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H Salmon

Publications and source records attributed to H Salmon.

At least 37 records · Page 2Linked to original sources
PubMed1994

Summary of workshop findings for porcine T-lymphocyte antigens.

Fifty-four mAb preselected in the first round of the first porcine CD workshop for their possible reactivity with T-lymphocyte specific antigens and/or activation antigens were further analysed in a second round. PBMC, thymocytes and nylon-wool purified T lymphocytes derived from peripheral blood, mesenteric lymph nodes and spleen served as target cells for flow cytometric analyses. For the classification of activation antigens several experiments were performed with activated, mitogen-stimulated T lymphocytes and long-term T-lymphocyte cultures. Out of the 54 mAb, 35 mAb could be distributed to six different CD clusters and two swine workshop clusters (SWC). Five mAb could be distributed to the porcine CD2, four mAb to the CD4. Six mAb seemed to recognize the porcine CD5 and two mAb the porcine CD6 analogue. Six mAb were directed against the porcine CD8, whereas two different epitopes could be defined. One mAb was directed against the porcine CD25 analogue. Nine mAb could be clustered to the SWC1, defining an antigen on T lymphocytes and cells of the myeloic linage. Two mAb with high T-cell specificity were clustered to the SWC2.

Animals↗
PubMed1994

Analysis of monoclonal antibodies reactive with the porcine CD2 antigen.

As result of the First International Swine CD Workshop, six monoclonal antibodies (mAbs) (numbers 014, 023, 024, 057, 128, and 130) clustered closely to the internal standard anti-porcine CD2 mAb, MSA4. Despite the close clustering, the cluster was split into two subgroups. To further characterize the relationship between these mAbs, they were used in flow cytometry to inhibit binding of MSA4 to porcine lymphocytes. mAbs 014 (1038-8-31), 023 (MAC83), 024 (MAC80), 057 (PG168), and 128 (MSA4) completely inhibited the binding of MSA4, mAb 130 (MSA2) failed to inhibit MSA4 binding. On dual parameter flow cytometry comparing MSA2 with MSA4, all MSA2+ cells were MSA4+, two thirds of the MSA4+ cells were MSA2-. We conclude that five of the mAbs bind to the same or a closely related epitope on porcine lymphocytes. mAb 130 appears to have aberrantly clustered with the CD2 group of mAb.

Animals↗
PubMed1994

Analysis of monoclonal antibodies reactive with the porcine CD4 antigen.

As result of the First International Swine CD Workshop, four monoclonal antibodies (mAb) (#002, 054, 118, and 127) clustered closely to the internal standard anti-porcine CD4 mAb, 74-12-4. To further characterize the relationship between these mAb, they were used in flow cytometry to inhibit binding of 74-12-4 to porcine lymphocytes. mAb #002 (74-12-4) and #054 (PT90) completely inhibited, while mAb #127 (10.2H2) and #118 (b38c6) partially inhibited (57% and 77% respectively), the binding of 74-12-4. Furthermore, none of the mAbs bound to a 74-12-4 negative strain of pigs. We conclude that the four mAb bind to the same, or a closely related, epitope on porcine lymphocytes.

Animals↗
PubMed1994

Analyses of monoclonal antibodies reactive with porcine CD5.

Among all monoclonal antibodies (mAbs) analyzed in the first porcine CD workshop, six mAbs showed reactivity to the porcine CD5 antigen (workshop mAbs 067, 068, 069, 070, 071 and 119). Because of lack of immunoprecipitation studies for five (067, 068, 069, 070 and 071) out of the six mAbs, only one mAb (119) could be definitely characterized as mAb against the monomeric 63 kDa porcine CD5 antigen. The five other mAbs included in this cluster are characterized by an identical labelling pattern in FCM and competition of the CD5 epitope recognized by mAb 119. These mAbs were allocated to the wCD5 subcluster.

Animals↗
PubMed1994

Analyses of mAb reactive with porcine CD8.

Among all mAb submitted to the first porcine CD workshop, based on FCM analyses six mAb could be identified to recognize the porcine CD8 analogue (workshop Nos. 004, 051, 052, 053, 108 and 109). In immunoprecipitation studies three mAb (Nos. 004, 108 and 109) recognized an antigen with an apparent molecular mass of about 35 kDa under reducing conditions and about 70 kDa under non-reducing conditions. The molecular masses of the antigens recognized by the three other mAb (Nos. 051, 052 and 053) are still unknown. Epitope analyses performed by blocking experiments led to the determination of two CD8 epitopes: CD8a and CD8b. CD8a is recognized by mAb Nos. 004, 051 and 052, and CD8b by Nos. 053, 108 and 109.

