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Induction of immunologic memory in Gambian children by vaccination in infancy with a group A plus group C meningococcal polysaccharide-protein conjugate vaccine.

Two hundred twenty-one Gambian children vaccinated previously with one, two, or three doses of a meningococcal conjugate vaccine or two doses of polysaccharide vaccine before the age of 6 months were revaccinated at the age of 18-24 months with either meningococcal polysaccharide, conjugate, or inactivated polio vaccines. Children who had previously received one, two, or three doses of conjugate vaccine had significantly (P < .001) higher anti-group C meningococcal antibody levels following revaccination than did children vaccinated with a polysaccharide vaccine for the first time. Children vaccinated previously with two doses of polysaccharide vaccine had a lower group C antibody response than did control children. Group A antibody responses following revaccination of children who had previously received polysaccharide or conjugate vaccine were not significantly higher than those in control children. Thus, immunologic memory was probably induced by the group C but not by the group A component of the conjugate vaccine.

Antibodies, Bacterial↗

Effect of viscous indigestible polysaccharides on pancreatic-biliary secretion and digestive organs in rats.

Effects of viscous indigestible polysaccharides on the pancreas exocrine function were investigated in growing rats. Rats were fed a nonfiber diet or a diet containing approximately 5% of one of the following fibers: apple pectin, lambda-carrageenan, locust bean gum, gum xanthan, guar gum or sodium (Na) alginate. Pancreatic-bile secretion was found to be elevated in rats fed for 2 wk the highly viscous polysaccharides, sodium alginate, locust bean gum, gum xanthan and guar gum. The polysaccharides may have interfered with the digestion and absorption of nutrients, resulting in a decreased digestibility and an enlargement of digestive organs. When alginic acid and calcium alginate, insoluble polysaccharides that did not contribute to viscosity, were given to rats, they had no effect on pancreatic and biliary secretion compared with sodium alginate. The results demonstrate that consumption of viscous indigestible polysaccharides leads to changes in the exocrine pancreatic-biliary function and may depress the process of digestion and absorption. Rats may compensate for the inefficiency of digestion and absorption with a hyperplasia/hypertrophy of digestive organs and an increased secretion of digestive juice.

Alginates↗

Viscous indigestible polysaccharides reduce accumulation of pentachlorobenzene in rats.

To investigate an effect of indigestible polysaccharides (cellulose as control, sodium alginate, guar gum or lambda-carrageenan) on the accumulation of pentachlorobenzene, male Sprague Dawley rats were fed experimental diets containing 5 g/100 g of these polysaccharides for 2 wk. They were then given orally 80 mumol (20 mg) of pentachlorobenzene along with their respective diets and the residual pentachlorobenzene was determined after 7 d. The ingestion of the viscous indigestible polysaccharides resulted in significantly lower accumulation of pentachlorobenzene in adipose tissue, liver and kidney than that found in rats fed a cellulose diet. Soon (5 h) after pentachlorobenzene administration, its concentration in the blood of rats fed sodium alginate and guar gum was higher than that of rats fed cellulose, but lower in the groups fed all three viscous polysaccharides after d 3. These results indicate that pentachlorobenzene excretion was increased by the ingestion of viscous indigestible polysaccharides. Lower relative weight of adipose tissue, a storage tissue for pentachlorobenzene, was found in the rats fed sodium alginate and guar gum. The lower adipose tissue mass was likely the main contributor to the enhancement of pentachlorobenzene excretion.

Administration, Oral↗

Effects of Chinese herbal polysaccharides on the immunity and growth performance of young broilers.

