria monocytogenes
was measured by quantitation of bacteria in spleens and mortality; delayed hypersensitivity to sheep erythrocytes was tested by the footpad reaction. Three different preparations of
P. aeruginosa
were used: the supernatant of a heat-killed culture, living bacteria, and heat-killed organisms. Similar results were obtained with the three preparations. Administration of
P. aeruginosa
24 h before
Listeria
infection reduced the resistance to the secondary challenge, as measured by increased bacterial multiplication in the spleen and rate of mortality. Cell transfer experiments showed that pretreatment of normal recipient mice with
P. aeruginosa
prevented them from being adoptively immunized against a
Listeria
challenge infection with spleen cells from immune donors. They also showed that treatment of donors with
P. aeruginosa
before immunization affected the capacity of their spleen cells to protect normal recipients against
Listeria.
Furthermore, spleen and peritoneal exudate cells obtained from mice given
P. aeruginosa
were capable of preventing immunization of normal recipients against
Listeria.
Similar results were obtained when the delayed hypersensitivity response to sheep erythrocytes was studied. The suppressive activity of
P. aeruginosa
-treated spleen cells was lost by removing adherent cells. Conversely, the adherent, heat-killed, anti-immunoglobulin-treated spleen cells exerted a suppressor effect. It thus appears that
P. aeruginosa
injection changes macrophage and T-lymphocyte activities and results in the development of adherent, macrophage-like suppressor cells in the spleen and peritoneal cavity.
Ontogeny of murine macrophages: functions related to antigen presentation
Authors: Lu C Y , Unanue E R
Published: January 2020

Macrophage function in neonates was dissected into four components: antigen uptake and catabolism, cytotoxicity, antigen presentation, and the production of the lymphostimulatory molecule interleukin-1 (also called thymocyte mitogenic protein or lymphocyte-activating factor). The uptake and catabolism of 125I-labeled Listeria monocytogenes was equivalent in macrophages from adult and neonatal mice. However, interactions between macrophages from neonates, heat-killed Listeria organisms, and immune T lymphocytes were impaired, and no cytocidal macrophages capable of killing tumor cells were generated. Previous studies with cells from adult mice had established that the development of cytocidal macrophages required Ia-bearing, antigen-presenting macrophages and histocompatibility at I-A between macrophages and T cells. To circumvent this requirement for antigen-presenting macrophages, an assay was used in which lymphokine was added directly to the macrophages from neonates. Strong cytocidal activity resulted. Thus, our studies confirmed that macrophages from neonates present antigen poorly but can acquire cytocidal function provided that the need for antigen-presenting function is bypassed. Similar conclusions were reached for the secretion of interleukin-1. Macrophages from neonates spontaneously secreted as much mediator as macrophages from adults, and the secretion was increased after the ingestion of heat-killed Listeria organisms or endotoxin. However, the marked increase in interleukin-1 production that follows antigen-macrophage-lymphocyte interaction was best seen in macrophages from adults. Macrophages from neonates could be activated to ingest C3b-coated sheep erythrocytes.
Alpha 2-macroglobulin in sulci from healthy and inflamed human gingivae
Authors: Condacci I , Cimasoni G , Ahmad-Zadeh C
Published: January 2020

The concentration of alpha 2-macroglobulin (alpha 2-M) in human gingival sulci has been investigated in two studies: first, in gingival washings during a 21-day period of experimental gingivitis in eight human volunteers and, second, in crevicular fluid collected with filter paper strips before and after initial periodontal therapy in 11 patients. The concentration of total alpha 2-M was found to increase in the washings of the volunteers throughout the period of experimental gingivitis. In the group of patients receiving periodontal therapy, the absolute amount of alpha 2-M in the fluid showed a significant decrease after therapy. The gingival index of inflammation and the crevicular fluid flow also decreased significantly. The specific content of the inhibitor (micrograms of alpha 2-M per mg of fluid per min), however, was found to increase in the fluid with decreasing inflammation. As detected by crossed immunoelectrophoresis, the fluid collected in these patients before therapy, in the presence of severe inflammation, invariably showed peaks of both free and complexed alpha 2-M. In contrast, the fluid collected from the same sites after healing of the inflammation contained no detectable free alpha 2-M.
Rubella-specific immune complexes after congenital infection and vaccination
Authors: Coyle P K , Wolinsky J S , Buimovici-Klein E , Moucha R , Cooper L Z
Published: January 2020