Animals↗
PubMed1994

Analysis of mAb reactive with the porcine SWC1.

Among 54 mAb determined to be reactive with porcine T lymphocytes and/or activation antigens, eight mAb (workshop Nos. 005, 031, 080, 091, 092, 093, 094 and 110) derived from different laboratories grouped together in the T11 cluster and were ordered into the SWC1. One mAb (No. 111) which belong also to this group was lost during the workshop. The SWC1 antigen is a molecule expressed on the majority of leukocytes, resting T lymphocytes, monocytes and granulocytes, but not on B lymphocytes. On T lymphocytes it is down-regulated after activation. The molecular mass of the antigen is unknown. Epitope analyses revealed that seven out of the nine mAb recognized similar epitopes on the SWC1 molecule.

Animals↗
PubMed1994

Local and systemic immune responses to soybean protein ingestion in early-weaned pigs.

The development of local and systemic immune responses to soybean proteins was investigated in early-weaned pigs. Pigs were given either antigenic (ASP, n = 10 pigs) or non-antigenic (NASP, n = 8 pigs) soybean products (6 g of protein/d) from d 5 to 9 of age by stomach tube. After weaning at d 21, pigs were fed diets containing the corresponding soybean products and slaughtered between d 28 to 30. Diarrhea was 2.4-fold more frequent, the size of duodenal villi was reduced by 24 to 36%, and the eosinophil density in the duodenal mucosa was 13 times greater (P < .02) in the ASP pigs compared with the NASP pigs. A larger erythema area (P = .006) was observed in the ASP group than in the NASP group 30 min after an intradermal injection of glycinin, but no significant difference could be detected with alpha- or beta-conglycinin or whole soybean extracts. No difference in skin fold thickness was apparent between groups 24 h later. Intestinal, mesenteric lymph node, and blood lymphocytes did not proliferate when cultured with soybean proteins, regardless of dietary treatment. By ELISA, no difference between groups was observed in the circulating levels of total immunoglobulins (Ig) and IgM. Immunoblotting patterns of raw soybean with sera from 28-d-old pigs showed two bands (22 and 36 kDa) recognized by IgA and IgM, respectively, in the ASP group only. Finally, the adverse effects observed with antigenic soybean flour can be overcome by the use of alcohol-treated products.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1994

[Immunohistochemical localization in the intestine of swine of the cellular and humeral components of the immune response].

By immunohistochemistry, lymphocyte subsets of the swine gut were localized either in the epithelium or in the lamina propria. In addition, the distributions of class I and class II antigens were also characterized, using the streptavidin-biotin-peroxidase complex as the revelator; the endogenous peroxidase activity was distinguished from the specific by cobalt chloride. The results show a compartmentalization in the distribution of lymphocytes: in the epithelium, all the cells were T lymphocytes, the majority of the CD8 phenotype; in contrast, in the lamina propria, T and B cells were represented in similar proportions: T cells were constituted of both CD4 and CD8 cells (with slightly more CD4 than CD8 cells), while majority of B cells harboured the IgA isotype. Class I MHC was present on epithelium cells of both the villi and crypts. In contrast MHC class II was only present on epithelial cells of the villi. Both SC and IgA were localized in the epithelium cells of the crypt. Thus, this compartmentalization suggests the possibility of an immune response in the gut.

Animals↗
PubMed1993

The use of PCR genome mapping for the characterisation of TGEV strains.

Previous studies on different transmissible gastroenteritis virus (TGEV) strains, including porcine respiratory coronavirus (PRCV), have identified regions within the genome that are polymorphic as regards insertions and deletions. For example the 672 base deletion within the S gene and multiple deletions 5', within and 3' of the ORF-3a gene were detected in strains of PRCV. The presence of deletions may be associated with a change in the virulence, attenuation or tissue tropism of the isolate. The Nouzilly (188-SG) TGEV vaccine strain was attenuated by passage of a cell culture adapted virulent isolate D-52 188 times through swine testis cells after treatment with gastric juice. PCR amplification with oligonucleotides, corresponding to known TGEV sequences, were used to analyse D-52 and 188-SG for genetic variation. Results with several pairs of oligonucleotides within the first 1565 nucleotides of the S gene did not identify a deletion within this region of the genome from either strain. However, oligonucleotides directed against the ORF-3a/3b region detected a deletion of about 250 nucleotides within the 188-SG genome but not in the D-52 genome. Since all the attenuated TGEV strains so far sequenced, PRCV, Miller SP and 188-SG, contained deletions within the ORF-3a/3b, it would suggest that this region of the TGEV genome is involved in regulating viral virulence.

