RESUMO
BACKGROUND: Psoriasis is a pro-inflammatory disease with unknown etiology, that is characterized by skin inflammation and keratinocytes hyperproliferation. Specific inhibition of inflammation has shown positive effects avoiding the progression of the psoriatic lesions in different animal models of the disease, turning this strategy as a remarkable therapeutic alternative. OBJECTIVE: To screen the effectiveness of a novel IFN-α/ß signalling inhibitor in the development reduction of skin lesions in IMQ and TPA mice models of psoriasis. METHODS: We used a Phage-peptide library for the screening of a peptide with inhibitory effects on the development of psoriasis-like lesions in mice. To evaluate the in vivo effect of the phage-peptides (Phpep3D) and the derived peptide (Pep3D), we administered Phpep3D or Pep3D intradermally in mice with imiquimod (IMQ)-induced psoriasis and 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced psoriasis. We scored the lesions, and we determined the number of neutrophils and the production of some pro-inflammatory cytokines in the lesions. RESULTS: In this work, we describe how the Ph3pepD and Pep3D reduced skin thickness, redness, and acanthosis despite the presence of the psoriasis inducers, IMQ or TPA. We also found that Pep3D reduced the number of GR1+ infiltrated cells and decreased the production of IL-17A and TNFα in the psoriatic skin of mice. In-silico, docking analysis showed that Pep3D may interact with the interferon-alpha receptor, but further analyses should be performed to uncover the mechanism of action of this peptide. CONCLUSION: Our results suggest that Pep3D could be used as a new treatment for psoriasis.
RESUMO
Diagnostic tests for toxoplasmosis are based on serological techniques due to their high sensitivity. Some IgG subclasses are related to clinical outcome in the congenital form. In this work, we determined the levels of IgG, IgA, IgG1, IgG2, IgG3 and IgG4 anti-Toxoplasma gondii antibodies in paired saliva and serum samples from 91 women by indirect ELISA using a crude extract of the RH strain. The levels of IgA, IgG2, IgG3 and IgG4 antibodies and, to a lesser extent, IgG1 did not correlate between saliva and serum, that is, most cases that were positive for one Ig class in a sample were negative or very low in the other, and vice versa. We also observed that most samples of saliva that were positive for one IgG subclass were also positive for at least 2 of the other 3; this contrasted with findings in serum, wherein each person was positive almost exclusively for one subclass, as demonstrated before by us and other researchers. Although these findings are disappointing for the use in diagnosis, the richer response in saliva might indicate local exposure to T. gondii antigens without systemic infection; thus, saliva might be reflecting a local (protective?) response against this protozoan.