Circulating immune complexes which contained rubella-specific immunoglobulins were detected in 21 out of 63 subjects with congenital rubella and in 39 out of 65 subjects vaccinated with attenuated rubella virus, but in none of 43 subjects susceptible to rubella or 87 subjects with remote naturally acquired immunity to rubella. The presence or level of circulating immune complexes and the presence of rubella-specific complexes did not correlate with conventional serum rubella hemagglutination inhibition antibody titers. In the group with congenital infection, the presence of specific complexes many years after birth was associated with late-emerging clinical problems involving several organ systems. In vaccinates, the presence of specific complexes was associated with a higher incidence of side reactions. Two-thirds of the vaccinates and all of those revaccinated showed specific immune complexes as late as 8 months after immunization.
Properties of Streptococcus mutans Ingbritt growing on limiting sucrose in a chemostat: repression of the phosphoenolpyruvate phosphotransferase transport system
Authors: Ellwood D C , Hamilton I R
Published: January 2020

Growth of Streptococcus mutans Ingbritt on limiting sucrose in a chemostat at dilution rates of 0.05 to 0.4 h-1 (mean generation time, 14 to 1.7 h) resulted in a heterofermentative pattern of metabolic end products. During fast growth, lactic acid was the major end product, whereas at slower growth rates, acetic and formic acids, as well as ethanol, increased to be major end products. The patterns obtained were similar to those seen with the same organism growing on glucose. The glycolytic rate by washed cells was maximum at the lowest dilution rates and decreased as the cells were made to grow faster. Transport of sucrose, glucose, and fructose via the phosphoenolpyruvate phosphotransferase system (PTS) was repressed during growth on sucrose after growth on glucose. Uptake rates suggested that sucrose was transported in the PTS as the intact disaccharide. Comparison of the rate of sugar uptake in the chemostat with the rate of PTS activity in the cells at each growth rate indicated that the PTS was capable of supporting growth only at a dilution rate of 0.05 h-1. Growth on sucrose at faster growth rates required the activity of a second transport system, supporting our earlier observations with glucose that S. mutans contains at least two sugar transport systems.
In vitro immunological activities of the polysaccharide fraction from Haemophilus influenzae type a endotoxin
Authors: Guenounou M , Raichvarg D , Hatat D , Brossard C , Agneray J
Published: January 2020

Mild hydrolysis of Haemophilus influenzae type a lipopolysaccharide by ion exchangers in the presence of chloroform, to remove the lipid moiety, yielded a nontoxic and immunogenic polysaccharide fraction. This polysaccharide selectively triggered murine B lymphocytes in vitro: (i) it induced enhancement of thymidine incorporation and stimulated antibody secretion in cultures of normal and nude mouse spleen cells; (ii) it did not stimulate splenic T lymphocytes; (iii) the activation of B lymphocytes was not absolutely dependent on the presence of macrophages. Sepharose 4B gel filtration showed that this polysaccharide consisted at least of two fractions: PS I (molecular weight [MW] 10(6)) and PS II (MW 10(4)). Only PS I was found to act as a polyclonal B cell activator. EDTA treatment dissociated the polysaccharide into PS III (MW 10(6)) and PS IV (MW 10(4)), which was not reassembled after the addition of 0.02 M CaCl2. Both fractions PS III and PS IV were unable to stimulate B lymphocytes. The immunological active fraction of H. influenzae polysaccharide is PS I. This fraction consists of a high-molecular-weight group (10(6)) and an association of 10(4)-MW aggregated units.
Dissociation of innate susceptibility to Salmonella infection and endotoxin responsiveness in C3HeB/FeJ mice and other strains in the C3H lineage
Authors: Eisenstein T K , Deakins L W , Killar L , Saluk P H , Sultzer B M
Published: January 2020

Studies of various mouse strains in the C3H lineage have shown that there is no correlation between innate susceptibility to Salmonella infection and sensitivity to the toxic or mitogenic effects of lipopolysaccharide (LPS). C3H/HeNCrlBR mice were Salmonella resistant, but sensitive to the toxic and mitogenic effects of LPS, whereas C3HeB/FeJ mice were Salmonella susceptible as the C3H/HeJ mice, yet were mitogenically responsive to LPS and sensitive to its lethal effects. Furthermore, other mouse strains (C3H/HeTex and C3H/HeDub) displayed intermediate susceptibility to Salmonella infection and were responders to the mitogenic and toxic effects of LPS. These results are interpreted to mean that endotoxemia cannot be a major factor in the pathogenesis of Salmonella infection and provide evidence for the involvement of multiple factors in the control of innate resistance to Salmonella infection in mice of the C3H lineage.
Repeated delayed-type hypersensitivity reactions against Mycobacterium lepraemurium antigens at the infection site do not affect bacillary multiplication in C3H mice
Authors: Løvik M , Closs O
Published: January 2020

