No abstract

The expression of HLA class H genes is regulated by a series of cis-acting elements and trans-acting factors. Several cis-acting elements have been identified and have been termed the Z box, X box, Y box, octamer, and "TATA" box. The Y box contains an inverted CCAAT box. By probing a phage Agtii library with double-stranded oligonucleotides, we have directly isolated a cDNA encoding a Y box-binding protein designated YB-1. YB-1 binding has an absolute requirement for the CCAAT box and relative specificity for the Y box. It has a M, of 35,414, contains 18% basic residues, and contains putative nuclear localization signals. An inverse correlation of YB-1 and HLA-DR (3 chain mRNA levels suggests that YB-1 is a negative regulatory factor.The transcription of major histocompatibility complex class II genes is regulated by a series of cis-and trans-acting elements (1). For class II genes, the majority of the cis-acting elements has been localized to the 5' flanking and intronic regions (2, 3). The promoter region within the 5' flanking region contains a series of sequence motifs that are highly conserved among all class II genes and the invariant chain gene (1-4). These motifs have been termed the Z box, X box, Y box, octamer, and "TATA" box. The Y box contains an inverted CCAAT box. The functional role of these motifs has been explored by using transfection and transgenic systems. Both the X box and Y box have been shown to be essential for transcription, while y interferon inducibility has been ascribed variably to the X box, Y box, and Z box (1,(5)(6)(7)(8) (12). ds Oligonucleotide Synthesis. ds oligonucleotides were prepared as described (11). Either the complementary strands were first hybridized and then 'y-32P-end-labeled, or each strand was y-32P-end-labeled and then hybridized. The labeled ds oligonucleotides were purified by gel electrophoresis through a 15% polyacrylamide gel.Filter Hybridization. The amplified library was plated, and the plates were overlaid with nitrocellulose filters saturated with 10 mM isopropyl thiogalactoside. Filters were prehybridized with 5% Carnation instant milk in 10 mM Hepes (pH 8.0) for 1 hr at room temperature and then washed twice for 10 min with 10 mM Hepes (pH 8.0) (13). Hybridization was done in 250 mM NaCl/5 mM MgC12/1 mM dithiothreitol/0.1 mM EDTA/10 mM Hepes, pH 8.0, containing 10 .tg of salmon sperm DNA or 10 gg of poly(I-C) per ml. After 10 min, 108 cpm of end-labeled ds oligonucleotide was added, and the incubation was continued for 2 hr at room temperature. Filters were washed twice for 10 min with hybridization buffer at room temperature and were autoradiographed.Molecular Weight Estimation of the Fusion Protein 13-Galactosidase-YB-1. Escherichia coli strain Y1088 or Y1090 (108) was infected with 106 plaque-forming units of the phage Agtll-YB-1 and grown at 370C until partial lysis was achieved.

Demand for total joint arthroplasty is projected to increase in the first three decades of the twenty-first century. With increasing frequency, patients who have a hip or knee replacement expect to, and choose to, participate in athletics following rehabilitation. In general, patients who have had a hip or knee replacement decrease their participation in, and intensity of, athletic activity following the total joint arthroplasty. The orthopaedic literature on athletic activity after total joint arthroplasty is limited to small retrospective studies with short-term follow-up. Expert opinion regarding appropriate athletic activity after total joint arthroplasty is available from the Hip Society and the Knee Society. When patients who have undergone joint replacements choose to participate in athletic activity, orthopaedic surgeons should provide information with which to evaluate the risk of sports activity and recommend appropriate athletic activity.

Antigen-specific T cell activation requires two independent signalling events, one mediated through T cell receptor engagement by the antigen-presenting cell-expressed peptide/ class II major histocompatibility complex, and the second through the cognate interactions of costimulatory molecules expressed on the T cell and antigen-presenting cell. There is evidence from in vitro and in vivo experimental systems suggesting that the CD28/B7 costimulatory pathway is crucial for induction of maximal T cell proliferation and T helper-B cell collaboration for IgG production. This pathway can be blocked by CTLA-4-Ig, a soluble form of CTLA-4 which binds with high avidity to the CD28 ligands, B7-1 and B7-2. Here, we show that CTLA-4-Ig treatment prevents clinical and histological manifestations of disease in a collagen-induced arthritis model of rheumatoid arthritis in the diabetes resistant BB/Wor rat, when therapy is initiated before immunization with bovine type II collagen (BUC). Anti-BUC antibody titers are reduced in CTLA-4-Igtreated rats compared to diseased control animals. Histologically, joints from CTLA-4-Ig-treated animals show no histological abnormalities, in contrast to control antibodytreated animals, which show complete erosion of the articular cartilage and bone. Despite the efficacy of CTLA-4-Ig in preventing clinical and histological signs of arthritis and reducing antibody responses to BIIC, delayed type hypersensitivity responses to collagen 18 d or more after CTLA-4-Ig treatment ends are similar in CTLA-4-Ig-treated and untreated rats, suggesting that the prolonged disease suppression observed does not result from induction of T cell anergy. (J. Clin. Invest. 1995. 96:987-993.)

Objective. To evaluate the efficacy and safety of tacrolimus as monotherapy in controlling the signs and symptoms of patients with rheumatoid arthritis (RA).Methods. This was a 6-month, phase III, doubleblind, multicenter study. Patients with active RA who had discontinued all disease-modifying antirheumatic drugs (DMARDs) for an appropriate washout period (at least 1 month) and who, after the washout period, had a stable joint count (at least 10 tender/painful joints and 7 swollen joints) were stratified according to DMARD intolerance or DMARD resistance, and randomized to receive a single daily oral dose of placebo, tacrolimus 2 mg, or tacrolimus 3 mg.Results. A total of 464 patients received at least 1 dose of study drug. Baseline characteristics were similar among the 3 treatment groups. American College of Rheumatology 20% improvement (ACR20) success (defined as completion of 6 months of treatment and an ACR20 response at the month 6 visit) for the placebo, tacrolimus 2 mg, and tacrolimus 3 mg groups was 10.2%, 18.8% (P < 0.05 versus placebo), and 26.8% (P < 0.0005 versus placebo), respectively. At the end of treatment, the ACR20 and ACR50 response rates in the 3-mg group were 32.0% (P < 0.005 versus placebo) and 11.8% (P < 0.05 versus placebo), respectively. DMARDintolerant patients had better ACR response rates than did DMARD-resistant patients. Although serum creatinine levels increased by >40% from baseline at some time during the trial in 20% and 29% of patients receiving tacrolimus 2 mg/day and 3 mg/day, respectively, the serum creatinine level remained within the normal range throughout the trial in ϳ90% of patients.Conclusion. Tacrolimus, at dosages of both 2 mg/day and 3 mg/day, is efficacious and safe as monotherapy for patients with active RA, but treatment with the 3-mg dose of tacrolimus resulted in generally better ACR response rates.Rheumatoid arthritis (RA) is a chronic autoimmune disorder that requires early diagnosis and aggressive treatment to minimize the morbidity associated with its progression (1,2). Disease-modifying antirheumatic drugs (DMARDs) and biologic modifiers have been used to accomplish these objectives (3-23). A common prominent feature of these agents is their immunosuppressive properties.Tacrolimus (Prograf, FK506), an orally available macrolide calcineurin inhibitor, is an immunomodulatory and antiinflammatory agent (24-31). It diminishes the ability of calcineurin to dephosphorylate and translocate the nuclear factor of activated T cells that initiates gene transcription for the synthesis of inflammatory cytokines such as tumor necrosis factor ␣, interleukin-2,