bluuebunny/crossref_metadata_2025 huggingface dataset:
51Cr release microassay for measuring cell-mediated immunity in chickens
Authors: Radwan A I , Buening G M , Loan R W
Published: January 2020

A microcytotoxic assay, based on the release of 51Cr from chicken erythrocytes by sensitized chicken lymphoid cells in the presence of the specific antigen, purified protein derivative (PPD), is described. The percentage of antigen-specific lysis was dependent on the lymphoid cell concentration, antigen concentration, time of incubation, and incubation temperature. Maximum antigen-specific lysis of nonspecific target cells was induced with a spleen-to-target cell ratio of 100:1 and with a peripheral blood lymphoid-to-target cell ratio of 1,000:1 in the presence of 100 mug of PPD per ml over a 20-h incubation period. As the concentration of PPD was increased from 25 to 200 mug/ml the specific lysis that incubation for 20 h. Incubation at 41 C produced significantly higher (P smaller than 0.05) antigen-specific cytotoxicity than incubation at 37 C.
Immunosuppression by hydroxystilbamidine isethionate, a lysosome-stabilizing, anti-proteolytic, antifungal drug
Authors: Folds J D , Orlando G , Spitznagel J K
Published: January 2020

Hydroxystilbamidine (HSB) is a potent suppressor of the plaque-forming cell response of mice injected with heterologous erythrocytes. HSB, given in varying doses and injection schedules, suppressed both the primary and secondary immune responses to bovine serum albumin. Apparently the effect is not simply a toxic effect on spleen cells, because there was no appreciable difference in cell numbers between control and HSB-treated mice. The effect of HSB was most apparent in the early phase of the immune respone.
Cytotoxic effect of Mycoplasma fermentans on mouse thymocytes
Authors: Gabridge M G , Schneider P R
Published: January 2020

The in vitro response of mouse thymocytes to various mycoplasmas was evaluated. Cultures of thymus cells from BALB mice were prepared in Earle minimal essential medium with 10 per cent fetal calf serum. After an initial drop in viability, cell populations stabilized at approximately 10-5 viable cells/ml for 3 to 5 days. Concentration of 10-6 to 10-8 colony-forming units of toxic isolates of Mycoplasma fermentans per ml killed over 50 per cent of these cells in a dose-dependent fashion. Four other mycoplasmas (M. pneumoniae, M. hominis, M. arthritidis and a nontoxic strain of M. fermentans) did not induce cytotoxicity of mouse thymocytes. Toxic isolates of M. fermentans multiplied in the presence of thymus cells as they were being inactivated. However, nonviable membrane preparations of these mycoplasma were also toxic, indicating that growth of the organisms is not a prerequisite for the toxic effect. The relevance of these findings for the isolation and identification of the membrane-associated toxic factor is discussed.
Response of irradiated mice to live-virus (TC-83) immunization
Authors: Spertzel R O , Hilmas D E , Brown J R , Mason D W
Published: January 2020

Studies were conducted to determine the effects of sublethal, acute, total-body irradiation (600 R) on the immune response of mice to a replicating antigen. Irradiation was performed at varying times (0 to 21 days) prior to immunization with attenuated Venezuelan equine encephalomyelitis virus, TC-83. Development of protective immunity was studied by inoculating subgroups of irradiated mice with virulent Venezuelan equine encephalomyelitis virus on days 1 through 28 after immunization. Irradiation failed to affect the overt clinical response of mice inoculated with the attenuated strain, but antibody responses and the onset of protective immunity was delayed, particularly in mice irradiated 2 h to 3 days prior to vaccination. Immunity afforded by TC-83 developed more rapidly as the interval between irradiation and vaccination increased: when this interval was 14 or more days, the temporal course of immune response in irradiated mice was similar to that of nonirradiated vaccines. Persistence of TC-83 viremia was greatly prolonged in irradiated mice through the irradiation recovery period and probably provided the antigenic stimulus responsible for delayed development of effective immunity.
Quantification of mouse macrophage chemotaxis in vitro: role of C5 for the production of chemotactic activity
Authors: Snyderman R , Pike M C , McCarley D , Lang L
Published: January 2020

Delineation of the mechanisms of macrophage accumulation at local tissue sites will further our understanding of immunologically mediated host resistance to infectious and neoplastic diseases. Since mice are frequently used for the study of immune function, we developed a method for the quantification of mouse macrophage chemotaxis in vitro. By this method it was found that the fifth component of complement is necessary for the production of chemotactic activity in mouse serum by inflammatory agents such as endotoxin or aggregated gamma globulin. The majority of macrophage chemotactic activity produced by these agents in mouse serum can be attributed to a low-molecular-weight (ca. 15,000) chemotactic factor. The data suggest that this factor is the biologically active cleavage product of the fifth component of complement, C5a.
Characterization of Escherichia coli obtained from newborn calves with diarrhea
Authors: Myers L L
Published: January 2020