Delayed-type hypersensitivity was induced in cyclophosphamide-pretreated C3H/TifBom mice by subcutaneous immunization in the thorax with ultrasonicated Mycobacterium lepraemurium bacilli in Freund incomplete adjuvant. Seven weeks after immunization, 2.5 X 10(7) acid-fast M. lepraemurium bacilli suspended in diluted sonicate were injected into one hind footpad, and during the next 6 weeks three additional infections of sonicate were given at intervals into the infected footpad. After each injection a strong local reaction developed, which after the first three injections peaked at 24 h. The kinetics of the reaction was accelerated after the repeat injections. Each time the reaction subsided within 1 week. From 2 days to 11 weeks after the inoculation of bacilli there was a 10-fold increase in bacillary numbers in the footpad and a 3,000-fold increase in the draining popliteal lymph node. The degree of bacillary multiplication was the same in animals which had experienced repeated local reactions and in control animals. Thus, repeated strong delayed-type hypersensitivity reactions to M. lepraemurium antigens apparently were without any measurable effect on the bacillary multiplication. This observation provides further evidence for a dissociation in C3H/TifBom mice between delayed-type hypersensitivity to soluble mycobacterial antigens and protective immunity against mycobacteria. Possible explanations for our findings are discussed.
Purification of two Clostridium perfringens enterotoxin-like proteins and their effects on membrane permeability in primary cultures of adult rat hepatocytes
Authors: Dasgupta B R , Pariza M W
Published: January 2020

We isolated two proteins, ET-1 and ET-2, from the sporangial extracts of Clostridium perfringens type A. Both proteins had some properties in common with the well-known C. perfringens enterotoxin. ET-1 and ET-2 behaved as single and distinct entities in anion exchange chromatography and disk gel electrophoresis. ET-2 was the more anionic protein since it eluted more slowly from the anion exchange column and migrated faster toward the anode in polyacrylamide disk gel electrophoresis (pH 8.5, native gels). Additionally, in this electrophoretic system ET-2 was not distinguishable from the enterotoxin. The amino acid compositions of ET-1 and ET-2 were similar but differed in a few amino acid residues. The values for both proteins were also similar to the published reports of others for the enterotoxin. Both ET-1 and ET-2 showed lines of identity in agar gel double immunodiffusion against anti-enterotoxin antiserum. Both ET-1 and ET-2 were toxic for rat hepatocytes in primary monolayer culture as determined by accelerated exodus of L-[14C]glucose from preloaded cells and by the rapid uptake of 45Ca2+ after exposure to the proteins. In this regard, ET-1 and ET-2 appeared to be identical in mechanism of action to what has been regarded in the literature as "the" C. perfringens enterotoxin. Interestingly, ET-2 was 3 to 10 times more toxic on a weight basis than ET-1 was.
Mycoplasma pneumoniae attachment: competitive inhibition by mycoplasmal binding component and by sialic acid-containing glycoconjugates
Authors: Chandler D K , Grabowski M W , Barile M F
Published: January 2020

Attachment of Mycoplasma pneumoniae to human WiDr cell culture monolayers was examined by using radiolabeled M. pneumoniae. The amount of attachment was proportional to the density of the WiDr cells and to the concentration of M. pneumoniae in the assay. Saturation of the monolayers was achieved with 40 micrograms of virulent strain M129 per assay, whereas binding of avirulent strain B176 was 70% less than that of strain M129. A competitive attachment inhibition assay was used to measure specific binding component activity. Attachment was inhibited when WiDr cells were pretreated with unlabeled virulent strain M129, whereas avirulent noncytadsorbing strain B176 did not inhibit attachment as well as the virulent strain. A protein-rich extract prepared from virulent, cytadsorbing strains of M. pneumoniae also inhibited attachment. The amount of inhibition was dependent on the amount of extract used, and units for binding component activity in the extract were calculated from the competitive attachment inhibition assays. The competitive attachment inhibition assay was also used to investigate the nature of the receptor site on the WiDr cells. Attachment was inhibited when the radiolabeled M. pneumoniae suspensions were pretreated with human sialoglycoproteins, such as orosomucoid and ceruloplasmin, and bovine gangliosides. These findings support the present concept that the mammalian receptor site for M. pneumoniae is a sialic acid-containing glycoprotein.
Soluble Peptidoglycan-Polysaccharide Fragments of the Bacterial Cell Wall Induce Acute Inflammation
Authors: Chetty Chamroen , Klapper David G. , Schwab John H.
Published: January 2020

