bluuebunny/crossref_metadata_2025 huggingface dataset:
Host Defenses in Experimental Scrub Typhus: Role of Spleen and Peritoneal Exudate Lymphocytes in Cellular Immunity
Authors: Catanzaro Phillip J. , Shirai Akira , Agniel Lucien D. , Osterman Joseph V.
Published: January 2020

Lymphocytes obtained from spleens or peritoneal exudates of immune donor mice were evaluated for their ability to passively confer protection on recipients subsequently challenged with virulent scrub typhus rickettsiae. Peritoneal exudate lymphocytes (PELs) injected intraperitoneally were able to transfer complete protection against rickettsial challenge by 5 days after immunization, whereas splenic lymphocytes (SpL's) required 15 days to exhibit similar resistance. When immune lymphocytes were transferred intravenously, cells from both anatomical compartments required 15 days after immunization before they were able to completely protect recipients. PELs maintained this protective capacity for 2 weeks, but the passive immunity induced by intravenously transferred SpL's rapidly diminished to insignificant levels. It was particularly interesting that the protective effect of SpL's could be dramatically reduced by the concomitant presence of a mineral oil-induced peritoneal exudate. Almost total abrogation of resistance was observed when SpL's obtained from exudate-bearing mice were transferred intravenously. The protective capacity of both PELs and SpL's was resistant to 1,200 rads of gamma radiation at 7 to 10 days after immunization, but resistance was transient and by 3 weeks was undetectable. It was not possible to determine from this study whether the transferred lymphocytes were proximate mediators of protection in scrub typhus infection of mice or whether they served to recruit the host's own defenses, or both. However, it was possible to conclude that PEL's and SpLs exhibited functional heterogeneity and that PELs were more efficient mediators of protection.
Effect of bursectomy and depletion of immunoglobulin A on antibody production and resistance to respiratory challenge after local or systemic vaccination of chickens with Newcastle disease virus
Authors: Ewert D L , Eidson C S
Published: January 2020

Surgical removal of the bursa of Fabricius from newly hatched chicks resulted in a depletion of immunoglobulin A (IgA) from serum and bile of 55 and 67% of the birds, respectively, up to 11 weeks of age. The occurrence of IgG and IgM in serum and IgG in bile was not affected by neonatal bursectomy (Bx). A slight compensatory increase in the occurrence of IgM in bile was noted in Bx birds. When exposed to a lentogenic strain of Newcastle disease virus by either intramuscular or intratracheal routes, the Bx group produced a level of serum hemagglutinating antibody and tracheal wash neutralizing antibody indistinguishable from that reached in the sham-Bx group. All of the vaccinated Bx birds challenged by intratracheal exposure to a velogenic strain of Newcastle disease virus remained healthy. These results suggest that IgA is not essential for the development of immunity in the chicken and that other locally produced immunoglobulins or transuded serum antibody may protect the tracheal mucosa in the absence of IgA.
Immunoglobulin E Anti-
Candida
Antibodies and Candidiasis
Authors: Mathur Subbi , Goust Jean-Michel , Horger Edgar O. , Fudenberg H. Hugh
Published: January 2020

Elevated levels of immunoglobulin E anti-
Candida
antibodies were observed in the sera of patients with systemic and vaginal candidiasis and in cervicovaginal washings of the latter.
Protection against challenge with Escherichia coli heat-labile enterotoxin by immunization of rats with cholera toxin/toxoid
Authors: Pierce N F
Published: January 2020

Rats were used to study dose-response curves to intestinal challenge with cholera toxin or Escherichia coli heat-labile enterotoxin. Prior immunization with cholera toxin/toxoid induced significant and equal protection against both toxins.
Hyperthermia and human leukocyte functions: effects on response of lymphocytes to mitogen and antigen and bactericidal capacity of monocytes and neutrophils
Authors: Roberts N J , Steigbigel R T
Published: January 2020

It has recently been demonstrated that fever, or hyperthermia, results in enhanced survival of lizards infected by Aeromonas hydrophila. In the present study, the effects of hyperthermia on certain immune functions were assayed in vitro with purified human leukocytes. Lymphocyte transformation responses to the mitogen phytohemagglutinin and the common antigen streptokinase-streptodornase were enhanced at 38.5 degrees C relative to 37 degrees C whether analyzed according to absolute counts per minute of incorporated tritiated thymidine or according to stimulation indexes. Enhancement of response was not accompanied by acceleration of response. Augmentation of transformation response was generally not seen at 40 degrees C; incubation at that temperature was associated with decreased cellular viability. Significant, though small, increases of the bactericidal capacity of polymorphonuclear leukocytes at 40 degrees C relative to 37 degrees C were shown at 1 h with Escherichia coli, Salmonella typhimurium, and Listeria monocytogenes, but not with Staphylococcus aureus. Mononuclear phagocytes did not show enhanced bactericidal capacity at the elevated temperature with any of these organisms in this in vitro system. Hyperthermia may enhance certain host defense mechanisms and warrants further study.
Role of complement in lethal bacterial lipopolysaccharide-induced hypotensive and coagulative changes
Authors: Ulevitch R J , Cochrane C G
Published: January 2020

