bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of hepatitis A antigen in human liver
Authors: Shimizu Y K , Shikata T , Beninger P R , Sata M , Setoyama H , Abe H , Tanikawa K
Published: January 2020

For the first time, hepatitis A viral antigen (HAAg) was shown in liver biopsy tissue from a patient in the acute phase of hepatitis type A by light and electron microscopy, using the peroxidase-antibody technique. Under light microscopy, the staining for HAAg appeared as a fine, granular reaction product, scattered throughout the cytoplasm of hepatocytes and sinusoidal lining cells. Standard thin-section electron microscopy revealed virus-like particles, 24 to 27 nm in diameter, in cytoplasmic vesicles of hepatocytes and Kupffer cells. By immunoperoxidase electron microscopy, HAAg was detected on particles aggregated within cytoplasmic vesicles of hepatocytes, thus demonstrating that the virus-like particles (24 to 27 nm) are hepatitis A virus. The surrounding membrane of the vesicles was also positive for HAAg. The distribution patterns of HAAg in human liver were virtually identical to those described for experimentally infected marmosets. It is notable that most HAAg was detected within vesicles of liver cell cytoplasm, suggesting the possibility of vesicle-oriented morphogenesis of hepatitis A virus.
Release of Mycoplasma pneumoniae substances after phagocytosis by guinea pig alveolar macrophages
Authors: Kist M , Jacobs E , Bredt W
Published: January 2020

Antibody-opsonized Mycoplasma pneumoniae cells with various radioactive markers were sedimented onto monolayers of guinea pig alveolar macrophages (AM). After 2 h of incubation, about 50% of the activity of [3H]palmitate-labeled mycoplasmas was associated with AM. Nonspecific attachment of the opsonized mycoplasmas to AM-free plastic surface areas was negligible. The occurrence of phagocytosis was proven by electron microscopy and monitoring of AM surface-bound antigen by 125I-labeled F(ab)2 fragments. The activity of [3H]palmitic acid-labeled mycoplasmas was only slowly released into the supernatant. About 55% of the activity remained AM-associated up to 70 h after phagocytosis. After phagocytosis of [3H]thymidine-labeled cells, about 70% of the radioactivity found non-precipitable by trichloracetic acid. 3H-amino acid-labeled protein was released to 50% within 8 h. Supernatants and AM were tested for M. pneumoniae antigen with enzyme-linked immunosorbent assay. Considerable amounts of antigenically active material could be found in the supernatant within 8 h. This antigen was totally inactivated by heat (80 degrees C). Trypsin treatment (1 mg/ml, 10 min) reduced the antigenicity by 80%. The results suggest a selective release of microbial material after phagocytosis.
In vitro kinetics of phagocytosis and intracellular killing of gonococci by peritoneal macrophages from mice deficient in complement component 5
Authors: Cooper M D , Floyd S A
Published: January 2020

Unstimulated resident peritoneal macrophages were harvested from complement-sufficient (C5+) and complement-deficient (C5-) mice by peritoneal lavage and cultured for 14 h. Adherence to cover slips was determined, and the monolayer was infected with transparent T1 gonococci. At various times after infection, the macrophages were observed for both attachment and phagocytosis of the gonococci by scanning and transmission electron microscopy. this analysis indicated that C5+ macrophages were capable of immediate phagocytosis of gonococci, with maximal phagocytosis occurring by 60 to 90 min. In contrast, C5- macrophages had a greater lag time before initiation of phagocytosis; this event was started by 30 min and completed by 90 min. The intracellular gonococci which were phagocytized by either C5+ or C5- mice were completely killed after 30 min of incubation. It appears that C5- mice are at a disadvantage in the early kinetics of the phagocytosis of gonococci, but that this does not affect the ultimate intracellular destruction of gonococci.
Temperature-modulated immunogenicity to Yersinia pestis from Yersinia enterocolitica O3
Authors: Alonso J M , Hurtrel B , Mazigh D , Chalvignac M A , Mollaret H H
Published: January 2020

The ability of Yersinia enterocolitica O3, grown at 25 degrees C, to promote cross-immunity to Y. pestis was lost after repeated subcultures at 37 degrees C, which selected for bacterial populations having lower in vivo survival. Subculturing Y. enterocolitica O3 from 37 to 25 degrees C restored the cross-immunogenicity although the in vivo survival remained low.
Pyocin-resistant lipopolysaccharide mutans of Neisseria gonorrhoeae: alterations in sensitivity to normal human serum and polymyxin B
Authors: Guymon L F , Esser M , Shafer W M
Published: January 2020

Pyocins from Pseudomonas aeruginosa were used to select several lipopolysaccharide (LPS) mutants of Neisseria gonorrhoeae strain FA19. Three classes of LPS mutans were found in the initial group selected for study. The LPS of one class lacked galactose. That of a second group lacked the typical heptose found in the parental LPS, was reduced in glucose, galactose, and N-acetylglucosamine content, appeared to contain a new unidentified sugar component, and consisted of two species of LPS separable on sodium dodecyl sulfate-polyacrylamide gels. The LPS of a third strain lacked the heptose, glucose, galactose, and N-acetylglucosamine found in the oligosaccharide portion of parental FA19 LPS. The minimal inhibitory concentration for polymyxin B of the mutant strains was 3 to 4 times that of the parental strain. The strains lacking only galactose were as resistant as the parent to the bactericidal action of normal human serum, but cells of the other two classes were quickly killed by serum. Gonococcal LPS thus appears to be important in determining phenotypic properties of the cells.
Evidence for the Involvement of Proton Motive Force in the Transport of Glucose by a Mutant of
Streptococcus mutans
Strain DR0001 Defective in Glucose-Phosphoenolpyruvate Phosphotransferase Activity
Authors: Hamilton I. R. , Martin E. J. St.
Published: January 2020