Peptidoglycan (PG)-polysaccharide (PS) polymers derived from group A streptococcal cell walls were solubilized by M-1 mutanolysin (endo-
N
-acetylmuramidase) and phage-associated lysin (
N
-acetylmuramyl-
l
-alanine amidase). Fragments were isolated by ultrafiltration and a series of gel filtrations and were injected intravenously into Sprague-Dawley rats. No fragments with a molecular weight of less than 5 × 10
6
were able to induce arthritis by systemic injection. However, the enzyme-derived fragments displayed a new biological activity. High-molecular-weight PG-PS fragments (≅500,000) derived from mutanolysin digests induced a severe edematous reaction in the front and hind limbs. The response started 5 to 10 min postinjection, reached maximum intensity in approximately 30 min, and disappeared by 10 h. The smallest dose capable of eliciting the response was 0.31 μg/g of body weight. Low-molecular-weight PG-PS (≅30,000) derived from the mutanolysin digests and the PG-PS fragments isolated from phage-associated lysin digests also induced edema; however, a higher dose was required to elicit the same response as that produced by high-molecular-weight PG-PS fragments. The active fragments contained rhamnose, glucosamine, muramic acid, alanine, glutamic acid, and lysine in various molar ratios. PG-PS fragments obtained by sonic degradation of cell walls (molecular weight ≥5.3 × 10
6
), as well as enzyme-treated PG preparations and muramyl dipeptide, failed to elicit the response. These findings indicate that PG-PS fragments of sizes too small to be arthritogenic can affect the vascular endothelium to induce a rapidly developing edema. Fragments with this biological property could have a key role in the pathogenesis of experimental arthritis by influencing the tissue distribution of arthritogenic PG-PS.
Chronic glucocorticosteroid therapy impairs staphylococcal clearance from murine lungs
Authors: Nugent K M , Pesanti E L
Published: January 2020

Since the clearance of Staphylococcus aureus from murine lungs after aerosol exposure depends only on regional defense processes and does not require the recruitment of neutrophils or other systemic factors, we used this model for pulmonary clearance to evaluate the effect of chronic glucocorticosteroid therapy on intrinsic pulmonary defense responses. Mice treated with oral prednisolone for 2 or more weeks had delayed clearance of S. aureus at both 6 and 22 h after aerosol exposure. Mice treated with prednisolone for 1 week had delayed clearance at 22h, and mice treated for 2 days had normal clearance. In mice that had been treated for 2 weeks, clearance returned to normal after 2 weeks off therapy, but not after 1 week. Prednisolone did not appear to alter the number of phagocytes in bronchoalveolar spaces or their ingestion capacity. These results suggest that chronic steroid therapy can alter pulmonary clearance functions independent of any effect on immune or inflammatory responses.
Analysis of the human serological response to proteins of Chlamydia trachomatis
Authors: Newhall W J , Batteiger B , Jones R B
Published: January 2020

Sera from individuals with culture-proven genital infection with Chlamydia trachomatis were analyzed for the presence of antibodies to chlamydial proteins by an immunoelectrophoretic transfer method. Protein antigens from representative strains of the 15 known serotypes were resolved by gel electrophoresis and transferred to a nitrocellulose solid support before being probed with serum. Sera from infected patients reacted with many different proteins. Most of these sera reacted with a 60,000- and a 62,000-molecular-weight protein which were present in each of the C. trachomatis serotypes and clinical isolates analyzed. In contrast, reactions with the major outer membrane protein were frequently observed but were usually weak. Sera from control groups of children, cloistered nuns, and college women, who were presumed not to have had prior chlamydial infections, did not usually have antibodies against the 60,000- or 62,000-molecular-weight protein, but did react with the major outer membrane protein and a 29,000-molecular-weight protein. These observations may have implications for the development of serodiagnostic tests as well as the identification of candidate antigens for vaccine development.
Interferon production by leukocytes infiltrating the lungs of mice during primary influenza virus infection
Authors: Wyde P R , Wilson M R , Cate T R
Published: January 2020