Two trials were conducted to study the effects of two Chinese herbal polysaccharides [achyranthan (ACH), a low-molecular-weight polysaccharide, and astragalan (APS), a high-molecular-weight polysaccaride] on the immunity and growth performance of young broilers. Trial 1 was a 28-d growth assay, in which 7-d-old broilers (n = 240) were randomly allotted to one of three dietary treatments, with eight replicate pens per treatment and ten chickens per pen. Dietary treatments included a control corn-soy-fishmeal (Treatment 1), a diet with 200 mg/kg APS (Treatment 2), and a diet with 200 mg/kg ACH (Treatment 3). Blood samples were collected by cardiac puncture on Days 7, 14, 21, and 28 for determination of serum parameters, and chickens were killed on Day 28 to measure immune organ indexes. Trial 2 was an in vitro trial to study the effects of different concentrations of polysaccharides on broiler splenocyte functions. In Trial 1, feeding either APS or ACH had no significant effects on growth performance of broilers relative to the control. However, compared to the control, feeding ACH significantly increased microhemagglutination inhibition (HI) antibody titers, bursa of Fabricius index, serum albumin, serum calcium, and nitric oxide (NO) concentrations at Day 28 (P < or = 0.05). In Trial 2, both polysaccharides showed significant immunostimulating effects. They increased NO and interleukin-2 (IL-2) production of splenocytes and enhanced splenocyte proliferation in a dose-dependent manner (P < 0.05). Those results indicate that the immunostimulating effects of APS are not as pronounced as those of ACH. Achyranthan showed immunostimulating effects in both the growth assay and in vitro studies. Therefore, ACH may be a Chinese herbal polysaccharide that has the potential to be used as a feed additive to improve broilers' immunity.

Animals↗

Serum antibodies to pneumococcal C polysaccharide in children: response to acute pneumococcal otitis media or to vaccination.

Immunoglobulin class-specific antibody responses to the pneumococcal C polysaccharide (CPS) and to the capsular polysaccharides of types 3, 6A, 18C and 19F were measured by enzyme-linked immunosorbent assay in the sera of children ages 6 months to 7 years. Twenty of these children had acute otitis media caused by pneumococci of type/group 3, 6, 18 or 19, whereas 20 received an injection of 14-valent pneumococcal capsular polysaccharide vaccine. Many of the children in both groups had large concentrations of IgG and/or IgM class anti-CPS antibodies in their first serum sample. Both the infection and the vaccine elicited anti-CPS responses in all three immunoglobulin classes, most notably IgA. The pneumococcal capsular polysaccharides used as antigens in the enzyme-linked immunosorbent assay were found to contain CPS in amounts ranging from less than 1 to 30%. As a result the enzyme-linked immunosorbent assay detected both anti-type-specific and anti-CPS antibodies. After elimination of the anti-CPS, type-specific pneumococcal antibodies were found only occasionally and in low concentrations in serum samples obtained in the acute phase of otitis or before vaccination. The infection induced homologous type-specific pneumococcal antibodies to varying degrees depending on the type: regularly to type 3; and fairly regularly to type 18C polysaccharide, but seldom to type 6 or 19. The pneumococcal vaccine induced type-specific antibodies to all four types measured, but the response to type 6A was poor.

Acute Disease↗

Antibodies to pneumococcal polysaccharides in human milk: lack of relationship to colonization and acute otitis media.

BACKGROUND: This study analyzed antibodies to pneumococcal polysaccharides in human milk and their effect on nasopharyngeal colonization and acute otitis media in breast-fed infants. METHODS: A total of 503 milk samples were collected from 310 mothers. Nasopharyngeal cultures were obtained from their children at 2, 6 and 10 months postpartum, and the capsular groups/types of the Streptococcus pneumoniae isolates were determined. RESULTS: Types 6A, 6B, 19A, 19F and 23F accounted for 54% of the pneumococcal isolates, but type 3 isolates were uncommon. Milk samples were analyzed for antibody activity to the common capsular polysaccharide types 6A, 19F and 23F; to the type 3 polysaccharide; to C-polysaccharide; and to phosphorylcholine (PC), a major component of the pneumococcal cell wall polysaccharide (CWPS). Anti-capsular antibody activity was low or absent in > 90% of the milk samples. In contrast anti-PC antibody activity was detected in 88% and anti-CWPS in 84% of the samples. The frequency of acute otitis media did not vary with the milk anti-capsular, anti-PC or anti-CWPS antibody activity. CONCLUSIONS: There was no reduction in nasopharyngeal carriage of S. pneumoniae among children fed milk with anti-capsular or anti-PC antibody activity, but carriage was increased in those children who received milk with anti-CWPS antibody activity. A protective role of antipolysaccharide or anti-CWPS antibodies in milk was not detected under the study conditions.

