THINOPYRUM BESSARABICUM和THINO-PYRUM ELONGATUM的基因组关系研究

对 2个八倍体 C.S- Thinopyrum bessarabicum( AABBDDJJ,2 n=8x=56)和 Goshawk( GHK) - Thinopyrum elongatum( AABBDDEE,2 n=8x=56)的根尖细胞染色体进行 C-分带 ,从中分检出 Th.bessarabicum和 Th.elongatum的各自染色体进行核型分析 ,结果表明 :Th.bessarabicum和 Th.elongatum的大多数染色体都具有端带 ,但 Th.bessarabicum的端带更强 ,很少有中间带 ;而 Th.elongatum的染色体除 E1外其它染色体的端带较弱 ,而且带纹较丰富 ,有较多的中间带。对 C.S- Th.bessarabicum和 GHK- Th.elongatum进行有性杂交 ,其杂交种F1的 PMC染色体在 MI的平均配对构型为 1 5.50 5.0 3 [ 1 4.2 0 ○ 0 .40 0 .2 1 ,其中 Th.bessarabicum和 Th.elongatum染色体平均配对成 2 .5个二价体 ,由 C-分带显示大多数 Th.bessarabicum和 Th.elongatum染色体呈单价体状态。因此推断 ,Th.bessarabicum和 Th.elongatum两物种的染色体应属不同的染色体组     

The role of IL-10 in crossregulation of TH1 and TH2 responses

The identification of helper T (T_H)-cell subsets has greatly improved understanding of the regulation of immune effector functions. In addition to controlling humoral and delayed-type hypersensitivity responses, these subsets crossregulate by secreting mutually inhibitory cytokines. In this review, Tim Mosmann and Kevin Moore examine these phenomena and in particular the role of interleukin 10, a cytokine secreted by T_H2 cells that inhibits T_H1-cell function.     

Interleukin 1 responsiveness and receptor expression by murine TH1 and TH2 clones

Murine Th1 and Th2 T cell lines differ in their responses to interleukin 1 (IL 1). Therefore, we examined two T-cell lines, D10.G4.1 (Th2) and MTg12B (Th1) in an attempt to correlate IL 1 receptor (IL 1R) expression with their IL 1 responsiveness. D10.G4.1 cells, which respond to IL 1, expressed two forms of the IL 1R, with molecular masses of approximately 80 kDa and approximately 60 kDa. In contrast, MTg12B cells failed to respond to IL 1 and only expressed the approximately 60 kDa receptor form. This suggests that the approximately 80 kDa receptor is essential for signaling. Expression of both IL 1R forms on D10.G4.1 cells could be inhibited by the anti-IL 4 antibody, 11B11. Antigen presentation reversibly upregulated both forms of the IL 1R, whereas stimulation with concanavalin A (ConA) and anti-CD3 only upregulated the approximately 60 kDa moiety. Upregulation of the approximately 80-kDa IL 1R by repeated antigenic stimulation resulted in a marked increase in sensitivity of D10.G4.1 cells to IL 1.     

Effects of aryl hydrocarbon receptor signaling on the modulation of TH1/TH2 balance

An orally active antiallergic agent, M50367, skews the Th1/Th2 balance toward Th1 dominance by suppressing naive Th cell differentiation into Th2 cells in vitro. Administration results in the suppression of IgE synthesis and peritoneal eosinophilia in vivo. In this report, we determined that M50354 (an active metabolite of M50367) was a ligand for the aryl hydrocarbon receptor (AhR); the immunological effects of this compound on in vitro Th1/Th2 differentiation from naive Th cells and Th1/Th2 balance in vivo were manifested through binding to AhR. These effects were completely abolished in AhR-deficient mice. AhR expression in the naive Th cell was significantly up-regulated by costimulation of TCR and CD28. Suppression of naive Th cell differentiation into Th2 cells via binding of M50354 to AhR was associated with inhibition of GATA-3 expression in Th cells. In addition, forced expression of a constitutively active form of AhR or activation of AhR by the addition of representative ligands suppressed naive Th cell differentiation into Th2 cells. Based on these results, we conclude that AhR functions as a modulator of the in vivo Th1/Th2 balance through activation in naive Th cells.     

Gangliosides: differentiation markers for murine T helper lymphocyte subpopulations TH1 and TH2.

On the basis of the pattern of lymphokines they secrete, murine T helper clones can be divided into two subsets, TH1 and TH2. This concept of two different T helper effector cells helps to explain the diversity of immune reactions occurring in different parts of the body. The in vivo localization of T helper subtypes is of great interest, but up to now no biochemical or surface markers were available to distinguish between them. We analyzed the glycolipids from altogether 12 murine TH1 and TH2 cell lines or clones. A comparison of the gangliosides by thin-layer chromatography showed differences between the TH1 and TH2 cells. Binding studies with specific antibodies to asialo backbone structures after degradation by neuraminidases showed that the main gangliosides from these lymphocytes shared a common GgOse4 backbone and thus differed only in their degree or position of sialylation. Two disialogangliosides appeared to be characteristic. They were isolated from the D10.G4.1 TH2 cell clone and identified by fast atom bombardment mass spectrometry as IVNeuAc,IINeuAc-GgOse4Cer (GD1a) and IVNeuAc,IIINeuAc-GgOse4Cer (GD1 alpha), respectively. GD1a was characteristically only detected in TH2 cells, whereas GD1 alpha was preferably, but not exclusively, expressed by TH1 lymphocytes. Although GD1a was also found in the lung, heart, kidney, and spleen, its expression within the murine immune cells under investigation was unique to TH2 lymphocytes. Scarcely any GD1a was found in thymocytes, B cells, or CD8 positive (cytolytic) T cells, but significant expression was seen in CD4 positive (helper) T cells which include the TH2 subpopulation.(ABSTRACT TRUNCATED AT 250 WORDS)