bluuebunny/crossref_metadata_2025 huggingface dataset:
Type specificity of complement-requiring and immunoglobulin M neutralizing antibody in initial herpes simplex virus infections of humans
Authors: Schmidt N J , Forghani B , Lennette E H
Published: January 2020

Studies comparing the enhancing effect of guinea pig complement on homotypic and heterotypic neutralizing antibodies produced in initial herpes simplex virus (HSV) infections of humans indicated that antibodies to HSV type 1 and HSV type 2 were enhanced to about the same extent, and there was no signigicant difference in the degree to which complement enhanced homotypic and heterotypic HSV-neutralizing antibody. Homotypic and heterotypic immunoglobulin G neutralizing antibodies were enhanced by complement to as great, or greater, an extent as immunoglobulin M (IgM) HSV antibodies in the same sera. In patients with initial HSV type 1 infections, the IgM neutralizing antibody response was type specific. On the other hand, patients with initial HSV type 2 infections produced both homotypic and heterotypic IgM neutralizing antibody. An initial HSV type 2 infection in an individual previously infected with HSV type 1 elicited the production of IgM neutralizing antibody to both HSV type 1 and HSV type 2. However, patients with recurrent HSV type 1 infections failed to produce IgM antibody to either HSV type during reactivation of the virus.
Experimental measles encephalitis: a genetic analysis
Authors: Haspel M V , Duff R , Rapp F
Published: January 2020

The encephalitogenic potential of nine temperature-sensitive mutants of measles virus was determined in newborn golden Syrian hamsters. The parental virus produced acute encephalitis without any prior adaptation. Six of the mutants were attenuated, two were virulent, and one was associated with hydrocephalus with acute onset. The attenuated mutants, blocked before measles virus antigen and ribonucleic acid synthesis at 39 C, were all members of one complementation group. The virulent temperature-sensitive mutants, defective in hemolysin antigen synthesis at 39 C, were members of a second complementation group. The hydrocephalus-inducing mutant was genetically distinct from the other mutants. The mechanism of attenuation most probably does not involve a temperature-induced inhibition of virus replication, but rather appears to be related to the partial defectiveness of the mutants under permissive conditions.
Effect of staphylococcal protein A on complement-potentiated neutralization of herpes simplex virus and immune lysis of virus-infected cells
Authors: Austin R M , Daniels C A
Published: January 2020

Interaction of staphylococcal protein A (SPA) with human serum depressed the ability of such serum to neutralize herpes simpled virus (HSV)-antibody labialis. SPA-induced depression of serum-dependent virus neutralization appeared to be due to consumption of complement by SPA. In addition, SPA attached to antibody-treated, HSV-infected cells and inhibited complement mediated immune cytolysis. The amount of inhibition obtained depended upon the with the infected cells. The possible significance of SPA in the pathogenesis of viral disease complicated by secondary staphylococcal infection is discussed.
Delayed-type hypersensitivity responses to a cell wall fraction of the mycelial phase of Coccidioides immitis
Authors: Ward E R , Cox R A , Schmitt J A , Huppert M , Sun S H
Published: January 2020

A skin test-active fraction was isolated from the mycelial-phase cell walls of Coccidioides immitis. This alkali-soluble, water-soluble antigen (C-ASWS) elicited positive reactions in 22 of 24 (92%) of the Coccidioides-sensitized guinea pigs whereas only 14 (54%) of the same guinea pigs reacted to commercial coccidioidin (BioCox). None of the 21 Histoplasma-sensitized guinea pigs cross-reacted with the C-ASWS antigen. Footpad tests in mice actively infected with Coccidioides further established the efficacy of the C-ASWS antigen in eliciting a delayed-type hypersensitivity response. One-microgram doses of C-ASWS produced reactions comparable to 100-mug doses of nondialyzable coccidioidin (Smith's lot 64 D4). The C-ASWS fractions isolated from three different C. immitis strains showed similar reactivity in terms of the number of positive reactions produced in Coccidioides-sensitized guinea pigs. However, the induration responses (diameter in millimeters) elicited by the C-ASWS fraction of one strain were significantly less than those elicited by the C-ASWS fractions of the other two C. immitis strains.
Neuropathological effects of persistent infection of mice by mouse hepatitis virus
Authors: Virelizier J L , Dayan A D , Allison A C
Published: January 2020

Mouse hepatitis virus (MHV3) can persist for months in strains of mice with genetically controlled "semisusceptibility" to this virus. The pathology of the chronic neurological disease induced in these animals has been investigated by conventional histology and immunofluorescence. A2G mice develop a chronic choroidoependymitis and meningitis leading to severe hydrocephalus and hydromyelia. In C3H mice a widespread vasculitis was observed, with both viral antigens and bound immunoglobulins in vessal walls. No significant glomerulonephritis was found. Systemic amyloidosis was present in the spleen, liver, and kidneys. The virus was not detected in neural tissues, but brain and spinal cord lesions were found near inflammatory areas surrounding damaged vessels. It is suggested that viral persistance in ependymal cells is directly responsible for the lesions in A2G mice, whereas an immunopathological lesion of blood vessels of the central nervous system underlines the damage to mice of the C3H strain.
Isolation and purification of two antigenically active, "complimentary" polypeptide fragments of tetanus neurotoxin
Authors: Matsuda M , Yoneda M
Published: January 2020