A total of 373 isolates of Escherichia coli were obtained from one or more calves with diarrhea in 155 herds during the 1974 calving season in Montana. Sixty-seven (18 percent) of the isolates representing 59 of the 155 herds were found to be enterotoxigenic as indicated by their ability to cause distention of the calf ligated intestinal segment. The 67 isolates of enterotoxigenic E. coli (ETEC) were placed in one of six different antigenic groups based upon agglutination of formolized whole cells in KO antiserum. Eighty-seven percent (58 of 67) of the ETEC had antigen 1, 2, or 3, whereas only 2.3 per cent (7 of 310) of the non-ETEC (NETEC) had antigen 1, 2, or 3. This antigen numbering system was used for convenience and is not related to any established typing system. Antigens 1, 2, and 3 do not belong to any of the O groups 1 to 157 or K groups 1 to 93 of the International Schema. Colony color or morphology of ETEC and NETEC grown on Tergitol-7 agar with triphenyltetrazolium chloride added could not be used as an indicator of enterotoxigenicity, although there was a tendency for E. coli with the smooth and mucoid colony type to be enterotoxigenic whereas rough colonies were seldom enterotoxigenic. Among ETEC isolates with antigen 1, 2, or 3, there was good correlation between colony type and antigen number. All 13 ETEC isolates with antigen 1 had the smooth colony type, 17 of 19 ETEC isolates with antigen 2 had the smooth, mucoid colony type, and all 25 isolates of ETEC with antigen 3 had the intermediate colony type. Conversely, of the 310 isolates of NETEC, none had antigen 1 and the smooth colony type; none had antigen 2 and the smooth and mucoid colony type; and only one isolate of NETEC had antigen 3 and the intermediate colony type. Sixteen of the 67 isolates of ETEC (24 percent) were motile. Fifteen of the 16 motile isolates of ETEC had the intermediate colony type, and none of the ETEC with smooth or smooth and mucoid colonies were motile.
Interactions between Mycoplasma pneumoniae and guinea pig complement
Authors: Bredt W , Bitter-Suermann D
Published: January 2020

The "toxic" effect of guinea pig serum (GPS) on Mycoplasma pneumoniae cells was tested under various conditions, using rounding and killing of the cells as test systems. Both activities could be inhibited by heat inactivation (56 C, 30 min). Killing required both Ca2+ and Mg2+, rounding only Mg2+. Both activities were temperature dependent and no rounding or killing occurred at 4C. Incomplete complement sequences with natural of artificial defects in C1, C4, or C6 resulted in lost or reduced killing. The rounding activity was only slightly affected. Anti-C3 antiserum blocked both phenomena; incubation of GPS with 10 mg of inulin per ml reduced the rounding activity, and the same treatment of GPS deficient in C4 inhibited rounding totally. Properdin factor D was shown to be necessary for rounding by GPS, with defects in either C1 or C4. By immune adherence bound C3b could be demonstrated on M. pneumoniae cells after GPS treatment, no antibodies against M. pneumoniae could be found in GPS by immune fluorescence. The results give evidence for complement being the toxic factor in GPS. Efficient killing requires the intact complement sequence. Furthermore, M. pneumoniae cells are able to activate the alternate pathway of complement. Activation of this pathway results in rounding of the cells, which are partly able to recover after this reaction. Biological consequences for the mycoplasmas are death or damage and possibly opsonization, even in the absence of specific antibodies. The host, too, is possibly affected by products of the reaction. The interaction of M. pneumoniae and complement could be involved in the early stages of the development of M. pneumoniae disease.
Defense mechanisms against infectious bovine rhinotracheitis virus: inhibition of virus infection by murine macrophages
Authors: Rouse B T , Babiuk L A
Published: January 2020

An in vitro method is described to measure the inhibitory activity of murine peritoneal exudate cells against viral plaque formation by a bovine herpes-virus-infectious bovin'e rhinotracheitis virus. Microtiter plates containing 96 bovine kidney cell monolayers were infected with a range of virus concentration and peritoneal exudate cells were subsequently added. When a sufficient number of cells was added, viral plaques were not detectable and free infectious virus did not occur in the culture fluids. The inhibitory cell type adhered to glass and was presumably a macrohage. Although inhibitory of viral plaques was presumably a macrophage. Although inhibition of viral plaques was complete and free virus could not be detected, virus was not eliminated from the monolayers since on removal of cells, the degree of virus cytopathology and yield of virus after a further 48 h of incubation was the same as in 48-h infected control monolayers. The significance of peritoneal exudate-cells-induced virus suppression as a model to understand herpesvirus latency is briefly discussed.?Author
Newly recognized distinctive M protein associated with certain M type 1 group A streptococci
Authors: Kholy A E , Guirguis N I , Wannamaker L W , Krause R M
Published: January 2020

Immunological and epidemiological characteristics of M1T1 and M1T8 (T8, 25, Imp.19) group A streptococci isolated in Egypt have been described. Both strains possess a common M1 antigen. The M1T8 strains possess a second antigen which has the immunological and biological characteristics of M protein. The M1T1 strains do not possess this second M antigen. Absorbed rabbit antisera which are specific for this second antigen do not react with extracts of any of the known M protein serotypes. This second antigen is therefore a newly recognized M protein. The M1T1 and M1T8 strains had mutually exclusive geographical and temporal distributions. This finding may have been a consequence of the immunity which occurred after the initial occurrence of the M1T8 strain.
Effect of immunosuppression on the genetic resistance of A2G mice to neurovirulent influenza virus
Authors: Fiske R A , Klein P A
Published: January 2020

