Gene expression profiles in rat mesenteric lymph nodes upon supplementation with Conjugated Linoleic Acid during gestation and suckling

Background Diet plays a role on the development of the immune system, and polyunsaturated fatty acids can modulate the expression of a variety of genes. Human milk contains conjugated linoleic acid (CLA), a fatty acid that seems to contribute to immune development. Indeed, recent studies carried out in our group in suckling animals have shown that the immune function is enhanced after feeding them with an 80:20 isomer mix composed of c9,t11 and t10,c12 CLA. However, little work has been done on the effects of CLA on gene expression, and even less regarding immune system development in early life. Results The expression profile of mesenteric lymph nodes from animals supplemented with CLA during gestation and suckling through dam's milk (Group A) or by oral gavage (Group B), supplemented just during suckling (Group C) and control animals (Group D) was determined with the aid of the specific GeneChip® Rat Genome 230 2.0 (Affymettrix). Bioinformatics analyses were performed using the GeneSpring GX software package v10.0.2 and lead to the identification of 89 genes differentially expressed in all three dietary approaches. Generation of a biological association network evidenced several genes, such as connective tissue growth factor (Ctgf), tissue inhibitor of metalloproteinase 1 (Timp1), galanin (Gal), synaptotagmin 1 (Syt1), growth factor receptor bound protein 2 (Grb2), actin gamma 2 (Actg2) and smooth muscle alpha actin (Acta2), as highly interconnected nodes of the resulting network. Gene underexpression was confirmed by Real-Time RT-PCR. Conclusions Ctgf, Timp1, Gal and Syt1, among others, are genes modulated by CLA supplementation that may have a role on mucosal immune responses in early life

Gene expression profiles in rat mesenteric lymph nodes upon supplementation with Conjugated Linoleic Acid during gestation and suckling

Background Diet plays a role on the development of the immune system, and polyunsaturated fatty acids can modulate the expression of a variety of genes. Human milk contains conjugated linoleic acid (CLA), a fatty acid that seems to contribute to immune development. Indeed, recent studies carried out in our group in suckling animals have shown that the immune function is enhanced after feeding them with an 80:20 isomer mix composed of c9,t11 and t10,c12 CLA. However, little work has been done on the effects of CLA on gene expression, and even less regarding immune system development in early life. Results The expression profile of mesenteric lymph nodes from animals supplemented with CLA during gestation and suckling through dam's milk (Group A) or by oral gavage (Group B), supplemented just during suckling (Group C) and control animals (Group D) was determined with the aid of the specific GeneChip® Rat Genome 230 2.0 (Affymettrix). Bioinformatics analyses were performed using the GeneSpring GX software package v10.0.2 and lead to the identification of 89 genes differentially expressed in all three dietary approaches. Generation of a biological association network evidenced several genes, such as connective tissue growth factor (Ctgf), tissue inhibitor of metalloproteinase 1 (Timp1), galanin (Gal), synaptotagmin 1 (Syt1), growth factor receptor bound protein 2 (Grb2), actin gamma 2 (Actg2) and smooth muscle alpha actin (Acta2), as highly interconnected nodes of the resulting network. Gene underexpression was confirmed by Real-Time RT-PCR. Conclusions Ctgf, Timp1, Gal and Syt1, among others, are genes modulated by CLA supplementation that may have a role on mucosal immune responses in early life

Use of antibody-coated polyacrylic plastic beads for semiquantittavie determination of cell surface antigens.

Polyacrylic plastic beads coated with specific antibodies, which had previously been shown to bind specifically to cells carrying the related antigen, are shown to react quantitatively with the antigen on individual cells. The number of beads per cell which can be counted by simple microscopy is a measure of the amount of antigen accessible on the cell surface. The method may also be used in combination with other methods for cell surface antigens, such as immunofluorescence, for multiple antigen determination

Fc-receptor-bearing cells in spleen of mice injected with cell-free Ehrlich ascites fluid (EAF).

The kinetics of different cell populations (T and B) and subpopulations (one bearing easily releasable FcR and one bearing stable FcR) was followed in spleens of mice after one single i.p. injection of EAF. The number of FcR bearing cells doubled within 2-7 days after EAF injection. This increase was due to cells temperature sensitive FcR and was accompanied by the doubling of theta positive cells. These results, supported by the demonstration of doubly labeled (theta + FcR +) cells, suggest that EAF injected into normal mice causes the appearance of T-cells expression easily releasable FcR. These cells, according to Fridman et al. (1977) are suppressor cells. Maximal increase of theta positive cells and of cells with temperature sensitive FcR detected in vitro coincided with the maximum of the suppressive activity of EAF detected in vivo

Particle-labeled antibodies. I. Anti T-cell antibodies attached to plastic beads by poly-l-lysine.

A simple and inexpensive method for the detection of T-cell surface antigens is introduced using polyacrylic plastic beads (PAA-beads) as indicator particles. The beads are easily visible in ordinary light microscope and make the method convenient for routine laboratory use, also in laboratories possessing no special equipment. The method is an indirect test using a first, absorbed rabbit anti-T serum to sensitize the cells and a second, sandwich antiserum (goat anti-rabbit Ig) coupled to the indicator beads. Instead of glutaraldehyde used by other investigators to attach antibodies to the beads, we used poly-l-lysine which did not affect antibody titers. The F(ab)2 fragment of the sandwich goat anti-rabbit Ig antibody was employed to avoid binding of antibody-coated beads to Fc-receptor-bearing cells. Sensitivity, specificity and reproducibility of the method were tested on murine and human lymphoid cells treated with the respective anti-T serum. The data obtained show that the sensitivity of the method depends on: (a) the bead concentration, (b) the concentration of F(ab)2 fragment of the second antiserum used to coat the beads, and (c) the concentration of specific antibody used to sensitize the cells. Specificity and reproducibility of the method were found to be good. The percentage of positive cells with this method are in good agreement with those reported by means of well established immunological methods