Leishmania (Viannia) braziliensis antigenic fractions: the immune response characterization of patients at the initial phase of disease

Abstract

American cutaneous leishmaniasis (ACL) has different clinical manifestations and those are dependent on the immunological status of the host. Since CD4 + and CD8 + T cells and its mediators play a fundamental role in the host response to Leishmania and that there is also a search for antigenic molecules to be used as future vaccines and tools for prognostic tests, this study characterized ACL patients immune response after stimulation with soluble and insoluble fractions of L. (V.) braziliensis. We demonstrated a prevailing production of the Th2 cytokines, IL-4 and IL-10, and a specific production of IFN-γ and TNF-α in patients before treatment. There was also a predominance of CD4 + T cells and a small percentage CD8 + T cells. The insoluble antigenic fraction primarily stimulated CD4 + T cells while the soluble antigenic fraction showed a mixed profile, with CD4 + T cells being the main responsible for Th2 cytokines and CD8 + T cells for Th1 cytokines. Therefore, our results showed that a down modulation of the Th1 type of response occurs in the initial phase of L. braziliensis disease being the antigenic fractions capable of stimulating a specific immune response.

Fcγ‐RI, Fcγ‐RII and IL‐10 as predictive biomarkers for post‐therapeutic cicatrization time in monocytes from cutaneous leishmaniasis patients

“…Monocytes play an intriguing role in CL because they are host cells for the parasites and at the same time immune response regulating cells equipped to destroy Leishmania . It has been described that, after treatment, these cells are activated by IFN‐γ produced by CD4 + and CD8 + T lymphocytes and NK cells and induced to produce TNF that, in synergy with IFN‐γ, activate iNOS to produce NO, which is responsible for the destruction of amastigote forms . Studies have focused on determining important aspects of the immune response in CL as mechanisms associated with natural resistance, the presence of active lesions, and healing after treatment .…”

Detection of TNF Alpha Level as Biomarker in Different Stages of Cutaneous Leishmaniasis Infection

“…After Leishmania are phagocytosed by neutrophils, they begin to secrete chemokines such as IL-8 which is critical to get more neutrophils to the infection site [9]. T-cell responses, CD4+ and CD8+ T cells operate as a source of biologically relevant cytokines for monocytes activation and macrophages in all CL clinical manifestations, hence determining susceptibility or resistance to the disease [10]. Cytokines are primarily associated with the cellular immunological response mediated by CD4+ T cells.…”