The effect of C3 depletion on the multiple pathophysiological changes produced by a lethal dose of Serratia marcescens lipopolysaccharide (LPS) was evaluated. The injection of this LPS into rabbits resulted in biphasic hypotensive changes and thrombocytopenia. These changes were characterized by an acute, transient decrease occurring within minutes after injection followed by a second more gradual decrease beginning 30 to 60 min post-LPS. Prior depletion of C3, with the anticomplementary protein from cobra venom (CoF), did not alter the extent of either the gradual hypotensive and platelet changes or the coagulative and metabolic changes when normal and C3-depleted rabbits were compared. Importantly, the lethal effects of S. marcescens LPS were not reduced by prior depletion of C3. Only the immediate, reversible thrombocytopenia and hypotension were abrogated by C3 depletion.
Enhanced resistance against encephalomyocarditis virus infection in mice, induced by a nonviable Mycobacterium tuberculosis oil-droplet vaccine
Authors: Lodmell D L , Ewalt L C
Published: January 2020

Female C57B1/10 mice injected intravenously (i.v.) with nonviable Mycobacterium tuberculosis Jamaica cells associated with oil-droplet emulsions (WCV) were highly resistant to the i.v. injection of encephalomyocarditis virus (EMCV). Resistance to infection (87% survival) was detected from 1 week to at least 12 weeks after injection of WCV. Mice vaccinated i.v. also were resistant to intraperitoneal, subcutaneous, or intramuscular virus challenge, but were not resistant to intracranial challenge. Mice vaccinated intraperitoneally also were resistant to virus infection, whereas WCV administered intramuscularly or subcutaneously did not protect mice from virus injected by any route. Less than 50% of WCV mice that survived virus challenge possessed serum anti-EMCV-neutralizing antibody (less than 1:10), and none had detectable (less than 1:10) serum interferon. Interferon was not detected in sera of WCV mice from 4 to 144 h after i.v. injection of EMCV. Studies concerning the effects of WCV on EMCV infection suggest that mice may be protected by mechanisms that inhibit early viral replication and spread of virus to the central nervous system.
Phage-induced changes in Vibrio cholerae: serotype and biotype conversions
Authors: Ogg J E , Shrestha M B , Poudayl L
Published: January 2020

Phage infection of Vibrio cholerae resulted in antigenic changes. A strain of biotype cholerae serotype Ogawa was converted into serotype Hikojima and gained the ability to synthesize antigenic factor C. Some phage-converted strains remained stable after subculture and were immune to superinfection with the same phage. The stable converted strains were lysogenic and released phage having a host range similar to the phage of the donor strain. Reinfection of unstable converted strains which had "lost" antigen C yielded types able to again synthesize this antigen. The polymyxin resistance character was expressed in the biotype cholerae strain after infection with some phage preparations. These polymyxin-resistant strains possessed three main characteristics of El Tor vibrios. The phage-induced changes described provide V. cholerae with the potential for innumerable genetic combinations.
Activation of the alternate complement pathway by peptidoglycan from streptococcal cell wall
Authors: Greenblatt J , Boackle R J , Schwab J H
Published: January 2020

Activation of the alternate complement pathway in human serum by several bacterial components was compared. Peptidoglycan from group A streptococcal cell walls was the most active material, on a weight basis, followed by cell walls, protoplast membranes, and whole cells. The group-specific carbohydrate was inactive. Treatment of peptidoglycan with low concentrations of lysozyme or short periods of sonic treatment enhanced complement activation. High concentrations of lysozyme or extended sonic treatment of peptidoglycan destroyed or greatly reduced the capacity to activate complement. Lysozyme treatment of group A streptococcal cell walls or lipopolysaccharide had no measurable effect. Activation of the alternate complement pathway by group D streptococcal cell walls was destroyed by lysozyme. Activity of peptidoglycan was not inhibited by N-acetyl glucosamine, N-acetyl muramic acid, or D-alanine-D-alanine. Conversion of C3 and factored B by peptidoglycan was shown to occur by immunoelectrophoresis and crossed immunoelectrophoresis.
Detection of heat-labile enterotoxin-like activity in stools of patients with cholera and Escherichia coli diarrhea
Authors: Echeverria P , Verheart L , Ulyanco C V , Santiago L T
Published: January 2020

The Y1 adrenal cell tissue culture assay was used to detect heat-labile enterotoxin-like activity in the stools of 14 of 74 patients with diarrhea. A positive effect of the stool on the adrenal cells was heat-labile and neutralized by cholera antitoxin. Enterotoxin-like activity was detected in the stools of 10 of 30 patients with cholera and in those of 2 of 4 from whom heat-labile Escherichia coli were isolated. None of the stools from nine individuals with Vibrio parahaemolyticus, Salmonella, or Shigella infections were positive. Two of 31 individuals from whom no pathogens were isolated had detectable toxin-like activity in their stools. The Y1 adrenal cell assay provides a rapid method of diagnosing heat-labile enterotoxigenic diarrhea and could be an adjunct in epidemiological studies of gastroenteritis.
Growth of Chlamydia psittaci in macrophages
Authors: Wyrick P B , Brownridge E A
Published: January 2020

