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Induction of immunologic tolerance in nursing neonates by absorption of tolerogen from colostrum.

Deaggregatedhuman gamma-globulin (DHGG) injected into female mice within 24 hr after delivery of a litter enters the colostrum and is absorbed intact through the intestine by nursing neonates. This absorbed HGG was present in the neonatal circulation at concentrations of 0.3 to 0.6 mg/ml of serum under the experimental conditions used. This absorption of HGG by the nursing neonate resulted in a complete, specific, tolerant state to HGG. This tolerant state was stable upon adoptive cell transfer and could not be abrogated by transfer of normal syngeneic spleen cells.

Absorption↗

Interferon response in colostrum-deprived newborn calves infected with bovine rotavirus: its possible role in the control of the pathogenicity.

Colostrum-deprived newborn calves were experimentally infected with cell-culture rotavirus. A similar process of infection was observed when the animals were inoculated immediately after birth or at the age of three days, with a corresponding delay in the onset of virus excretion and interferon production in the later case. With high doses of virus, interferon was produced very early and no symptoms were observed. With lower doses of virus, interferon production was delayed and preceded by a severe but transient diarrhoea. In all cases, several waves of interferon production were observed. Our data indicate that interferon plays an important role in the control of viral diseases in calves and in their natural recovery.

Animals↗

Studies on neonatal calf diarrhoea caused by rotavirus: transmission of the disease and attempted vaccination of colostrum-deprived calves.

Mild to severe scouring could be produced in colostrum-deprived calves with tissue culture-adapted rotavirus and feacal material from field cases of calf diarrhoea. The feaces of experimentally infected calves contained rotavirus for at least 3 days. Pathogenic bacteria were presented in one calf only and this calf also showed the most severe gastroenteritis. Eight calves were vaccinated with a live rotaviral calf diarrhoea vaccine and subsequently challenged with infective rotavirus. Mild scouring was observed after vaccination, but the calves remained normal after challenge. Rotavirus particles were detectable in the faeces for a few days after vaccination and challenge.

Animals↗

[Attempt at the experimental reproduction of rotavirus diarrhea in newborn calves deprived of colostrum].

Colostrum-deprived newborn calves were orally inoculated with different doses of cell-culture bovine rotavirus or with bacterium-free filtrates of calf stools containing rotavirus. None of the animals that received high doses of cell-culture rotavirus developed diarrhoea or any other clinical sign, although all of them excreted virus for several days and produced specific antibodies; calves inoculated with lower doses of cell-culture virus or with stool filtrates showed a transient diarrhoea 48 h after inoculation. Such paradoxical results might be due to a phenomenon of interference, as bovine rotavirus is susceptible to interferon. In experimental conditions, rotavirus produces only a mild and transient diarrhoea: this contrasts with the situation observed in farms, where that virus may provoke important problems. In association with the virus itself, numerous other factors such as the environmental conditions or the response of the calf to the infection also play a role in the evolution of the disease.

Animals↗

Rotavirus associated diarrhoea in nursing piglets and detection of antibody against rotavirus in colostrum, milk and serum.

A blocking method of ELISA for the detection and quantification of antibody against porcine rotavirus in serum, colostrum and milk has been compared with a plaque reduction test. The results obtained with the two techniques correlated (Fig. 1). Antibody against rotavirus was demonstrated in 384 serum samples representing 25 swine farms, indicating a widely spread and dense distribution of the infection with porcine rotavirus among Danish swine. The antibody contents in milk samples from 7 gilts and sows from 2 farms with a previously diagnosed problem with rotavirus associated diarrhoe showed a rapid decline during the first few days of the lactation periods (Fig. 1). An increase in the contents of rotavirus specific antibody was observed from day 15 in the milk samples from one of the gilts. The excretion of rotavirus with feces from the 7 litters of piglets were followed through the suckling period. Rotavirus war found in all litters but one and the virus was excreted in periods ranging from 4 to 9 days.

Animal Population Groups↗

Transforming growth factor activity in human colostrum.