Lung fluids and leukocytes were obtained from unprimed C3H mice by transpleural lavage at intervals after infection with influenza A/Hong Kong/68 virus and were tested for interferon activity. Lavage fluid interferon titers correlated directly with lung virus titers and with initial increases in leukocyte yields from infected lungs. In contrast to cultured lymph node cells from infected animals or leukocytes from lungs of uninfected mice, washed leukocytes obtained from the lungs of mice infected 2 to 6 days earlier produced interferon spontaneously in culture. The physiochemical, biological, and antigenic properties of both the interferon in lavage fluids and that produced by lung lavage leukocytes were similar and characteristics of alpha interferon. Fractionation studies indicated that macrophages and T lymphocytes were primarily responsible for the interferon produced in culture. The early presence and significant numbers of interferon-producing leukocytes in infected lungs suggests that these cells have an early role in defense against influenza virus infection.
Staphylococcal clearance and pulmonary macrophage function during influenza infection
Authors: Nugent K M , Pesanti E L
Published: January 2020

Direct infection of pulmonary macrophages with influenza virus in vitro does not alter macrophage functions necessary for staphylococcal clearance. To determine whether these functions are altered during viral pneumonitis, we evaluated macrophages recovered from influenza-infected mice which had undergone aerosol challenge with Staphylococcus aureus. Sublethal infection with influenza A/PR8 produced patchy hemorrhagic pneumonia in CF1 mice and significantly reduced the intrapulmonary killing of staphylococci inhaled during aerosol challenge. However, only a small fraction of macrophage monolayers established from animals with influenza expressed viral hemagglutinin on their plasma membrane, and alveolar macrophages from infected mice ingested staphylococci and yeast cells in vitro at the same rate as control macrophages. The in vitro intracellular bactericidal activity against staphylococci ingested in vivo was comparable in monolayers from control and PR8-infected mice. In experiments with more severe influenza infections (mortality greater than 50% by day 7), a larger fraction of the staphylococci recovered by bronchoalveolar lavage appeared to be ingested in vivo during the aerosol exposure in the PR8-infected mice than in the control mice, but intracellular killing by macrophages during in vitro incubation was similar in control and PR8 monolayers. Hence, the severity of viral infection did not influence intracellular bactericidal activity. In virus-infected mice, a significantly larger fraction of viable staphylococci in the lower respiratory tract at the end of aerosol exposure was adherent to the trachea and major bronchi. In summary, PR8 infection established by intranasal inoculation impaired staphylococcal killing in the lung even though these infections did not alter in vivo ingestion rates or in vitro intracellular killing rates of macrophage populations in bronchoalveolar spaces.
Stimulation of migration of human monocytes by bacterial cell walls and muramyl peptides
Authors: Ogawa T , Kotani S , Fukuda K , Tsukamoto Y , Mori M , Kusumoto S , Shiba T
Published: January 2020

Bacterial cell walls, water-soluble fragments of the wall peptidoglycan, N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP), and 6-O-acyl derivatives of MDP were examined for migration-stimulating activity on human peripheral blood monocytes by using a multiwell chemotaxis assembly. Cell walls isolated from 11 bacterial species caused a definite increase in monocyte migration, but the walls of Micrococcus lysodeikticus were scarely active. The migration-enhancing activity of Staphylococcus epidermidis cell walls was retained by a monomer as well as a polymer of disaccharide peptides which were prepared by digestion of the peptidoglycan with enzymes. It was finally revealed that the migration of monocytes was enhanced by MDP. 6-O-Octadecanoyl-MDP, 6-O-(2-tetradecylhexadecanoyl)-MDP, and 6-O-(3-hydroxy-2-docosylhexacosanoyl)-N-acetylmuramyl-L-seryl-D-isoglutamine were active, but to a lesser extent. A checkerboard assay demonstrated that the increased monocyte migration caused by S. epidermidis cell walls was directed toward a positive stimulus (chemotaxis).
Regulatory Interactions Between Macrophages and T-Cell Subsets in
Listeria monocytogenes
-Specific T-Cell Activation
Authors: Kaufmann Stefan H. E. , Simon Markus M. , Hahn Helmut
Published: January 2020