Survival and growth of L-cell-cultivated Chlamydia psittaci occurred in mouse macrophages in vitro. Two major factors governing the intracellular fate of chlamydiae in macrophages are: (i) the multiplicity of infection (MOI), i.e., the elementary body (EB)-to-macrophage ratio, and (ii) the state of the EB. At a low MOI (1:1) survival and growth of live, untreated chlamydiae were optimal. The chlamydiae were internalized in macrophages within 30 to 40 min. EB proceeded to differentiate into reticulate bodies, which underwent multiplication and further matured into infectious EB in the professional phagocytic cells. In contrast, at a high MOI (100:1), survival of untreated chlamydiae was greatly reduced as a result of immediate damage to the macrophages. eb that were pretreated with heat (56 degrees C for 10 to 30 min) or coated with homologous antibody were rapidly destroyed in macrophage phagolysosomes. Fusion of ferritin-labeled lysosomes with heat-treated or opsonized EB-laden phagosomes occurred in 2 to 4 h, resulting in transfer of the ferritin marker into phagolysosomes.
Isoelectric point of cell-free K99 antigen exhibiting hemagglutinating properties
Authors: Morris J A , Stevens A E , Sojka W J
Published: January 2020

The isoelectric point of the K99 antigen in partially purified preparations isolated from Escherichia coli B41 was 4.2. Electrofocused K99 antigen hemagglutinated guinea pig and sheep erythrocytes and gave a single precipitin line on diffusion against antisera to E. coli B41 and absorbed factor K99 antisera.
Differences in serological responses and excretion patterns of volunteers challenged with enterotoxigenic Escherichia coli with and without the colonization factor antigen
Authors: Evans D G , Satterwhite T K , Evans D J , DuPont H L
Published: January 2020

Double-blind studies were performed to compare the virulence of enterotoxigenic Escherichia coli with and without the fimbriate colonization factor antigen (CFA), using young healthy adults (mean age, 23 years) as volunteers. In the first study one group of volunteers ingested 1 X 10(6) E. coli H-10407, the CFA-positive strain, and another group ingested 1 X 10(6) E. coli H-10407-P, the CFA-negative spontaneous derivative of strain H-10407. The second study was similar except that the test strains were administered at a dose of 1 X 10(8) viable cells. Three parameters of infection were monitored: (i) diarrhea and associated symptoms; (ii) excretion pattern of test strains; and (iii) humoral antibody response to CFA, somatic antigen, and heat-labile enterotoxin. Significant signs of illness occurred only in six of seven volunteers who ingested E. coli H-10407 at a dose of 1 X 10(8). At both doses, E. coli H-10407-P appeared in the stool on day 1 postchallenge and disappeared by day 4. In contrast, strain H-10407 was persistently excreted from the first to the last day of the study. Also, only those volunteers in the H-10407 challenge groups (12 of 13 analyzed) responded with a fourfold antibody titer rise to CFA, somatic antigen, and/or heat-labile enterotoxin. No reversion of H-10407-P to H-10407 was detected.
Toxicity of Pneumococcal Neuraminidase
Authors: Kelly Richard , Greiff Donald
Published: January 2020

Sterile sonic-treated materials of pneumococci grown in media containing
N
-acetylmannosamine as the carbohydrate source were lethal for mice. Purification of the toxic factor led to its identification as the enzyme neuraminidase.
Deoxyribonucleic Acid Heterogeneity Between Human and Murine Strains of
Chlamydia trachomatis
Authors: Weiss E. , Schramek S. , Wilson N. N. , Newman L. W.
Published: January 2020

We compared the polynucleotide sequence relationships of three strains of
Chlamydia trachomatis
of human origin (MRC-1/G, TW-3, and Lgv), one of murine origin (MoPn), and the MN strain of
C. psittaci.
The four strains of
C. trachomatis
have the same base ratio, about 42.5 moles per cent guanine plus cytosine, which is significantly higher than the base ratio of MN (39.5). Single strands of deoxyribonucleic acid (DNA) fragments of MRC-1/G reassociated with immobilized DNA of TW-3 and Lgv almost as well as with the homologous DNA. The duplexes produced in these reactions were about equally thermostable. On the other hand, reassociations between MRC-1/G and MoPn involved 60 or 30% of the DNA, depending on the stringency of the conditions for reassociation, and the duplexes were thermolabile. MoPn reassociated only to a very small degree with MN. We also compared glucose catabolism of MRC-1/G, MoPn, and MN under several sets of conditions. These tests failed to reveal any qualitative phenotypic differences among the three strains. It can be concluded that, judging by polynucleotide sequence, the three human strains of
C. trachomatis
are closely related but appreciably different from a murine strain.
Antibody Type Specificity to Trachoma in Eye Secretions of Saudi Arab Children
Authors: McComb Dorothy E. , Nichols Roger L.
Published: January 2020

The presence of trachoma antibody in eye secretions of Saudi Arab children appears to be a direct response to the infecting organism. In 35 of 36 cases, the trachoma antibody type found in eye secretions was identical to the strain type isolated concurrently. Strain types were identified by use of donkey hyperimmune sera prepared against types 1, 1b, and 2. The specificity of the sera was enhanced by absorption with trachoma antigens of heterologous type. Similarly, antibody types were determined by absorbing samples of eye secretions with types 1, 1b, and 2. Complete absorption of trachoma antibody activity was achieved only by the antigen type homologous to the patient's own strain. In one instance, antibody could not be typed. No change in antibody or strain type was seen in four children examined twice during a 3- to 6-month period. Typing of trachoma antibody from eye secretions has potential as an immunological and epidemiological tool.
Cellular Responses of Mice to Diffusion Chambers I. Reactions to Intraperitoneal Diffusion Chambers Containing
Listeria monocytogenes
and to Bacteria-Free Chambers
Authors: Osebold John W. , Outteridge P. M. , Pearson L. D. , DiCapua R. A.
Published: January 2020

