bluuebunny/crossref_metadata_2025 huggingface dataset:
Phagocytosis and intracellular killing of the contagious equine metritis organism by equine neutrophils in serum
Authors: Bertram T A , Coignoul F L , Jensen A E
Published: January 2020

Equine neutrophils were combined with Haemophilus equigenitalis (contagious equine metritis organism; CEMO) or Escherichia coli in low- and high-antibody-titer serum to evaluate the neutrophils ability to phagocytize and kill these bacteria. More E. coli than CEMO were phagocytized at each time period. After 120 min in low-antibody-titer serum, 56.3% of the E. coli and 34.3% of the CEMO were phagocytized. A total of 45% of CEMO and 74.9% of E. coli were phagocytized by 120 min when neutrophils were in high-antibody-titer serum. More than 75% of the ingested E. coli and 90% of the ingested CEMO were killed within 210 min of incubation. Fewer E. coli than CEMO were killed at any given time period. Ultrastructural examination showed CEMO to be degraded in the neutrophil. Degradation was the most extensive in neutrophils in high-titer serum. It is suggested that CEMO is a pathogenic extracellular bacterium incapable of prolonged intracellular survival and that it is slower to be phagocytized than a nonpathogenic E. coli.
Trypanosoma brucei
Infection Stimulates Receptor-Mediated Phagocytosis by Murine Peritoneal Macrophages
Authors: Fierer Joshua , Askonas Bridgitte A.
Published: January 2020

Trypanosoma brucei
infection results in hypertrophy of the reticuloendothelial system. Peritoneal macrophages from infected mice were larger, spread out more on glass, and had increased receptor-mediated phagocytic activity both for C3b-and immunoglobulin G-coated erythrocytes. These observations suggest that macrophages were activated as a result of this infection.
Antibody to Trichomonas vaginalis in human cervicovaginal secretions
Authors: Su K E
Published: January 2020

Human cervicovaginal secretions were obtained from patients at the Gynecology and Obstetrics Clinics at National Taiwan University Hospital and Cathay General Hospital, Republic of China. Among the 500 patients examined, 33 (6.6%) were infected with Trichomonas vaginalis as determined by the culture method. Secretions from 24 of the infected patients and 30 noninfected women were assayed for anti-T. vaginalis immunoglobulins by the indirect immunofluorescent antibody technique. A few serum samples from both infected and noninfected persons were also included in this study. Immunoglobulin G (IgG) antibody against T. vaginalis was detected in 17 (70.8%) secretions from the infected women. Among the 17 positive secretions, anti-parasite IgA was found in two specimens, IgE was found in three, and IgM was found in one. Of the 30 secretions, 7 (23.3%) from noninfected women also contained anti-parasite IgG. Low levels of natural anti-trichomonad IgG and IgM were detected in the sera of normal persons. Infection with T. vaginalis caused an increase in the serum IgG antibody titer. Cross-reaction between T. vaginalis and Pentatrichomonas hominis was also observed.
Influence of antibodies to mannophosphoinositides on phospholipid synthesis in Mycobacterium smegmatis ATCC 607
Authors: Penumarti N , Khuller G K
Published: January 2020

Antiserum to mannophosphoinositides had a significant inhibitory effect on phospholipid synthesis in Mycobacterium smegmatis ATCC 607 at different phases of growth; however, the inhibition was more pronounced in the exponential phase. The rate of synthesis of total phospholipids and individual phospholipids, viz., cardiolipin, phosphatidylethanolamine, and mannophosphoinositides, decreased in the presence of antiserum as compared with normal serum. The maximum inhibitory effect of antiserum was exerted on the synthesis of mannophosphoinositides, particularly on tetraacylated dimannophosphoinositide. Antiserum also had a growth inhibitory effect as compared with normal serum.
Enumeration of antigenic sites of influenza virus hemagglutinin
Authors: Jackson D C , Murray J M , White D O , Gerhard W U
Published: January 2020

The antigenic sites on the hemagglutinin of X-31 (H3) influenza virus have been defined by using a competitive radioimmunoassay with a panel of monoclonal antibodies which includes those known to select variants with substitutions of particular amino acids. The capacity of each monoclonal antibody to block the binding of other radioiodinated monoclones to purified hemagglutinin permitted classification of the panel into four separate groups, each of which defined a particular antigenic site on the hemagglutinin molecule. Three of these are located on the polypeptide backbone and correspond to the "hinge," the "loop," and the "tip/interface" of the X-ray crystallographic model of Wiley et al. (Nature [London] 289:373-378, 1981). Nonreciprocal blocking of certain anti-interface antibodies by anti-loop antibody suggests that much of the exposed surface of the head of the hemagglutinin molecule extending from the loop to the interface may be a continuum of epitopes. A fourth antigenic site is carbohydrate in nature, presumably situated on the antigenic oligosaccharide side chains. These four domains are in addition to two antigenic sites defined by monoclonal antibodies that inhibit neither hemagglutination nor infectivity (Breschkin et al., Virology 113:130-140, 1981;' Yewdell et al., Nature [London] 279:246-248, 1979).
Use of an anti-human leukocyte interferon monoclonal antibody for the purification and radioimmunoassay of human alpha interferon
Authors: Meurs E , Rougeot C , Svab J , Laurent A G , Hovanessian A G , Robert N , Gruest J , Montagnier L , Dray F
Published: January 2020