Peritoneal exudate T lymphocytes from
Listeria monocytogenes
-immune mice in the presence of the homologous antigen (heat-killed
L. monocytogenes
) and normal macrophages showed
L. monocytogenes
-specific proliferative responses. Proliferation was inhibited by macrophages from
L. monocytogenes
- or
Corynebacterium parvum
-pretreated mice as well as by exogenous prostaglandin E
2
. Macrophage-dependent inhibition of T-cell proliferation—at least in part—could be reversed by addition of indomethacin. When selected
L. monocytogenes
-immune Lyt T-cell subsets were cultured in the presence of inhibitory macrophages, pretreatment with anti-Lyt 1 antiserum plus complement completely abrogated proliferation and pretreatment with anti-Lyt 2 and anti-Lyt 3 antisera plus complement markedly reduced proliferation. However, a mixture (1:1) of the two preselected Lyt T-cell subsets resulted in complete reconstitution of proliferative responses. In contrast, when
L. monocytogenes
-immune peritoneal exudate T lymphocytes were treated with anti-Lyt antisera plus complement after culture, only treatment with anti-Lyt 1 antiserum plus complement affected proliferation, suggesting regulatory interactions between Lyt 1
+
23
−
and Lyt 1
−
23
+
T cells during in vitro culture which result in proliferation within the Lyt 1
+
23
−
T-cell subset. After rigorous depletion of residual macrophages and in the presence of indomethacin, pretreatment with anti-Lyt 1 antiserum plus complement, but not with anti-Lyt 2 and 3 antisera plus complement, eliminated proliferation. The data presented indicate that interactions between macrophages and Lyt T-cell subsets regulate
L. monocytogenes
-specific T-cell activation.
Effect of quinonyl-N-acetyl muramyl dipeptide on immune responses in tumor-bearing mice
Authors: Saiki I , Tanio Y , Yamamoto K I , Yamamura Y , Azuma I
Published: January 2020

The efficacy of 6-O-QS-10-N-acetyl muramyl-L-valyl-D-isoglutamine methyl ester (quinonyl-MDP-66) for restoring impaired immune status was examined in mice bearing Lewis lung carcinoma. Quinonyl-MDP-66 suspended in phosphate-buffered saline was shown to restore the depressed allogeneic cell-mediated cytotoxicity of spleen cells from mice with Lewis lung carcinoma when the chemical was injected twice intraperitoneally, intravenously, or intratumorally. However, primary tumor size and the numbers of lung metastases were not affected when quinonyl-MDP-66 was administered under the present experimental conditions. Intraperitoneal injection of quinonyl-MDP-66 in mice with Lewis lung carcinoma enhanced host resistance to Listeria monocytogenes infection.
Characterization of Staphylococcus aureus isolates from patients with toxic shock syndrome, using polyethylene infection chambers in rabbits
Authors: Scott D F , Kling J M , Kirkland J J , Best G K
Published: January 2020

Isolates of Staphylococcus aureus from patients with toxic shock syndrome (TSS) were compared with non-TSS strains of S. aureus with respect to their virulence in rabbits. When the organisms were injected into subcutaneous chambers (perforated polyethylene golf balls) to assess virulence, a rapid mortality was observed with TSS but not with non-TSS strains. Of 16 TSS strains, 11 caused lethal infections in 33 rabbits tested, and none of the 5 control strains caused mortality in 10 rabbits. This evidence of enhanced virulence associated with TSS strains did not appear to be associated with the size of the inoculum. In addition, strains which produced lethal infections appeared to do so despite a reduction in the size of the original inoculum during the first 24 h. All of the TSS strains and none of the non-TSS strains elaborated extracellular protein(s) with a neutral pI when grown in a dialyzed beef heart medium. No other physiological difference was noted between the TSS and non-TSS strains.
Isolation, purification, and partial characterization of Brucella abortus matrix protein
Authors: Moriyon I , Berman D T
Published: January 2020

Peptidoglycan sacculi with peptidoglycan-associated proteins were prepared from cell envelopes of Brucella abortus by extraction with sodium dodecyl sulfate (SDS) at 50 degrees C. On extraction of these preparations with SDS at 100 degrees C, a protein was obtained whose removal from peptidoglycan was confirmed by electron microscopy. Incubation of the 50 degrees C SDS-extracted cell envelopes with 50 mM MgCl2 in SDS-2-beta-mercaptoethanol at 37 degrees C also extracted the protein, along with lipopolysaccharide. At temperatures below 60 degrees C, the protein did not bind SDS strongly and had an apparent molecular weight greater than 92,000 in SDS-polyacrylamide gel electrophoresis. At higher temperatures, SDS bound strongly, and the apparent molecular weight was 38,000. Urea at 5 M did not alter the electrophoretic mobility of this 38,000-molecular-weight form. Immunoelectrophoresis in detergents with antisera to cell envelopes, carbohydrate staining of SDS-polyacrylamide gels, and production of anti-lipopolysaccharide antibodies by mice immunized with the purified protein indicated that lipopolysaccharide was present in free and protein-bound forms. Sequential gel filtration in SDS-EDTA and SDS-NaCl removed most lipopolysaccharide. After further purification by preparative SDS-polyacrylamide gel electrophoresis, a gas-liquid chromatographic analysis showed residual lipid tightly associated with the protein. The results suggested that the interactions between matrix proteins and other outer membrane components are stronger in B. abortus than in Escherichia coli, which was used as a control throughout.
Peroral Immunization of Rats with
Escherichia coli
Heat-Labile Enterotoxin Delivered by Microspheres
Authors: Klipstein Frederick A. , Engert Richard F. , Sherman William T.
Published: January 2020