Adult↗

Response to a heptavalent conjugate Streptococcus pneumoniae vaccine in children with recurrent infections who are unresponsive to the polysaccharide vaccine.

OBJECTIVE: To determine whether children with recurrent respiratory infections who failed to respond to the conventional polysaccharide vaccine would respond to a pneumococcal conjugate vaccine. METHODS: Children referred to our clinic for recurrent respiratory infections who had no known primary or secondary immunodeficiencies were immunized with a 23-valent pneumococcal polysaccharide vaccine. IgG antibodies to pneumococcal serotypes 1, 3, 4, 6B, 9V, 14, 18C, 19F and 23F were determined by enzyme-linked immunosorbent assay before and 4 to 6 weeks after immunization. An adequate IgG antibody response to an individual serotype was arbitrarily defined as a postimmunization antibody titer > or =1.3 microg/ml or at least 4 times the preimmunization value. Immunization with an experimental CRM197-heptavalent pneumococcal conjugate vaccine was offered to patients without an adequate response to 4 or more vaccine serotypes (nonresponders). Post-conjugate immunization antibody concentrations were measured 4 to 6 weeks later. RESULTS: In nonresponder patients (n = 17) geometric mean post-conjugate immunization (C) serum antibody concentrations (microg/ml) compared with post-polysaccharide (PS) concentrations were: (serotype, C vs. PS) 4, 1.11 vs. 0.30 (P = 0.000227); 6B, 0.46 vs. 0.20 (P = 0.017267); 9V, 0.82 vs. 0.29 (P = 0.002163); 14, 1.88 vs. 0.27 (P = 0.000615); 18C, 0.98 vs. 0.32 (P = 0.021962); 19F, 1.24 vs. 0.34 (P = 0.002844); and 23F, 0.87 vs. 0.16 (P = 0.000194). In responder patients (n = 67), after 1 dose of the polysaccharide vaccine, geometric mean antibody concentrations were: 4, 1.05; 6B, 0.96; 9V, 1.55; 14, 1.65; 18C, 1.62; 19F, 1.30; and 23F, 1.02. CONCLUSIONS: Our results show that a pneumococcal conjugate vaccine is capable of inducing an IgG response in patients with recurrent infections who had failed to mount an adequate response to the polysaccharide vaccine. Conjugate vaccines may be of value in the management of children with recurrent pneumococcal respiratory infections.

Adolescent↗

Detection of polysaccharide cell wall antigen of Neisseria gonorrhoeae in a rabbit model by counterimmunoelectrophoresis.

A rabbit chamber model was developed and inoculated with 10(9) colony-forming units (cfu) of viable Neisseria gonorrhoeae to determine whether the lipopolysaccharide-derived Gc2 polysaccharide cell wall antigens could be detected by counterimmunoelectrophoresis (CIE). Four hours after inoculation, a polymorphonuclear leukocyte response was noted in the chambers; this response was followed by progressive phagocytosis of the organisms and a fall in number of cfu/ml. All visible bacteria were intracellular, and chamber fluids were sterile 6 hr after inoculation. Use of sero specific antisera permitted detection by CIE of the Gc2 polysaccharide antigen in sera of all rabbits within 48 hr after inoculation of the chambers, whereas blood cultures remained sterile throughout the experiment. At 2-6 hr after inoculation, the Gc2 polysaccharide antigen was also detected as a single precipitin band in the chamber fluid of inoculated rabbits. At 24 hr the precipitin band was not observed; rather, a halo above the antigen well was noted. The halo was found to be a nonspecific complex containing the Gc2 polysaccharide antigen and no antibody. In the rabbit model studied, CIE was sufficiently sensitive to detect concentrations of the Gc2 polysaccharide antigen of greater than or equal to 0.97 microgram/ml in serum and chamber fluid.

Animals↗

Dosage escalation, safety and immunogenicity study of four dosages of a tetravalent meninogococcal polysaccharide diphtheria toxoid conjugate vaccine in infants.