Diffusion chambers made with membranes having a pore size of 0.22 μm were implanted in the peritoneal cavities of mice. Chambers that contained no cells induced splenic lymphoreticular hyperplasia and a proliferation of fibroblasts around the chambers. When the chambers contained the bacterium,
Listeria monocytogenes
, there was strong and continuous chemotaxis of phagocytic cells to the membrane surface. The tendency to incite fibrosis around the chambers containing bacteria produced a tissue reaction resembling a chronic abscess or granuloma. The important difference from a natural lesion was the prevention of direct parasite-host cell interactions. In studies on the pathogenesis of long persisting host-parasite relationships, one might successfully use diffusion chambers to investigate the role of humoral antimicrobial substances as well as the effects of chronic inflammation, with its local concentration of metabolic products and constituents of phagocytic cells. On the other hand, the presence of diffusion chambers in the tissues is an abnormal situation and changes arising from their presence may complicate the interpretations of some experiments.
Isolation and Biological Characterization of
Pasteurella pestis
Endotoxin
Authors: Albizo Johnnie M. , Surgalla Michael J.
Published: January 2020

Endotoxin containing 2.1% nitrogen, 1.6% phosphorus, 22.5% neutral hexose, 15% hexosamine, 25% esterified and amide-linked fatty acids, and 1.4% protein was isolated from
Pasteurella pestis
strain Alexander by slight modification of a method adapted by Tauber and Russell. The lipopolysaccharide exhibited classical endotoxic biological properties including: (i) toxicity in mice, guinea pigs, and rabbits; (ii) antigenicity in rabbits; (iii) capacity to evoke a biphasic pyrogenic response in rabbits; (iv) capacity to induce tolerance in mice to the lethal effect of endotoxin; (v) capacity to stimulate rapidly acquired resistance in mice to bacterial infection, and (vi) the capacity to produce the localized and generalized Shwartzman phenomena in rabbits. Findings obtained during the study concerning the occurrence, isolation, toxicity, and other biological properties of
P. pestis
endotoxin provide new evidence that endotoxin could contribute to death in plague.
Isolation, Characterization, and Immunogenicity of
Mycoplasma pneumoniae
Membranes
Authors: Pollack J. Dennis , Somerson Norman L. , Senterfit Laurence B.
Published: January 2020

Membrane and soluble fractions of
Mycoplasma pneumoniae, M. pulmonis
, and
M. laidlawii
B were prepared by hypotonic lysis of whole cells. The membranes of
M. pneumoniae
and
M. laidlawii
B contained, as percentage of dry weight: 34 to 37% protein, 59 to 61% lipid, 3 to 4% carbohydrate as hexose, and 0.2% ribonucleic acid as ribose. NADH
2
and NADPH
2
oxidase activities were localized in the soluble fractions of
M. pneumoniae
and in the membrane fraction of
M. laidlawii
B. NADH
2
oxidase activity was localized in the soluble fraction of
M. pulmonis
. The lipids of
M. pneumoniae
were labeled when the organism was grown in the presence of either radioactive palmitic acid, oleic acid, cholesterol, or glycerol. The lipids were not labeled when grown in the presence of radioactive acetate. Palmitic acid radio-activity was found in neutral lipid, glycolipid, and phosphatide fractions. Immunodiffusion analyses of whole cells and membrane fractions demonstrated three reactive antigens. Two immunodiffusion antigens were localized in the membrane fraction. One of these apparently contains lipid. A third antigen, also considered lipoidal, was found in whole cells. Membrane and soluble fractions of
M. pneumoniae
were immunogenic. The immunogens eliciting metabolic-inhibiting antibodies were localized in the membrane. The membrane preparation also induced the formation of antibodies which fixed complement with an antigen extracted with lipid solvent. The soluble fraction contained a distinct immunogen which induces antibodies reactive in complement fixation with an antigen prepared by phenol extraction.
Inhibition of
Shigella flexneri
by the Normal Intestinal Flora III. Interactions with
Bacteroides fragilis
Strains in Vitro
Authors: Hentges David J. , Maier Bruce R.
Published: January 2020

Five strains of
Bacteroides fragilis
isolated from human feces were assayed for their inhibitory activities against
Shigella flexneri
in vitro. Inhibition was not detected when
Shigella
and the
Bacteroides
strains were simultaneously inoculated into a defined liquid medium containing glucose. Inhibition was apparent only when
Shigella
was inoculated into established
Bacteroides
cultures. In exponential-phase cultures, the
Shigella
growth rate was diminished and logarithmic growth was prematurely interrupted.
Shigella
failed to multiply at all in stationary-phase
Bacteroides
cultures. An analysis of the stationary-phase cultures revealed that acetic and propionic acids were present in sufficiently high concentrations and the
p
H of the culture medium was sufficiently low to account for the inhibition of
Shigella
growth. In glucose-free
Bacteroides
cultures,
Shigella
multiplied almost as well as in control cultures, despite the presence of high concentrations of volatile fatty acids. At the high
p
H levels present in the glucose-free cultures, the acids were not toxic for
Shigella.
These results reaffirm the importance of the relationship between volatile fatty acids and
p
H in the inhibition of
Shigella
growth.
Lipid metabolism of Borrelia hermsi
Authors: Livermore B P , Bey R F , Johnson R C
Published: January 2020