Streptococcus mutans
DR0001 and a glucose-phosphotransferase (PTS)-defective mutant, DR0001/6, were grown anaerobically in a chemostat with a glucose limitation at dilution rates (
D
) of 0.04 to 0.6 h
−1
(mean generation time, 17 to 1.2 h). The mutant possessed only 15% of glucose-PTS activity of the wild type and gave cell yields (19%) less than those of the wild type. Glucose-PTS activity in strains DR0001 was maximum at
D
= 0.1 h
−1
and was adequate to account for transport in the chemostat at all dilution rates except
D
= 0.6 h
−1
, at which it was 80% of the actual glucose uptake activity. The mutant DR0001/6, on the other hand, possessed only sufficient glucose-PTS activity to sustain growth at below
D
= 0.1 h
−1
, indicating the presence of an alternate transport activity. This was confirmed in glycolytic rate experiments with washed cells, which demonstrated that the mutant showed rates 11- to 27-fold higher than that accountable via glucose-PTS activity alone. The wild-type organism contained both a high (
K

s

, 6.7 to 8.0 μM)- and a low (
K

s

, 57 to 125 μM)-affinity transport system, whereas the glucose-PTS-defective mutant contained only the low-affinity system (
K

s

, 62 to 133 μM). The glucose-PTS was shown to be the high-affinity system. Glucose uptake by the mutant was unaffected by 8 mM sodium arsenate, 10 mM azide, and 10 mM dinitrophenol but was completely inhibited by 0.05 mM sodium iodoacetate. Glycolysis in the organism was almost completely inhibited by 0.25 mM
N
′,
N
′ -dicyclohexylcarbodiimide (DCCD), indicating the involvement of an ATPase in glucose uptake. The ionophores carbonylcyanide-
m
-chlorophenylhydrazone and tetrachlorosali-cylanilide were inhibitory at concentrations of 10 μM, suggesting that a proton gradient was important in the transport process. Higher levels of DCCD and the ionophores were required to inhibit the wild-type organism to the same degree. A mechanism is proposed for the alternative transport system whereby proton motive force is created by the extrusion of protons by the DCCD-sensitive ATPase and glucose is transported down a proton gradient in a symport with protons.
Increase of mouse resistance to Candida albicans infection by thymosin alpha 1
Authors: Bistoni F , Marconi P , Frati L , Bonmassar E , Garaci E
Published: January 2020

Studies were carried out to assess the ability of thymosin alpha 1 to prolong the survival of mice challenged with Candida albicans. Two- to four-month-old mice were treated with graded doses of thymosin alpha 1 before, after, or before and after intravenous challenge with C. albicans. Significant resistance ot lethal infection was afforded by 100 micrograms of thymosin alpha 1 per kg given before or before and after challenge, whereas no protection was found in mice treated with thymosin alpha 1 administered at any dose level after inoculation. Pretreatment with thymosin alpha 1 also prevented the increased susceptibility to C. albicans infection of mice pretreated with cyclophosphamide on day -6. The results showed that thymosin alpha 1 was capable of protecting untreated or cyclophosphamide-pretreated mice from C. albicans infection at an optimal dose and schedule of administration.
Transovarian passage, visceral distribution, and pathogenicity of salmonella in snakes
Authors: Chiodini R J
Published: January 2020

Transovarian passage of salmonella was evaluated in snakes by cesarean delivery and subsequent bacteriological examination of fetuses. In all cases, the same Salmonella serotype was isolated from the feces of gravid females and their fetuses. The visceral distribution of salmonella in normal snakes was found to involve almost all visceral organs. Of nonenteric organs examined, salmonella was recovered most often from the livers and ureters. Experimental infections with Salmonella typhimurium and Salmonella arizonae were established by oral, intracardial, and intracoelomic routes. Animals infected orally shed the organism in feces, but did not develop humoral antibodies or any detectable adverse effect. Animals injected by the intracardiac and intracoelomic routes developed antibody titers of 1:256 to the respective salmonella serotypes, but remained normal throughout the experiment. On the basis of results, salmonella was regarded as an opportunistic organism in reptiles.
Cross-protection against fecal excretion of Yersinia enterocolitica and Yersinia pseudotuberculosis in mice by oral vaccination of viable cells
Authors: Uchida I , Kaneko K , Hashimoto N
Published: January 2020

Mice given orally either the O3, O9, or O5B serovar of Yersinia enterocolitica showed protection upon subsequent oral challenge with another of these strains. Excretion of serovar O3 in the feces was inhibited in mice surviving oral challenge with Yersinia pseudotuberculosis IVA. Cross-reaction of O antigen among these four strains was 32 or more times lower than the homologous titers.
Genital antibody response to a parenteral gonococcal pilus vaccine
Authors: McChesney D , Tramont E C , Boslego J W , Ciak J , Sadoff J , Brinton C C
Published: January 2020

A parenteral gonococcal pilus vaccine which has previously been shown to be safe and antigenic also results in the production of specific local genital antibody. All three major antibody classes were present in the local secretions, but immunoglobulin A predominated, a portion of which is dimeric 11S immunoglobulin A. This mucosal antibody is also capable of blocking the attachment of gonococci to epithelial cells. The antibody cross-reacted with five heterologous pili in a solid-phase radioimmunoassay. These results are encouraging and suggest that a gonococcal pilus vaccine may be efficacious in preventing gonorrhea.
Electrophoretic analysis of polypeptides immune precipitated from cytomegalovirus-infected cell extracts by human sera
Authors: Pereira L , Hoffman M , Cremer N
Published: January 2020