BACKGROUND: Young children have the highest incidence of meningococcal infection. Approximately 50% of disease in United States children less than 2 years of age is caused by serogroups C and Y. In the developing world, serogroups A and W-135 cause outbreaks and epidemics of infection. METHODS: Three groups of 30 infants were enrolled. The first group of infants was given 3 doses of a quadrivalent (group A, C, Y, W-135) polysaccharide meningococcal vaccine conjugated to diphtheria toxoid (MCV-4) at a dosage of 1 microg of each serogroup polysaccharide. The second group of infants was given MCV-4 at a dosage of 4 microg, and the last group of children received a 10-microg dosage. Vaccinations were given at 2, 4 and 6 months of age.A subset of these children was vaccinated at 15 to 18 months of age with licensed meningococcal polysaccharide (A, C, Y, W-135) vaccine. Serum bactericidal antibody (SBA) titers were measured with baby rabbit complement. RESULTS: The proportion of infants with local reactions increased significantly with increasing dosages after Injection 1 and 3. Approximately 1 month after completion of the primary series, the proportion of infants with an SBA titer > or = 1/8 ranged from 54 to 92%, depending on the serogroup and dose of polysaccharide contained in the vaccine. The SBA geometric mean titer varied from 17.4 to 101.6. There was no statistically significant difference between the SBA responses among the 3 dosage groups. After vaccination with polysaccharide vaccine at 15 to 18 months of age, mean fold increases in SBA of 4.9 to 170.3 were observed, suggesting an anamnestic response. CONCLUSIONS: MCV-4 appears to have a reactogenicity profile acceptable to parents and health care providers. It was only modestly immunogenic in infants, but it appeared to prime the immune system of the majority of infants given three doses in infancy. There is no statistically significant immunologic advantage conferred by increasing the dosage beyond 4 microg/ml, and local reactions are more frequent after the 10-microg/ml dosage.

Antibodies, Bacterial↗

Immunoelectron microscopic study of the location of group-specific and type-specific polysaccharide antigens on isolated walls of group B streptococci.

The ultrastructural locations of the group-specific polysaccharide and the type-specific polysaccharides Ia, Ib, II and III of group B streptococci (Streptococcus agalactiae) were studied on isolated walls by the direct immunoferritin technique. The type polysaccharides were located exclusively on the outer side of the wall on which they formed a distinct capsule. Except for strain 58/59 (type Ia) the thickness of the capsule was characteristic of each strain investigated. In all strains the type-specific ferritin labelling was confined to the outer surface of the capsule. The group-specific polysaccharide could be demonstrated on the inner surface in all strains tested. It could also be demonstrated on the outer surface in strains 59/59 (type Ib) and 8/66 (group B variant) and on most of the walls of strain 58/59 (type Ia). The failure to detect this antigen on the outer side of the walls of strains 60/59 (type II) and 13/63 (type III) and on some walls of strain 58/59 was probably due to the thickness of the type polysaccharide capsule.

Cell Wall↗

Immunological relationship between the capsular polysaccharides of Neisseria meningitidis serogroups Z and 29E.

The immunological relationship between serogroups 29E and Z of Neisseria meningitidis was investigated using bacterial agglutination, precipitin-in-gel, primary antigen binding and immune lysis assays. The two capsular polysaccharides were both cross immunogenic and cross reactive. Demonstration of the relationship using group Z antisera depended on which assay was used. It was most readily apparent in assays of immune lysis, less apparent when precipitins were sought in gel and inapparent when bacterial agglutination, the standard assay for determining serogroup, was employed. The cross reacting epitope was expressed 10-fold more within the group 29E polysaccharide than within the group Z polysaccharide. These findings imply that inclusion of either polysaccharide in a polyvalent meningococcal vaccine may obviate the need to include the other polysaccharide.

Agglutination Tests↗

The role of surface polysaccharide in determining the resistance of Serratia marcescens to serum killing.

Two O14:H12 strains of Serratia marcescens with different sensitivities to killing by normal pooled human serum were investigated. Complement binding, studied by measuring hydrophobicity and using rocket immunoelectrophoresis with anti-human C3, showed the sensitive cells (S1220) rapidly bound and fixed complement whereas the resistant cells (4444-60) bound less C3b. The strains had identical membrane protein composition. Crossed immunoelectrophoresis suggested that in S1220 cells the polysaccharide material including LPS was less antigenic and present in smaller amounts than in 4444-60 cells. This was confirmed by examining extracted polysaccharide material chemically and by SDS-PAGE. The resistant strain had 33% more phenol-extractable polysaccharide material than the sensitive strain, possibly comprising LPS with longer O antigen chain lengths, or a microcapsule of O antigen polysaccharide. Extra polysaccharide material on the surface of the resistant strain prevents complement components binding and reaching the hydrophobic membrane where lytic lesions occur.