Tetanus neurotoxin (molecular weight approximately 160,000) was purified from bacterial extracts (intracellular toxin) and mildly trypsinized and from culture filtrates (extracellular toxin). Both purified preparations could be dissociated reversibly into two polypeptide chains, with molecular weights of 53,000 (fragment alpha) and 107,000 (fragment beta), by treatment with 100 mM dithiothreitol (DTT) and 4 M urea with concomitant loss of toxicity. Upon removal of DDT and urea from the dissociated toxin preparation by dialysis, these fragments reassociated, forming the whole toxin. The two fragments were isolated and purified from the dissociated toxin by gel filtration on an Ultrogel AcA 44 column equilibrated with buffer containing 2 M urea and 1 mM DTT. The preparation of fragment alpha was nontoxic whereas that of fragment beta was slightly toxic. Immunodiffusion analyses, using horse antitoxin, showed that the antigenicities of fragment alpha and fragment beta were distinct from each other but were partially identical with that of undissociated toxin. The abilities of these fragments to precipitate antitoxin were lost on heating at 60 C for 5 min. The molecular substructure of tetanus neurotoxin is discussed on the basis of these findings.
Use of Bacillus subtilis minicells to demonstrate an antigenic relationship between the poles and lateral cylindrical regions of rod-shaped cells
Authors: Coyne S I , Mendelson N H
Published: January 2020

Purified minicells produced by Bacillus subtilis div IV-B1 mutants were used to immunize rabbits. Immune serum was obtained that agglutinated minicells and was able to form precipitin lines when reacted with minicell antigens in double-diffusion or immunoelectrophoretic procedures. Antiminicell serum agglutinated rod-shaped B. subtilis cells to long filaments produced by growth of a cell division-defective mutant at restrictive temperature. These findings indicate that minicells are immunogens capable of eliciting the production of antibodies that cross-react with the lateral, cylindrical regions of B. subtilis rods. It appears, therefore, that poles share a common antigen(s) with cylindrical regions of the cell.
Monocyte activation in horses persistently infected with equine infectious anemia virus
Authors: Banks K L
Published: January 2020

The monocytes of horses infected with equine infectious anemia virus were shown by their failure to migrate from capillary tubes and their increased adherence to erythrocytes to be activated.
Passive immunization in experimental Herpesvirus hominis infection of newborn mice
Authors: Luyet F , Samra D , Soneji A , Marks M I
Published: January 2020

Infection of newborn mice with Herpesvirus hominis type 2(HVH-2) was used as an experimental model of disseminated HVH infection in newborn humans. Mice were challenged with 103 plaque-forming units of HVH-2 intranasally and were given 0.2 ml of rabbit serum intraperitoneally. Passive immunizations with rabbit anti-HVH-2 serum resulted in a significant decrease in mortality and prolongation of survival time. This effect correlated with the neutralizing antibody titer of the serum against HVH-2 and was more pronounced when immune serum was administered 1 h after infection as compared with 24 h. These results suggest that administration of high-titer anti-HVH-2 immunoglobulins shortly after delivery could afford significant protection to the newborn of a mother with genital HVH-2 infection.
Determination of subgroup-specific feline oncornavirus-neutralizing antibody
Authors: Schaller J P , Olsen R G
Published: January 2020

A microneutralization assay was developed for antibody-to-subgroup-specific feline oncornaviruses. This study combines the economic advantage of a microtiter system and the quantitative focus reduction method which permits contruction of multiplicity curves for determination of virus-neutralizing titers. A twofold increase in Synder-Theilen feline sarcoma virus (ST-FeSV) on feline embryo cells decreased by approximately twofold the titer of reference goat serum prepared against Kawakami-Theilen feline leukemia virus. Similar dose effects with FeLV serotype virus preparations were not observed. An assay system utilizing FeLV serotypes on sarcoma-positive leukemia-negative cells demonstrated slightly greater sensitivity than one employing ST-FeSV on FE cells. Differential antibody responses to the three subgroup-specific feline oncornaviruses (A, B ,and C) were observed in reference goat sera. This test demonstrated good reproducibility as well as sensitivity and constitutes a significant improvement over end point dilution assay systems.
In vitro radiolabeling procedure which labels the proteins of Newcastle disease virions with carbon-14
Authors: McMillen J , Consigli R A
Published: January 2020

A convenient and gentle procedure was used for in vitro radioisotopic labeling the proteins of Newcastle disease virus. This method, which utilizes [14C]formaldehyde and sodium borohydride, labels all the proteins of purified Newcastle disease virus. Virions labeled in this manner retained biological and biopysical integrity
Effect of neonatal thymectomy on experimental subacute sclerosing panencephalitis in adult hamsters
Authors: Johnson K P , Feldman E G , Byington D P
Published: January 2020