A2G mice are genetically resistant to lethal infection with neurotropic and pneumotropic influenza viruses. A possible immunological explanation for this resistance was sought by assessing the effect of cyclophosphamide and X irradiation immunosuppression on the infection of A2G mice with lethal doses of neurovirulent virus. Immunosuppressed A2G mice survived lethal infection enen though rendered unable to produce specific antiviral antibody or to generate cell-mediated delayed-type hypersensitivity responses. Measurement of infectious virus replication and detailed observation of the infection by immunofluorescence microscopy show that immunosuppression does not potentiate or allow spread of the virus in A2G brains. Interferon levels were essentially the same in normal and immunosuppressed A2G brains but were 3 to 5 times lower than in the brains of susceptible mice dying of the infection. The results strongly suggest that the genetic resistance of A2G mice to the acute lethal effects of neurovirulent influenza virus infection does not depend on the induction of primary immune mechanisms as we currently understand them. Other possible explanations for this resistance are considered.
Changing agglutination activities of salivary immunoglobulin A preparations against oral streptococci
Authors: Bratthall D , Gibbons R J
Published: January 2020

Immunoglobulin A (IgA) was prepared from samples of parotid saliva collected from two individuals over a 150-day period. Standardized solutions of the IgA were tested for agglutinating antibody activity against strains of streptococcus salivarius, S. sanguis, S. mitis, and S. mutans that had been isolated from a homologous individual on day 30 and preserved in the lyophilized state. The agglutinating activity of the standardized IgA preparations against these strains was found to change over time, whereas the agglutination patterns of IgA prepared from saliva samples collected 3 days apart were generally similar. Differences in agglutination titers were also observed between IgA samples prepared from saliva collected on day 0 and day 150. The data indicate that the oral cavity may harbor streptococci of different antigenic composition representing the same species at a given time and that parotid IgA agglutinating antibody against these serotypes changes over time.
T lymphocyte function as the principal target of lymphocytic choriomeningitis virus-induced immunosuppression
Authors: Bro-Jorgensen K , Güttler F , Jorgensen P N , Volkert M
Published: January 2020

Plaque-forming cell responses against sheep erythrocytes, Escherichia coli lipopolysaccharide, pneumococcal polysaccharide, and polyvinylpyrrolidone were examined in mice infected with lymphocytic choriomeningitis virus. A 92 to 96 percent reduction of the thymus-dependent anti-sheep erythrocyte responses was observed 2 to 4 weeks after infection. However, the thymus-independent responses against the three other antigens were close to normal at all stages of the infetion. Studies on allograft immunity of infected C3H mice against DBA/2 mastocytoma cells revealed a severe suppression of the T cell-mediated cytotoxic response which was temporally related to the impaired humoral responsiveness against sheep erythrocytes. The capacity of spleen cells from infected mice to restore immune responsiveness of lethally irradiated recipients against sheep erythrocytes was significantly reduced. The adoptive responses, however, were clearly improved when normal thymus cells were added to the inferior spleen cells. Moreover, it appeared that the spleen cells from immunosuppressed donor mice could not confer suppression to normal lymphoid cells. The presented findings are consistent with the assumption that a numeric deficiency of T cells, or cells belonging to some T cell subpopulation, is the primary cause of lymphocytic choriomeningitis virus-induced immunosuppression.
Chemical modulation of diphtheria toxin action on cultured mammalian cells
Authors: Ivins B , Saelinger C B , Bonventre P F , Woscinski C
Published: January 2020

Ammonium chloride (4 times 10-3 M) rendered HEp-2 monolayers completely insensitive to the action of diphtheria toxin, as measured by de novo protein synthesis. Total protection was observed even with large amounts of toxin (400 minimum lethal doses/ml). Ammonium chloride did not reduce toxicity by direct action on the protein, nor did it prevent the adsorption of toxin to the cell membrane. Although the ammonium salt did not block the initial interaction between cell and toxin, it did maintain the toxin at a site amenable to neutralization with antitoxin. Surface-adsorbed toxin was inactivated by cellular enzymes or alternatively was desorbed from the membrane during a 12-h incubation in the presence of ammonium chloride. In addition, ammonium chloride provided protection to both toxin-sensitive guinea pig peritoneal macrophages and a partially toxin-resistant strain of HEp-2 cells. Sodium arsenite was effective in protecting cell monolayers from the action of diphtheria toxin; unlike ammonium chloride, its action was not dependent upon continued incubation with cells during exposure to toxin. Inhibitors of energy metabolism abolished toxin action either totally (sodium fluoride) or partially (dinitrophenol and sodium cyanide). Inhibitors of cellular proteases, on the other hand, did not modify toxin activity. The ability of several modifiers of membrane function to alter expression of toxicity for HEp-2 cells was also examined. One compound known to enhance endocytic activity, Tuftsin, had no effect, whereas poly-L-ornithine provided partial protection. Of the two compounds known to alter membrane fluidity, cytochalasin B provided partial protection for HEp-2 cell cultures, whereas colchicine had no effect. Agents that bind to sulfhydryl groups on the cell surface had no apparent effect on toxicity, suggesting that the initial toxin-cell interaction does not involve sulfhydryl groups. Those compounds that provide virtually full protection against the action of diphtheria toxic on cell monolayers (i.e., ammonium chloride, sodium fluoride, and sodium arsenite) had no inhibitory effect on the in vitro enzyme activity associated with fragment A of the toxin.
Effects of bile and gastrointestinal secretions on the infectivity of Newcastle disease virus
Authors: Lee J S , Hanson R P
Published: January 2020