The synthesis of complex lipids by Borrelia hermsi while growing in Kelly medium was investigated by labeling cultures with D-[14C]glucose or [14C]palmitic acid. Labeled glucose was incorporated into phosphatidyl choline, phosphatidyl glycerol, monogalactosyl diglyceride, cholesterol glucoside, and acylated cholesteryl glucoside. The fatty acid composition reflected that of the medium suggesting that this spirochete directly incorporates acyl chains unaltered from its external milieu. Furthermore, the distribution of labeled carbon between acyl groups (lipid-soluble) and water-soluble moieties indicates that there is no metabolic exchange between these two pools. The relationship of B. hermsi to other spirochetes is discussed in terms of lipid metabolism as a generic characteristic.
Evidence for a disseminated plasmid in Streptococcus mutans
Authors: Macrina F L , Scott C L
Published: January 2020

Based on a survey of 86 isolates, approximately 5% of all naturally occurring strains of Streptococcus mutans contains a 3.6 X 10(6)-dalton (3.6-megadalton) multicopy plasmid of unknown function. The amount of plasmid deoxyribonucleic acid per chromosome varies from 2 to 6% depending on the host strain. About 13% of the total covalently closed circular deoxyribonucleic acid in each of the four plasmid-containing strains consists of dimeric molecules, with interlocked circular forms predominating. Site-specific restriction endonucleases have been identified that cleave this 3.6-megadalton plasmid at single and at multiple sites. Each of the four plasmids is cleaved once by the HindIII and BamHI restriction enzymes. The HpaI, TaqI, and HhaI enzymes generate two, five, and six components, respectively, and the digestion products of each of the four plasmids are identical. Because the four plasmid-containing S. mutans strains are physiologically unique with respect to one another, we conclude this plasmid to be a disseminated extrachromosomal element in S. mutans.
Association of hemolysin production, hemagglutination of human erythrocytes, and virulence for chicken embryos of extraintestinal Escherichia coli isolates
Authors: Minshew B H , Jorgensen J , Counts G W , Falkow S
Published: January 2020

One hundred forty-two strains of Escherichia coli isolated from extraintestinal infections were examined for colicin V (ColV) and hemolysin (Hly) production. For comparison, 20 strains isolated from the feces of normal individuals and 12 enteropathogenic strains of E. coli were tested for these properties. Thirty-five to 59% of extraintestinal isolates were Hly+, but only one fecal strain was Hly+. Colicin V biosynthesis was found for 12% of blood culture isolates, 7% of urine culture isolates and 16% of the strains from other extraintestinal infections. None of the fecal isolates was ColV+. Selected strains were tested for virulence in 13-day-old chicken embryos; these same strains were tested for their ability to hemagglutinate chicken or human erythrocytes. Of 22 extraintestinal isolates, 13 (59%) killed greater than or equal to 60% of the embryos within 72 h. Only one of eight normal fecal isolates and two of three enteropathogenic strains tested were virulent. About 80% of the virulent strains were Hly+. The most striking finding, however, was the hemagglutination of human erythrocytes by virulent extraintestinal isolates. It seems possible that the hemagglutination property reflects a specific common adherence factor.
Effect of zinc and calcium ions on the production of alpha-toxin and proteases by Clostridium perfringens
Authors: Sato H , Yamakawa Y , Ito A , Murata R
Published: January 2020

Clostridium perfringens produced at least three distinct proteases in a synthetic medium containing calcium. Two of them, thiol and ethylenediaminetetraacetic acid disodium salt-sensitive proteases, appeared at an early stage of growth, but the other one, perhaps being identical to the one produced in a calcium-deficient medium, appeared at a late stage. The production of these proteases depended on Ca2+ but not on Zn2+ in the medium. Alpha-toxin, perhaps being a zinc-containing metalloenzyme, was rather resistant to the proteases, but toxin, produced in a zinc-deficient medium or deprived of zinc with ethylenediaminetetraacetic acid disodium salt, was very sensitive. By adding Zn2+, the toxin lacking zinc may have been converted to the zinc-containing metalloprotein that is resistant to proteases. This may explain why alpha-toxin activity increased progressively in a zinc-containing medium in spite of simultaneous production of potent proteases and why it disappeared rapidly in a zinc-deficient medium.
Suppression of cellular responses in mice during Trypanosoma cruzi infections
Authors: Rowland E C , Kuhn R E
Published: January 2020

Immunosuppression has been reported to occur in several protozoan parasitic infections. The significance of this suppression on host resistance or on parasite avoidance of immune destruction has not, however, been determined. In the present study two strains of mice that differ with respect to resistance to Trypanosoma cruzi were examined during the course of infection for differences in expression of suppression of blastogenic responses to phytohemagglutinin and an antigen preparation of these parasites. It was found that in vitro blastogenic responses were suppressed in both strains of mice: on day 12 for C57BL/6 mice (resistant strain) and on day 17 for C3H(He) mice (susceptible strain). Neither C3H(He) nor C57BL/6 lymph node cells (LNC) responded to a crude sonically treated antigen of these parasites, although C57BL/6 LNC were inhibited by this antigen later in infection. There was no abrogation of suppression of LNC responses late in infection, when decreases in spleen weight or total spleen cell numbers occurred, in the resistant C57BL/6 mice. LNC from normal uninfected mice were found to be completely suppressed in responsiveness to phytohemagglutinin when cultured at a 2:1 ratio with LNC from C57BL/6 mice with 18-day infections. Attempts to characterize the cell type responsible for this suppression showed it to be a non-thy 1.2-bearing, nylon wool-adherent cell.
Measles virus nucleocapsids: large-scale purification and use in radioimmunoassays
Authors: Moore P M , Hayes E C , Miller S E , Wright L L , Machamer C E , Zweerink H J
Published: January 2020

