A competitive quantitative polymerase chain reaction assay for bovine transforming growth factor-B1 mRNA

Differential cytokine gene expression in CD4+ and CD8+ T cell subsets of calves

The distinct patterns of cytokine expression in CD4+ and CD8+ T cells are well understood in mice and humans. However, little information is available about cytokine expression in bovine CD4+ and CD8+ T cells. In this study, mRNA expression of 19 different cytokines was analyzed in CD4+ and CD8+ T cells of calves with or without Concanavalin A (Con A) stimulation. CD4+ and CD8+ T cell populations were enriched to 98% purity by positive selection using magnetic cell sorting (MACS). CD4+ T cells spontaneously expressed the mRNAs of interleukin-1alpha (IL-1alpha), IL-1beta, IL-2, IL-6, IL-7, IL-8, IL-10, IL-18, IFN-gamma, TNF-alpha, TNF-beta and TGF-beta, and augmented the mRNA expression of IL-10, IFN-gamma and TNF-beta after Con A stimulation. The mRNAs of IL-3, IL-4, IL-5, IL-13 and GM-CSF were newly expressed in Con A-stimulated CD4+ T cells. CD8+ T cells displayed spontaneous mRNA expression of IL-6, IL-18, TNF-alpha, TNF-beta and TGF-beta, and newly expressed the mRNA of IL-2, IL-7, interferon-gamma (IFN-gamma) and GM-CSF after Con A stimulation. It was found that CD4+ T cells expressed the mRNA of 17 cytokines except for IL-12 and IL-15, while CD8+ T cells expressed only the mRNA of 9 cytokines after Con A stimulation. The profile of cytokine mRNA expression was substantially different in the CD4+ and CD8+ T cells of calves, indicating that CD4+ T cells can be distinguished from CD8+ T cells by the cytokine gene expression of IL-1alpha, IL-1beta, IL-3, IL-4, IL-5, IL-8, IL-10 and IL-13. Differential cytokine expression between CD4+ and CD8+ T cells serve to interpret an individual function of T cell subsets in the immune system of calves.

Differential Gene Expression of Cytokine and Cell Surface Molecules in T cell Subpopulation Derived from Mammary Gland Secretion of Cows

PROBLEM

As T cell subpopulations in the mammary gland secretion (MGS) of cows dynamically vary through the lactation cycle, their functional analysis is important to understand the mammary immune responses.

METHOD OF STUDY

T cell subpopulations were positively selected from MGS during lactation period and non-lactation period (dry period) by a magnetic cell sorter. The messenger RNA (mRNA) expression of cytokine and cell surface molecules in the subpopulations stimulated with anti-CD3 was investigated using reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

CD4+ T cells from MGS significantly expressed mRNA of interferon (IFN)-gamma, interleukin (IL)-2, granulocyte-macrophage colony-stimulating factor (GM-CSF), transforming growth factor (TGF)-beta, tumor necrosis factor (TNF)-alpha, IL-4, CD40 ligand (CD40L), Fas ligand (FasL) and IL-2 receptor (IL-2R) during dry period, and mRNA of IFN-gamma, IL-2 and TGF-beta during lactation period. Their expression during lactation period was always less than that during dry period. CD8+ T cells from MGS substantially expressed mRNA of IFN-gamma, IL-2, GM-CSF, TGF-beta, TNF-alpha, FasL and IL-2R during dry period and mRNA of IFN-gamma, GM-CSF, TGF-beta, TNF-alpha and c-kit during lactation period. The TGF-beta, TNF-alpha, c-kit and IL-2R mRNA expression of T cells in MGS during lactation period mostly depended on gammadelta T cells. Interestingly, c-kit mRNA was exclusively expressed in gammadelta T cells.

CONCLUSIONS

The cytokine expression of T cells in MGS of cows depended on the T cell subpopulations. The present findings suggested that the activation of gammadelta T cells via c-kit receptor participated in the suppressed expression of cytokine mRNA in T cells during lactation period.

Reduction of endothelial cell related TGFbeta activity by thiols

Transforming growth factor beta (TGFbeta) may play an important role in diseases characterized by pulmonary fibrosis. We have previously demonstrated that thiols inhibit the pro-oxidant effects of TGFbeta1 in bovine pulmonary artery endothelial cells (BPAEC). To help define the mechanism of this observation we have examined the effect of reduced (GSH) and oxidized (GSSG) glutathione, N-acetyl cysteine (NAC) and cysteine (CYS) on the biological activity of a) TGFbeta released by bovine pulmonary artery endothelial cells (BPAEC) into culture medium, and b) commercially available porcine platelet TGFbeta1. The biological activity of TGFbeta (following activation) released into the medium from cultured BPAEC was significantly reduced when the cells were cultured in the presence of 10 mM GSH or 10 mM NAC for 24 h (10 mM GSH: 85.7 +/- 50 pg/ml/10(6) cells and 10 mM NAC: 127.3 +/- 35 pg/ml/10(6) cells, compared with control: 541 +/- 8.9 pg/ml/10(6) cells; p < 0.05). Thiols (10 mM GSH, 10 mM NAC and 5 mM cysteine), added directly to cell-free conditioned medium or to a commercially available preparation of porcine platelet TGFbeta1 for 6-24 h had a similar inhibitory effect on the biological activity of TGFbeta and altered the structure of porcine platelet TGFbeta1 as determined by mass spectroscopy. These thiols failed to reduce the expression of TGFbeta mRNA in BPAEC as measured by a competitive polymerase chain reaction assay. Incubating endothelial cells or cell-free conditioned medium with GSSG did not alter the biological activity of TGFbeta. Lower doses of thiols (0.1-1 mM), that we have shown inhibit the antiproliferative and pro-oxidant effects of exogenous TGFbeta1 on BPAEC, had no direct effect on TGFbeta bioactivity. In summary, thiols are capable of reducing the effects of TGFbeta in biological systems through a direct effect on the TGFbeta molecule. However, this action appears to be dose-dependent, and at low doses (0.1-1 mM) thiols may also inhibit the actions of exogenous TGFbeta1 in cell culture through a mechanism involving the cellular redox status.

Quantitative analysis of alpha-fetoprotein mRNA in circulating peripheral blood of patients with hepatocellular and alpha-fetoprotein-producing gastric carcinomas

In conjunction with strategies introduced in recent years to identify cancer micrometastasis through amplification of cancer-associated mRNA, we developed a highly sensitive system to detect alpha-fetoprotein mRNA in circulating peripheral blood of hepatocellular carcinoma patients. The aim of the present study was to make our original system quantitative. Peripheral venous blood from patients with hepatocellular carcinoma and alpha-fetoprotein-producing gastric carcinoma was subjected to reverse transcription followed by our original three-step polymerase chain reaction co-amplifying both the original sequence and our synthetic competitor. We succeeded in modifying our system for quantitative analysis, and investigated the perioperative change, the postoperative change and the change after chemotherapy in order to illustrate the possible application of this method. The quantitative analysis of alpha-fetoprotein mRNA present in the peripheral blood represents a useful tool for analyzing the relationship of surgery to recurrence, the effect of chemotherapy, and to predict impending recurrence in patients with hepatocellular and alpha-fetoprotein-producing gastric carcinomas.