Robert Sabat

Mapping protein-protein contact sites using cellulose-bound peptide scans.

SummaryWe have characterized the interaction of two monoclonal antibodies with their respective antigens using cellulose-bound sets of overlapping peptides (peptide scans). Both antibodies CB/RS/5 and CB/MT/1 recognize discontinuous epitopes present in human interleukin-10 (IL-10) and tumor necrosis factor alpha (TNF-α). In addition, the interaction between TNF-a and its 55-kDa receptor (TNF-R) was investigated by the same approach. Both antibodies, as well as TNF-α, interacted with two or more regions of the peptide scans. Antibody-binding competition studies between the native antigens and peptides, covering single parts of the binding regions, enabled us to distinguish between binding to the paratope or other regions of the antibody. The combination of these experimental approaches allowed the identification of short antigen-derived sequences that are separated on the primary sequence but close in space on the surface of IL-10 and TNF-α, thus representing putative discontinuous epitopes. In the case of the TNF-R-derived peptide scans, two of the identified regions interact with the structurally similar TNF-β in the TNF-β-TNF-R complex. These data indicate that this approach should be generally applicable for mapping nonlinear protein-protein contact sites.

The treatment of psoriasis with IL-10: rationale and review of the first clinical trials

By virtue of its anti-inflammatory and immunosuppressive properties, IL-10 plays a crucial role in several immune reactions, including regulatory mechanisms in the skin. In psoriasis, a common cutaneous immune disease, a relative deficiency in cutaneous IL-10 expression is observed. Several lines of evidence suggest that IL-10 could have antipsoriatic abilities. One pilot and two Phase II trials with sc. IL-10 administration over 3 - 7 weeks in patients with moderate to severe psoriasis have supported this hypothesis. The therapy was well-tolerated and clinical efficiency was found in the majority of patients. Immunosuppressive effects (depressed monocytic HLA-DR expression, TNF-α and IL-12 secretion capacity, IL-12 plasma levels and responsiveness to recall antigens) as well as a shift towards a Type 2 cytokine pattern (increasing proportion of IL-4, IL-5, and IL-10 producing T-cells, selective increase in IgE serum levels) were observed. These investigations suggest that IL-10 is of major importance in psoriasis and show that IL-10 administration represents a new therapeutic approach. However, long-term administration of large recombinant protein limits the value of this novel therapeutic approach. As such, neither oral nor topical applications are possible; there is a risk of the development of neutralising antibodies.

Psoriasis: Diagnosis and Management

Practical and user-friendly, this is the ideal guide to the diagnosis and treatment of psoriasis, helping you navigate a logical management pathway through a complex maze of possibilities. Psoriasis is a cruel disease that can seriously affect the sufferer’s quality and length of life. It is also highly idiosyncratic, with features that vary greatly from patient to patient; this being mirrored in the highly variable response to treatment. It is increasingly recognized that psoriasis is not a discrete disease and that many patients suffer two or three comorbid conditions that can complicate the efforts of doctors treating patients. Psoriasis: Diagnosis and Management will provide dermatologists of all levels with a practical, well-illustrated approach to fully understanding the disease, including clear, clinical guidance to enable best-practice and effective management of patients. In full color throughout and excellently illustrated, key highlights include: