Immunopathogenic competences ofLeishmania(V.)braziliensisandL.(L.)amazonensisin American cutaneous leishmaniasis

Abstract

The immunopathogenic competences of Leishmania (V.) braziliensis and L. (L.) amazonensis were reviewed in the light of more recent features found in the clinical and immunopathological spectrum of American cutaneous leishmaniasis. It was shown a dichotomy in the interaction between these Leishmania species and human T-cell immune response; while L. (V.) braziliensis shows a clear tendency to lead infection from the localized cutaneous leishmaniasis (LCL), a moderate T-cell hypersensitivity form at the centre of the spectrum, toward to the mucocutaneous leishmaniasis (MCL) at the T-cell hypersensitivity pole and with a prominent Th1-type immune response, L. (L.) amazonensis shows an opposite tendency, leading infection to the anergic diffuse cutaneous leishmaniasis (ADCL) at the T-cell hyposensitivity pole and with a marked Th2-type immune response. Between the central LCL and the two polar MCL and ADCL, the infection can present an intermediary form known as borderline disseminated cutaneous leishmaniasis, characterized by an incomplete inhibition of T-cell hypersensitivity but with a evident supremacy of Th1 over Th2 immune response (Th1 > or = Th2). These are probably the main immunopathogenic competences of L. (V.) braziliensis and L. (L.) amazonensis regarding the immune response dichotomy that modulates human infection outcome by these Leishmania parasites.

Real-Time PCR Assay for Detection and Quantification of Leishmania (Viannia) Organisms in Skin and Mucosal Lesions: Exploratory Study of Parasite Load and Clinical Parameters

“…The differences in parasite load between CL and ML lesions could be associated with the differential immunopathological manifestations documented in ATL (36). CL is characterized by a moderate T-cell hypersensitivity, whereas ML represents the extreme expression of the T-cell hypersensitivity pole with an exacerbated Th1-type immune response.…”

Euthanasia for the Zoonosis Control Program

“…As a result of these interactions a spectrum of clinical histopathologic and immunological manifestation could be observed (Silveira et al, 2009) (Figure 2). The immunopathogenesis of American cutaneous leishmaniasis (ACL) has been regarded one of most interesting features concerning this parasitic protozoal disease in viewing of the complex interaction process between the variety of Leishmania species causing the disease and the human immune response.…”

“…Moreover, these Leishmania parasites can also induce an intermediary form between the central LCL and the two polar MCL and ADCL, the borderline disseminated cutaneous leishmaniasis (BDCL), which is distinguished by a partial inhibition of T-cell response (Silveira et al, 2005). Furthermore, as BDCL can be caused by parasites belong to both subgenus of Leishmania, Viannia and Leishmania, as well as there are some clinical and immunological characteristics that differ between Viannia and Leishmania cases, then BDCL can occupy the two places between the centre (LCL) and the two polar forms (MCL and ADCL) in the clinical spectrum of disease (Silveira et al, 2009). …”

Muco-cutaneous leishmaniasis in the New World

“…This pathology has been associated with hyperactivity of the specific T cell immune response, with an exuberant, usually progressive, inflammatory response, that is not yet well understood. 4 High levels of pro-inflammatory cytokines such as IFNγ and TNFα, and decreased responses to IL-10 and TGFβ, have been described in references 5 and 6. MCL development is associated with persistent immune responses having elevated pro-inflammatory mediator expression (higher levels of TNFα, CXCL10 and CCL4), with a mixed intra-lesional ©2 0 1 1 L a n d e s B i o s c i e n c e .…”