Mouse monoclonal antibody directed against human leukocyte alpha interferon (IFN-alpha) was coupled to Sepharose and used as an immunoadsorbent to purify human IFN-alpha. Leukocyte and lymphoblastoid (Namalva) IFNs were retained by the immunoadsorbent with a specificity of 80 to 100% and 40 to 60%, respectively. Human IFN-beta or -gamma and mouse IFN were not retained. The purified IFN-alpha retained its antiviral and anticellular properties as well as its ability to induce the 2-5A synthetase in human cells with a specific activity similar to that of the crude IFN. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of radioactively labeled IFN showed that it consisted of several proteins in the molecular weight range of 17,000 to 27,000. 125I-labeled IFN-alpha with a high specific activity (2,000 Ci/mmol) was used in a radioimmunoassay for the titration of IFN-alpha.
Effect of neonatal thymectomy on immune responses of rats to Streptococcus mutans
Authors: Ebersole J L , Taubman M A , Smith D J , Frey D E
Published: January 2020

The effect of neonatal thymectomy on secretory and systemic antibody responses in rats was studied. Groups of normal or thymectomized (Tx) rats were infected or immunized and infected with Streptococcus mutans 6715. Tx rats exhibited a significantly lower level of salivary immunoglobulin A (IgA) antibody to S. mutans after a 45- to 65-day infection. Similarly, after multiple local injections of formalinized S. mutans, Tx rats showed a delay in the appearance and lower levels of salivary IgA antibody to S. mutans. Serum IgG antibody levels were also decreased in Tx rats with both experimental protocols. In contrast, salivary IgG and serum IgM anti-S. mutans activity in Tx and normal rats were similar during the experiments. These results demonstrated that thymus deprivation at birth produces profound effects on the ability of rats to manifest secretory IgA antibody responses to the pathogenic microorganism S. mutans.
Teichoic acids from chemostat-grown cultures of Streptococcus mutans and Lactobacillus plantarum
Authors: Wicken A J , Evans J D , Campbell L K , Knox K W
Published: January 2020

We examined the effect of growth conditions in chemostat culture on the quantity and composition of the cell wall teichoic acids of Streptococcus mutans BHT and Lactobacillus plantarum NCIB 7220 and the membrane lipoteichoic acid from S. mutans Ingbritt. With the cell wall teichoic acids, which are covalently linked to peptidoglycan, the amount of teichoic acid is independent of the growth conditions employed. However, the extent of glucosyl substitution of the polymer from L. plantarum was dependent on growth conditions. S. mutans Ingbritt lipoteichoic acid, on the other hand, was little affected by growth conditions in terms of composition or serological activity, but the amount produced was markedly affected by changes in growth conditions.
Phospholipase A and the interaction of Rickettsia prowazekii and mouse fibroblasts (L-929 cells)
Authors: Winkler H H , Miller E T
Published: January 2020

L-929 cells were killed when approximately 50 viable Rickettsia prowazekii organisms per L-cell were centrifuged onto a monolayer. The glycerophospholipids of the L-cell were hydrolyzed to lysophosphatides and free fatty acids. Concomitantly, there was a loss of membrane integrity as shown by release of lactate dehydrogenase and 86Rb and permeability to trypan blue dye. No glycerophospholipid hydrolysis or cytotoxicity occurred when the rickettsiae were inactivated by heat, UV irradiation, N-ethylmaleimide, or metabolic inhibitors before their addition to the L-929 cells. On the other hand, treatment of the L929 cells with the cytoskeleton agents colchicine or cytochalasin B or with N-ethylmaleimide inhibited neither the phospholipase A activity nor the loss of membrane integrity. Cytochalasin B-treated cells could be damaged by even small numbers of rickettsiae. We suggest that this phospholipase A activity is used by the rickettsiae to escape from the phagosomes into the cytoplasm of host cells.
Four different monoclonal antibodies against type C1 toxin of Clostridium botulinum
Authors: Oguma K , Agui T , Syuto B , Kimura K , Iida H , Kubo S
Published: January 2020

Monoclonal antibodies against type C1 toxin produced by Clostridium botulinum type C strain Stockholm (C-ST) were prepared by fusion of BALB/c myeloma cells P3X63-Ag8, with spleen cells from the mice immunized by C-ST toxoid. About 5% of single-cell colonies in wells were found to produce antibodies against the toxin as determined by an enzyme-linked immunosorbent assay (ELISA). Four different hybridoma cell lines, no. 9, 12, 14, and 17, were established, cloned by limiting dilution, and intraperitoneally injected into mice to obtain the ascites fluids containing high-titered antibodies. The reactions of these antibodies to type C1 and D toxins of strains C-ST, D-1873, and D-South African (D-SA) were observed by both neutralization and ELISA tests. Three monoclonal antibodies, no. 9, 14, and 17, reacted with C-ST toxin, but only no. 17 highly neutralized the toxin. These antibodies did not react with type D toxins. On the contrary, no. 12 reacted with toxins of both C-ST and D-SA (but not of D-1873) and commonly neutralized these two toxins. This indicates that there is a common antigenic part between C-ST and D-SA toxin molecules which participates in the toxin-neutralizing reaction. The neutralization profiles of C-ST toxin by no. 12 and 17 antibodies were different in a time-to-death test of mice. The mechanisms of neutralization by no. 12 and 17 may be different.
Live influenza A/Victoria/75 (H3N2) virus vaccines: reactogenicity, immunogenicity, and protection against wild-type virus challenge
Authors: Cate T R , Couch R B
Published: January 2020

Four live influenza A/Victoria/75 (H3N2) recombinant virus vaccines were administered intranasally to a total of 50 volunteers who had little or no detectable serum neutralizing antibody. A recombinant with ts-1[E] having a 38 degrees C shut-off temperature caused febrile reactions or systemic reactions or both in 21% of the volunteers, but one with ts-1A2 having a 37 degrees C shut-off temperature caused no illness. Two recombinants prepared with cold-adapted A/Ann Arbor/6/60 caused 9% febrile reactions or systemic reactions or both. Virus shedding occurred in a minority of the 50 volunteers, but 90% developed a serum neutralizing antibody response. Wild-type A/Victoria/75 virus challenge of 34 of the vaccinated volunteers and 12 others who had had prior natural A/Victoria/75 virus infection revealed similar and significant protection when compared with the 96% infection and 68% febrile illness or systemic illness or both observed in 25 unvaccinated volunteers with little or no serum antibody. These results encourage continued efforts toward development of live influenza virus vaccines.
Effect of decreased salivation and pH on the adherence of Klebsiella species to human buccal epithelial cells
Authors: Ayars G H , Altman L C , Fretwell M D
Published: January 2020

To assess the role of reduced salivary flow and intraoral pH on gram-negative bacterial colonization of the oropharynx, we studied in vitro Klebsiella adherence to normal human buccal epithelial cells at various pH values and to buccal cells from patients with pathological xerostomia (decreased saliva flow). Reduced pH significantly increased adherence of Klebsiella pneumoniae 84 to normal buccal epithelial cells (P less than 0.001). In contrast, two clinical isolates of K. oxytoca showed no significant pH-dependent change in adherence. A corollary of this was that patients with pathological xerostomia had significantly increased adherence of K. pneumoniae 84 to their buccal epithelial cells as compared with normal controls (P less than 0.01). These results suggest that reduced salivary flow and the concomitant reduction of intraoral pH may predispose patients to bacterial colonization with K. pneumoniae.
Effects of ionophores and dicyclohexylcarbodiimide on Mycoplasma gallisepticum adherence to erythrocytes
Authors: Banai M , Razin S , Schuldiner S , Zilberstein D , Kahane I , Bredt W
Published: January 2020

To test the influence of the electrochemical ion gradient across mycoplasma membranes on the capacity of organisms to adhere to host cells, Mycoplasma gallisepticum cells were treated with valinomycin, carbonylcyanide m-chlorophenylhydrazone, and N,N'-dicyclohexylcarbodiimide (DCCD) singly or in combination. Uptake of [3H]tetraphenylphosphonium by the treated cells was employed as a measure of the effects of the ionophores on membrane potential. In the absence of K+, valinomycin increased, whereas carbonylcyanide m-chlorophenylhydrazone, and DCCD decreased [3H]tetraphenylphosphonium uptake. However, with a high level of K+ or with DCCD, uptake of [3H]tetraphenylphosphonium in the presence of valinomycin decreased below control levels, indicating that, generally, the ionophores affected membrane potential in the expected manner. The treated organisms were tested for their capacity to attach to glutaraldehyde-fixed human erythrocytes. DCCD was the best inhibitor of mycoplasma attachment, and in combination with valinomycin attachment, capacity decreased by about 40%. The combination of valinomycin plus carbonylcyanide m-chlorophenylhydrazone was less effective; it decreased attachment by about 15 to 25%. It was concluded that the dissipation of ion gradients across cell membranes decreases only partially mycoplasma adherence, in line with previous findings that isolated mycoplasma membranes retain the major part of the attachment capacity of intact cells.
Evaluation of Two
Salmonella typhimurium
Hybrids as Challenge Organisms in a System for the Assay of Typhoid Vaccines
Authors: Johnson E. M. , Diena B. B. , Lior H. , Ryan A. , Krol P. , Baron L. S.
Published: January 2020

A mouse-virulent
Salmonella typhimurium
hybrid (H42), which expresses the
Salmonella typhi
Vi antigen in addition to
S. typhi
O antigens 9 and 12, and a mouse-virulent
S. typhimurium
hybrid (H1), which expresses only the 9 and 12 antigens of
S. typhi
, were compared in their behavior as challenge organisms in a system developed to assay the protective capabilities of typhoid vaccines. Swiss-Webster white mice, vaccinated intraperitoneally with live
Escherichia coli
hybrids expressing the
S. typhi
O antigens 9 and 12, were significantly protected against death from intraperitoneal challenge with each of the
S. typhimurium
hybrid strains. Vaccination with an
E. coli
hybrid expressing the
S. typhi
Vi antigen in addition to O antigens 9 and 12 was seen to confer no advantage in protection against either
S. typhimurium
hybrid challenge organism over that obtained by vaccination with an
E. coli
hybrid expressing only the O antigens of
S. typhi.
However, a notable difference in the behavior of the two
S. typhimurium
hybrids was seen in mice vaccinated with the parent of the
E. coli
hybrid vaccinating strains,
E. coli
F464, which expresses no surface antigens common to either of these
S. typhimurium
hybrid challenge organisms. A nonspecific (with respect to the vaccinating strain) protective effect, believed to be associated with Vi antigen expression by the challenge organism, was seen against the challenge with
S. typhimurium
hybrid H42 after F464 vaccination, whereas no protection was conferred by F464 vaccination against the challenge with Vi-nonexpressing
S. typhimurium
hybrid H1. Inasmuch as neither
S. typhimurium
hybrid discriminates between the expression or nonexpression of the Vi antigen in a vaccinating strain, it is concluded that the Vi-nonexpressing
S. typhimurium
hybrid H1, which more clearly indicates the vaccine-specific protective role of the
S. typhi
O antigens and does not exhibit the nonspecific protection response of hybrid H42, is the better choice as challenge organism for this vaccine assay system.
Humoral and cellular responses of mice to infection with a cold-adapted influenza A virus variant
Authors: Mak N K , Zhang Y H , Ada G L , Tannock G A
Published: January 2020