Syrian golden hamsters were thymectomized in the first 48 h of life, raised, and then inoculated intracerebrally with the HBS strain of hamster-adapted subacute sclerosing panencephalitis virus when over 12 weeks old. Two groups soon become apparent; one group showed progressive neurological susmptoms and the other group remained healthy. The sick hamsters became moribund between days 8 and 17 postinoculation, and they had large amounts of complete virus in their brains, no antibodies to measles virus in their sera, and a demonstrated lack of thymus tissue. Pathological changes in the central nervous system included marked focal necrosis, numerous giant and inclusion-bearing cells, and slight inflammation. The healthy animals, killed at day 22 or 35 postinoculation, contained no central nervous system virus, moderate amounts of measles antibody in their sera, minimal or absent central nervous system pathology, and histologically identifiable remnants of thymus tissue. These studeis indicate that, in the hamster, the immune system is essential in recovering from central nervous system measles infection and that the antibody response to measles probably requires helper T lymphocytes to develop. Im the absence of antibody to measles, the virus did not undergo modification to a cell-associated state, as noted in previous hamster studies and in human subacute aclerosing panencephalitis. This model system may be useful for passive transfer studies to further clarify the effect of the n vivo immune response to acute and persistent central nervous system measles virus infections9
Thymus dependence of tapeworm (Hymenolepis diminuta) elimination from mice
Authors: Isaak D D , Jacobson R H , Reed N D
Published: January 2020

Although normal mice eliminated the lumen-dwelling intestinal cestode Hymenolepis diminuta by day 21 post-cysticercoid inoculation, congenitally thymus-deficient (nude) mice maintained their work burdens. Nude mice grafted with thymus glands or injected with thymus cells eliminated their worms.
Inhibition of water absorption in the intestine by Staphylococcus aureus delta-toxin
Authors: Kapral F A , O'Brien A D , Ruff P D , Drugan W J
Published: January 2020

Water absorption in intestinal segments was monitored by measuring the concentration of polyethylene glycol, a nonabsorbable reference marker, in a balanced salt solution continuously perfused through the lumen. Staphylococcus aureus delta-toxin inhibited water absorption in rabbit jejunum and ileum perfused in vivo and in guinea pig ileum perfused in vitro. Cholera toxin also interfered with water absorption in guinea pig ileum maintained in vitro, but S. aureus enterotoxin B had no demonstrable effect on this tissue.
Indigenous microorganisms prevent reduction in cecal size induced by Salmonella typhimurium in vaccinated gnotobiotic mice
Authors: Tannock G W , Savage D C
Published: January 2020

Germfree CD-1 mice challenged by the oral route with Salmonella typhimurium had ceca that were abnormal in appearance and reduced in size compared to those of germfree controls. Similarly, germfree mice injected with heat-killed S. typhimurium or gnotobiotes associated with three indigenous microbes (Lactobacillus, Bacteroides, Clostridium), and subsequently challenged with S. typhimurium also had small ceca. By contrast, gnotobiotic mice that had been both injected with the heat-killed S. typhimurium and associated with the three indigenous microbes before challenge with S. typhimurium had ceca similar in size and appearance to germfree mice. Thus, indigenous microorganisms could interfere with the mechanism by which the pathogen induced the decrease in cecal size, but could do so only in mice injected with heat-killed bacteria. This phenomenon suggests synergism between the interference effected by the indigenous bacteria and the resistance mechanisms of the animal.
Selective adherence as a determinant of the host tropisms of certain indigenous and pathogenic bacteria
Authors: Gibbons R J , Spinell D M , Skobe Z
Published: January 2020

The relationship between the selective abilities of bacteria to adhere and their predilections for colonizing different mammalian hosts was investigated by using bacteria indigenous to the tongue dorsum of humans and rats as models. Streptococcus salivarius and S. sanguis averaged 22.6 and 2.8%, respectively, of the cultivable bacteria recovered from swab samples of the tonges of five humans, but these organisms were not indigenous on the tongues of rats (Charles River strain). S. faecalis and serum-requiring diphtheroids were consistently prominant on the tongues of rats, but they were not detected on the tongues of the humans examined. The ability of these organisms to adhere to the tongue surface of the hosts was compared by introducing mixtures of streptomycin-resistant strains into the mouths of human volunteers and rats. S. salivarius adhered in higher proportions to the dorsal tongue surface of humans than did strains of S. faecalis and the serum-requiring diphtheroid. S. sanguis also adhered to human tongues better than the serum-requiring diphtheroid. However, S. faecalis and the serum-requiring diphtheroid sorbed in higher proportions to the tongues of rats. In an in vivo assay, human strains of S. pyogenes and S. salivarius attached in higher numbers to buccal epithelial cells derived from humans than to those obtained from rats, whereas the reverse was observed with a serum-requiring diphtheroid derived from rats. Collectively, these studies show that bacteria sorb with a high degree of specificity to the tissues of different mammalian hosts, and the relative adherence of the organisms studied correlated with their natural host tropisms. The selective adherence of S. salvarius and S. faecalis was similar to the tongues of conventional and germ-free rats, suggesting that the presence of an indigenous bacterial flora did not significantly influence their attachment selectivity. Moreover, the ability of these organisms to colonize the tongues of gnotobiotic rats lacking an indigenous flora paralleled their adherence selectivity. Direct scanning microscopic observations indicated that the tongue dorsum of conventional rats is highly papillated but contains relatively sparse bacterial populations. Indigenous organisms colonized the bases of papillae on the anterior tip and lateral edges of the tongue as discrete microcolonies, but bacteria were rarely observed on other papillae. This localized and restricted pattern of colonization and the spatial distribution of the microcolonies of indigenous bacteria present also suggest that antagonistic interactions are unlikely to account for the bacterial tropisms observed for colonization of the tongues of rats.
Murine leukemia: depressed response to interferon induction correlated with a serum hyporeactive factor
Authors: Stringfellow D A
Published: January 2020