Serodiagnosis of cytomegalovirus (CMV) infection by complement fixation tests depends on showing a fourfold rise in antibody titer from acute- to convalescent-phase sera. Freeze-thaw and glycine-extracted, infected cell culture antigens used for these tests give markedly different titers in reactions with the same sera. In this study, we characterized the CMV-infected cell polypeptides contained in freeze-thaw and glycine-extracted antigens and identified the proteins precipitated by 23 pairs of human acute and convalescent sera. Our results were as follows. First, freeze-thaw and glycine-extracted antigens prepared from infected cells radiolabeled with [35S]methionine and subjected to electrophoresis in sodium dodecyl sulfate-polyacrylamide gels yielded similar patterns, and the bulk of the label was contained in late structural proteins and glycoproteins. Glycine-extracted preparations contained a greater proportion of soluble 66,000- and 50,000-molecular-weight proteins than did freeze-thaw antigens. Second, convalescent sera precipitated proteins migrating with apparent molecular weights of 150,000, 130,000, 110,000, 96,000, 74,000, 66,000, 50,000, 34,000, 32,000, and 25,000. Of these the 130,000-, 110,000-, 96,000-, 66,000-, 50,000-, and 25,000-molecular-weight proteins comigrated with glucosamine-labeled polypeptides. Both immunoglobulin G and M antibodies in human sera precipitated these proteins from CMV-infected cell preparations. Implications of the results for serodiagnosis of CMV infections are discussed.
Serology of Neisseria gonorrhoeae: coagglutination serogroups WI and WII/III correspond to different outer membrane protein I molecules
Authors: Sandstrom E G , Chen K C , Buchanan T M
Published: January 2020

The 125I-labeled tryptic peptides of the outer membrane protein I of 33 previously characterized serological reference strains of Neisseria gonorrhoeae were investigated by peptide maps in relation to their coagglutination W serogroup. Serogroup WI strains tended to have lower-molecular-weight protein I molecules than did WII strains, and WIII strains had the highest-molecular-weight protein I molecules, although the serogroup could not be predicted from the molecular weights of the protein I molecules for a given strain. All 13 strains belonging to serogroup WI were found to have 11 peptides in common, as judged by their migration with respect to one another and to the internal marker valine in the peptide maps. Common peptides isolated from a given strain were found to comigrate with the corresponding common peptides from other strains in the same serogroup under various electrophoretic conditions. The 20 strains belonging to serogroups WII and WIII were all found to have 10 common peptides by the same criteria. When common peptides from serogroup WI were compared with the common peptides of serogroups WII and WIII, only three of these peptides appeared to be similar. Thus, two different outer membrane protein I molecules seem to exist which are mutually exclusive. Protein IA molecules contain the antigens recognized as serogroup WI, and protein IB molecules contain the antigens that characterize serogroups WII and WIII.
Genetic control of cell-mediated immunity in rats: involvement of RT1.B locus determinants in the proliferative response of T lymphocytes to Listeria antigens
Authors: Jungi T W , Jungi R
Published: January 2020

The cellular requirements for Listeria monocytogenes antigen-induced, specific [3H]thymidine incorporation into lymphoid cells were analysed. Nylon-nonadherent lymph node and peritoneal exudate cells from infected athymic rats and mice failed to respond by proliferation, whereas control cells of thymus-bearing animals gave significant responses. In mice, cells expressing Thy-1 at a high density were required for the initiation of the proliferative response, but cells with lower density also participated in proliferation. Immune T cells alone failed to respond to L. monocytogenes antigen, but the addition of accessory cells provided optimal responses. These were nylon wool adherent, absent from thoracic duct lymph, but present in thymus and lymph nodes and particularly abundant in spleens of nonimmune rats. Accessory cells had to be matched at the B region of RT1, the major histocompatibility complex, to provide a stimulatory signal for L. monocytogenes antigen-specific T cells. Thus, the genetic restriction criteria were the same as for the transfer of delayed-type hypersensitivity to L. monocytogenes antigen, but differed from those controlling the transfer of acquired cellular resistance. The interaction between T cells and accessory cells could be blocked by alloantisera directed against Ia-antigens expressed on the accessory cell population. The study suggests that killed L. monocytogenes bacteria are presented by Ia-positive adherent cells in a RT1.B-restricted fashion to provide a proliferative signal for sensitized T cells.
Alterations of mitochondrial metabolism and protein concentrations in subacute septicemia
Authors: Tavakoli H , Mela L
Published: January 2020