Bile aspirated from chicken gall bladders was found to contain substances neutralizing Newcastle disease virus (NDV). Nonspecific factors were present in the bile, probably the bile acids, which caused a reduction in the infectivity of the virus. Specific anti-NDV activity was found in the bile of birds that had been vaccinated with a lentogenic strain, Ulster, and challenged with a velogenic, viscerotropic strain, California 1083. Immunoglobulins were also found in these secretions and demonstrated to include the immunoglobulin A class as well as immunoglobulin G. Variability in the neutralizing capacity of bile was found with two different plaque clones of strain 1083, indicating antigenic heterogeneity in the viral population. No difference was found between bile from uninfected birds and the bile from NDV-immune birds in their activities against influenza strain Turkey Ontario 7732, whereas activity existed against a non-viscerotropic strain of NDV, Texas GB. These findings suggest that the specific activity of the secretions was most probably due to the presence of secretory antibody. The importance of the antiviral substances present in the alimentary tract was discussed with respect to the protection of the chicken against the viscerotropic pathotype of NDV.
Multiple sclerosis-induced reduction in the yield of a mouse cell line
Authors: Carp R I , Licursi P C , Merz G S
Published: January 2020

Cultures of a mouse cell line (PAM) were treated with 71 multiple sclerosis (MS) and 45 non-MS samples. Of the cultures treated with MS material, 80 percent (58) showed a reduction in cell yield (compared to untreated controls) of at least 20 percent by the third passage after inoculation. The MS samples were from 40 MS cases, and a total of 36 cases yielded at least one positive sample. The agent responsible for the decrease was not limited to nervous tissue, but was also found in serum, cerebrospinal fluid, spleen, kidney, and lymph node of MS patients. Positive samples were present at every stage of the disease. None of the non-MS samples yielded cell counts significantly different from untreated controls. The non-MS category included 12 samples from healthy individuals, 13 assorted non-central nervous system disease samples, and the following central nervous system disease samples: six subacute sclerosing panencephalitis, three Huntington's chorea, two Parkinsonism, six amyotrophic lateral sclerosis, one stroke, one encephalopathy, and one epilepsy. Brain homogenates from mice inoculated with MS tissues elicited the decrease, whereas brain homogenates from mice inoculated with non-MS samples did not.
Effects of human and rabbit serum on viability, permeability, and envelope lipids of Serratia marcescens
Authors: Beckerdite-Quagliata S , Simberkoff M , Elsbach P
Published: January 2020

The major action of serum on gram-negative organisms is thought to be on the microbial envelope. We compared the effects of normal human and rabbit serum on the envelope lipids of two strains of Serratia marcescens, one sensitive and one resistant to the bactericidal effects of serum. During killing by either serum, the sensitive strain underwent rapid permeability changes coincident with degradation of microbial phospholipids. The resistant strain exhibited none of these effects. The phospholipid degradation that accompanies killing of the sensitive strain by serum could be caused by phospholipases present in serum or by Serratia's own phospholipid-splitting enzymes. The results indicate that phospholipid breakdown is caused by activation of bacterial of bacterial phospholipases and not by serum phospholipases. This conclusion is based upon the following findings.(i1 Although rabbit serum phospholipase A was at least 10 times more active than human serum phospholipase A, phospholipid degradation in the sensitive Serratia strain was comparable during (equally rapid) killing by human or rabbit serum. (ii) Heat treatment (56 C) of both sera eliminated bactericidal activity as well as microbial lipid degradation but abolished phospholipase activity of human serum only. (iii) Virtually complete removal of phospholipase A activity from human serum by adsorption onto autoclaved Micrococcus lysodeikticus had no effect on the extent of phospholipid hydrolysis or on bactericidal activity. Activation by serum of endogenous phospholipase activity in S. marcescens was accompanied by enhanced incorporation of lipid precursors into bacterial lipids. No evidence was found for increased turnover of protein or ribonucleic acid during killing by serum.
Partial purification and characterization of RTG-2 fish cell interferon
Authors: de Sena J , Rio G J
Published: January 2020

Interferon produced by rainbow trout gonadal cells (RTG-2) was partially purified. The physical, chemical, and biological properties of this in vitro produced fish cell interferon were studied. Purification was achieved by ultracentrifugation, molecular sieve gel chromatography, ion exchange chromatography, and polyacrylamide gel electrophoresis. The isoelectric point of RTG-2 interferon, as determined by CM-Sephadex (C-50) chromatography, was 7.1. Filtration through Sephadex G-150 showed that RTG-2 interferon had a molecular weight of 94,000. The partially purified material was not sedimented at 105,000 times g for 2 h at 4 C. The fish cell interferon was non-dialyzable and exhibited heat and pH stability. The partially purified material was inactivated by treatment with trypsin or 2-mercaptoethanol, but was resistant to treatment with deoxyribonuclease or ribonuclease. RTG-2 interferon which was induced by infectious pancreatic necrosis virus exhibited antiviral activity against challenge with infectious hematopoietic necrosis virus or infectious pancreatic necrosis virus. Partially purified RTG-2 interferon exhibited greater species specificity than the crude material.
Preparation and chemical composition of the cell walls of Streptococcus mutans
Authors: Cooper H R , Chorpenning F W , Rosen S
Published: January 2020

Purified cell walls from Streptococcus mutans strain BHT were prepared without the use of proteolytic enzymes in order to retain all cell wall constituents for chemical analysis. Of four methods employed, the Ribi cell fractionator produced disrupted cell suspensions which could be most thoroughly purified on sucrose gradients. Results of chemical analyses on purified cell walls prepared in this 8.9% glycerol teichoic acid, 33.6% non-peptidoglycan polysaccharide, and 49.9% peptidoglycan.
Biological properties of a canine distemper virus isolate associated with demyelinating encephalomyelitis
Authors: Confer A W , Kahn D E , Koestner A , Krakowka S
Published: January 2020

