Attenuation of lpr-graft-versus-host disease (GVHD) in MRL/lpr spleen cell-injected SCID mice by in vivo treatment with anti-V beta 8.1,2 monoclonal antibody

Exuberant expression of chemokine genes by adult human articular chondrocytes in response to IL-1beta

OBJECTIVE

To provide a more complete picture of the effect of interleukin-1 beta (IL-1beta) on adult human articular chondrocyte gene expression, in contrast to the candidate gene approach.

DESIGN

Chondrocytes from human knee cartilage were cultured in medium containing IL-1beta. Changes in gene expression were analyzed by microarray and reverse transcriptase-polymerase chain reaction analysis. The ability of transforming growth factor beta-1 (TGF-beta1), fibroblast growth factor (FGF)-18, and bone morphogenetic protein 2 (BMP-2) to alter the effects of IL-1beta was analyzed. Computational analysis of the promoter regions of differentially expressed genes for transcription factor binding motifs was performed.

RESULTS

IL-1beta-treated human chondrocytes showed significant increases in the expression of granulocyte colony stimulating factor-3, endothelial leukocyte adhesion molecule 1 and leukemia inhibitory factor as well as for a large group of chemokines that include CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, CXCL8, CCL2, CCL3, CCL4, CCL5, CCL8, CCL20, CCL3L1, CX3CL1 and the cytokine IL-6. As expected, the mRNA for matrix metalloproteinase (MMP)-13 and BMP-2 also increased while mRNA for the matrix genes COL2A1 and aggrecan was down-regulated. A subset of chemokines increased rapidly at very low levels of IL-1beta. The phenotype induced by IL-1beta was partially reversed by TGF-beta1, but not by BMP-2. In the presence of IL-1beta, FGF-18 increased expression of ADAMTS-4, aggrecan, BMP-2, COL2A1, CCL3, CCL4, CCL20, CXCL1, CXCL3, CXCL6, IL-1beta, IL-6, and IL-8 and decreased ADAMTS-5, MMP-13, CCL2, and CCL8. Computational analysis revealed a high likelihood that the most up-regulated chemokines are regulated by the transcription factors myocyte enhancer binding factor-3 (MEF-3), CCAAT/enhancer binding protein (C/EBP) and nuclear factor-kappa B (NF-kappaB).

CONCLUSION

IL-1beta has a diverse effect on gene expression profile in human chondrocytes affecting matrix genes as well as chemokines and cytokines. TGF-beta1 has the ability to antagonize some of the phenotype induced by IL-1beta.

T-cell receptor Vbeta gene expression in experimental lupus nephritis

A limited T-cell receptor (TCR) Vbeta repertoire employed by autoreactive T cells may be related to the development and course of autoimmune diseases. Vbeta repertoire skewing has been observed not only in man, but also in animal models of several human autoimmune diseases, such as MRL-lpr mice, which spontaneously develop a systemic lupus erythematosus (SLE)-like disease. Murine chronic graft-versus-host disease (GVHD) is an inducible model for SLE, involving direct interaction between donor T cells and recipient B cells. It is not known whether Vbeta-specific T-cell subsets are pathogenically involved in this model. Retroviral superantigens such as Mls-1 are known to have a profound impact on the TCR Vbeta repertoire in mice. Restriction of the peripheral TCR repertoire may result from intrathymic expression of Mls-1, which causes deletion of T cells expressing Vbeta6, -7, -8.1, or -9. Mls-1 incompatibility between donor and recipient can be used to determine the involvement of these TCR Vbeta families in GVHD. In the present study we induced GVHD in several strain combinations to investigate TCR Vbeta gene expression during GVHD, and the effect of Mls-1 incompatibility on the TCR Vbeta repertoire. TCR Vbeta gene expression was determined using an RNase protection assay. Our results indicate that T cells expressing the Vbeta2 or Vbeta16 chain play an important pathogenetic role, while T cells bearing the Vbeta1 or Vbeta6 chain may be related to self-limitation of the lupus-like disease in this model.

Participation of NK1.1+ T cells in the rejection of lpr alphabetaT cells when bone marrow cells of lpr mice are transplanted into B6 mice

When C57BL/6 (B6) mice were irradiated (9 Gy) and received bone marrow (BM) cells of B6-lpr/lpr mouse origin (i.e., lpr-->B6), all mice died within 6 days. In the irradiated B6 mice, radioresistant CD3 IL-2Rbeta+ NK cells and IL-2Rbeta+ CD3int cells (i.e., CD3int cells of extrathymic origin) remained, especially in the liver. There were two subsets, NK1.1+ and NK1.1-, among the IL-2Rbeta+ CD3int cells. However, the NK1.1+ subset (i.e., NK1.1- T cells) was much more radioresistant, and the majority of CD3int cells belonged to this subset in irradiated mice. The expansion of lymphocytes from injected BM cells did not occur in the irradiated B6 mice. However, such expansion did take place in irradiated B6-lpr/lpr mice injected with both BM cells of B6-lpr/lpr and B6 origin. As a result, the mice subjected to BM cells survived. Irradiated B6 mice were treated in vivo with anti-NK1.1 mAb or anti-asialoGM1 antibody to eliminate NK cells alone or both NK cells and NK1.1+ T cells. When irradiated B6 mice were pretreated with anti-NK1.1 mAb, the mice could survive. These results suggest that intact NK1.1+ T cells of extrathymic origin may recognize abnormal BM cells with the lpr gene and inhibit the expansion of lymphocytes, including abnormal double-negative CD4 8 cells, in B6-lpr/lpr mice. To inhibit the expansion of lymphocytes, mechanisms other than Fas ligand/Fas molecules on extrathymic T cells may be responsible.

Characterization of a single-chain antibody to the beta-chain of the T cell receptor

In this report the VH and VL genes of the anti-T cell receptor (TCR) antibody KJ16, which recognizes the TCR V beta 8.1 and V beta 8.2 regions in mice, were cloned and expressed as a single-chain antibody (scFv) in Escherichia coli. A 29-kDa protein was obtained after renaturation from inclusion bodies. The KJ16 scFv had a relative affinity for the native TCR that was slightly higher than KJ16 Fab fragments. The scFv and Fab fragments of the KJ16 antibody, together with monovalent forms of two other anti-TCR antibodies, were evaluated as antagonists of the T cell-mediated recognition of a peptide-class I complex or of a superantigen, Staphylococcus enterotoxin B (SEB) bound to a class II product. Each of the anti-TCR antibodies was efficient at inhibiting the recognition of the SEB-class II complex. In contrast, only the clonotypic antibody, which binds to epitopes on both V beta and V alpha regions, inhibited the recognition of peptide-class I complex. We conclude that the TCR binding site for the SEB-class II ligand encompasses a larger surface area than the TCR binding site for the peptide-class I ligand.