Nucleocapsids in quantities approaching 1 mg were purified from 109 measles virus-infected cells. They contained one polypeptide species with a molecular weight of 59,000. Antiserum was raised in rabbits against purified nucleocapsids and used in a competitive radioimmunoassay. Because of their instability, purified nucleocapsids were not suitable for use in such an assay. Instead partially purified nucleocapsids from HEp-2 cells persistently infected with measles virus and labeled in vitro with [35S]methionine were used as the source of radioactive antigen. The radioimmunoassay thus developed measured less than 5 ng of nucleocapsids in infected cells.
Characterization of the TO strains of Theiler's mouse encephalomyelitis viruses
Authors: Lipton H L
Published: January 2020

Theiler's mouse encephalomyelitis virus isolates from the central nervous systems of spontaneously paralyzed mice and stools of asymptomatic mice resemble Theiler's original virus isolates. In this study four such strains were adapted by blind subpassage to replicate and to produce cytopathic effect in cell culture. These viruses were then found to be closely related to each other and to GDVII virus by cross-neutralization and to form small plaques. Bovine serum was found to contain cross-reacting antibodies to these viruses.
Morphological and Cytochemical Characterization of Cells Infiltrating Mouse Lungs After Influenza Infection
Authors: Wyde Philip R. , Peavy Duane L. , Cate Thomas R.
Published: January 2020

To initiate evaluation of the cell-mediated immunological response to influenza virus in a major site of disease, lung cells were obtained by transpleural lavage from lungs of uninfected mice and from those infected 3 or 6 days previously with 5 50% mouse infectious doses (MID
50
) of avirulent (P3) or virulent (P9) influenza A Hong Kong (H3N2) virus. The number of cells recovered by lavage was dependent on the dose, time after inoculation, and the type of virus used for inoculation. Although lavage pools were shown to contain peripheral blood leukocytes, this contamination was shown to be consistently less than 5% of the total leukocytes harvested. Among the ca. 0.75 × 10
6
lavage cells obtained from each uninfected mouse, about 90% were macrophages or lymphocytes in approximately equal proportion. T, B, and null (lyphocytes lacking theta or surface immunoglobulin markers) lymphocytes averaged 23, 9, and 7% of cells in these suspensions, respectively. After infection with either P3 or P9 virus, increased numbers of activated macrophages and lymphoblasts were observed. The major change during P3 infection was an increase in absolute numbers of null lymphocytes. In contrast, during P9 infection, T and B lymphocytes and macrophages progressively increased in absolute numbers while null cells decreased. These data suggest that cell-mediated immunological responses to influenza virus occur in the lung during infection, but that the responses to virulent and avirulent variants may differ both qualitatively and quantitatively.
Escherichia coli pili as possible mediators of attachment to human urinary tract epithelial cells
Authors: Edén C S , Hansson H A
Published: January 2020

Presence of pili of fimbriae on Escherichia coli bacteria isolated from the urine of patients with urinary tract infection was related to the ability of the bacteria to attach to human uroepithelial cells. Piliated E. coli strains agglutinated guinea pig erythrocytes. D-Mannose and alpha-methyl-D-mannopyranoside inhibited this agglutination with all but one of the 12 strains tested. D-Mannose, D-galactose, alpha-methyl-D-mannopyranoside, and L-fucose did not afect attachment of piliated strains to uroepithelial cells. Heating as well as washing of piliated strains caused a parallel decrease of piliation and adhesive ability. Growth in glucose-enriched medium increased capsule formation but decreased piliation and adhesion. Capsulated strains retained their adhesive ability provided that pili extended outside the capsule.
Protective ability of Salmonella ribosomal protein and RNA in inbred mice
Authors: Misfeldt M L , Johnson W
Published: January 2020

Ribosomal vaccines prepared from Salmonella typhimurium were effective immunogens in A/J, C3H/HeDub, and C3H/HeJ mice. Purified ribosomal components were also tested as immunogens in the inbred mice. Protein isolated from a Salmonella ribosomal fraction could protect all three mouse strains. Although purified RNA was shown to be protective for A/J and C3H/HeDub mice, it was not protective for C3H/HeJ mice. Protective immunity could be induced in A/J and C3H/HeDub mice by various immunostimulants. Immunity in C3H/HeJ mice, however, could only be induced by Salmonella ribosomes or protein isolated from the Salmonella ribosomal fraction.
Intestinal distribution of Vibrio cholerae in orally infected infant mice: kinetics of recovery of radiolabel and viable cells
Authors: Baselski V S , Parker C D
Published: January 2020

Kinetics of distribution of Vibrio cholerae in the gastrointestinal tract of orally challenged infant mice were examined by determining recovery of input dose from the whole gut and from individual segments of stomach, upper bowel, and lower bowel. The strains studied were 569B, CA401, and VB12 (a rough CA401). Recovery was determined as a percentage of either input radiolabel using 35S-labeled cells or input colony-forming units. We found clearance of radiolabel and viable cells from the stomach into the intestines by 2 h. Early whole-gut clearance of label was greater for 569B and heat-killed CA401 than for CA401, VB12, or Formalinized CA401. At early times postchallenge, significant differences occurred between strains in the upper bowel, with greater recovery of label and viable cells for CA401 than for 569B or VB12. Beginning at 8 h postchallenge, radiolabel accumulated in the lower bowel with all experimental groups except CA401-challenged mice, where diarrhea was noted and label disappeared from the intestines. In vitro evaluation of mucosal association of these strains with bowel sections was also done. CA401 and VB12 associated to a greater extent than 569B or heat-killed or Formalin-killed CA401.
Biological evaluation of a methanol-soluble, heat-stable Escherichia coli enterotoxin in infant mice, pigs, rabbits, and calves
Authors: Burgess M N , Bywater R J , Cowley C M , Mullan N A , Newsome P M
Published: January 2020