A canine distemper virus (CDV), DESIGNATED R252, originally recovered from a dog with demyelinating encephalomyelitis was shown to reproduce this disease in gnotobiotic dogs with a high incidence as compared to other CDV strains, which produced an acute fatal infection. In this investigation, R252 was propagated for the first time in Vero cells and compared to two known strains of CDV, Snyder-Hill (SH) and Onderstepoort (Ond). The results of this study revealed that intracellular R252 accumulated more slowly than either SH or Ond. There was extensive destruction of Vero monolayers infected with either R252 or SH. Each virus induced the formation of intracytoplasmic and intranuclear inclusions. Ond infection resulted in minimal cytopathic changes and intracytoplasmic inclusions. Immunofluorescence studies indicated that the spread of R252 infection within the monolayers was intermediate between the rapidly spreading SH and slowly spreading Ond. R252-infected cells developed characteristic immunofluorescent cytoplasmic inclusions. Initially, each stained homogeneously and later appeared as a non fluorescent body surrounded by a fluorescent ring. This characteristic pattern of fluorescence was observed only infrequently in thelate stage of SH infection and was absent in Ond-infected cultures. Reciprocal neutralization studies indicated that the three strains are of one serotype. These findings suggest that R252-CDV has biological properties which differ from two other strains of CDV and which may have bearing upon the in vivo capability of this virus to produce demyelinating encephalomyelitis.
Long-term Visna virus infection of sheep choroid plexus cells: initiation and preliminary characterization of the carrier cultures
Authors: Trowbridge R S
Published: January 2020

Two sheep choroid plexus cell cultures were maintained and propagated for 413 days since being infected with strain K796 visna virus. The majority of the cells in these cultures contained visna virus-specific antigen on days 93 and 105 after infection. Reverse transcriptase-like activity similar to that present in visna virus preparations was obtained from these cultures when very little plaque-forming virus was being synthesized. The persistently infected cultures are resistant to the cytopathic effect which occurs in uninfected cultures upon exposure to visna virus. Persistently infected cells require more time than uninfected cells to become confluent. Less than 0.02 percent of the persistently infected sheep choroid plexus cells form macroscopic colonies within 14 days, whereas 20 to 30 percent of the cells from uninfected cultures form macroscopic colonies within this time.
Effect of Body Fluids and Macromolecular Substances on the Lysis of Group A Streptococci by Muramidases of
Streptomyces albus
Authors: Ginsburg Isaac
Published: January 2020

The lysis of group A streptococci by muramidases of
Streptomyces albus
is strongly inhibited by human, rabbit, and calf serum as well as by human synovial fluids and pus. Rabbit antisera to heat-killed streptococci were no more inhibitory to the lysis of the streptococci by the lytic enzyme than normal rabbit serum. The results indicate that muramidases of
S. albus
will not be useful for the in vivo treatment of chronic granulomatous lesions which had been induced by insoluble cell wall components of streptococci.
Significane of intravascular coagulation in canine endotoxin shock
Authors: From A H , Spink W W , Knight D , Gewurz H
Published: January 2020

The contribution of disseminated fibrin clot formation to the pathogenesis of canine endotoxin shock was explored in control dogs and in those defibrinated with a purified fraction of Malayan pit viper venom. The hemodynamic and humoral responses after the administration of an intravenous challenge dose of Escherichia coli endotoxin were comparable as was mortality. It is concluded that, although the role of the coagulation sequence in canine endotoxin shock is unclear, it does not appear to be determinative.
Immunodepression by Rowson-Parr virus in mice: effect of Rowson-Parr virus and Friend leukemia complex infections on contact sensitivity in susceptible and resistant mice
Authors: Bendinelli M , Campa M , Toniolo A
Published: January 2020

Contact sensitivity to 2-phenyl-4-ethoxymethilene oxazolone, as a probe for cell-mediated immunity, was investigated in susceptible BALB/c and resistant C57BL/6 mice after infection with Friend leukemia complex (FLC) or with Rowson-Parr virus (RPV). In BALB/c mice, FLC depressed contact sensitivity when given before primary sensitization but had no effect on established contact sensitivity nor on the response elicited by a booster application of the sensitizer. These findings, together with the failure to alter reactivity to an aspecific inflammatory stimulus, indicate that FLC impairs the afferent limb of the response. In the same strain of mice RPV infection did not significantly depress contact sensitivity, as judged by the extent of the reaction 24 h after challenge, but slightly inhibited the early antibody-mediated phase of this reaction. In C57BL/6 mice neither viral preparation affected contact sensitivity.
Virion and soluble antigens of japanese encephalitis virus
Authors: Eckels K H , Hetrick F M , Russell P K
Published: January 2020

Japanese encephalitis virions contain a 58 X 10-3-molecular-weight envelope glycoprotein antigen that can be solubilized with sodium lauryl sulfate and separated from other virion structural polypeptides and viral ribonucleic acid by gel filtration chromatography. The 58 X 10-3-molecular-weight envelope protein is the major antigen responsible for cross-reactivity of the virion in complement fixation tests with other closely related arboviruses. A naturally occurring soluble complement-fixing antigen is found in Japanese encephalitis mouse brain preparations after removal of particulate antigens. After partial purification by gel filtration and isoelectric focusing, the 53 X 10-3-molecular weight soluble complement-fixing antigen is more type specific than the Japanese encephalitis envelope antigen in complement fixation tests. Further, the Japanese encephalitis soluble complement-fixing antigen is stable to treatment with sodium lauryl sulfate and 2-mercaptoethanol, whereas virion complement-fixing antigens are unstable after this treatment.
Characterization of enterotoxin purified from Clostridium perfringens type C
Authors: Skjelkvålé R , Duncan C L
Published: January 2020