Male Sprague-Dawley rats were made septic by cecal ligation for a period of 6 days. Sham-operated rats were used as control animals. Septic rats developed gram-negative bacteremia within 18 to 24 h. Blood cultures were positive for Escherichia coli, Proteus spp., and Klebsiella spp. in all cases. Significant loss of body weight was observed in septic rats during the 6-day period, whereas control rats exhibited a steady gain in body weight after the second postoperative day. Liver and muscle mitochondria were isolated and analyzed 6 days after the operation in control and septic rats. Liver mitochondrial cytochrome a(a3), b, and c concentrations were normal in septic rats. Oxygen utilization rates in state 3 (during ATP synthesis) were also within the normal range. State 4 respiratory rates, however, were increased with glutamate and pyruvate as substrates, resulting in low respiratory control ratios in septic rats. Muscle mitochondria from septic rats exhibited several abnormalities: the yield of cytochromes b, c, and a(a3) per gram of tissue was 34% below normal in septic rats. ATP synthesis rates declined significantly with pyruvate as substrate. Respiratory control ratios were below normal with all substrates studied except glutamate. These data are in agreement with previous reports on loss of muscle proteins and abnormalities in energy fuel utilization in septic patients.
Antibody-dependent cell-mediated cytotoxicity against varicella-zoster virus-infected targets
Authors: Kamiya H , Starr S E , Arbeter A M , Plotkin S A
Published: January 2020

Antibody-dependent cell-mediated cytotoxicity (ADCC) against cryopreserved varicella-zoster virus-infected human foreskin fibroblasts was detected in a 51Cr release assay. Target cells, samples of seropositive or seronegative sera, and mononuclear cells obtained by Ficoll-Hypaque centrifugation of human peripheral blood were added to microtiter plate wells and allowed to incubate at 37 degrees C for 4 h. Fibroblasts infected for 48 to 96 h were susceptible to ADCC. Effector cells from seropositive and seronegative normal children were equally active in the assay. Antibody titers were determined by testing serial dilutions of sera in the ADCC assay. Zoster immune globulin had a titer of 204,800. Sera from 40 naturally seropositive individuals were compared by assays for ADCC and fluorescent antibody to membrane antigen. All sera that were negative by fluorescent antibody to membrane antigen (less than 2) were also negative by ADCC (less than 20). All sera that were positive by fluorescent antibody to membrane antigen were also positive by ADCC, but titers of individual sera were frequently 5 to 20 times higher in the ADCC assay.
Cell-Mediated Cytotoxicity Toward Measles Virus-Infected Target Cells in Randomly Bred Syrian Hamsters
Authors: Cremer Natalie E. , O'Keefe Beatrice , Hagens Shirley J. , Diggs Janice
Published: January 2020

Cell-mediated cytotoxicity (CMC) toward measles virus-infected cells was studied by a
51
Cr release assay with spleen cells from hamsters inoculated with measles virus (strain Lec) or control antigen and with spleen cells from normal hamsters. Spleen cells from measles virus-inoculated hamsters showed greater CMC toward infected than toward noninfected target cells (designated specific CMC). Specific CMC was maximal 7 days after virus inoculation and was declining by 9 to 10 days. Effector cells were present in a nonadherent cell population. Specific CMC was reduced after treatments of effector cells with antithymocyte serum plus complement. The decrease in cytotoxicity was greater toward infected target cells than toward noninfected target cells. Treatment of infected target cells with antimeasles serum did not increase specific CMC by effector cells from the majority of virus-inoculated hamsters. CMC toward infected target cells by normal spleen cells (natural killer cells) or spleen cells from hamsters inoculated with control antigen was approximately the same as, or more often less than, CMC toward noninfected target cells. Natural killer cells were present in a nonadherent cell population. Treatment of natural killer cells with antithymocyte serum plus complement caused a similar decrease in cytotoxicity toward both infected and noninfected target cells. This study demonstrated virus-specific cellular cytotoxicity of effector spleen cells from measles virus-inoculated hamsters. Although the data were compatible with T cells as the source of effector cells in the virus-specific CMC, definitive identification could not be made. Additional membrane markers for better characterization of hamster lymphocyte subpopulations are required.
Sensitization or tolerance to Mycobacterium leprae antigen by route of injection
Authors: Shepard C C , Walker L L , Van Landingham R M , Ye S Z
Published: January 2020

Aqueous suspensions of heat-killed Mycobacterium leprae in a dose of 10(7) organisms were highly immunogenic when injected intradermally (i.d.). The same dose of bacteria did not sensitize when given intraperitoneally (i.p.) or intravenously (i.v.), and did so only minimally at best when given subcutaneously. The i.d. route was the most immunogenic for sheep erythrocytes also. M. leprae injected i.p. or i.v. stimulated immune tolerance to M. leprae challenge i.d. In older mice (greater than or equal to 8 weeks), the i.v. injections gave more complete tolerance. Mice that had been rendered tolerant by i.v. injections maintained their tolerance for at least 168 days. Prior UV irradiation of intact mice prevented sensitization by the i.d. route. In normal mice, living M. bovis BCG given i.d. produced good sensitization to M. leprae. Mice that had been made tolerant by i.v. injection of M. leprae could be partially sensitized to M. leprae by i.d. immunization with BCG; mixtures of living BCG and heat-killed M. leprae were no more effective than BCG alone. These findings appear to have relevance to the pathogenesis of lepromatous leprosy and its immunoprophylaxis.
Mechanism of depletion of T lymphocytes from the spleen of mice infected with Listeria monocytogenes
Authors: Chan Y Y , Cheers C
Published: January 2020

Marked changes in the splenic lymphocyte populations during murine infection with Listeria monocytogenes were observed histologically and quantitated by the immunofluorescence of Thy-1+ immunoglobulin (Ig-) (T) and Ig+ (B) cells. Cells were depleted from the T-dependent areas of the spleen, and the number of T cells in suspensions prepared from spleens of mice 1 to 3 days after primary or secondary infection were less than 1/10 of normal. High numbers of alcohol-killed Listeria sp. did not cause any depletion. Depletion was not prevented by adrenalectomy. Although injected radiolabeled T cells distributed normally between spleen, liver, lymph node, and gut in infected mice, there appeared to be a barrier to their entry into depleted T-dependent areas of the spleen. Evidence for the destruction of T cells, but not of B cells, in the infected mouse spleen was obtained.
Ultrastructure of the invasion of human hair in vitro by the keratinophilic fungus Microsporum gypseum
Authors: Kanbe T , Tanaka K
Published: January 2020

