Human recombinant IL-2 augments immunoglobulin and induces rheumatoid factor production by rheumatoid arthritis lymphocytes engrafted into severe combined immunodeficient mice

Next-Generation Sequencing Profiles of the Methylome and Transcriptome in Peripheral Blood Mononuclear Cells of Rheumatoid Arthritis

Using next-generation sequencing to decipher methylome and transcriptome and underlying molecular mechanisms contributing to rheumatoid arthritis (RA) for improving future therapies, we performed methyl-seq and RNA-seq on peripheral blood mononuclear cells (PBMCs) from RA subjects and normal donors. Principal component analysis and hierarchical clustering revealed distinct methylation signatures in RA with methylation aberrations noted across chromosomes. Methylation alterations varied with CpG features and genic characteristics. Typically, CpG islands and CpG shores were hypermethylated and displayed the greatest methylation variance. Promoters were hypermethylated and enhancers/gene bodies were hypomethylated, with methylation variance associated with expression variance. RA genetically associated genes preferentially displayed differential methylation and differential expression or interacted with differentially methylated and differentially expressed genes. These differentially methylated and differentially expressed genes were enriched with several signaling pathways and disease categories. 10 genes (CD86, RAB20, XAF1, FOLR3, LTBR, KCNH8, DOK7, PDGFA, PITPNM2, CELSR1) with concomitantly differential methylation in enhancers/promoters/gene bodies and differential expression in B cells were validated. This integrated analysis of methylome and transcriptome identified novel epigenetic signatures associated with RA and highlighted the interaction between genetics and epigenetics in RA. These findings help our understanding of the pathogenesis of RA and advance epigenetic studies in regards to the disease.

Multicenter Phase 2 Study of Interleukin-2 and 13-Cis Retinoic Acid as Maintenance Therapy in Advanced Non-Small-Cell Lung Cancer

High serum levels of vascular endothelial growth factor (VEGF) are a poor prognostic factor for patients with advanced non-small-cell lung cancer (NSCLC). We have previously shown that low-dose interleukin (IL)-2 and 13-cis retinoic acid (RA) decreased VEGF and improved the immune function of patients with advanced tumors treated with chemotherapy. The primary end point of this study was to verify whether IL-2 and RA decreased serum VEGF in NSCLC patients showing a clinical benefit from chemotherapy. The secondary end point was the evaluation of clinical outcome. We treated 38 patients with advanced NSCLC who had a complete or partial response or disease stability to chemotherapy and had a median serum VEGF level of 508 ng/mL; as maintenance therapy, they received subcutaneous IL-2 (1.8 x 10(6) IU) and oral RA. Matched controls (n = 87) were selected from a large cohort of patients with a similar disease status, including clinical benefit from chemotherapy. The most common adverse events were mild cutaneous skin rash and fever. Serum VEGF decreased to a mean level of 152 ng/mL (P = 0.0002). A statistically significant improvement in immune function was observed (lymphocyte and natural killer cell numbers and CD4+/CD8+ ratio) with respect to baseline values and controls. An improvement in the clinical outcome was also observed compared with controls. These data show that the administration of low-dose subcutaneous IL-2 and oral RA to patients with advanced NSCLC showing a clinical benefit from chemotherapy is feasible with a low-toxicity profile, decreases VEGF, and seems to improve progression-free and overall survival.

Immunoglobulin and cytokine expression in mixed lymphocyte cultures is reduced by disruption of gap junction intercellular communication

Connexins (Cx), the protein subunits assembled into gap junction intercellular communication channels, are expressed in primary lymphoid organs and by circulating leukocytes. Human tonsil-derived T and B lymphocytes express Cx40 and 43; circulating human T, B, and NK lymphocytes express Cx43 and directly transfer between each other a low molecular dye indicative that functional gap junctions exist. We now identify specific properties in the immune system underwritten by gap junctions. Mixed lymphocytes cultured in the presence of two reagents with independent inhibitory action on gap junction communication, a connexin mimetic peptide and 18-alpha-glycyrrhetinic acid, markedly reduced the secretion of IgM, IgG, and IgA. The secretion of these immunoglobulins by purified B cells was also reduced by the two classes of gap junction inhibitors. Complex temporal inhibitory effects on the expression of mRNA encoding interleukins, especially IL-10, were also observed. The results indicate that intercellular signaling across gap junctions is an important component of the mechanisms underlying metabolic cooperation in the immune system.

Primary Th1 Cell Immunization Against HIVgp160 in SCID-hu Mice Coengrafted with Peripheral Blood Lymphocytes and Skin

SCID-hu mouse models are of interest in the pathologic investigation of HIV infection, but obtaining a T cell response in SCID-hu-PBL mice is still controversial. We have developed a SCID model by engrafting human skin and autologous PBLs from HIV-seronegative individuals. The study describes the ability of this human-mouse chimera to generate in vivo a primary T lymphocyte response against HIV Ag. The injection of human autologous PBLs was performed 4 to 5 wk after the skin engraftment. Two weeks after injection of PBLs, chimeric mice were immunized with recombinant canary pox virus expressing HIV-1 LAIgp160 (vCP-LAIgp160) and supplemented or not with rIL-2. Intradermal vCP-LAIgp160 injection induced an intradermal perivascular human lymphocytic infiltrate and an epidermic network of CD1a+, CD80+, and CD86+ cells. We derived CD4+ T cell lines (STLs) from the human skin graft of immunized mice, showing that STLs mediated an MHC class II-restricted cytolytic activity directed against HIV-LAIgp160 Ags. Cytokine gene expression in both human skin cells and in STLs showed a predominance of IL-2, IFN-γ, and IL-12 transcripts. Finally, the T cell repertoire analysis using the immunoscope technique showed a very limited CDR3 length polymorphism in the skin infiltrating lymphocytes suggesting an Ag-specific repertoire. The ability to induce a primary Th1 cell response in vivo affords a useful preclinical model for testing vaccine strategies.