Mice injected by the intraperitoneal route with either L1210 or P388 leukemic cells progressively developed a state of hyporeactivity to interferon induction that was dependent upon inducer and time of administration. A circulating factor was detected in the serum of both L1210 and P388 leukemic mice that could transfer hyporeactivity to normal murine cells in vitro. A direct relationship existed between the concentration of serum factor and development of hyporeactivity to interferon induction in vivo. Characterization of the serum hyporeactive factor from P388 or L1210 leukemic mice indicated that both were similar to a hyporeactive factor previously detected in serum from virus-infected mice. These results suggest a cause-effect relationship between the serum hyporeactive factor and development of hyporeactivity in vivo.
Influenza virus population dynamics in the respiratory tract of experimentally infected mice
Authors: Larson E W , Dominik J W , Rowberg A H , Higbee G A
Published: January 2020

Virus population dynamics in the lungs, trachea, and nasopharynx of Swiss-ICR mice were studied after respiratory challenge with mouse-adapted preparations of strain A2/Aichi/2/68 influenza virus. Markedly higher doses of virus were required to produce infection with nasopharyngeal challenge than with bronchoalveolar challenge. In all of the infections, the highest virus concentrations were observed in the lungs. Peak concentrations in the trachea were lower than in the lungs but higher than in the nasopharynx. Decreasing virus levels were observed by 120 h after challenge and were generally below detectable levels by the end of 10 days. A compartmental model of a single mathematical form was developed which provided close fits of the virus concentration measurements regardless of the challenge dose, site of initial deposition, or respiratory tissue considered. The model includes seven compartments with five associated rate parameters. The application of compartmental modeling techniques and expression of the virus population dynamics in mathematical terms is regarded as a new approach to the study of the pathogenesis of infections.
Partial characterization of the principal soluble antigens associated with the coronavirus of transmissible gastroenteritis by complement fixation and immunodiffusion
Authors: Stone S S , Kemeny L J , Jensen M T
Published: January 2020

A microtiter complement fixation (CF) test to detect transmissible gastroenteritis (TGE) viral antigen was developed, using TGE hyperimmune pig serum as an antibody source. Sera from TGE covalescent pigs did not fix complement by this test. Maximal virus and soluble antigen (SA) titers were obtained 36 to 48 h after inoculation of swine testes cells. Cell-associated virus and SA titers were higher than those in the culture fluid, which had to be concentrated 20X before use as antigen in agar immunodiffusion tests (ID). By sucrose density-gradient centrifugation, the SA had a buoyant density of 1.10 g/ml and could be separated from the virus that banded in the 1.19-g/ml region. Virus and SA from three different isolates of TGE had the same buoyant densities. Heating and proteolytic enzyme digestion established the protein nature of the SA. As assayed by CF and ID, there were stability differences between crude and purified preparations of SA. Antibody prepared in rabbits against the SA neutralized the TGE virus.
Antigenicity of the M proteins of group A hemolytic streptococci: further evidence for shared determinants among serotypes
Authors: Wittner M K
Published: January 2020

Shared antigenic determinants between M proteins of group A streptococci appear to be widespread among serotypes. This is demonstrated by the ability of purified M proteins to absorb opsonic antibody from a variety of heterologous antisera prepared against whole cells or purified M proteins. This absorption procedure has the capacity to separate passive mouse protecting and passive hemagglutinating antibodies from opsonic antibodies measured in vitro. When whole cells or M proteins are used as heterologous absorbents, immunoglobulin may be recovered from the cells or precipitates. The recovered antibody has most of the opsonic and some of the precipitating qualities of the original unabsorbed serum, but hemagglutinating titers are significantly lower. These data provide additional evidence that shared antigenicity among M proteins can be the result of common antigenic determinants. Arguments are presented that these cross-reactions are not the result of a nonspecific protein fraction associated with purified M proteins.
Antibacterial activity in colostrum and milk associated with protection of piglets against enteric disease caused by K88-positive Escherichia coli
Authors: Rutter J M , Jones G W , Brown G T , Burrows M R , Luther P D
Published: January 2020

Piglets suckled by dams that had been vaccinated with K88 antigen were significantly more resistant to deaths caused by neonatal diarrhea after challenge with a large dose of a K88-positive enteropathogenic strain of Escherichia coli than piglets suckled by control dams. The factors most likely to be involved in protection of the piglets were investigated by comparing the antibacterial activities of serum and mammary secretions from the two groups of dams. Vaccination stimulated the production of K88 antibodies, which were associated with anti-adhesive activity directed against the adhesive properties of the K88 antigen, and of O8 antibodies; the latter antibodies were attributed to traces of O8 antigen in the vaccine. Neutralizing activity against heat-labile enterotoxin was present in several dams before vaccination but was not stimulated by bacteriostatic activities were similar in serum and mammary secretions from both groups of dams and appeared to play no significant role in the protective after parturition were atrributed to exposure of the dams to the challenge strain excreted by the piglets. It was concluded that neutralization of the adhesive properties of K88 antigen by K88 antibodies in colostrum and in milk contributed significantly to the protection of piglets from vaccinated dams. However, the contribution of antibacterial activities associated with the greater levels of O8 antibodies in colstrum from the vaccinated group cannot be entirely excluded.
Synergistic protective effect in rabbits of immunization with Vibrio cholerae lipopolysaccharide and toxin/toxoid
Authors: Svennerholm A M , Holmgren J
Published: January 2020