The pattern of invasion of human hair in vitro by the dermatophyte Microsporum gypseum was studied by transmission and scanning electron microscopy. Mycelia that invaded the hair cortex through the edge of cuticles showed a flattened "frond" growth in contrast to the filamentous form seen on ordinary laboratory media. The frond cells were characterized by the presence of vesicles formed by invaginations of plasmalemma, and lomasomes were prominent in the region adjacent to the hard keratinized tissue of the hair cortex being degraded as well. The initial perforating organ, which originated from the frond mycelium, appeared as an enlarged spherical cell which integrated with the laterally branched hyphae, as revealed by analysis of a three-dimensional model reconstructed from a series of sections. The fully developed perforating organ consisted of a column of wide and short cells which penetrated perpendicularly through the hair cortex. Through the medulla the filamentous hyphae had grown profusely in a longitudinal direction. Our studies confirm earlier light microscope observations and provide new ultrastructural details on the development of the eroding frond and the perforating organ.
Three human rotavirus serotypes demonstrated by plaque neutralization of isolated strains
Authors: Urasawa S , Urasawa T , Taniguchi K
Published: January 2020

Human rotaviruses were isolated directly from stool specimens of gastroenteritis patients in MA-104 cells in the presence of trypsin. For the plaque assay of the isolated strains, the optimal composition of overlay medium was determined. The antigenicity of the isolated strains was investigated by a plaque neutralization method, using antisera prepared against six strains having different electropherotypes of viral RNA, and three different neutralization serotypes were demonstrated.
Enhanced saliva-mediated bacterial aggregation and decreased bacterial adhesion in caries-resistant versus caries-susceptible individuals
Authors: Rosan B , Appelbaum B , Golub E , Malamud D , Mandel I D
Published: January 2020

A study of saliva-mediated aggregation and adhesion has been carried out in a group of caries-resistant (CR) and caries-susceptible (CS) individuals. The submandibular saliva of the CS group had a much greater potency, as determined by dilution, in promoting adherence to hydroxyapatite beads than did the saliva of CR group. In contrast, the CR group demonstrated a twofold enhancement of saliva-mediated aggregation compared with the CS group. These observations support the hypothesis that saliva-mediated aggregation and adherence are important factors in caries resistance.
Localization of distinct surface antigens on Chlamydia trachomatis HAR-13 by immune electron microscopy with monoclonal antibodies
Authors: Clark R B , Nachamkin I , Schatzki P F , Dalton H P
Published: January 2020

Monoclonal antibodies were produced against the HAR-13 strain (A) of Chlamydia trachomatis. By an indirect immunofluorescence technique, three clones (1-7, 2-8, 9F) were found to produce antibody that reacted only with serotype A strains. Clone 3-5 produced antibody that cross-reacted with serotypes A, C, H, I, and J. Using an indirect immunoferritin technique, we examined the binding of these antibodies to strain HAR-13 by electron microscopy. Antibodies from all four clones were shown to bind to the outer membrane surface of both reticulate and elementary bodies. Two distinct binding patterns were demonstrated. Antibodies from clones 1-7 and 9F bound to the outer membrane surface in a homogeneous pattern, whereas antibodies 2-8 and 3-5 bound to the outer membrane surface in an irregular, patchy distribution. There was a direct correlation between the distribution of antigen on the outer membrane surface and neutralization of C. trachomatis HAR-13 infectivity in vitro. Neutralization of HAR-13 infectivity by antibodies 1-7 and 9F was complement dependent, whereas antibodies 2-8 and 3-5 did not neutralize under any conditions.
Effects of a phagocytosis-stimulating factor on the phagocytic process of polymorphonuclear neutrophils
Authors: Ishibashi Y , Yamashita T
Published: January 2020

The effect of phagocytosis-stimulating factor (PSF) on phagocytosis was studied in detail. PSF did not affect the Fc receptor-mediated phagocytosis, whereas PSF enhanced the ingestion step, but not attachment step, of C3b receptor-mediated phagocytosis by polymorphonuclear neutrophils (PMNs), suggesting that PSF may specifically modulate the C3b receptor function of PMNs. PSF generated from guinea pig PMNs enhanced phagocytosis by rabbit PMNs, and rabbit PMN-produced PSF accelerated the phagocytosis by guinea pig PMNs, indicating that PSF is not specific for animal species. The effects of PSF on some PMN functions, such as O2- generation, chemotaxis, adherence, and enzyme release, were also studied. Only O2- generation from PMNs was significantly increased in the initial phase of phagocytosis, and this stimulation of O2- generation was completely parallel with the stimulation of phagocytosis by PSF. Resting PMNs hardly generated the superoxide anions by PSF treatment, suggesting that PSF does not affect the O2- forming system directly.
Polyclonal B cell activation in hamsters infected with parasites of the genus Leishmania
Authors: Campos-Neto A , Bunn-Moreno M M
Published: January 2020