Escherichia coli P16 was shown to produce two heat-stable toxins (ST) with differing biological activity. The toxins were separated by methanol extraction, and the first, STa, was methanol soluble, partially heat stable, active in neonatal piglets (1 to 3 days old) and infant mice, but inactive in weaned pigs (7 to 9 weeks old); the second, STb, was methanol insoluble, active in weaned pigs and rabbit ligated loops, but inactive in infant mice. It is therefore suggested that use of suckling mice as indicators of ST production will fail to identify certain ST-producing strains.
Increase in the Population of Duodenal Immunoglobulin A Plasmocytes in Axenic Mice Associated with Different Living or Dead Bacterial Strains of Intestinal Origin
Authors: Moreau M. C. , Ducluzeau R. , Guy-Grand D. , Muller M. C.
Published: January 2020

Various bacterial strains were tested for their ability to stimulate immunoglobulin A (IgA) plasmocytes to populate the duodenal lamina propria in axenic mice. The mice were associated with the strains for at least 4 weeks. The strains inhabiting the conventional mouse intestine and belonging to the genera
Lactobacillus, Streptococcus, Eubacterium, Actinobacillus, Micrococcus, Corynebacterium
, and
Clostridium
(including the extremely oxygen-sensitive ones) are only slightly or nonimmunogenic, whereas the strains belonging to the genera
Bacteroides
and
Escherichia
have an immunogenic effect. The same result was obtained with
Bacteroides
and
Escherichia
strains isolated from the digestive tract of other animal species. The kinetics of appearance of intestinal IgA plasmocytes are similar in axenic mice monoassociated with a stimulatory strain and in conventional mice. The association of two or more strains with axenic mice leads either to the same or a greater number of duodenal IgA plasmocytes as that obtained with the most stimulatory strain monoassociated with axenic mice. The maximum stimulation recorded in all of these trials represents about two-thirds of that observed in conventional mice and was obtained in the duodenum of gnotoxenic mice harboring four bacterial strains isolated from the conventional mouse microflora. The orally administered killed cells of two immunogenic strains,
E. coli
and
Bacteroides
sp., are as immunogenic as the living cells, provided that their concentration in the digestive tract is sufficient.
Comparative ultrastructural study on the cell envelopes of Rickettsia prowazekii, Rickettsia rickettsii, and Rickettsia tsutsugamushi
Authors: Silverman D J , Wisseman C L
Published: January 2020

Rickettsia tsutsugamushi differs from other rickettsiae in its cell envelope organization. The differences were made evident through a comparative study of the outer envelope of R. tsutsugamushi, R. prowazekii, and R. rickettsii by electron microscopy.
Histoplasma capsulatum infection in nude mice
Authors: Williams D M , Graybill J R , Drutz D J
Published: January 2020

Congenitally athymic nude (nu/nu) mice, when injected intraperitoneally with Histoplasma capsulatum, developed a rapidly fatal disseminated infection characterized by heavy parasitization of reticuloendothelial tissues. In contrast, their heterozygous (nu/X) littermates, which possessed a functioning thymus, developed only a low-grade infection which was apparently self-limited and rarely fatal. Transplantation of thymic tissue into nu/nu mice diminished greatly the severity of infection and reduced mortality by about 50%. These studies emphasize the importance of cell-mediated immunity in host defense against histoplasmosis and suggest that the nude mouse may be a valuable model for the study of this chronic intracellular infection.
Inhibition of the secretory activity of Escherichia coli heat-stable enterotoxin by indomethacin
Authors: Madsen G L , Knoop F C
Published: January 2020

The effect of indomethacin on the net intestinal accumulation of fluid induced by Escherichia coli heat-stable (ST) enterotoxin in the infant mouse model was examined. Indomethacin, when administered with ST enterotoxin, caused a striking decrease in net intestinal fluid accumulation. This inhibition of ST activity was dose dependent with various concentrations of indomethacin (P less than 0.01). A significant inhibition of toxicity was also observed when indomethacin was given before (P less than 0.01) or after (P less than 0.02) ST enterotoxin challenge. No significant differences in fluid accumulation were observed between control mice treated with buffer alone and those challenged with only indomethacin. These data indicate that indomethacin markedly decreases the net intestinal fluid accumulation induced by E. coli ST enterotoxin. Further studies on the potential use of indomethacin in both the prophylaxis and the therapy of diarrheal diseases appear warranted.
Penetration of Cultured Mouse Fibroblasts (L Cells) by
Rickettsia prowazeki
Authors: Walker T. Stuart , Winkler Herbert H.
Published: January 2020