When human milk was examined for the presence of transforming growth factor (TGF) activity, high levels of the activity were found in milk collected in the early days after delivery. Fractionation of an acid-ethanol extract of colostrum by Bio-Gel P-60 column chromatography revealed that the activity was found in two molecular weight ranges; over 45,000 and from 10,000 to 20,000 daltons. The activity of the milk TGF did not compete with epidermal growth factor (EGF) for EGF receptor and was potentiated by the addition of EGF when assayed using normal rat kidney (NRK) cells.

Animals↗

The use of specific antibodies to demonstrate the glycocalyx and spatial relationships of a K99-, F41- enterotoxigenic strain of Escherichia coli colonizing the ileum of colostrum-deprived calves.

Electron microscopy was used to study the interaction between the glycocalyx of enterotoxigenic Escherichia coli strain 210 (09:K30+;K99-;F41-:H-) and the glycocalyx of epithelial cells in then ileum of experimentally infected newborn colostrum-deprived calves. Fixation of tissues in anti-K30 antibody and ruthenium red was used to stabilize the bacterial glycocalyx so that the spatial relationship between the bacteria and the intestinal epithelial cells could be characterized. When strain 210 was grown in vitro and reacted with anti-K30 antibody prior to staining with ruthenium red, the extensive glycocalyx could be clearly visualized surrounding the bacterial cells. By negative staining, an unidentified pilus was also seen. Sections of ileum from infected calves, which were not fixed in antibody nor stained with ruthenium red, revealed attached bacteria which were surrounded by an electron-translucent zone and no visible bacterial glycocalyx. When ruthenium red staining was used, the bacterial glycocalyx partially collapsed during the dehydration steps of fixation, but could be seen as either a fibrous capsule or an electron-dense accretion on the bacterial cell surface. When ileal tissue was reacted for one hour in anti-K30 antibody before staining with ruthenium red, the bacterial glycocalyx was seen as a discrete electron-dense structure up to 1.0microm thick which was in intimate contact with the glycocalyx of the epithelial cells. The importance of the bacterial exopolysaccharide to microcolony formation on the villi could be clearly visualized.

Animals↗

Treatment of calf scours with colostrum.

The calf of a cow vaccinated with an E coli strain 1751 bacterin developed scours 14 hours after oral challenge with E coli strain B44. The calf became almost moribund but fully recovered in several days after repeated oral administration of the dam's colostrum.

Animals↗

[Levels of S-IgA in human colostrum and milk; a longitudinal study in 48 nursing mothers].

Human colostrum and milk collected at different times after the on-set of lactation (from 1st to 180th days) were tested for the levels of S-IgA. The technique of radial immunodiffusion with a anti-S.C. antiserum was employed. The highest percentage of S-IgA was found during the first five days post partum even if it rapidly declined during this time, thereafter remaining constant up to the 180th day of lactation. Absolute intake of S-IgA in infants during the first five days post partum was, in the same way, highest, but the amount of S-IgA intake remained high throughout the period of lactation ranging from 285 to 385 mg/die. On this basis it is suggested that breast-feeding is particularly important during the whole period of lactation and not only during its early stages.

Colostrum↗

Biosynthesis of blood-group I and i substances. Specificity of bovine colostrum beta-N-acetyl-D-glucosaminide beta 1 leads to 4 galactosyltransferase.

Highly purified bovine colostrum beta-N-acetylglucosaminide beta 1 leads to 4 galactosyltransferase was used to investigate the galactosylation of the synthetic, branched trisaccharide GlcNAcbeta 1 leads to 3(GlcNAcbeta 1 leads to 6)Gal, which is the branching point in blood-group I antigenic structures. Two galactose residues could readily be incorporated from UDP-galactose into the trisaccharide, yielding a pentasaccharide with the following structure: Galbeta 1 leads to 4GlcNAcbeta 1 leads to 3(Galbeta 1 leads to 4GlcNAcbeta 1 leads to 6)Gal. From a partially completed incubation an intermediate tetrasaccharide was isolated, the structure of which was investigated by use of an acetolysis method, involving high-pressure liquid chromatography and double labelling techniques. It appeared that this intermediate consisted for more than 95% of one of two possible structures: GlcNAcbeta 1 leads to 3(Galbeta 1 leads to 4GlcNAcbeta 1 leads to 6)Gal. This reveals that the enzymatic galactosylation of the trisaccharide proceeds in a highly preferred order, in which the 1 leads to 6-linked N-acetylglucosamine residue is galactosylated first and thus that the galactosyltransferase displays a high degree of 'branch specificity'. Kinetic data suggest that galactosylation of the 1 leads to 6-linked N-acetylglucosamine in the trisaccharide enhances the acceptor properties of the 1 leads to 3-linked N-acetylglucosamine residue.