The antigenicity of the
Escherichia coli
heat-labile enterotoxin was not protected against the adverse effect of gastric acidity when the toxin was given together with bicarbonate for peroral immunization to rats, but immunization with the heat-labile enterotoxin encapsulated in pH-dependent microspheres aroused the same strong degree of serum and mucosal antitoxin responses and of protection against challenge as was achieved by peroral immunization after ablation of gastric secretions by pretreatment with cimetidine.
Respiratory infection with attenuated Mycobacterium tuberculosis H37Ra in malnourished guinea pigs
Authors: McMurray D N , Carlomagno M A , Cumberland P A
Published: January 2020

Specific pathogen-free guinea pigs were infected via the respiratory route with viable, attenuated Mycobacterium tuberculosis H37Ra and maintained on purified isocaloric diets. The control diet contained 30% protein (ovalbumin) and 50 ppm of added zinc (50 micrograms/g), the low protein diet contained 10% protein and 50 ppm of added zinc, and the low zinc diet contained 30% protein and no added zinc. Guinea pigs from each diet treatment were skin tested with purified protein derivative 48 h before sacrifice at 3, 4, and 5 weeks postinfection. Protein-deficient animals exhibited significantly reduced body weight, spleen weight, serum total proteins, and serum albumin. Zinc deficiency was characterized by loss of weight and progressive reductions in plasma zinc concentrations. The number of viable M. tuberculosis H37Ra cells was significantly higher in the lungs of both malnourished groups at 3 weeks, but fell below control viable counts by 5 weeks postinfection. A similar pattern was seen in the spleens and bronchotracheal lymph nodes. Both the proportion and intensity of delayed hypersensitivity reactions increased steadily between 3 and 5 weeks in control animals, whereas the two malnourished groups were essentially anergic at all intervals, despite systemic infection. These results demonstrate that both protein and zinc deficiencies exert a significant influence on the development of pulmonary tuberculosis but that the nature of the influence depends upon the interval studied. In both malnourished groups, the pulmonary infection tended to peak early and decline, whereas the disease developed more slowly in control animals. Apparent control of mycobacterial populations in the tissues was accomplished by malnourished animals in the absence of demonstrable delayed hypersensitivity.
Component(s) of Sendai virus that can induce interferon in mouse spleen cells
Authors: Ito Y , Hosaka Y
Published: January 2020

To identify the active component of Sendai virus that induces interferon in mouse spleen cells, infectious and noninfectious viruses, envelope particles derived from them, and isolated hemagglutinin-neuraminidase (HN) glycoproteins were examined for interferon induction. The interaction between membranous structures containing Sendai virus HN glycoprotein and the receptors on the cell surface was shown to be sufficient for interferon induction in mouse spleen cells, suggesting that the actual inducer of interferon in mouse spleen cells is the HN glycoprotein of Sendai virus. When mouse spleen cells were stimulated in vitro with Sendai virus grown in eggs or LLC-MK2 cells or with membranous structures containing glycoproteins obtained from these viruses, interferon could be detected in the culture fluid. Furthermore, isolated HN glycoprotein per se could induce interferon in the cells. A linear correlation was found between the titer of interferon induced and the hemagglutinating activity of the membranous structure containing the HN glycoprotein. It was concluded from these findings that HN glycoprotein was the active component of Sendai virus responsible for interferon induction in mouse spleen cells and that viral RNA and F glycoprotein were not required. The results also showed that the interaction between HN glycoprotein and receptors on the cell surface triggered production of type I interferon (IFN-alpha and IFN-beta). Although when Sendai virus was incubated at 56 degrees C for 5 min it lost its hemolytic and hemagglutinating activities, it induced a considerable amount of interferon in the culture fluid of mouse spleen cells. The interferon-inducing ability of heat-inactivated virus could be absorbed with mouse spleen cells but not with sheep erythrocytes or mouse erythrocytes, indicating that the inactivated virus retained ability to bind to mouse lymphoid cells.
Influence of physicochemical parameters on adsorption of Actinomyces viscosus to hydroxyapatite surfaces
Authors: Wheeler T T , Clark W B , Lane M D , Grow T E
Published: January 2020