The serum antibody response and four different cellular immune responses (cytotoxic T cells, delayed-type hypersensitivity T cells, natural killer cells, and cytotoxic macrophage levels) induced in CBA/H mice were measured at different times after intranasal inoculation of a cold-adapted (ca) variant of influenza A virus, influenza virus A/Ann Arbor/6/60-ca, or the parental virus, influenza virus A/Ann Arbor/6/60. At the highest dose of virus inoculated (5 log10 50% tissue culture infective doses), all four cellular responses reached high levels in the lungs of both groups of mice, and serum antibody titers were detected on day 20 after inoculation of either virus. However, whereas extensive replication of the parental virus occurred in the mouse lungs, very limited replication of the ca variant was observed. Macroscopically, infection with the parental virus caused gross lung damage, whereas such damage was almost absent in mice inoculated with the ca variant. Inoculation of 2 to 5 log10 50% tissue culture infective doses of the parental virus induced high cytotoxic T-cell responses, whereas only the highest dose of the ca variant caused a clearly significant cytotoxic T-cell response. As an inoculum of 5 log10 50% tissue culture infective doses of the ca variant caused a substantial primary immune response without appreciable lung damage, the avirulence of the ca variant may be primarily related to its limited ability to replicate productively in mouse lungs.
Cell Wall-Associated Protein Antigens of
Streptococcus salivarius
: Purification, Properties, and Function in Adherence
Authors: Weerkamp Anton H. , Jacobs Ton
Published: January 2020

Three cell wall-associated protein antigens (antigens b, c, and d) were isolated from mutanolysin-solubilized cell walls of
Streptococcus salivarius
HB and purified to apparent homogeneity by a combination of ion-exchange chromatography, gel filtration, and immunoadsorption chromatography. Antigens b and c were also isolated from culture supernatants. Antigen b consisted of more than 80% protein and had an apparent molecular weight as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of 320,000. Antigen c consisted of 57% protein, about 30% neutral sugar, and about 13% amino sugar, and its glycoprotein nature was confirmed by specific staining techniques. During sodium dodecyl sulfate-polyacrylamide gel electrophoresis antigen c resolved into two or more bands, depending on the source or the isolation procedure, in the molecular weight range from 220,000 to 280,000. Antigen d consisted of 95% protein and was observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as two bands with molecular weights of 129,000 and 121,000. Under nondenaturing conditions all three antigens had molecular weights in the range from 1 × 10
6
to 3 × 10
6
as determined by gel filtration. The amino acid compositions of antigens b, c, and d were characterized by low amounts of basic amino acids and relatively high levels of nonpolar amino acids. Among oral streptococcal species antigens b and c were virtually restricted to strains of
S. salivarius
and most often to serotype I strains. Antigen b was recognized as the factor that mediates coaggregation of
S. salivarius
with
Veillonella
strains. The purified protein retained its biological activity. Antigen c could be linked to functions relating to adhesion of the streptococci to host tissues on the basis of its absence in mutant strains and blocking by specific antisera. The purified molecule had no detectable biological activity. Antigen d could not be linked to an established adhesion function.
Heterogeneic Autoantibody Against Neurofilament Protein in the Sera of Animals with Experimental Kuru and Creutzfeldt-Jakob Disease and Natural Scrapie Infection
Authors: Aoki Tomonobu , Gibbs Clarence J. , Sotelo Julio , Gajdusek D. Carleton
Published: January 2020

Heterogeneic autoantibodies against axonal neurofilament proteins of mature mouse neurons grown in vitro were detected by the indirect immunofluorescence technique in 12.7% (9 of 71) of the sera from nonhuman primates infected with kuru, in 14.5% (17 of 117) and 4% (1 of 25), respectively, of the sera from nonhuman primates and laboratory rodents infected with Creutzfeldt-Jakob disease, and in 35% (7 of 20) of the sera from sheep naturally infected with scrapie. Autoantibody titers ranged from 1:16 to 1:512 in Creutzfeldt-Jakob disease-infected animals, 1:32 to 1:512 in kuru-infected animals, and 1:64 to 1:1,024 in sheep with natural scrapie. The sera from 11 monkeys and 17 hamsters infected with scrapie and from 19 chimpanzees inoculated with brain tissues from humans with other neurological diseases did not contain autoantibodies. Of the 41 chimpanzees with Creutzfeldt-Jakob disease, 6 had autoantibodies against neurofilament proteins before experimental inoculation, whereas 6 others developed autoantibodies after inoculation, 4 developed autoantibodies during the asymptomatic phase, and 2 developed autoantibodies during the terminal clinical phase. Of the 48 chimpanzees with kuru, 2 had autoantibodies before inoculation, 6 developed autoantibodies after inoculation, 3 developed autoantibodies during the asymptomatic phase, and 3 developed autoantibodies during the terminal clinical phase. Among the normal nonhuman primate controls, 4.6% (9 of 195) had autoantibodies. In contrast, no autoantibodies were detected in 49 control rodents and 13 control sheep. The increased incidence of autoantibodies against neurofilament proteins in animals with kuru, Creutzfeldt-Jakob disease, and scrapie constitutes the first evidence of an immunological reaction in this group of atypical infections caused by unconventional viruses and suggests that neurofilaments may be involved in pathogenesis.
Isolation and characterization of phagosomes containing Chlamydia psittaci from L cells
Authors: Zeichner S L
Published: January 2020