Subcutaneous immunization of rabbits with a combination of Vibrio cholerae lipopolysaccharide (LPS) and enterotoxin induced a more than 100-fold-higher degree of protection against intestinal challenge with live cholera vibrios than did vaccination with either of the two antigens alone. Such a synergistic effect was also obtained by immunization with a combination of LPS and choleragenoid. The immunization with LPS and toxin (or toxoid) in combination did not enhance the reistance to toxin challenge above that induced by the toxin component alone. This, together with data from titrations of anti-LPS and antitoxin antibodies in serum and in intestinal washings, contradicts enhanced immune responses due to adjuvant action of the two antigens as the explanation for the synergistic effect of the combined vaccines. A more likely explanation would be that the antibacterial and antitoxic immune responses, without being increased in themselves, function synergistically by interfering with two separate events in cholera pathogensis.
Preparative isotachophoretic separation of skin test antigens from blastomycin purified derivative
Authors: Lancaster M V , Sprouse R F
Published: January 2020

This investigation examined the theoretical and practical parameters requisite to preparatory istachophoretic separation of blastomycin purified derivative. It resulted in a relatively simple, two-step procedure for preparation of blastomycin antigens in milligram quantitites that exhibited sensitivity and specificity in experimentally infected guinea pigs. Analysis of the nine isotachophoretic fractions for skin test sensitivity and specificity provided some insight into the generally accepted unreliability of blastomycin when used for immunological evaluation.
Nonspecific bactericidal activity of the lactoperoxidases-thiocyanate-hydrogen peroxide system of milk against Escherichia coli and some gram-negative pathogens
Authors: Reiter B , Marshall V M , BjörckL  , Rosén C G
Published: January 2020

Two strains of Escherichia coli and one strain each of Salmonella typhimurium and Pseudomonas aeruginosa were killed by the bactericidal activity of the lactoperoxidase-thiocyanate-hydrogen peroxide system in milk and in a synthetic medium. H2O2 was supplied exogenously by glucose oxidase, and glucose was produced at a level which was itself noninhibitory. Two phases were distinguished: the first phase was dependent on the oxidation of SCN(-) by lactoperoxidase and H2O2, which was reversed by reducing agent, and the second phase was dependent on the presence of accumulated H2O2, which was reversed by catalase. The latter enzyme could also reverse the first phase, but only when present in excessive and unphysiological levels. The bactericidal activity was greatest at pH 5 and below, and it depended on the SCN(-)concentration and on the number of organisms. Since raw or heated milk neutralizes the acid barrier against infection in the stomach, the bactericidal system discussed may contribute to the prevention of enteric infections in neonates.
Attachment of Mycoplasma pneumoniae to respiratory epithelium
Authors: Powell D A , Hu P C , Wilson M , Collier A M , Baseman J B
Published: January 2020

The attachment of radioisotope-labeled Mycoplasma pneumoniae to hamster tracheal rings in organ culture was examined by radioautography and liquid scintillation counting. Radioautographs of individual rings exposed for 8 h to (3H) thymidine-labeled virulent M. pneumoniae revealed a dense extracellular collection of emulsion grains along the luminal surface of epithelial cells. Similar exposure of rings to isotope-labeled avirulent M. pneumoniae resulted in no accumulation of emulsion grains. The numbers of attached virulent mycoplasmas, as measured by liquid scintillation counting of infected rings, were found to increase in a nearly linear fashion over an 8-h incubation period. Viability of the mycoplasmas and metabolic integrity of the tracheal rings were important for optimal attachment. Pretreatment of rings with neuraminidase or sodium periodate significantly impaired orgainism adherence. These data suggest a specificity of interation between virulent M. pneumoniae and tracheal epithelial cells that can be further examined through the use of isotopically labeled mycoplasmas.
Activation of purified human T cells by mitogens: diminished mitogen-induced deoxyribonucleic acid synthesis in human T cells compared with autologous peripheral blood lymphocytes
Authors: Schmidtke J R , Hatfield S
Published: January 2020

Human thymus-derived (T) cells were isolated from peripheral blood after rosette formation with neuraminidase-treated sheep erythrocytes (SRBC). After separation on Ficoll-hypaque, SRBC were removed from T cells by treatment with tris(hydroxymethyl)aminomethane-NH4Cl. Human T cells and autologous peripheral blood lymphocytes (PBL) were then incubated with phytohemagglutinin, concanavalin A, or pokeweed mitogen. Human T cells, in the absence of other cell types, responded with less deoxyribonucleic acid (DNA) synthesis (measured by uptake of [3H]thymidine) than equal numbers of autologous PBL. Further experimentation established that, compared with autologous PBL, the diminished capacity of human T cells to be activated by mitogens was due neither to differences in the mitogen dose-response relationship nor to the time of peak DNA synthesis of T cells or autologous PBL. Fragments or components of SRBC were not detected on human T cells, and treatment of the T cell-SRBC mixture with tris(hydroxymethyl)aminomethane-NH4Cl did not contribute to the results. Increased cell density or a period of preculture before addition of mitogen also did not influence the degree of decreased DNA synthesis in human T cells compared with the response of autologous PBL incubated with the same mitogens. When mixed with the cells remaining at the Ficoll-media interface, purified human T cells did not suppress the mitogenic response of this cell mixture to PHA or concanavalin A. The data indicated that human T cells, in the absence of other cell types, were activated by mitogens to a lesser degree than autologous PBL. Furthermore, T cells responded with DNA synthesis after direct T cell-mitogen interaction.
Studies of mycobacterial antigens, with special reference to Mycobacterium leprae
Authors: Kronvall G , Stanford J L , Walsh G P
Published: January 2020

