Mixed inflammatory/regulatory cytokine profile marked by simultaneous raise of interferon‐γ and interleukin‐10 and low frequency of tumour necrosis factor‐α+ monocytes are hallmarks of active human visceral Leishmaniasis due to Leishmania chagasi infection

• Published in: Clinical and experimental immunology Vol. 146; no. 1; pp. 124 - 132
• Main Authors: Peruhype‐Magalhães, V., Martins‐Filho, O. A., Prata, A., Silva, L. De A., Rabello, A., Teixeira‐Carvalho, A., Figueiredo, R. M., Guimarães‐Carvalho, S. F., Ferrari, T. C. A., Van Weyenbergh, J., Correa‐Oliveira, R.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-10-2006; Blackwell; Blackwell Science Inc
• Subjects: Adolescent; Adult; Aged; Basic Immunology; Biological and medical sciences; Cells, Cultured; cellular immune response; Child; Child, Preschool; Cytokines - blood; cytometric bead array; Female; flow cytometry; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Immunity, Cellular; Immunopathology; immunoregulation; Interferon-gamma - blood; Interleukin-10 - blood; Leishmaniasis, Visceral - blood; Leishmaniasis, Visceral - immunology; Leukocytes, Mononuclear - immunology; Male; Medical sciences; Middle Aged; Monocytes - immunology; Nitrates - blood; Nitrites - blood; Tumor Necrosis Factor-alpha - blood; visceral Leishmaniasis; cellular immune response; Flow cytometry; Protozoal disease; Kala azar; cytometric bead array; Cellular immunity; Low frequency; Leishmania chagasi; Immunology; immunoregulation; Kinetoplastida; Human; Immunopathology; Protozoa; Immune response; Monocyte; Cytokine; Inflammation; Leishmaniasis; Parasitosis; Infection; Tumor necrosis factor; Mixed; Interleukin 10; visceral Leishmaniasis; Gamma interferon
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2006.03171.x

Summary
Considering the complexity of the immunological events triggered during active visceral Leishmaniasis (VL), the relevance of the segregation of the immune response during human VL into type 1 and type 2 still remains unclear. For this purpose, in individuals living in risk areas for VL, we have evaluated especially asymptomatic individuals and patients with active VL, the plasmatic levels of cytokines and reactive nitrogen species under ex vivo conditions. In addition, we have also performed an analysis of intracellular cytokine patterns of circulating leucocytes after short‐term culture, particularly in the absence of antigenic‐specific stimulation, in order to reflect dynamic events of immune response in vivo during Leishmania chagasi infection. Although asymptomatic individuals and non‐infected subjects presented a similar immunological profile, an outstanding inflammatory/regulatory profile, based on higher plasmatic levels of cytokines such as interleukin (IL)‐8, interferon (IFN)‐γ, tumour necrosis factor (TNF)‐α, IL‐6 and IL‐10, was associated with clinical status observed in active VL. In this context, we hypothesize that IL‐10, through its ability to inhibit anti‐leishmanial macrophage activation, associated with the lower frequency of TNF‐α+ monocytes and ordinary levels of nitrite and nitrate are the major mechanisms associated with disease onset.