The obligate intracellular procaryote Chlamydia psittaci enters host cells by a mechanism similar to, but distinct from, conventional phagocytosis. To better understand chlamydial uptake, L-cell phagosomes containing a single chlamydial cell were isolated and studied. Two rounds of dextran rate-zonal gradient centrifugation of L cells homogenized 1 h after infection with C. psittaci yielded phagosomes relatively free of other membranous structures. In double-label experiments, the phagosomes were enriched over 40-fold for radioactivity derived from chlamydiae as compared with the initial homogenate. Several lines of evidence showed that the structures isolated on dextran gradients were chlamydial phagosomes. These structures and free chlamydiae banded at different positions on discontinuous sucrose gradients. The difference was destroyed by the nonionic detergent Nonidet P-40, which disrupts plasma membranes but has no effect on C. psittaci. Material labeled on the surface of the L-cell plasma membrane cosedimented with the phagosome fractions. Electron microscopy of these fractions revealed structures having the appearance of a chlamydial elementary body surrounded by a unit membrane. Sodium dodecyl sulfate-polyacrylamide gels of the phagosome membranes displayed 10 major protein bands, less than the total number of surface-labeled proteins in the L-cell plasma membrane. Seven of the proteins of phagosome membranes had electrophoretic mobilities corresponding to those of proteins exposed on the surface of L cells. Two of them were cleaved by both trypsin and chymotrypsin, enzymes that decrease the susceptibility of L cells to infection with C. psittaci. These proteins may therefore be involved in the attachment and ingestion of C. psittaci by L cells.
Entry of Rickettsia tsutsugamushi into polymorphonuclear leukocytes
Authors: Rikihisa Y , Ito S
Published: January 2020

Factors involved in the phagocytosis and entry into polymorphonuclear leukocytes (PMNs) of Rickettsia tsutsugamushi were studied by electron microscopy. R. tsutsugamushi propagated in baby hamster kidney cell cultures was incubated with guinea pig peritoneal PMNs in vitro at 35 degrees C. Structurally intact and degenerating rickettsiae were found in phagosomes, but only intact rickettsiae escaped phagosomes and specifically entered the glycogen-rich cytoplasm. The extraphagosomal cytoplasmic rickettsiae were found within 30 min after incubation; continued incubation for 4 h increased the rickettsial entry about fourfold as seen in ultrathin sections. Most rickettsiae in phagosomes were degenerating after 4 h of incubation. When incubated at 25 degrees C, no entry and very few phagocytized rickettsiae were observed. At 40 degrees C, rickettsial entry was greatly reduced, but more rickettsiae were found in phagosomes than at 35 degrees C. Preincubation of rickettsiae at 56 degrees C for 20 min with trypsin or with 2,4-dinitrophenol inhibited entry, but many rickettsiae were in phagosomes. Glutaraldehyde or formaldehyde fixation of rickettsiae and addition of 2-deoxyglucose, iodoacetamide, cytochalasin B, colchicine, or vinblastine inhibited all rickettsial uptake by PMNs. Acid phosphatase cytochemistry of infected PMNs revealed the enzyme activity only in phagosomes with degenerated rickettsiae and not in those with intact rickettsiae. These observations indicated that rickettsiae are passively phagocytized by PMNs, and only those that are intact actively escape from phagosomes, which selectively inhibits lysosomal fusion.
Synergistic protective effect of antibodies against Escherichia coli enterotoxin and colonization factor antigens
Authors: Ahrén C M , Svennerholm A M
Published: January 2020

We studied the ability of antisera against different Escherichia coli surface antigens, both alone and in combination with anti-enterotoxin, to decrease fluid secretion induced by intestinal challenge with enterotoxigenic E. coli in rabbits. Antiserum against lipopolysaccharide protected significantly against O group homologous bacteria. Monospecific antisera against pilus-associated colonization factor antigens CFA/I and CFA/II were also effective, giving highly significant protection against enterotoxigenic E. coli strains bearing the corresponding colonization factor antigens. Protection was also observed with Fab fragments of the CFA/I antibodies. Addition of the anti-lipopolysaccharide serum to a protective antiserum against purified heat-labile enterotoxin resulted in an antisecretory effect which slightly exceeded the sum of the effects obtained with each preparation alone. The combination of antiserum against CFA/I or CFA/II with anti-enterotoxin gave protection that equaled the product of the effects obtained with each antiserum alone; i.e. the antisera cooperated synergistically.
Effect of microbial interaction on the colonization rate of Actinomyces viscosus or Streptococcus mutans in the dental plaque of rats
Authors: Beckers H J , van der Hoeven J S
Published: January 2020

The resident oral microflora of conventional Osborne-Mendel rats was challenged with Actinomyces viscosus or Streptococcus mutans strains. The adherence of the inoculated organism to the tooth surface and the subsequent growth were studied by means of viable counts determination. The initial growth rate of S. mutans in conventional rats was lower than in mono-associated gnotobiotic rats (doubling time, td = 5 h versus td = 1.1 h). The delayed start of growth and the low initial growth rate indicated that a competitive interaction between S. mutans and the resident microflora occurred. The initial growth rate of A. viscosus in conventional rats (td = 3.1 h) was approximately the same as that in gnotobiotic rats (td = 2.8 h). The start of growth of A. viscosus was only slightly delayed compared with the start in gnotobiotic rats. These results suggest a neutralistic relationship between A. viscosus and the resident microflora. A. viscosus reached a stationary level about 7 days after inoculation, whereas the S. mutans strains did not reach stationary levels until 2 weeks after inoculation.
Potentiation of lymphocyte natural killing by mixtures of alpha or beta interferon with recombinant gamma interferon
Authors: Weigent D A , Langford M P , Fleischmann W R , Stanton G J
Published: January 2020

