Structure-activity relationship of a guanine-free oligodeoxynucleotide as immunopotent inhibitor

Therapeutic peptides for the treatment of systemic lupus erythematosus: a place in therapy

INTRODUCTION

Studies in vitro and in vivo have identified several peptides that are potentially useful in treating systemic lupus erythematosus (SLE). The rationale for their use lies in the cost-effective production, high potency, target selectivity, low toxicity, and a peculiar mechanism of action that is mainly based on the induction of immune tolerance. Three therapeutic peptides have entered clinical development, but they have yielded disappointing results. However, some subsets of patients, such as those with the positivity of anti-dsDNA antibodies, appear more likely to respond to these medications.

AREAS COVERED

This review evaluates the potential use of therapeutic peptides for SLE and gives an opinion on how they may offer advantages for SLE treatment.

EXPERT OPINION

Given their acceptable safety profile, therapeutic peptides could be added to agents traditionally used to treat SLE and this may offer a synergistic and drug-sparing effect, especially in selected patient populations. Moreover, they could temporarily be utilized to manage SLE flares, or be administered as a vaccine in subjects at risk. Efforts to ameliorate bioavailability, increase the half-life and prevent immunogenicity are ongoing. The formulation of hybrid compounds, like peptibodies or peptidomimetic small molecules, is expected to yield renewed treatments with a better pharmacologic profile and increased efficacy.

Structure, mechanism and therapeutic utility of immunosuppressive oligonucleotides

Synthetic oligodeoxynucleotides that can down-regulate cellular elements of the immune system have been developed and are being widely studied in preclinical models. These agents vary in sequence, mechanism of action, and cellular target(s) but share the ability to suppress a plethora of inflammatory responses. This work reviews the types of immunosuppressive oligodeoxynucleotide (Sup ODN) and compares their therapeutic activity against diseases characterized by pathologic levels of immune stimulation ranging from autoimmunity to septic shock to cancer (see graphical abstract). The mechanism(s) underlying the efficacy of Sup ODN and the influence size, sequence and nucleotide backbone on function are considered.

An immune regulatory CCT repeat containing oligodeoxynucleotide capable of causing hair loss in male mice

An oligodeoxynucleotide with CCT repeats (CCT ODN) has been found in our previous study to selectively downregulate Toll-like receptor 7/9 (TLR7/9)-mediated immune responses both in vitro and in vivo. In this study, we unexpectedly found that CCT ODN induced severe patchy hair loss around the mouth in male F1 mice (female Balb/c × male C57BL/6) with lupus-like nephritis induced by injecting allogenic lymphocytes and also in male Balb/c mice, but not in female F1 mice and Balb/c mice and either gender of C57BL/6 mice. Increased infiltration of natural killer group 2, member D (NKG2D⁺) cells in hair loss skin and upregulated interferon-gamma (IFN-γ) messenger RNA expression in cultured splenocytes were observed in male Balb/c mice. The CCT ODN-conditioned supernatants of cultured mouse splenocytes caused catagen-like changes to hair follicles (HFs). We hypothesized that the CCT ODN could induce patchy hair loss in the male mice with certain genetic traits by mobilizing NKG2D⁺ cells to HFs and by inducing the production of IFN-γ from immune cells. Taken together these data indicated that a gender and genetic preference of immune-regulatory oligonucleotides is causing unexpected clinical situations such as hair loss.