Mesocricetus auratus (golden hamsters) infected with leishmania developed characteristic B cell immune responses that depended on the infecting species of leishmania. Thus, hamsters infected with viscerotropic leishmania (Leishmania donovani) developed antileishmania antibodies and hypergammaglobulinemia due to polyclonal activation of B cells as measured by reverse hemolytic plaque assay. In contrast, dermotropic leishmanias (L. braziliensis braziliensis and L. mexicana amazonensis) stimulated antileishmania antibodies with no increase in either serum immunoglobulin concentration or in the number of antibody-forming cells per spleen. The dermotropic leishmanias were unable to stimulate polyclonal activation even in hamsters in which visceralization had occurred with high splenic parasitization. These findings suggest that species-specific leishmania antigens (or factors) might be the modulators of the altered immune response present in these diseases.
Inhibition of fibroblast proliferation by Actinobacillus actinomycetemcomitans
Authors: Shenker B J , Kushner M E , Tsai C C
Published: January 2020

We have examined soluble sonic extracts of Actinobacillus actinomycetemcomitans for their ability to alter human and murine fibroblast proliferation. We found that extracts of all A. actinomycetemcomitans strains examined (both leukotoxic and nonleukotoxic) caused a dose-dependent inhibition of both murine and human fibroblast proliferation as assessed by DNA synthesis ([3H]thymidine incorporation). Addition of sonic extract simultaneously with [3H]thymidine had no effect on incorporation, indicating that suppression was not due to the presence of excessive amounts of cold thymidine. Inhibition of DNA synthesis was also paralleled by decreased RNA synthesis ([3H]uridine incorporation) and by a decrease in cell growth as assessed by direct cell counts; there was no effect on cell viability. The suppressive factor(s) is heat labile; preliminary purification and characterization studies indicate that it is a distinct and separate moiety from other A. actinomycetemcomitans mediators previously reported, including leukotoxin, immune suppressive factor, and endotoxin. Although it is not clear how A. actinomycetemcomitans acts to cause disease, we propose that one aspect of the pathogenicity of this organism rests in its ability to inhibit fibroblast growth, which in turn could contribute to the collagen loss associated with certain forms of periodontal disease, in particular juvenile periodontitis.
Cytomegalovirus-infected cell polypeptides immune-precipitated by sera from children with congenital and perinatal infections
Authors: Pereira L , Stagno S , Hoffman M , Volanakis J E
Published: January 2020

Congenital or perinatally acquired human cytomegalovirus (CMV) infections in children may be symptomatic or asymptomatic. In this study, we characterized the electrophoretic properties of CMV-infected cell polypeptides immune-precipitated by sera from children with different types of CMV infections from birth to 4 years of age. Sodium dodecyl sulfate-polyacrylamide gel analysis of immune precipitates formed with radiolabeled extracts of cells infected with CMV strain AD169 showed the following. (i) Electrophoretic profiles of CMV polypeptides immune-precipitated by sera from children with perinatal and congenital infections were similar. At least 11 polypeptides with apparent molecular weights of 150,000, 140,000, 110,000, 100,000, 74,000, 66,000, 50,000, 49,000, 34,000, 25,000, and 20,000 were precipitated. Antibody titer in anticomplement immunofluorescence tests and virus titer in urine correlated with the intensity of polypeptide profiles in autoradiograms. (ii) The initial immune response of children with symptomatic congenital infections was delayed as compared to that of children with asymptomatic congenital and perinatal CMV infections. Sera obtained serially from symptomatic children for years after birth continued to precipitate CMV polypeptides, whereas sera from children with subclinical congenital infections precipitated lesser amounts over time. (iii) Immune precipitates obtained with sera from CMV-infected patients and with monoclonal antibodies to CMV contained polypeptides with comparable electrophoretic and immunological properties.
Deficit of interleukin 2 production associated with impaired T-cell proliferative responses in Mycobacterium lepraemurium infection
Authors: Hoffenbach A , Lagrange P H , Bach M A
Published: January 2020

C57BL/6 and BALB/c mice were infected intravenously with 10(7) Mycobacterium lepraemurium (MLM). At various times after infection, spleen cells were tested for their capacity to proliferate in vitro in response to concanavalin A (ConA) and to allogeneic cells. The generation of alloreactive cytotoxic T lymphocytes was also studied. The mitogen- and allogeneic-cell-induced blastogenesis of splenocytes from MLM-infected C57BL/6 and BALB/c mice was shown to be depressed during infection. The maximal decrease occurred 6 months after infection. Conversely, no reduction in the ability to generate alloreactive cytotoxic T lymphocytes was observed even after 6 months of infection. At the same time, interleukin 2 (IL2) activity generated by ConA stimulation of infected splenocytes was measured in both strains. IL2 activity in the ConA-stimulated culture supernatants was decreased as early as 1 month after MLM inoculation as compared with supernatants from age-matched control mice. Thus, IL2 production by infected-mouse spleen cells was shown to decline earlier than their proliferative responses to ConA and to allogeneic cells. ConA-induced T-cell blasts from infected mice showed a reduced ability to proliferate when incubated with an IL2-containing reference supernatant from ConA-stimulated normal spleen cells. These data suggest that a defect in IL2 production and utilization might contribute to the impairment of T cell-mediated immunity observed in MLM-infected mice.
Evaluation of Pseudomonas aeruginosa exotoxin A and elastase as virulence factors in acute lung infection
Authors: Blackwood L L , Stone R M , Iglewski B H , Pennington J E
Published: January 2020