The association of
Rickettsia prowazeki
with L cells was examined by using a novel radioactive assay in which [α-
32
P]ATP-labeled rickettsiae were incubated with L-cell monolayers. Rickettsial association with the monolayer involved adherence and internalization steps that could be experimentally distinguished. Since
R. prowazeki
but not L cells possess an ATP-ADP obligate exchange transport system, addition of excess unlabeled ATP resulted in exchange of the labeled ATP from external, adherent rickettsiae but not from internalized rickettsiae. Rickettsial association was temperature dependent and was a linear function of both time and concentration. More than 90% of the biologically active rickettsiae associated with L cells was internalized. Rickettsial internalization required active participation of both rickettsiae and L cells; inactivation of either greatly reduced internalization. Rickettsial adherence to poisoned L cells was a saturable function of time and concentration. Adherence showed less temperature dependence than did internalization, but like rickettsial internalization, the extent of adherence was extremely low at 0°C. The rate and extent of adherence by inactivated and native rickettsiae to inactivated L cells were similar. Although inactive rickettsiae adhered to active and inactive L cells to a similar extent, inactive rickettsiae were internalized poorly by active L cells. These data form the basis for the hypothesis that
R. prowazeki
are internalized by the host cell through a process of “induced phagocytosis” and that inactivated rickettsiae adhere to the host cell differently from native rickettsiae, failing to trigger the endocytosis mechanism.
Experimental Q fever infection in congenitally athymic nude mice
Authors: Kishimoto R A , Rozmiarek H , Larson E W
Published: January 2020

Congenitally athymic nude (nu/nu) mice and their phenotypically normal (nu/+) euthymic littermates were exposed to Coxiella burnetii administered as small-particle aerosols. After challenge, both strains of mice became infected, as characterized by rickettsemia, viable rickettsiae in the spleen, and serological conversion. The major difference noted was that euthymic animals had cleared rickettsiae from peripheral circulation and the spleen within 14 days. In contrast, rickettsiae were detected and isolated from spleen and blood of athymic mice through 60 days.
Hyporeactivity factor produced after induction of immune interferon in mice sensitized with BCG
Authors: Minagawa T , Ho M
Published: January 2020

Sera from BCG-sensitized ICR and C57BL/10J mice challenged with BCG were examined. Two types of hyporeactive factor (HF), which produced refractoriness to induction of interferon (IF) by Newcastle disease virus in mouse embryo fibroblasts, were produced in addition to type II immune IF. One was destroyed at pH 2, and the other was not. The acid-labile HF, together with immune IF, appeared 2 h after challenge with BCG. Acid-labile HF and immune IF were not neutralized by antiserum against L-cell IF and may be one substance. On the other hand, acid-stable HF appeared later and was neutralized by antiserum against L-cell IF. Furthermore, acid-stable HF was more stable at 56 degrees C than were immune IF and pH-labile HF. Induction of IF by Newcastle disease virus was also reduced in mice 6 h after receiving one injection of BCG, irrespective of whether the animals were previously sensitized to BCG.
Influence of cadmium on the phagocytic and microbicidal activity of murine peritoneal macrophages, pulmonary alveolar macrophages, and polymorphonuclear neutrophils
Authors: Loose L D , Silkworth J B , Simpson D W
Published: January 2020

A significant depression in the phagocytic capacity of elicited peritoneal macrophages, pulmonary alveolar macrophages, and elicited peritoneal polymorphonucleated neutrophils was manifested when the cells were incubated in medium containing cadmium chloride. With the exception of the neutrophils, a similar influence was observed when the cells were exposed to cadmium acetate. The impaired phagocytic capacity was related to the concentration of the cadmium in the medium. Peritoneal macrophages and neutrophils did not demonstrate any alteration in their microbicidal activity (percentage of ingested yeast which were killed) in the presence of the cadmium salts. However, a significant suppression in the intracellular microbicidal activity of alveolar macrophages was observed when the cells were incubated in medium containing either cadmium chloride or cadmium acetate. This unique response to Cd2+ may be related to general metabolic characteristics of these cells living at an elevated O2 tension.
Cellular Changes in Lungs of Mice Infected with Influenza Virus: Characterization of the Cytotoxic Responses
Authors: Wyde Philip R. , Cate Thomas R.
Published: January 2020

Transpleural lavage of lungs from uninfected C3H mice yielded an average of 300,000 leukocytes per mouse. This number increased eightfold within 6 days after intranasal inoculation with virulent influenza A/Hong Kong/68 (H3N2) virus. Macrophages and lymphocytes in approximately equal numbers comprised 90% or more of the leukocytes both before and during infection. B, T, and null lymphocytes comprised, respectively, 9, 21, and 18% of the leukocytes before infection and 7, 26, and 5% by day 6. In absolute numbers, macrophages and T lymphocytes provided the major increments during infection. Cytotoxic activity of mononuclear cells from lung lavages was compared in a chromium release assay using syngeneic L929 target cells with the activity of mediastinal lymph nodes, spleens, and peripheral blood of uninfected and infected C3H mice. Nonspecific cytotoxicity for target cells infected with H3hkNeq1 or B/Lee influenza virus was found with mononuclear cells from uninfected mice. This activity tended to be highest with lavage leukocytes and was associated with adherent cells, presumably macrophages. Increased virus-specific cytotoxicity was detected with lavage cells by day 6 and persisted through day 9, the period of maximal pneumonia. Similar cytotoxic activity also appeared in cells from the nodes and spleen at this same time but was not detected in peripheral blood cells. The virus-specific cytotoxicity of lavage cells was due largely to a nonadherent cell possessing Fc receptors and theta antigen but lacking C3 receptors; these properties are compatible with actively cytotoxic T lymphocytes. The cytological characteristics of the infiltrating leukocytes and the cytotoxicity data suggest that the local T cell response to influenza virus infection in the lung is a major contributor to the pneumonia observed in this mouse model.