Human lymphocytes were treated with human alpha (IFN-alpha), beta (IFN-beta), or recombinant gamma (IFN-gamma) interferons separately or in combination to determine their ability to enhance natural killing against mouse L cell targets. Our results showed that recombinant IFN-gamma was approximately 50 times more active per unit of antiviral activity than either IFN-alpha or IFN-beta. Moreover, the levels of natural killing by lymphocytes treated with combinations of IFN-alpha and IFN-beta were additive, whereas combinations of recombinant IFN-gamma and IFN-alpha or recombinant IFN-gamma and IFN-beta were synergistic. The development of natural killing in lymphocytes treated with recombinant IFN-gamma did not occur more rapidly but reached higher levels (62%) than that observed with lymphocytes treated with IFN-alpha or IFN-beta (15%). The results suggest the importance of IFN-gamma and mixtures of IFN-gamma with IFN-alpha or IFN-beta in the enhancement of natural killing activity against virus infections and neoplasia.
Preparation and immunochemical characterization of meningococcal group C polysaccharide-tetanus toxoid conjugates as a new generation of vaccines
Authors: Beuvery E C , Miedema F , van Delft R , Haverkamp J
Published: January 2020

Neisseria meningitidis group C polysaccharide-tetanus toxoid conjugates have been prepared by using high-molecular-weight polysaccharide and purified tetanus toxoid and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide as a coupling reagent. The influence of three conditions of preparation was studied. Biochemical assays, the enzyme-linked immunosorbent assay, and isopycnic CsCl gradient ultracentrifugation have been used to characterize the conjugates. The polysaccharide-to-protein ratios of the various conjugate preparations showed differences. The ability of the group C polysaccharide component to react with specific antibodies was reduced, whereas most of the tetanus toxoid seemed to be hidden by the polysaccharide. The composition of the conjugate was not homogeneous, and at least 10% of free polysaccharide was present. Thermostability in lyophilized condition in the presence of lactose was excellent.
Inhibition of Human Polymorphonuclear Leukocyte Function by Components of Human Colostrum and Mature Milk
Authors: Pickering Larry K. , Cleary Thomas G. , Caprioli Richard M.
Published: January 2020

To compare the effect of human colostrum (days 1 to 3 postpartum) and mature milk (days 170 ± 24 postpartum) on the function of polymorphonuclear leukocytes (PMNL), Ficoll-Hypaque-separated PMNL from the blood of 60 healthy volunteers were incubated with whole colostrum, colostral lipid, and colostral aqueous phase from 30 mothers, or with mature whole milk and its separated components from 30 mothers, and tested for resting and zymosan-stimulated oxidative metabolism, functional activity, and the presence of Fc receptors. Stimulated oxygen consumption, quantitative nitroblue tetrazolium dye reduction, [1-
14
C]glucose utilization, and Fc receptors were significantly (
P
< 0.05 to
P
< 0.001) less in PMNL exposed to whole human colostrum or colostral lipid than in non-lipid-exposed cells or cells exposed to the aqueous phase of colostrum. In contrast, PMNL exposed to whole mature milk or to its lipid or aqueous phase caused no significant decrease in any of these parameters when compared to nonexposed cells. In assays of phagocytosis, colostral PMNL or blood PMNL exposed to colostral lipid had a significant (
P
< 0.001) decrease in their ability to ingest [
methyl
-
3
H]thymidine-labeled
Staphylococcus aureus
when compared to non-lipid-exposed PMNL. Blood PMNL exposed to lipid from mature milk had no decrease in ability to ingest
S. aureus.
Analysis of total lipid and total and individual fatty acid content revealed a uniform increase in all components in mature milk when compared to colostrum. Lipid or lipid-soluble material present in human colostrum but not mature milk causes inhibition of phagocytosis and respiratory burst-related activities of PMNL.
Search for Sendai 6/94 viral RNA in the antigen-free cell line Cl-C-2 isolated from human multiple sclerosis brain tissue
Authors: Neubert W J , Hofschneider P H , Koprowski H
Published: January 2020

The viral antigen-free cell line Cl-C-2, obtained from multiple sclerosis brain tissue by cell fusion with CV-1 cells, was examined for the presence of intracellular virus-specific RNA sequences of the persistent Sendai 6/94 virus by nucleic acid hybridization. As a specific probe for this assay, an in vitro synthesized cDNA was used. Oligodeoxyguanidylic acid served as a primer for the initiation of cDNA synthesis. The 6/94 RNA was detectable as expected in the viral antigen-expressing cell lines Cl-E-8 and Cl-F-2, which were used as a reference of the same source. In the viral antigen-free cell line Cl-C-2, however, no viral RNA sequences have been found by hybridization experiments. Corresponding superinfection studies confirmed the conclusion that in cell line Cl-C-2 no viral components are present. The lack of expression of viral proteins and of protection against superinfection seems to be correlated with the lack of viral RNA in Cl-C-2 cells, which may eliminate the persistent virus by a cellular defense mechanism.
Identification of an antigen-specific immunoglobulin M antibody associated with acute Toxoplasma infection
Authors: Erlich H A , Rodgers G , Vaillancourt P , Araujo F G , Remington J S
Published: January 2020

We used the protein gel transfer technique (Western blotting) to analyze the immune response to individual electrophoretically resolved Toxoplasma antigens. Toxoplasma antigens were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The array of resolved proteins was electrophoretically transferred to CNBr-activated filter paper and incubated with serum samples from patients with either acute or chronic Toxoplasma infections or with serum samples from seronegative controls. Serum immunoglobulin G and immunoglobulin M bound to individual Toxoplasma antigens were detected by radioiodinated staphylococcal protein A and a goat anti-human immunoglobulin M antibody, respectively. A complex array of Toxoplasma antigens was revealed by this procedure. Immunoglobulin M directed against a low-molecular-weight antigen was detected in sera from all acutely infected adults (19 sera tested) and was absent from all sera from individuals with chronic infections (9 sera tested) and from sera from seronegative controls (9 sera tested).
Immunochemical characterization of Aspergillus fumigatus antigens
Authors: Kurup V P , Ting E Y , Fink J N
Published: January 2020