Enterotoxin produced by a sporulating culture of Clostridium perfringens type C, which had been isolated from a case of severe necrotic enteritis, was purified. The molecular weight was estimated to be 36,000 by gel chromatography on Sephadex G-100 and 33,400 by ultracentrifugation. The sedimentation coefficient S20,W was 2.92. The toxin protein exhibited unusual behavior on sodium dodecyl sulfate gels, and toxin aggregates having molecular weights of 68,000, 85,000, 105,000, and 140,000 were obtained. The purified enterotoxin often separated, apparently due to slight charge differences, into two protein bands on 7% polyacrylamide gels. Electrofocusing of enterotoxin on polyacrylamide gels gave an approximate isoelectric point of 4.3, with the enterotoxin being fractionated into four distinct protein bands. The specific toxicity of the enterotoxin was about 1,900 mouse mean lethal doses per mg of calculated nitrogen. The data obtained indicate that the enterotoxin from C. perfringens type C is identical in most respects to that obtained from type A strains. Whether or not this toxin plays a role in the necrotic enteritis caused by type C strains is unknown at present.
Immunogenicity of an aerogenic BCG vaccine in T-cell-depleted and normal mice
Authors: Morrison N E , Collins F M
Published: January 2020

Aerogenic infection of adult thymectomized, lethally irradiated, bone marrow-reconstituted (THXB) C57B1 times C3H F1 hybrid mice with 1 to 3,000 viable BCG Montreal was followed by an extended period of logarithmic growth to a maximum population of 5 times 10-6 bacilli by day 35. The infection spread to the liver, spleen, and bone marrow with extensive multiplication in all test organs before the growth curves abruptly entered a stationary phase. Up to 30% of the THXB mice eventually died as a result of the ongoing BCG infection. There was no sign of an antimicrobial immune response in the THXB mice analogous to that seen in the control animals beginning about day 30. The THXB mice developed considerable immediate but no delayed hypersensitivity to PPD. Intravenous challenge of the BCG-vaccinated THXB mice with 105 virulent Mycobacterium tuberculosis Erdman indicated that they were as susceptible to the tuberculous challenge as a group of unvaccinated controls. Visible surface lesions developed on the lung 90 days postinfection in the T-cell-depleted host with a sharp rise in counts to 175 per lobe on day 120 followed by a plateau for the remainder of the study. Control mice developed visible lesions about day 50, with 225 lesions per lobe by day 70 and a sharp decline to undetectable levels by day 90. The histopathology of these changes was examined carefully, together with the rate of cellular proliferation (tritiated thymidine uptake) by lung and spleen cells as the BCG infection progressed in the THXB mice. Peak uptake by both organs was depressed during the early stages of the BCG infection in the T-cell-depleted mice, but later the incorporation rates were significantly elevated above control values as the infection progressed.
Susceptibility of thymectomized and irradiated mice to challenge with several organisms and the effect of dapsone on infection with Mycobacterium leprae
Authors: Levy L , Ng H , Evans M J , Krahenbuhl J L
Published: January 2020

B6C3F1 mice that had been thymectomized at 8 to 12 weeks of age, subjected to 950 R of whole-body X irradiation, and transfused with syngeneic bone marrow were challenged in a footpad with Mycobacterium leprae or M. marinum, or intravenously or intraperitioneally with Listeria monocytogenes. Also, mice inoculated with M. leprae in a hind footpad were administered dapsone in the mouse chow. The thymectomized-irradiated (T + R) mice did not survive as well as non-thymectomized mice when housed in the vivarium with no special precautions, but survived sufficiently well to permit the completion of some long-term experiments. M. leprae multiplied to a higher "ceiling" and survived longer in the T + R mice than in the non-thymectomized controls. But a ceiling to multiplication of M. leprae was imposed, and finally the organisms were killed. The histopathological appearance of the footpad tissues, studied by electron microscopy, was consistent with the measurements of bacterial numbers and viability. Swelling of the footpad after local inoculation with M. marinum was greater in T + R mice than in non-thymectomized controls. Similarly, the number of L. monocytogenes following intravenous challenge was greater in the spleens of T + R than of non-thymectomized mice, and the survival of the T + R mice was impaired after intraperitoneal challenge with L.monocytogenes, compared to the survival of non-thymectomized mice. None of these differences was striking, suggesting that these T + R mice had retained or regained some immune competence. The effects of dapsone treatment of T + R mice inoculated with M. leprae were much the same as those of treatment of non-thymectomized mice. Because these T + R mice were not greatly immunosuppressed, they would not have provided a model of human lepromatous leprosy suitable for chemotherapeutic studies.
Chronic proliferative arthritis of mice induced by Mycoplasma arthritidis: demonstration of a cell-mediated immune response to mycoplasma antigens in vitro
Authors: Cole B C , Golightly-Rowland L , Ward J R
Published: January 2020

Lymphocytes taken from mice chronically infected with Mycoplasma arthritidis exhibited a significant blastogenic response as measured by (3H)thymidine uptake when exposed in vitro to M. arthritidis antigens. The lymphocytes taken from 9 of 12 control mice of similar age exhibited an inhibition of (3H)thymidine uptake when exposed to M. arthritidis antigens.
Interaction of complement components with a serum-resistant strain of Salmonella typhimurium
Authors: Reynolds B L , Rother U A , Rother K O
Published: January 2020