Animals↗

Antibacterial antibodies in swine colostrum.

Antibacterial antibody activities were examined in 138 samples of swine colostrum by O-agglutinin test with serotypes of Escherichia coli (O-6, 0-45, 0-81, 0-83, 0-115, 0-138, O-139, and O-126), Salmonella typhimurium, and Salmonella cholerae suis. The mean agglutinin titer of E coli O-83 was the highest; E coli O-115 was next highest. The mean agglutinin titer of S cholerae suis was lowest; S typhimurium was next to lowest. Correlation coefficients among these O-agglutinin titers were between 0.109 and 0.693. Correlations of S typhimurium were the poorest; those of E coli O83, E coli O-138, and S cholerae suis were also poor. By principal component analysis, it was possible to classify ten kinds of O-agglutinins into four groups. The cumulative proportion of the first four principal components accounted for 77.97% of the total variance. Cumulative coefficients of factor loadings were from 65.25% to 99.50% of these O-agglutinins.

Agglutinins↗

Scanning and transmission electron microscopic study of the small intestine of colostrum-fed calves infected with selected strains of Escherichia coli.

Colostrum-fed calves were fed milk replacer containing 10(11) enteropathogenic Escherichia coli (EEC) or nonenteropathogenic E coli (NEEC). The NEEC failed to colonize the small intestine or to be associated with the intestinal wall. The EEC colonized the middle and caudal portions of the small intestine, and in these areas, 80% of the organisms were associated with the intestinal wall. Light, immunofluorescence, scanning, and transmission electron microscopic studies demonstrated a layer of EEC adherent to the mucosal surface of the jejunum and ileum of infected calves. Transmission electron microscopy revealed that each EEC was surrounded by an electron-lucent zone and that some organisms had dense fuzzy surface structures which resembled pili. In the staining with ruthenium red, the electron-lucent areas were occupied by thick capsular material which seemed to be in contact with the microvilli. In some areas of contact with EEC, the microvilli were elongated and projected into the intestinal lumen. Light microscopy demonstrated stunted, thickened, and fused villi with the lamina propria expanded by inflammatory infiltrate. Changes in the villous surface topography, such as denudation of the tips of the villi and exposure of the lamina propria into the lumen, were observed by light and scanning microscopies in samples taken after death of the calves, but not in adjacent samples removed from calves under general anesthesia.

Animals↗

[Secretory antibodies to homologous and heterologous strains of staphylococci in rabbit colostrum].

The titers of agglutinins to homologous and heterologous staphylococcal strains in the colostric sera of female rabbits immunized into the mammary gland tissue and in the colostric and blood sera of the control female rabbits were studied. Immunization into the mammary gland tissue induced an increase in the titers of colostric antibodies to both homologous and heterologous staphylococcal strains (1:320 and 1:160, respectively). Secretory IgA were predominant among antistaphylococcal antibodies in rabbit colostrum.

Animals↗

[Lactate dehydrogenase isoenzymes in the colostrum of cows].

Investigated was the isoenzyme spectrum of lactatedehydrogenase in the colostrum of cows which was obtained at various intervals after calving. It was found that the activity of lactate dehydrogenase was most effective immediately following calving when a total of 5 isoenzymes were established, which lowered their activity with the extention of milk secretion.

Animals↗

The role of colostrum antibodies and the significance of antigenic competition in young lambs.