Amino Acid Sequence↗
PubMed1993

Lymphocyte subsets in the mammary gland of sows.

The presence and localisation of lymphocyte subsets together with class II bearing cells in the mammary gland of sows, were studied at different periods of the reproductive cycle by immunohistochemistry and compared with blood. All cell types involved in the immune response were present in the mammary gland at the different stages of gestation and lactation and nearer the alveolar epithelium as gestation proceeded: T lymphocytes, including CD4+ and CD8+, B lymphocytes and class II bearing cells (epithelial cells and macrophages). The results indicated an early accumulation of T lymphocytes, specifically T helper cells, during pregnancy; the specific increase of IgA lymphocytes occurring after this phase could suggest a role for these T cells in the induction of IgA response. The local accumulation of immune cells sustains the view that the mammary gland is able to mount a true local immune response and the increase in CD8+ cells near the epithelium suggests a role in local immune defence.

Animals↗
PubMed1991

Induction of lactogenic immunity to transmissible gastroenteritis virus of swine using an attenuated coronavirus mutant able to survive in the physicochemical environment of the digestive tract.

A transmissible gastroenteritis (TGE) coronavirus mutant (188-SG), selected as attenuated and resistant to acidity and proteases of the digestive tract of adult pigs, was used as vaccine ("Nouzilly strain") in sows to protect suckling piglets against a challenge exposure carried out with a highly virulent TGEV strain. The pregnant sows were immunized once (42-49 days before farrowing) or twice (42-49 and 7-15 days before farrowing) by the oral, intramuscular or conjunctival route with the 188-SG strain. Sows exposed to virulent TGEV in the field and experimentally infected sows (two oral inoculations during pregnancy) were used as positive controls leading to high protection. The neutralizing antibody response to vaccination and/or infection was studied in serum and milk. No protection against mortality was observed in the litters of (1) the nine seronegative, susceptible sows, with piglet mortality of 65/70, (2) the seven once orally vaccinated sows, with mortality of 44/54, (3) the seven sows vaccinated twice by the conjunctival route, with mortality of 55/76. Moderate protection was observed in (1) the eight sows vaccinated intramuscularly twice with piglet mortality of 36/90, (2) the seven orally and intramuscularly vaccinated sows with piglet mortality of 31/51. In of 3 contrast, improved protection was observed in (1) the 10 sows vaccinated twice orally, with piglet mortality of 23/95, (2) the four naturally infected sows with piglet mortality of 6/41, (3) the six sows experimentally infected with virulent TGEV with piglet mortality of 1/59. No correlation was found between neutralizing antibodies titers in serum and milk and protection rate of the piglets. The results indicate that relative protective lactogenic immunity against TGEV is induced only by repeated ingestion of the attenuated 188-SG strain of TGEV.

Administration, Oral↗
PubMed1991

Histocompatible miniature pig (d/d haplotype): generation of hybridomas secreting A or M monoclonal antibody.

Two Hypoxanthine/Aminopterin/Thymidine-sensitive cell sublines (L142 and L231) have been derived from independent lymphoblastoid cell lines of B lineage. After propagation for more than 100 population doublings (1 year) in culture, these cells still retained a doubling time between 19 to 20 hours, near diploïdy and relatively low (L142) and high (L231) secretion rate of M immunoglobulins. Near diploid hybrid cells were easily generated with leukocytes from the spleen, the gut lamina propria or the mesenteric lymph nodes of pigs immunized against the transmissible gastroenteritis virus. Both the tumor sublines and the B cells were derived from histocompatible miniature pigs (d/d haplotype). Demonstration of fusion between the tumor sublines and B-cells was supported by the selection of hybridomas making the antigen-specific heavy (alpha isotype) and light chains from the B cell parent as well as the heavy and light chains of the lymphoblastoid parent. Moreover, some hybridomas were found to secrete only class A (dimeric) or class M immunoglobulins (0.2-10 micrograms/ml). Forty hybridomas secreted antibodies reactive in a virus-enzyme-linked cell immunoassay against cell-bound antigens and two were found to produce an antibody active only against the infected cell monolayer. Construction of intraspecies hybridoma can be used to perpetuate lymphocyte subsets useful for the study of the porcine immune system.

Animals↗