Antigens from Leishmania amastigotes inducing clinical remission of psoriatic arthritis

Management of Infections in Psoriatic Patients Treated with Systemic Therapies: A Lesson from the Immunopathogenesis of Psoriasis

Modern treatments continue to be developed based on identifying targets within the innate and adaptive immune pathways associated with psoriasis. Whilst there is a sound biologic rationale for increased risk of infection following treatment with immunomodulators, the clinical evidence is confounded by these agents being used in patients affected with several comorbidities. In an era characterized by an ever greater and growing risk of infections, it is necessary to always be updated on this risk. In this mini-review, we will discuss recent updates in psoriasis immunopathogenesis as a rationale for systemic therapy, outline the risk of infections linked to the disease itself and systemic therapy as well, and provide an overview of the prevention and management of infections.

Current and potential immune therapies and vaccines in the management of psoriasis

Psoriasis is a chronic, immune skin disease associated with significant morbidity. Development of psoriasis is influenced by numerous genes, one allele is HLA-CW*0602. Other genes and single nucleotide polymorphisms affect immunologic pathways and antimicrobial peptide synthesis. Dendritic cells initiate psoriasis by activating T-cells toward a Th1 and Th17 response, with increased cytokines including TNF-α, IL-6, -12, -17, -22, and -23. IL-22 appears to promote keratinocyte dedifferentiation and increased antimicrobial peptide synthesis while TNF-α and IL-17 induce leukocyte localization within the psoriatic plaque. These recent insights identifying key cytokine pathways have led to the development of inhibitors with significant efficacy in the treatment of psoriasis. While a strategy for vaccine modulation of the immune response in psoriasis is in progress, with new technology they may provide a cost-effective long-term treatment that may induce tolerance or targeted self-inhibition for patients with autoimmune disorders, such as psoriasis.

Clinical and Immunological Analysis of Cutaneous Leishmaniasis before and after Different Treatments

Amastigotes from L. (L.)amazonensis (La), L. (L.)venezuelensis (Lv), L. (V.)brasiliensis (Lb), and L. (L.)chagasi (Lch) were cultured in a free cells liquid culture medium. Patients (n = 87) from a cutaneous leishmaniasis (CL) hyperendemic region receiving different treatments were followed up from January 1994 to August 2000. Time for remission of lesions were spontaneous remission (SR) 7 weeks; Glucantime (Glu) chemotherapy 9 weeks; immunotherapy with La, Lv, Lb, and Lch amastigotes Tosyl-Lysil Chloromethyl-ketone (TLCK) treated and Nonidet P-40(NP-40) extracted (VT) 7 weeks. Delayed type hypersensitivity (DTH) response with leishmanine intradermic reaction (IDR) was higher in CL patients than healthy controls (P < 0.05) and increased in active secondary versus primary infection (P < 0.001) with diagnostic value 1.74 for active infection and 1.81 postclinical remission. Antibodies to amastigotes characterized by Enzyme Linked Immunosorbent Assay (ELISA) decreased in sera postclinical remission versus active infections (P < 0.001), with a diagnostic value from 1.50 to 1.84. Immunoblottings antigenic bands frequency as well as Integral Optical Density (IOD) Area Densitometry decreased with sera from SR, after Glu or VT treatments in CL volunteers. Intracellular parasitism is due to normal antibodies recognizing parasite antigens after inoculation by vector. VT vaccine induced mainly cellular immunity, for remission of lesions and protection from CL infection.

Analysis of the protective potential of antigens released by Leishmania (Viannia) shawi promastigotes

Leishmania (Viannia) shawi causes cutaneous lesions in humans. Parasite antigens conferring significant protection against American tegumentar leishmaniosis (ATL) might be important for the development of effective vaccine. Therefore, this work evaluates the protective effect of antigenic fractions released by L. shawi. Antigens released by promastigotes to culture medium were concentrated and isolated by SDS-PAGE. The three main fractions LsPass1 (>75 kDa), LsPass2 (75-50 kDa) and LsPass3 (<50 kDa) were electro-eluted according with their molecular mass. Immunized BALB/c mice were challenged with L. shawi promastigotes and the course of infection monitored during 5 weeks. LsPass1-challenged mice showed no protection, however, a strong degree of protection associated to smaller lesions and high expression of IFN-γ and TNF-α by CD4(+) T, CD8(+) T and double negative CD4CD8 cells was achieved in LsPass3-challenged mice. Furthermore, LsPass2-challenged mice showed an intermediated degree of protection associated to high levels of IFN-γ, IL-4 and IL-10 mRNA. In spite of increased expression of IFN-γ and TNF-α, high amounts of IL-4 and IL-10 mRNA were also detected in LsPass3-challenged mice indicating a possible contribution of these cytokines for the persistence of a residual number of parasites that may be important in inducing long-lasting immunity. Therefore, LsPass3 seems to be an interesting alternative that should be considered in the development of an effective vaccine against ATL.