Culture filtrate antigens of Aspergillus fumigatus Ag 534 were purified by preparative isoelectric focusing and affinity chromatography. One of the pooled antigen fractions from the preparative isoelectric focusing step (pool 2) was passed through a concanavalin A column and yielded two components, designated antigens IIa and IIb. Antigen IIb reacted more strongly than antigen IIa with all of the aspergilloma and allergic bronchopulmonary aspergillosis sera tested by enzyme-linked immunosorbent assay. The glycoprotein nature of antigen IIb was shown by the concanavalin A binding properties and staining reactions of the components.
Colonization of murine ganglia by a superinfecting strain of herpes simplex virus
Authors: Meignier B , Norrild B , Roizman B
Published: January 2020

We report on the colonization of murine trigeminal ganglia after sequential infection of mice by herpes simplex viruses (HSVs). In preliminary studies, we have established that whereas the HSV-1(F) strain efficiently colonizes ganglia when inoculated by either the ear or eye routes, the HSV-1 X HSV-2 recombinant C7D colonizes ganglia when inoculated by the eye route only. The experimental design consisted of inoculating the right eye with C7D on day 1 and with HSV-1(F) in both left and right eyes on day 26. Both right and left trigeminal ganglia were removed and analyzed independently for latent virus on day 52. Our studies indicate that HSV-1(F) viruses were recovered from all left trigeminal ganglia but from only a small number of right trigeminal ganglia. Some right trigeminal ganglia yielded no viruses, whereas others yielded both C7D and HSV-1(F) viruses identified on the basis of plaque morphology and restriction enzyme cleavage patterns of viral DNA. The results indicate that more than one virus may colonize the same ganglion and that trigeminal ganglia may be protected from colonization by a superinfecting virus by determinants acting at a local level in the absence of demonstrable virus.
Identification and preliminary characterization of Treponema pallidum protein antigens expressed in Escherichia coli
Authors: Stamm L V , Kerner T C , Bankaitis V A , Bassford P J
Published: January 2020

We have previously described the construction in Escherichia coli K-12 of a hybrid plasmid colony bank of Treponema pallidum (Nichols strain) genomic DNA. By screening a portion of this bank with an in situ immunoassay, we identified six E. coli clones that express T. pallidum antigens. In this study, the recombinant plasmids from each of these clones have been analyzed in E. coli maxicells and have been found to encode a number of proteins that are not of vector pBR322 origin and are, therefore, of treponemal origin. In each case, several of these proteins can be specifically precipitated from solubilized maxicell extracts by high-titer experimental rabbit syphilitic serum. Certain of these proteins are also precipitated by high-titer latent human syphilitic sera (HSS). The T. pallidum DNA inserts in these plasmids range in size from 6.2 to 14 kilobase pairs, and from the restriction patterns of the inserts and the protein profiles generated by each plasmid in maxicells, it is apparent that we have recovered a total of four unique clones from our colony bank. Recombinant plasmids pLVS3 and pLVS5 were of particular interest. Plasmid pLVS3 encodes three major protein antigens with molecular weights of 39,000, 35,000, and 25,000. These three proteins, which were not recognized by pooled normal human sera, were efficiently precipitated by most secondary HSS, latent HSS, and late HSS tested. These proteins were also precipitated, although somewhat inefficiently, by most primary HSS tested. Plasmid pLVS5 encodes a major protein antigen with a molecular weight of 32,000 and several minor protein antigens that, although efficiently precipitated by experimental rabbit syphilitic serum, were generally not recognized by the various HSS tested. Evidence is presented indicating that the protein antigens encoded by plasmids pLVS3 and pLVS5 are specific for pathogenic treponemal species. We have also demonstrated that immunoglobulin G antibodies directed against these protein antigens can be detected in rabbits experimentally infected with T. pallidum Nichols as early as 11 days postinfection.
Salmonella typhimurium infection in calves: protection and survival of virulent challenge bacteria after immunization with live or inactivated vaccines
Authors: Robertsson J A , Lindberg A A , Hoiseth S , Stocker B A
Published: January 2020

Salmonella typhimurium SL1479, an auxotrophic mutant strain having a complete block in the aromatic biosynthetic pathway and therefore requiring p-aminobenzoic acid and 2,3-dihydroxybenzoate not available in mammalian tissues, was given orally in a dose of 10(10) live bacteria to 4- to 5-week-old calves. Only a mild transient fever response was seen. Strain SL1479 was unable to colonize and persist in the calves for more than 2 weeks. In a vaccination experiment, groups of six calves were (i) orally vaccinated with the live S. typhimurium SL1479 strain, (ii) subcutaneously vaccinated with a heat-inactivated S. typhimurium SVA1232 strain with aluminum hydroxide as adjuvant, or (iii) not vaccinated, to serve as controls. Calves were orally challenged with the live, calf-virulent S. typhimurium SVA44 strain: either 10(6) bacteria (equivalent to 100 25% lethal doses [LD25S]) or 10(9) bacteria (100,000 LD25S doses). The live oral vaccine gave significantly better protection than the heat-vaccinated, subcutaneously injected vaccine since (i) only control calves and calves given the killed vaccine developed profuse diarrhea, (ii) clinically, the mild fever responses seen after challenge in calves given the live vaccine were significantly lower (P less than 0.0005), (iii) autopsies performed 21 days after the challenge infection revealed normal findings in calves given the live vaccine, whereas calves given the killed vaccine showed signs of acute enteritis and chronic salmonellosis, (iv) all 12 calves given either 100 X or 100,000 X the LD25 survived the 21-day observation period; the mean survival time in nonvaccinated calves was 8.0 days; in calves given heat-inactivated vaccine and 100 X the LD25 it was 21.0 days, and in calves given 100,000 X the LD25 it was 11.5 days, (v) the fecal bacterial counts of the challenge S. typhimurium SVA44 strain were significantly lower (P less than 0.0005) in both groups given the live vaccine, and (vi) upon autopsy followed by culture, the qualitative recovery of the challenge strain from the alimentary canals and tissues of calves given the live vaccine was significantly lower (P less than 0.005).
Salmonella typhimurium infection in calves: cell-mediated and humoral immune reactions before and after challenge with live virulent bacteria in calves given live or inactivated vaccines
Authors: Lindberg A A , Robertsson J A
Published: January 2020