Antigens, Bacterial↗

Identification of two chemical types of K21 capsular polysaccharide from klebsiellae.

Strains of Klebsiella pneumoniae of serotype K21 are frequently involved in outbreaks of nosocomial infections. The type strain of Klebsiella pneumoniae K21 (which we have renamed K21a) produces capsular polysaccharide that contains mannose, galactose and glucuronic acid in the ratio 2:2:1. In contrast, all eight of the randomly chosen isolates of Klebsiella pneumoniae that were initially typed as K21 were shown by paper chromatography and NMR spectroscopy to produce a different capsular polysaccharide. We have designated this new polysaccharide K21b. The K21b capsular material appears to have a closely similar immunodominant side chain to K21a. However, K21b polysaccharide has two molecules of rhamnose in the polysaccharide backbone replacing the two molecules of mannose found in the K21a capsule. Our results suggest that the K21b Klebsiella serotype may be more frequently distributed than the classical K21a type.

Chemical Phenomena↗

Comparison of polysaccharides produced by Myxococcus strains.

Exopolysaccharides were prepared from cultures of four Myxococcus strains grown on solid and in liquid media, and also from the fruiting bodies. Lipopolysaccharides could be extracted with aqueous phenol from the vegetative bacteria, but were absent from microcysts. Mannose and D-glucose were present in all the exopolysaccharides and three of the lipopolysaccharides examined. Other monosaccharides identified in the exopolysaccharides were D-galactose, N-acetylglucosamine and N-acetylgalactosamine. The composition of the lipopolysaccharides was more complex than that of the exopolysaccharides and, in addition to the neutral hexoses and amino sugars, rhamnose was identified in two preparations and ribose in another. No lipopolysaccharide preparations contained O-methyl xylose or heptose. The polysaccharides secreted by the bacillary forms grown on solid or in liquid media closely resembled the polysaccharides isolated from the fruiting bodies, in which they provided a matrix surrounding the microcysts. Each pair of polysaccharides contained the same monosaccharides, although in slightly different proportions. Differences were found in preparations from different strains. These results suggest that in the development cycle of the genus Myxococcus, considerable use is made of pre-existing enzyme systems to synthesize the precursors necessary for polysaccharide synthesis. Any specific difference between the polysaccharide produced by the bacilli and that surrounding the microcysts may lie in the fine structure, rather than in the individual components.

Acetylgalactosamine↗

Extracellular and surface-exposed polysaccharides of non-tuberculous mycobacteria.

We studied the outermost constituents of the cell envelopes, which are involved in the interaction between the bacilli and the host cells, of five pathogenic and non-pathogenic mycobacterial species for comparison with those we have previously characterized from M. tuberculosis. The extracellular materials (ECMs) were isolated by ethanol precipitation and compared to the surface-exposed materials (SXMs) extracted by mechanical means. The materials from both sources were composed almost exclusively of polysaccharides and proteins. Two groups of mycobacteria were clearly distinguishable. The first group comprised the pathogenic species M. kansasii which produced large amounts of ECM, the glycosyl composition of which was similar to that of the SXM. The second group comprised M. avium and the non-pathogenic strains of M. gastri, M. phlei and M. smegmatis which produced small amounts of ECK This latter group could be subdivided into those which produced carbohydrate-rich ECM (M. avium and M. gastri) and those forming protein-rich ECM (M. phlei and M. smegmatis), a classification that correlated with the difference in the growth rate of the two subgroups. The glycosyl composition of the ECM of a given species was qualitatively similar to that of the SXM, except for M. avium and M. phlei whose SXM were devoid of arabinose. In addition to glucose, mannose and arabinose, xylose was detected in the hydrolysis products of the ECM and SXM of M. smegmatis, the SXM of M. phlei and the ECM of some batches of M. avium. The polysaccharide constituents of the ECM and SXM of the different mycobacteria were purified by anion-exchange and gel-filtration chromatography; all were found to be neutral compounds devoid of acyl substituents. The extracellular polysaccharides consisted of high-molecular-mass glycogen-like glucans, arabinomannans and mannans, structurally similar to the corresponding substances previously characterized from the capsule of M. tuberculosis. The same types of polysaccharides were characterized from the SXM of all the strains, except M. avium and M. phlei which were devoid of arabinomannans. This study questions the unique and universal representation of the mycobacterial cell envelope and the existence of the so-called acidic polysaccharide-rich outer layer.