Adsorption of Actinomyces viscosus strains T14V and T14AV to saliva-treated and untreated hydroxyapatite (HA) under various environmental conditions was studied. Strain T14V adsorption to saliva-treated HA was not influenced by pH, whereas strain T14AV adsorbed in higher numbers under acidic conditions. The addition of cations inhibited adsorption of strains T14V and T14AV to saliva-treated HA. Strain T14V possessed a greater affinity for hydrophobic gels than did strain T14AV, but incorporation of non-ionic detergents, which inhibit hydrophobic interactions, did not influence adsorption of strain T14V to saliva-treated HA. Adsorption of strain T14V to saliva-treated HA increased in the presence of an anionic detergent; however, strain T14AV adsorption was not affected. Strain T14V adsorption decreased in the presence of a cationic detergent, whereas strain T14AV adsorption increased. Collectively, these data suggest that electrostatic interactions, but not hydrophobic interactions, are of major importance in the adsorption of strain T14V to saliva-treated HA.
Influence of growth temperature of Escherichia coli on K1 capsular antigen production and resistance to opsonization
Authors: Bortolussi R , Ferrieri P , Quie P G
Published: January 2020

When Escherichia coli strains that produce K1 capsular polysaccharide antigen at 37 degrees C were grown at 22 degrees C, K1 antigen was not detected in the supernatant or washed-cell fraction of broth cultures. Significant amounts of K1 polysaccharide were detected only when the organism was grown at temperatures of 30 degrees C or higher. Rabbits immunized with an E. coli K1 strain (serotype O18ac:K1:H7) grown at 37 degrees C produced agglutinating antibody to somatic antigen and precipitating and agglutinating antibody to capsular K1 antigen; those immunized with this strain grown at 22 degrees C produced antibody to somatic antigen, but not to K1 antigen. Antibody to somatic antigen was markedly reduced by adsorption with the organism grown at 22 degrees C, while antibody to capsular antigen was not. E. coli K1 strains grown at 37 degrees C (K1 present) resisted phagocytosis and killing if they were opsonized solely by the alternative complement pathway (ACP) using magnesium ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid-chelated serum. When these strains were grown at 22 degrees C (K1 absent), they were opsonized efficiently by the ACP (28 versus 94% killing, respectively; P less than 0.001). In addition, a non-K1 mutant of an E. coli K1 strain was opsonized efficiently by the ACP although its encapsulated K1 parent was not. Sensitivity of E. coli strains to the bactericidal activity of serum was observed in strains with and without K1 capsular antigen. These studies demonstrated that production of K1 polysaccharide antigen was regulated by environmental temperature and that K1 capsule plays an essential role in rendering the organism resistant to opsonization by the ACP.
Quantitation of in vitro opsonic activity of human antibody induced by a vaccine consisting of the type III-specific polysaccharide of group B streptococcus
Authors: De Cueninck B J , Eisenstein T K , McIntosh T S , Shockman G D , Swenson R M
Published: January 2020

Human antibody, induced by a vaccine consisting of undegraded and highly purified extracellular type III-specific polysaccharide of group B streptococcus, was shown to increase the rate of phagocyte-mediated killing of bacteria of the homologous type. The bactericidal effect was mediated by type III-specific antibody and was complement dependent. An assay which permitted quantitation of "opsonic activity" was developed. In this assay, loss of CFUs occurred at a constant rate, and the rate constant was used as a measure of opsonic activity of antisera. A linear relationship between type III-specific antibody concentration (40 to 500 ng/ml) and the rate constant of killing was observed. When sets of immune sera were tested, some sera reacted anomalously, mediating significantly higher or lower rates than expected on the basis of their antibody content. Since type III-specific antibody in immune sera was found almost exclusively in the immunoglobulin G class, we hypothesize that differences in immunoglobulin G subclass distribution of specific antibody may have been the source of this variation.
Adherence of an enterotoxigenic Escherichia coli strain, serotype O78:H11, to purified human intestinal brush borders
Authors: Cheney C P , Boedeker E C
Published: January 2020

The human enterotoxigenic Escherichia coli pathogen designated H10407 expresses two different types of surface pili, one designated type 1 pili and the other designated colonization factor antigen I (CFA/I), CFA/I pili are thought to promote the adherence of H10407 to the mucosa of the human small bowel. H10407 was grown under conditions which promoted the expression of either type 1 pili or CFA/I pili, and in each case, the adherence of H10407 to purified human intestinal brush borders was quantitated. The adherence assays revealed that H10407 adhered to human brush borders only when it expressed CFA/I pili. It appears that in vitro adherence of H10407 to human intestinal epithelial cells is dependent on the expression of CFA/I.