Salmonella typhimurium C5 is under normal conditions (physiological saline containing 0.002 M Mg2+) resistant to the action of antibody and complement (C). It becomes sensitive, however, when suspended in tris(hydroxymethyl)-aminomethane buffer (Reynolds and Pruul, 1971; Reynolds and Rowley, 1969). The interaction of complement components with this strain sensitized with specific antibody has been studied to identify the intermediate step at which inhibition occurs. The components C1 yields C2 react normally, as has been shown by lysis of complement-treated cells incubated with complement in ethylenediaminetetraacetic acid. Also, the reaction of C3 can be demonstrated by positive immune adherence and agglutination with anti-C3. The complement-treated cells do not, however, react with rabbit C6 to 9 or rabbit serum lacking C6 in tris(hydroxymethyl)aminomethan buffer. We conclude from these date that C5 can not react effectively under normal conditions. In contrast, if bacteria-antibody complexes are pretreated with rabbit serum lacking C6 in tris(hydroxymethyl)aminomethane buffer, they are readily lysed by incubation with C6 to 9. Thus, C5 can react with the bacterial surface in tris(hydroxymethyl)-aminomethane buffer.
Inhibition of the steroidogenic effects of cholera and heat-labile Escherichia coli enterotoxins by GM1 ganglioside: evidence for a similar receptor site for the two toxins
Authors: Donta S T , Viner J P
Published: January 2020

The effects of three different ganglioside preparations on cholera enterotoxin (CT) and heat-labile Escherichia coli enterotoxin (ECT)-induced steroidogenesis in Y1 and OS3 adrenal tumor cells in tissue culture were examined. Only with GM1 ganglioside was any inhibition of the toxins' effects noted. Concentrations of the crude ECT preparation that gave similar morphogenic and steroidogenic effects as CT were inhibited by the same amount or less of GM1 as that required to inhibit the effects of CT. The results of competition experiments also demonstrated that previous incubation of GM1 with one toxin could inhibit the ganglioside's ability to inactivate the other toxin. These findings indicate that at least for Y1 and OS3 adrenal tumor cells, GM1 may resemble or be the receptor for both CT and ECT.
Effect of silica on virus infections in mice and mouse tissue culture
Authors: duBuy H
Published: January 2020

Silica injections of mice have been reported to kill macrophages, thus allowing herpes simplex virus (HSV) to spread rapidly and leading to an increased severity of HSV infection. Thus, silica presumably could be used to eliminate lactic dehydrogenase virus (LDV) (a model for slow viruses), which is known to multiply exclusively in macrophages. Contrary to expectation, it was found that the LDV titers were increased in silica-injected mice as compared to the titers in control mice. Counts of peritoneal cells at different periods after silica injection showed that silica-induced macrophage damage in vivo resulted in proliferation and migration of macrophages, thus providing additional target cells for LDV replication and leading to high LDV titers. In vitro, silica ingestion also damaged the macrophages, but since no replacement of cells could occur by infiltration, decreased LDV titers were found. Similar findings were obtained with HSV. It is suggested that all persistent viruses multiplying in macrophages will show a similar recrudescence under comparable conditions.
Effect of Cell Dose and Dose of Infectious Agent on Expression of Protection Against
Listeria monocytogenes
and Ectromelia Virus in Cell Transfer Models
Authors: Zinkernagel R. M. , Pang T. , Blanden R. V.
Published: January 2020

Two parameters (immune cell dose and dose of infectious agent) influencing the expression of protection by transferred immune spleen cells in
Listeria monocytogenes
and ectromelia virus infection in mice were investigated. First, when recipient mice were infected with a constant dose of ectromelia virus, a linear relationship between log
10
cells transferred and the protection obtained expressed as log
10
decrease in virus plaque-forming units per spleen was obtained, as has been described previously for the
Listeria
system. Second, the detectable protection was greatly affected by the number of viable bacteria or virus plaque-forming units relative to the number of transferred cells. An otherwise very effective number of transferred immune cells became ineffective when too great a dose of infection was used. Mouse strain differences could also have influenced the results. The impact of these and other parameters on the experimental outcome and its interpretation are discussed.
In Vivo Behavior of Revertants from
Staphylococcus aureus
L-Phase Variants Compared with the Parent Strain
Authors: Watanakunakorn Chatrchai , Glotzbecker Cheryl
Published: January 2020

The in vivo behavior of revertants of
Staphylococcus aureus
L-phase variants were studied in mice. The Giorgio strain of
S. aureus
was induced into L-phase variants by methicillin. After 13 serial passages in methicillin agar and six passages in antibiotic-free agar, reversion occurred. Six revertants, all phage untypable, coagulase negative, and mannitol negative, were inoculated intravenously into Swiss albino mice in comparison with the parent strain. Inoculation of 10
8
colony-forming units resulted in 38% mortality at 28 days for the Giorgio group and 0 to 2% for the revertants. The geometric mean titer of staphylococci in the kidneys was 3.5 × 10
5
for the Giorgio group and 0.5 × 10
0
to 1.0 × 10
2
for the revertants. Serial colony counts of blood, lungs, spleen, liver, and kidneys in mice inoculated with 10
7
colony-forming units showed faster clearance and failure of the revertant to colonize the kidneys. It is concluded that the in vivo behavior of the L-phase revertants was vastly different from that of the parent Giorgio strain.
Immunochemical Studies on the Human Pathogen
Sporothrix schenckii
: Effects of Chemical and Enzymatic Modification of the Antigenic Compounds upon Immediate and Delayed Reactions
Authors: Shimonaka H. , Noguchi T. , Kawai K. , Hasegawa I. , Nozawa Y. , Ito Y.
Published: January 2020