Eight individual antigens were detected in soluble antigen preparations from Mycobacterium leprae bacilli by using pools of serum samples from lepromatous leprosy patients as antibody reagents in crossed immunoelectrophoresis. Two of these antigens were analyzed further. Antgent no. 1 gave an elution pattern on Sephadex G-200 corresponding to a molecular weight of 285,000. This antigen was also present in three slow-growing and eight fast-growing mycobacterial species. There was a reaction of complete identity in immunological tests using lepromatous serum pools as well as with rabbit antisera raised against M. leprae and M. smegmatis. Antigen no. 21 of M. leprae showed antigenic heterogeneity when compared with other species. Three types of antigenic determinants were detected; one, called 21A, was shared by all mycobacteria, another, called 21B, was limited to antigen no. 21 of M. leprae; a third, called 21C, was present in all mycobacteria except the leprosy bacillus. This submolecular heterogeneity may indicate a separate taxonomic position of M. leprae among the mycobacteria.
Antigenic analysis of Neisseria gonorrhoeae by crossed immunoelectrophoresis
Authors: Smyth C J , Friedman-Kien A E , Salton M R
Published: January 2020

Crossed immunoelectrophoresis was used to study two complex antigenic preparations from Neisseria gonorrhoeae, one of cytoplasmic origin and the other derived by Triton X-100 extraction of isolated washed gonococcal envelopes, with the aim of developing suitable reference antigen-antibody systems that could be subsequently used to investigate the immune response to gonococcal infection and to monitor envelope preparations for cytoplasmic contamination. A number of parameters were investigated to optimized and standardize antigen preparation, e.g., harvesting and washing of gonococci, methods of bacterial disruption, and washing of envelopes. The effects of Triton X-100 concentration, initial total envelope protein concentration, and the composition, pH, and concentration of buffer on cell envelope extractability were studied to obviate the need to concentrate material before use in crossed immunoelectrophoresis. The electroendoosmotic properties of agarose were a major determining factor in resolving envelope antigens. From 25 to 30 immunoprecipitates were revealed in the envelope antigen-antibody system; 75 to 80 were revealed in the cytoplasmic sytem. Envelope immunoprecipitates with reduced nicotinamide adenine dinucleotide and lactate dehydrogenase activities were identified. Crossed immunoelectrophoresis with intermediate gels revealed the presence of antibodies in a preimmune rabbit antiserum pool to a distinctive fact-moving component in both the envelope and cytoplasmic antigen preparations. The intermediate gel technique also demonstrated that extensive washing of envelope preparations with buffer did not remove cytoplasmic ontamination completely. The method provides a much more sensitive means of monitoring the purity of envelope fractions than the use of single enzy,e markers as indexes of such contamination. The use of rabbit antisera raised to formolized gonococci in intermediate gels indicated that both reference antigen-antibody systems were of potential use in screening immune responses to N. gonorrhoeae.
Modified hemolytic plaque technique for the detection of bluetongue virus antibody-forming cells
Authors: Oellermann R A , Carter P , Marx M J
Published: January 2020

A hemolytic plaque assay was developed for the detection of antibody-forming cells to bluetongue virus (BTV). Sheep erythrocytes (SRBC), onto which BTV had been absorbed, served as the indicator of lysis due to the presence of BTV antibody-forming cells. The ratio of BTV to SRBC was found to be critical for optimum hemolytic plaque formation. For routine use, 50 mul of 12% BTV SRBC, 0.1 ml of a spleen cell suspension, and 0.5 ml of 0.5% agarose in a balanced salt solution were mixed and plated on a microscope slide precoated with 0.1% aqueous agarose. Slides were incubated for 1 h at 37 C in a humidified incubator and subsequently flooded with 0.4 ml of a 1:15 dilution of complement. Incubation was continued for a further 2 h before the hemolytic plaques were scored. It was not possible to establish BTV serotype specificity by this technique.
Selective activation of classical and alternative pathways of human complement by "promptly serum-sensitive" and "delayed serum-sensitive" strains of Serratia marcescens
Authors: Traub W H , Kleber I
Published: January 2020

Chelation of fresh human serum with 0.01 M MgCl2 (Mg) plus 0.01 M ethylene glycol tetraacetic acid failed to abrogate the bactericidal activity against "delayed serum-sensitive" strains of Serratia marcescens, whereas previously "promptly serum-sensitive" strains of S. marcescens and control strain Escherichia coli C were killed after an extended period of incubation. The addition of 0.01 M ethylenediametetracetate to fresh human serum neutralized bactericidal activity against S. marcescens of either serum sensitivity category.
Antinuclear antibodies and elevated anti-Epstein-Barr virus titers in cancer patients
Authors: McCormick N K , McCormick K J , Trentin J J
Published: January 2020