Acute Pseudomonas aeruginosa pneumonia was established in guinea pigs by intratracheal instillation of bacteria. Challenge strains included PAO-1, a strain known to produce exotoxin A, alkaline protease, and elastase, and several PAO-1 mutants deficient in either biologically active exotoxin A or elastase production. Survival, intrapulmonary killing of bacteria, and blood cultures were compared among the groups. Strains of P. aeruginosa deficient in active elastase production appeared to be less virulent than the parent strain and were more easily cleared from the lung. Opposite results were obtained for the exotoxin A-deficient mutants. These data suggest that elastase, but not exotoxin A, was an important virulence factor during acute pneumonia due to P. aeruginosa.
Antibody Responses to
Haemophilus influenzae
Type b and Diphtheria Toxin Induced by Conjugates of Oligosaccharides of the Type b Capsule with the Nontoxic Protein CRM
197
Authors: Anderson Porter
Published: January 2020

Oligosaccharides were made from
Haemophilus influenzae
type b capsular polysaccharide and conjugated to CRM
197
by reductive amination. Conjugates were made with a range of lengths and multiplicities of saccharide chains. All elicited a strongly enhanced anti-
H. influenzae
type b capsular polysaccharide response when injected into weanling rabbits. One series of conjugates also elicited antibodies to diphtheria toxin.
Cell-mediated immunity against herpes simplex virus envelope, capsid, excreted, and crude antigens
Authors: Kalimo K O , Joronen I A , Havu V K
Published: January 2020

Cell-mediated immunity to herpes simplex virus envelope, capsid, excreted, and crude antigens was studied by in vitro lymphocyte stimulation tests during 198 recurrent attacks in 69 patients. Excreted antigen caused no blast transformation. Envelope and capsid antigen-induced lymphocyte stimulation was at the maximum 7 to 14 days postinfection, declining thereafter to a rather constant level in 1 to 2 months. The lowest levels were measured just a few days before a new attack. In persons with frequent relapses, the fluctuation was more rapid and stimulation index levels stayed higher, although no protective level seemed to exist. Cultures stimulated with the crude antigen in autologous serum showed rapid increases and declines in the stimulation index values, contrary to those grown in agamma serum, in which the stimulation level stayed rather constant up to 1 year postinfection.
Identification and characterization of the major cell envelope proteins of oral strains of Actinobacillus actinomycetemcomitans
Authors: Di Rienzo J M , Spieler E L
Published: January 2020

The major cell envelope protein compositions of seven Actinobacillus actinomycetemcomitans strains of human origin were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The major envelope polypeptides were homogeneous, in relation to molecular weight, in all of the strains that were examined. The characterization of the five major proteins, designated Env1 through Env5, in the leukotoxic strain Y4 revealed that proteins Env2 to -5 may reside in the outer membrane as suggested by differential detergent extractions and 125I-labeling experiments. The proteins did not demonstrate covalent or ionic interactions with the peptidoglycan; however, one protein, Env2, displayed heat-modifiable properties, having apparent molecular weights of 32,000 and 45,000 when heated in sodium dodecyl sulfate at 50 and 100 degrees C, respectively. The protein composition of the extracellular "bleb" material, normally released by strain Y4, was determined, and proteins Env1 to -4 were the predominant protein species found. A comparison of the cell envelope proteins of strain Y4 with those of other members of the human oral flora, including species within the genera Capnocytophaga, Bacteroides, and Fusobacterium, revealed distinct differences on the basis of molecular size and heat-modifiable properties. However, the membrane proteins of Haemophilus aphrophilus showed a remarkable degree of homology with those of A. actinomycetemcomitans.
Hyperthermic enhancement of serum antimicrobial activity: mechanism by which fever might exert a beneficial effect on the outcome of gram-negative sepsis
Authors: Mackowiak P A , Marling-Cason M
Published: January 2020

We have previously demonstrated heightened antibiotic activity at temperatures at the upper end of the physiological range. In the present studies we examined the effect of physiological variations in temperature on the antibacterial activity of antibiotic-free pooled human serum by comparing serum minimal inhibitory and bactericidal titers for gram-positive and gram-negative bacterial strains at 33, 37, and 41 degrees C. We observed a progressive rise in both minimal inhibitory and minimal bactericidal titers with temperature for all classes of gram-negative bacilli studied. However, gram-positive cocci were generally resistant to serum, even at the highest experimental temperature. Bacterial strains adapted to growth at temperatures normally encountered on body surfaces were more susceptible to the enhancing effect of hyperthermia on serum inhibition than were strains adapted to 37 degrees C. In addition, in vitro adaptation of one bacterial strain to different temperatures within the physiological range resulted in readily apparent variations in colonial morphology. These in vitro observations indicate that serum antibacterial activity and bacterial morphology may vary in response to minor changes in either the temperature to which bacteria are adapted before examination or the temperature of the assay system. If similar principles operate in vivo, hyperthermically augmented serum antimicrobial activity might represent one mechanism by which fever exerts a beneficial effect on the outcome of gram-negative sepsis.
Histopathological study of protective immunity against murine salmonellosis induced by killed vaccine
Authors: Nakoneczna I , Hsu H S
Published: January 2020