Groups of six calves, 4 to 5 weeks old, were vaccinated either orally with a live auxotrophic Salmonella typhimurium (O-antigen 1,4,12) SL1479 vaccine (10(8) bacteria on day zero, 10(10) bacteria on days 7 and 14) or subcutaneously with a heat-inactivated (56 degrees C, 30 min) S. typhimurium SVA1232 vaccine (10(10) bacteria suspended in 30% [vol/vol] aluminum hydroxide on days zero, 7, and 14). The calves were then orally challenged with either 10(6) (approximately 100 X the 25% lethal dose) or 10(9) (approximately 100,000 X the 25% lethal dose) live bacteria of the calf-virulent S. typhimurium SVA44 strain. The immune reactivity of these calves and of nonvaccinated control calves was followed before and after the challenge infection up to 42 days by (i) intradermal injection of S. typhimurium crude extract, outer membrane protein preparation (porins), and lipopolysaccharide (LPS), (ii) in vitro stimulation of peripheral blood lymphocytes estimated by using uptake of [3H]thymidine, with S. typhimurium crude extract, porins, LPS, and polysaccharide (O-antigenic polysaccharide chain free of lipid A), and Salmonella sp. serotype thompson (O-antigen 6,7) strain IS40 LPS and polysaccharide, and (iii) estimation of the class-specific immunoglobulin G (IgG) and IgM antibody responses against S. typhimurium LPS and porins, and Salmonella sp. serotype thompson LPS. The immune studies showed that in calves given the live vaccine orally, the skin test reactivity and lymphocyte stimulation indices were significantly higher (P values ranging from less than 0.025 to less than 0.0005) against homologous, but not heterologous, antigens than those seen in calves given the heat-inactivated vaccine subcutaneously. In contrast, the IgG and IgM antibody titers against homologous LPS and porins were significantly higher (P less than 0.0005) in sera collected on day 21 from calves given the heat-inactivated vaccine than in calves given the live vaccine. After the oral challenge, calves given the live vaccine showed reduced cell-mediated immune reactions, in agreement with the observation that the host defense could eradicate the challenge organism, whereas calves given the heat-inactivated vaccine showed significantly increased cell-mediated immune reactions (P values ranging from less than 0.025 to less than 0.005), in agreement with the observation that in these calves, the challenge strain caused enteritis as well as systemic invasion. The increased cell-mediated immune reactivity in calves given the live vaccine correlated well with the excellent protection against challenge infection seen in these animals.
Monoclonal immunoglobulin M antibody to Japanese encephalitis virus that can react with a nuclear antigen in mammalian cells
Authors: Gould E A , Chanas A C , Buckley A , Clegg C S
Published: January 2020

An immunoglobulin M (IgM) class monoclonal antibody raised against Japanese encephalitis virus reacted with an epitope on the nonstructural virus protein P74 (NV4 in the old nomenclature) of several flaviviruses and also with an antigen present in the nuclei of a variety of mammalian cell types. This antigen had a characteristic granular distribution by immunofluorescence and may correspond to a polypeptide of molecular weight 56,000 seen in nitrocellulose transfers of sodium dodecyl sulfate-polyacrylamide gels. Cross-reactivity with nuclear antigen was also occasionally observed in the IgM antibody fraction of mice early after infection with Japanese encephalitis virus and also in acute sera from some clinical cases of encephalitis containing IgM antibody to Japanese encephalitis virus.
Clostridium tetani growth and toxin production in the intestines of germfree rats
Authors: Wells C L , Balish E
Published: January 2020

Germfree rats were challenged orally and intrarectally with spores of Clostridium tetani. Although C. tetani spores remained viable in the intestinal tract, they were unable to germinate. Germfree rats were then challenged orally with vegetative cells of C. tetani. Vegetative cells were able to colonize the intestinal tract, replicate, and produce toxin. Tetanus antitoxin, but no tetanus toxin, was detected in the sera of monoassociated rats.
Rotavirus-associated traveler's diarrhea: neutralizing antibody in asymptomatic infections
Authors: Smith C C , Aurelian L , Santosham M , Sack R B
Published: January 2020

The sera of patients with traveler's diarrhea were assayed for rotavirus-specific immunoglobulins in enzyme-linked immunosorbent and micro-neutralization assays. The antigenically related simian rotavirus SA-11 was used in both assays. Although similar titers of rotavirus-specific binding immunoglobulin G and A were observed in the sera of both symptomatic and asymptomatic subjects, clinical illness appeared to correlate with the failure to detect increased (greater than or equal to fourfold) titers of neutralizing antibodies in the post- as compared with the pretravel sera.