One and one-half percent of human sera from patients seen at a clinic for treatment of cancer contained antibodies to the nuclei of chick kidney cells by indirect immunofluorescence tests. In the group of sera containing antinuclear antibodies, the geometric mean titer to Epstein-Barr virus (EBV) capsid antigen was significantly elevated. Sera obtained from normal adults or from patients with similar histological types of tumors that possessed no antinuclear antibodies contained lower levels of anti-EBV antibodies. The elevated titers to EBV were correlated with the presence or absence of antinuclear antibodies and not with a particular type or site of neoplastic disease.
Immunoglobulin classes in genital secretions of mycoplasma-infected and normal heifers
Authors: Corbeil L B , Hall C E , Lein D , Corbeil R R , Duncan J R
Published: January 2020

Immunoglobulin levels were studied in the genital secretions of seven heifers which had been bred to a bull infected with Mycoplasma agalactiae var. bovis and three heifers bred to a noninfected bull. The median immunoglobulin G (IgG)/IgA ratio ratio for vaginal secretions was 0.7, for cervical secretions 21.9, and for uterine secretions 13.0. This indicated that IgA was the mahor immunoglobilin class in the most superficial portion of the reproductive tract and that IgG was the major class in secretions of the deeper tract. The response to infection was studied by comparing animals infected with mycoplasma and noninfected controls. The IgG/IgA ratios were significantly lower in infected animals than in controls, apparently due to high IgA values in infected animals. Low mycoplasmal agglutinin titers were detected in secretions of three of the infected animals, but there appeared to be no relationship between agglutinin titers and histopathological lesions or between agglutinin titers and IgG/IgA ratios in this group of animals.
Effect of tilorone on susceptibility of mice to primary or secondary infection with Listeria monocytogenes
Authors: Gruenewald R , Levine S
Published: January 2020

Subcutaneous administration of the drug tilorone did not increase the susceptibility of CD-1 male mice to intravenous or intraperitoneal infection with an alpha-toxin-deficient mutant of the Smith diffuse strain strain of Staphylococcus aureus. In contrast, a single injection of this drug greatly increased the susceptibility of mice to an intravenous or an intraperitoneal infection with Listeria monocytogenes, an intracellular parasite. The effects of tilorone, which were maximal when the drug was administered on the day of the listerial challenge or one day thereafter, were reflected by relatively lower mean lethal dose values and enhanced proliferation of Listeria in the spleen and liver. The ability of tilorone, administered at the time of listerial challenge, to decrease the resistance against the challenge was partially abrogated by previous administration of the same drug. Tilorone, administered at the time of immunization with a very small number of viable Listeria, greatly enhanced the potency of the immunization. On the other hand, tilorone, administered to Listeria-immunized mice near to the time of a listerial challenge, slightly reduced the protective effects of the prior immunization.
Rapid quantitation of interferon with chronically oncornavirus-producing cells
Authors: Aboud M , Weiss O , Salzberg S
Published: January 2020

The capacity of interferon to inhibit virus production in cells chronically infected with oncornavirus enabled us to develop a simple system for interferon quantitation that was independent of exogenous viral infection. The release of the virus to the culture medium was determined by its reverse transcriptase activity. The inhibitory effect of interferon in this system was linearly proportional to the log of its dilution over a range between 5 and 80% inhibiton. The sensitivity of the system was comparable to that of the vexicular stomatitis virus plaque reduction assay, whereas its reproducibility was found to be even better. This method is very rapid and can be completed within less than 24 h.
Lysis of Acholeplasma laidlawii by antibodies and complement
Authors: Brunner H , Dörner I , Schiefer H G , Krauss H , Wellensiek H J
Published: January 2020

Membranes of Acholeplasma laidlawii were used to determine the membrane components involved in immune lysis and to eventually detect enzymatic changes in the membrane components during this reaction. In a previous publication we reported that A. laidlawii can be killed by antibody and complement and that antibodies to membrane proteins are by far more effective than antibodies to membrane lipids in the complement-dependent killing of this organism. In this report we demonstrate that membrane damage occurs after the combined action of antibody and complement. In addition, the cytoplasmic enzyme hexokinase is released during immune killing. As visualized by electron microscopy, the organisms lost their cytoplasm and were transformed into ghosts. In the majority of organisms, tears in the membrane could be seen. Ultrastructural lesions of about 8.0 to 10 nm in diameter were visible when the organisms were incubated with antiserum and complement. 14C-labeled fatty acids were incorporated during growth into A. laidlawii membrane lipids. After incubation of labeled organisms with antiserum and complement, release of radioactive material into the supernatant and changes in the lipid composition were not observeed. Enzymatic degradation of membrane lipids of A. laidlawii during immune lysis was not detected.
Distribution of dengue-2 antigens by electron immunocytochemistry
Authors: Cardiff R D , Lund J K
Published: January 2020

The distribution of dengue-2 antigens was studied in infected monkey kidney cells (LLC MK2) using an indirect, horseradish peroxidase-conjugated immunoglobulin technique. This procedure allowed both light and electron microscopic examination of serial-step sections of individual cells cut in a plane perpendicular to the monolayer. Both virion and nonvirion antigens were identified on the plasma membrane with this technique. A diffuse cytoplasmic reaction product was also present. The intensity and distribution of the cytoplasmic reaction product was related to disruption of the plasma membrane.
Diffusible viral interference during arbovirus plaque formation
Authors: Stanton G J
Published: January 2020