Swiss-Webster mice were vaccinated with heat-killed salmonellae and then were infected with virulent Salmonella typhimurium. Only 1 of the 18 vaccinated mice died from a challenge of 10(4) X the 50% lethal dose, and about 70% of them survived a challenge of 10(5) X the 50% lethal dose. Histopathological examinations of the lesions developed in these vaccinated mice showed that they followed the characteristic features of a primary lesion in murine salmonellosis. There was an early necrosis with infiltration of polymorphonuclear leukocytes and abscess formation within the first 6 to 7 days after infection. However, these abscesses remained small and discrete. By days 7 to 10, the lesions began to transform into granulomas, first with the appearance of peripheral mononuclear cells and then by the replacement of polymorphs. By the third week of the infection, minute and discrete granulomas were seen scattered in the spleen, liver, and lymph nodes. Beyond this stage, healing and tissue regeneration followed. Thus, the characteristics of infectious lesions developed in mice vaccinated with heat-killed salmonellae are distinctly different from those developed in mice protected by the avirulent vaccine.
Coccidioides immitis
Vaccine: Potential of an Alkali-Soluble, Water-Soluble Cell Wall Antigen
Authors: Lecara Grace , Cox Rebecca A. , Simpson Russell B.
Published: January 2020

C-ASWS-M, the alkali-soluble, water-soluble cell wall antigen of
Coccidioides immitis
mycelia, was evaluated for its vaccine potential in mice. Vaccination with 0.5-, 1.5-, or 3-mg doses of C-ASWS-M in complete Freund adjuvant provided a significant level of protection against intraperitoneal challenge with 1,500 arthroconidia (
P
< 0.0001 with each dose). Vaccination with 1 mg of C-ASWS-M protected mice against intranasal challenge with 50 (
P
< 0.05) and 500 (
P
< 0.01) arthroconidia, but not against intranasal challenge with 1,500 arthroconidia (
P
> 0.05).
Laboratory and Wild-Type
Klebsiella pneumoniae
Strains Carrying Mannose-Inhibitable Adhesins and Receptors for Coliphages T3 and T7 Are More Pathogenic for Mice Than Are Strains Without Such Receptors
Authors: Pruzzo Carla , Valisena Sebastiano , Satta Giuseppe
Published: January 2020

We have shown previously that
Klebsiella pneumoniae
receptors for coliphages T3 and T7 also mediate mannose-inhibitable adherence to human epithelial cells and protect bacteria from phagocytosis and intracellular killing by human polymorphonuclear cells. In this paper we analyze the possible role of such mannose-inhibitable adhesins and T3-T7 receptors (MIAT) in
K. pneumoniae
intraperitoneal pathogenicity for mice. We showed that intraperitoneal pathogenicity for mice of four different
Klebsiella
strains (one laboratory and three wild-type) that carry the MIAT was approximately 60-fold higher than that of four derivative strains that lost such receptors by spontaneous mutation. The MIAT could be repressed by
Klebsiella
phage AP3 lysogenic conversion. Two laboratory and two wild-type strains converted by phage AP3 were also approximately 60-fold less pathogenic for mice than parental strains and showed a pathogenicity level equal to that of the MIAT-negative mutants. Studies of protection in mice with anti-whole cell antisera showed that passive immunization against MIAT-positive cells was more protective than immunization against MIAT-negative cells. Studies of protection in mice by both active and passive immunization with lipopolysaccharide and purified outer membrane proteins have shown that the proteins are the most protective outer membrane components. Since it has been shown previously that the
Klebsiella
receptors for T3-T7 have a proteic component and that an outer membrane protein is missing in the strains resistant to T3-T7 (C. Pruzzo et al.,
in
R. C. Berkely (ed.),
Microbial Adhesion to Surfaces
, 1980); the latter finding further supports the role of MIAT in the pathogenicity of
Klebsiella
for mice.
Time course of antilisterial activity by immunologically activated murine peritoneal macrophages
Authors: Godfrey R W , Horton P G , Wilder M S
Published: January 2020

Murine peritoneal macrophages were rapidly rendered listericidal after exposure to lymphokine-rich supernatants (LRSs) derived from antigen-pulsed Listeria monocytogenes-immune spleen cells. A 6-h incubation period with LRSs was sufficient to induce microbicidal activity in resident macrophages. In vitro induction of macrophage listericidal activity by constant exposure to LRSs persisted for 18 h, after which time spleen cell factors were no longer capable of modifying intracellular inactivation of Listeria. Results obtained by utilizing a short assay indicated that the killing kinetics is extremely rapid, with large numbers of bacteria destroyed during the first 15 min of infection. Intracellular killing at this time appeared to be greatly dependent upon the stage of growth from which the microorganisms were harvested. Induction of bactericidal macrophages by infection of mice with a sublethal dose of virulent Listeria cells and subsequent intraperitoneal elicitation with heat-killed homologous bacteria was similarly a transient event. Macrophages harvested 18 h after antigenic challenge displayed dramatic antibacterial activity during the first 22 h in culture. After 22 h, activity was lost, and stasis was observed during the ensuing 23 h. At 68 h, macrophages were devoid of antilisterial action. Activity, however, could be recalled after incubation with LRSs.
Purification and immunochemical characterization of Streptococcus sanguis serotype I carbohydrate antigen
Authors: Okahashi N , Koga T , Akada H , Hamada S
Published: January 2020

The serotype-specific antigen of Streptococcus sanguis ST3 (serotype I, biotype A) was extracted, chromatographically purified, and characterized by immunological and chemical methods. The antigen was extracted from purified cell walls with hot trichloroacetic acid, followed by ion-exchange chromatography on a DEAE-Sephadex A-25 column and gel filtration through a Sephadex G-100 column. A peak fraction was obtained that gave a single precipitin band when reacted with anti-type I serum. The type I antigen was a polysaccharide composed of glucose, rhamnose, and N-acetylglucosamine in a molar ratio of 1.4:2.5:1.0. Quantitative precipitin inhibition tests with various haptenic sugars indicated that an alpha-glucosidic linkage is the immunodeterminant of the type I antigen.