Young lambs were fed with a small amount of pooled colostrum and injected at either 1, 3, 6 or 12 weeks after birth with the antigen hen egg albumin (Ea). Five days before the Ea injection the experimental group were given a large dose of pooled vaccines (competing antigens). Blood samples were collected at regular intervals after the Ea injection. The results showed marked antigenic competition of Ea at both 6--and 12--weeks of age but the results were partially confounded by the presence of unexpected passive antibodies to Ea in the pooled fed. The experiment was repeated with a separate group of conventionally reared lambs given the same competing antigens but using human serum albumin (HSA) as the suppressed antigen. In this experiment the results differed since antibody concentrations and avidities to HSA were similar in 1, 6 and 12-week-old animals and there was no evidence for antigenic competition. The data presented illustrate the difficulties both of measuring immune responses in young ruminants and also of interpreting such results.

Animals↗

Anti-TNP antibodies from bovine serum and colostrum.

Specifically purified anti-TNP antibodies of subclass IgGI and IgG2 were isolated using immunoadsorbent prepared from AH-Sepharose and TNP-BSA. Isoelectric focusing in poliacrylamide gel showed differences between antibodies obtained from colostrum and serum. These differences were more observable when H chains of IgG1 subclasses were compared. No differences were observed in L chains. The antibodies obtained were the non-precipitating ones. Spectral measurements in the presence of SO3- ions, showed that the antibodies studied were of low affinity (below 10(-6) M). The difference spectra showed, that binding of a hapten (epsilon-TNP aminocapronate acid) to the investigated antibodies caused the shift of the hapten's absorption bands indicating that the binding occured in the hydrophobic pocket of the antibody binding site. The strongest effect was observed in the case of antibodies of IgG1 subclass.

Animals↗

Proline-rich polypeptide (PRP)--an immunomodulatory peptide from ovine colostrum.

The structure and properties of a new immunomodulatory peptide isolated from ovine colostrum are described. PRP acts both in vivo and in vitro, and is not species specific. PRP increases permeability of skin vessels, and causes differentiation of murine thymocytes into functionally active T cells. It can simultaneously change surface markers and function of cells. The polypeptide is able to reduce binding of peanut agglutinin (PNA) to PNA+ thymocytes and to increase the binding of PNA to PNA- cells. PRP is also able to transform cortisone-resistant thymocytes into cortisone-sensitive, and vice versa. The observed changes occurred concomitantly, i.e. changes in binding of PNA were accompanied by changes in resistance to cortisone and in expression of helper or suppressor activity. The fact that changes induced by PRP are reversible after the second exposure of the cells to the polypeptide makes it unique among known immunomodulators. An active nonapeptide fragment: Val-Glu-Ser-Tyr-Val-Pro-Leu-Phe-Pro was isolated from the products of PRP digestion. It shows full spectrum of biological activities of PRP. The sequence-Pro-Leu-Phe- is responsible for the immunological effect of the peptide.

Adjuvants, Immunologic↗

Bactericidal and haemolytic activity of complement in bovine colostrum and serum: effect of proteolytic enzymes and ethylene glycol tetraacetic acid (EGTA).

Bovine colostral whey (CW) possessed heat-labile bactericidal activity against an enteropathogenic serum-susceptible strain of Escherichia coli. Activity was readily destroyed by trypsin or rat pancreatic juice, and less readily by chymotrypsin. Loss of activity due to trypsin, but not by chymotrypsin, could be prevented by addition of excess bovine colostral trypsin inhibitor. A second enteropathogenic strain of E. coli was killed by CW only if exogenous complement was added. This activity was maintained, however, even if the complement was heated 56 degrees C during 15 min. CW possessed only very weak haemolytic activity against sensitised rabbit erythrocytes, but could augment the haemolytic titre of bovine serum and could partially restore haemolytic activity to heat-inactivated bovine serum. These observations indicate that low but significant amounts of complement may occur in bovine colostrum. Sequestration of Ca++ by EGTA abolished all bactericidal and haemolytic activity in CW, and reduced but did not completely abolish these activities in bovine serum or in CW + exogenous complement. The activity of colostral complement therefore appears to be mediated entirely by the classical pathway whereas the alternate pathway may play some part in the bactericidal and haemolytic activities of bovine serum or of CW + exogenous complement.

Calcium↗