The rhamnose-containing polysaccharide-peptide compound derived from the cells of the pathogenic fungus
Sporothrix schenckii
has been shown to contain 87.1% carbohydrate and 12.5% peptide and to give rise to both immediate- and delayed-type reactions in sensitized guinea pigs. The capacity to induce immediate-type reaction, passive cutaneous anaphylaxis, was completely lost by degradation of the carbohydrate moiety by periodate, whereas the ability to induce the delayed-type reactions of migration inhibition (in vitro) and the sporotrichin reaction (in vivo) were only slightly affected by periodate treatment. On the other hand, delayed “reactivities” to the compound were considerably reduced by treatment with papain, whereas the immediate-type reaction remained positive. These results lead to a conclusion that the rhamnose-containing polysaccharide of the polysaccharide-peptide antigenic compound plays an important role in the immediate-type reaction, whereas the peptide is largely responsible for the delayed-type reaction.
Immunogenicity of Ribosomal Vaccines Isolated from Group A, Type 14
Streptococcus pyogenes
Authors: Schalla W. O. , Johnson W.
Published: January 2020

A ribosomal preparation isolated from group A, type 14
Streptococcus pyogenes
protected mice against a challenge of 1,000 mean lethal doses. Optimal immunization consisted of subcutaneous administration of 326 μg of protein with Freund incomplete adjuvant. Animals immunized with higher or lower antigen concentrations showed decreased survival. Freund incomplete adjuvant was necessary to insure optimum immunization. Immunochemical studies showed no M protein or C carbohydrate present in the ribosomal preparation. Mice optimally immunized with the type 14 ribosomal preparation were protected against heterologous challenge with M types 2, 5, 8, and 12. Protein-free ribonucleic acid extracts isolated from the type 14 ribosomal preparation did not protect mice against homologous challenge. But ribonucleic acid-free protein extracts showed 100% protection in mice after homologous challenge.
Platelet Kinetics in Canine Ehrlichiosis: Evidence for Increased Platelet Destruction as the Cause of Thrombocytopenia
Authors: Smith Ronald D. , Ristic Miodrag , Huxsoll David L. , Baylor Richard A.
Published: January 2020

A significant (
P
< 0.025) increase in the mean platelet diameter occurred in five
Ehrlichia canis
-infected dogs when platelet numbers decreased to 100,000/μl or less. Maximal incorporation of [
75
Se]selenomethionine into platelets of six uninfected dogs was 0.080 ± 0.019% (mean ± standard error) and occurred 5 to 6 days after dosage, whereas maximal incorporation was 0.036 ± 0.004% within 2 to 3 days after dosage in seven chronically infected dogs that had thrombocytopenia. Analysis of the [
75
Se]selenomethionine curves yielded a platelet lifespan of 9 days in uninfected dogs versus 4 days in chronically infected dogs. Thus, megakaryocyte maturation and/or platelet release occurred at an accelerated rate in infected dogs, whereas increased destruction of newly produced labeled platelets diminished their number of peripheral blood. [
51
Cr]sodium chromate-labeled platelet survival was exponential, with a half-life of approximately 1 day in two dogs at 2 to 4 days postinfection and three chronically infected dogs. Platelet survival time was 8 days and rectilinear in four uninfected dogs. Platelet recovery was 39.43 ± 2.86% in infected dogs as compared with 68.2 ± 10.72% in uninfected dogs. Whole-body scans of one dog prior to and 7 days after infection showed that labeled platelets were destroyed primarily in the spleen. It is concluded that the thrombocytopenia in
E. canis
-infected dogs is the result of increased platelet destruction which begins within a few days after infection.
Bacteremia in Suckling Rabbits After Oral Challenge with
Vibrio parahaemolyticus
Authors: Calia Frank M. , Johnson David E.
Published: January 2020

Vibrio parahaemolyticus
, a halophilic marine enteropathogen, produces diarrhea in man after ingestion of contaminated seafood. Only strains capable of producing beta-hemolysis (Kanagawa-positive strains) are enteropathogenic. Yet the majority of marine isolants are nonhemolytic and Kanagawa negative. Studies were initiated in suckling rabbits in an attempt to elucidate pathogenetic mechanisms. Fasting animals were infected orally with Kanagawa-positive and Kanagawa-negative strains of
V. parahaemolyticus, V. cholerae
, two enteropathogenic strains of
Escherichia coli, Shigella flexneri
, and strains of salmonellae. Seven hours postchallenge, cardiac blood, liver, and spleen cultures were obtained.
V. parahaemolyticus
strains failed to induce intestinal fluid accumulation during this study period. Bacteremia occurred in animals challenged with Kanagawa-positive
V. parahaemolyticus, S. flexneri
, and salmonella strains only. Animal passage increased the ability of
V. parahaemolyticus
to cause bacteremia. Liver and spleen cultures were positive in approximately 50% of animals challenged with the Kanagawa-positive strains of
V. parphaemolyticus
. The ability of this organism to penetrate the intestinal epithelium of suckling rabbits may represent a specific property that plays a role in pathogenesis.