A radially diffusing zone of nonspecific interference was observed surrounding plaques of Western equine encephalitis virus. The increase in diameters of the zones of interference were linear and more rapid than increases in plaque diameters. These observations raise the possibility that viral-induced interference could account for the diminished growth of Western equine encephalitis virus plaques with time or even the initial formation of plaques. In addition, this system could be used as a model to study localized host defenses during early infection of solid tissues in vivo.
Adjuvant activity of mycobacterial fractions: adjuvant activity of synthetic N-acetylmuramyl-dipeptide and the related compounds
Authors: Azuma I , Sugimura K , Taniyama T , Yamawaki M , Yamamura Y
Published: January 2020

Immunological activity of synthetic cell wall peptidoglycan subunits was examined in guinea pigs and mice. It was concluded that the minimal adjuvant-active subunit of cell wall peptidoglycan for the induction of delayed-type hypersensitivity to monoazobenzenearsonate-N-acetyl-L-tyrosine and for circulating-antibody formation to bacterial alpha-amylase and the thymus-independent antigen DNP-Ficoll was N-acetylmuramyldipeptide, MurNAc-L-Ala-D-isoGln. N-acetylmuramyldipeptide and 6-O-stearoyl-N-acetylmuramyldipeptide showed no adjuvant activity in the generation of cell-mediated cytotoxic effector cells in the spleens of C57Bl/6J mice after in vivo immunization with the allogeneic antigen mastocytoma P815-X2 cells, but N-acetylmuramyldipeptide showed adjuvant activity after in vitro sensitization of C57Bl/6J mouse spleen cells to the alloantigen mitomycin C-treated DBA/2 mouse spleen cells. It was also shown that 6-O-stearoylation of N-acetylmuramylpeptide could not potentiate the adjuvant activity of N-acetylmuramyldipeptide. Mitogenic and antitumor activities were not observed in either N-acetylmuramyldipeptide or 6-O-stearoyl-N-acetylmuramyldipeptide in mouse systems.
Interaction of virulent Mycoplasma pneumoniae with hamster tracheal organ cultures
Authors: Hu P C , Collier A M , Baseman J B
Published: January 2020

Exposure of hamster tracheal organ cultures to virulent Mycoplasma pneumoniae leads to alterations in ribonucleic acid (RNA) and protein biosynthesis and metabolism of the respiratory epithelium. An examination of the turnover rates of RNA and protein in infected tracheal organ cultures indicates that the rates of degradation of both prelabeled host cell RNA and protein are similar to those of uninfected controls. Infected tracheal organ cultures shifted to a nonpermissive medium within 24 h after infection and further incubated in the nonpermissive medium for 72 or 96 h behaved as normal uninfected cultures in terms of metabolic precursor uptake. Under these conditions, mycoplasmas remained attached to the respiratory epithelium. Cell membranes prepared from virulent mycoplasmas by several procedures neither attached to nor altered the metabolic activity of tracheal cultures. These data indicate that the intimate contact between virulent mycoplasmas and the respiratory epithelium does not alone account for the subsequent interruption of host cell metabolism but must be accompanied by continued multiplication and biochemical function of attached mycoplasmas.
Nonpilar surface appendages of colony type 1 and colony type 4 gonococci
Authors: McGee Z A , Gross J , Dourmashkin R R , Taylor-Robinson D
Published: January 2020

The nature and distribution of surface appendages morphologically distinct from pili were examined in three strains of gonococci. As reported previously by others, large appendages were seen emanating from colony type 1 gonococci when negatively stained preparations were examined by electron microscopy. Whereas the diameter of pili was 4 to 6 nm, the appendages varied from 8 to 40 nm in diameter with bulbous enlargements of up to 130 nm. However, in contrast to previous findings, the appendages were not limited to virulence-associated colonial types but occurred with almost equal frequency on organisms from colonial types 1 and 4. Thus, the presence of these appendages on gonococci was unrelated to colonial morphology, and there is currently no reason to associate them with gonococcal virulence. The large appendages were seldom seen if the organisms were suspended in isotonic fluid rather than in distilled water, which was used in previous studies. This suggests that the large appendages may occur infrequently in the isotonic environment of tissues or in slightly hypertonic purulent exudates. Nevertheless, we did observe small appendages or cell wall blebs on the surface of gonococci suspended in isotonic medium and noted similar structures as spheres free in the surrounding milieu. These findings suggest that the material of which the large appendages consist may form small appendages or cell wall blebs and be shed into the milieu under isotonic conditions. Such cell wall blebs have been demonstrated on meningococci and been shown to consist of endotoxin.
Effect of systemic BCG infection in syrian golden hamsters
Authors: Zwilling B S , Davis G W
Published: January 2020

The response of Syrian golden hamsters to systemic infection with several doses of Mycobacterium bovis (strain BCG) was assessed. Large numbers of organisms (10(7)), injected intravenously, were lethal for hamsters, whereas all animals survived infection with 10(4) colony-forming units of BCG. Animals responded immunologically to purified protein derivative as assessed by increased footpad swelling and splenic lymphocyte proliferation. The immediate cause of death was a diffuse granulomatous interstitial pneumonia.