Antigens, Bacterial↗

Skin reaction and macrophage migration inhibition tests for polysaccharides from Aspergillus fumigatus and Candida albicans.

Guinea pigs sensitized with purified galactomannan from Aspergillus fumigatus and mannan from Candida albicans, each containing negligible quantities of nitrogen, were examined for their immunological responses against the corresponding polysaccharides with respect to the delayed-type skin reaction and the macrophage migration inhibition phenomenon. In both cases, the delayed-type skin reaction test and the macrophage migration inhibition test showed positive results. The reactivity was stronger in animals sensitized with polysaccharides in Freund's complete adjuvant than those sensitized with the same polysaccharides in Freund's incomplete adjuvant. Polysaccharides chemically modified by partial acid degradation or by periodate oxidation were found to be completely incapable of eliciting such immune responses. These results are also discussed in relation to the antigenic determinant of the polysaccharides in such immune responses and the precipitin reaction previously observed by us and other investigators.

Animals↗

Chemical compositions of cell walls and polysaccharide fractions of spirochetes.

Cellular polysaccharide fractions of various representative members of genera of the family Spirochaetaceae were obtained by the ammonium hydroxide extraction method. The sugar composition of the polysaccharide preparations was complex and many kinds of sugars such as rhamnose, fucose, ribose, xylose, mannose, galactose, and glucose were detected in all of the spirochetes tested. Of particular interest was the presence of 4-O-methylmannose as a constituent polysaccharide in members of the genus Leptospira. This sugar was not detected in the polysaccharides of Spirochaeta, Borrelia, and Treponema. The chemical compositions of cell wall fractions were also examined. 4-O-Methylmannose was detected in the cell wall polysaccharides of the genus Leptospira but not in cell walls prepared from the Spirochaeta, Borrelia, and Treponema. The diaminopimelic acid present in cell wall peptidoglycans of the genus Leptospira was meso-diaminopimelic acid (A2pm). The molar ratios of alanine, glutamic acid, A2pm, glycine, muramic acid, and glucosamine in leptospiral cell walls were found to be approximately 2:1:1:1:1:1. In contrast to the Leptospira, the peptidoglycans of genera Spirochaeta, Borrelia, and Treponema contained ornithine (Orn) but not A2pm. Since 4-O-methylmannose and A2pm were found in the cell wall fractions of genus Leptospira but not in Spirochaeta, Borrelia, or Treponema, it was suggested that the chemical compositions of the cell wall might become an important criterion for the chemotaxonomy of Spirochaetales.

Carbohydrates↗

Radioallergosorbent test (RAST) studies with insolubilized polysaccharides.

Polysaccharide preparations from Aspergillus fumigatus and Candida albicans when used with some human sera were found to fix complement and precipitate with specific antibodies present in the sera. Precipitins consisted predominantly of IgG with traces of IgM and IgA. Following insolubilization of the fungal polysaccharide preparations with the N-carboxyanhydride of L-leucine, reactivity with serum precipitins was retained and reaction with IgE antibodies was demonstrated using the radioallergosorbent test (RAST). Results showed that for A. fumigatus and C. albicans at least, polysaccharide-specific IgE antibodies probably occur in sera from some hypersensitive individuals. We suggest that chemical methods of the type described which induce polymerization or cross-linking will be useful for detecting IgE antibodies in the RAST. Such an approach could be used with a variety of polysaccharide preparations which cannot be coupled to polysaccharide solid supports by the usual methods.

Antibodies, Fungal↗