Combined neutralization of interferon gamma and tumor necrosis factor alpha induces IL-4 production but has no direct additive impact on parasite burden in splenic cultures of human visceral leishmaniasis

PLoS One. 2018 Jun 28;13(6):e0199817. doi: 10.1371/journal.pone.0199817. eCollection 2018.

Abstract

Immune activating cytokines Interferon (IFN)-γ and Tumor necrosis factor (TNF)-α are known to activate macrophages for killing of Leishmania parasite. IFN-γ provides therapeutic potential while TNF-α has been recognized to mediate protection in visceral model of infection. In the present study we investigated whether combination of IFN-γ and TNF-α has better therapeutic strength than individually using one of these cytokines in Visceral Leishmaniasis (VL) patients. We performed combined blockade of IFN-γ and TNF-α in VL splenic biopsies and demonstrated it's impact on number of viable amastigotes and cytokine production. Additionally, selective depletion of splenic cell subsets was performed to establish the cellular sources of IFN-γ and TNF-α. Treatment of splenic aspirate cells with combination of anti-IFN-γ and anti-TNF-α monoclonal antibodies for 72 hours enabled no direct additive impact of these cytokines on parasite replication and IL-10 secretion, but IL-4 production was induced. Further assessment of splenic biopsies put forward CD4+ T cells as a source of IFN-γ whereas CD14+ cells contribute towards TNF-α production. Overall our results suggest, the interplay of pro-inflammatory cytokines IFN-γ derived from CD4+T lymphocytes and TNF-α from CD14+ cells has no direct additive impact on parasite replication but induces IL-4 production. Our data does not support direct targeting of IFN-γ and TNF-α for combination therapy but targeting these cytokines as an adjuvant in patients with exaggerated tissue inflammatory responses can have favourable patient outcome.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Monoclonal, Murine-Derived / immunology
  • Antibodies, Monoclonal, Murine-Derived / pharmacology*
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / pathology
  • Female
  • Humans
  • Interferon-gamma* / antagonists & inhibitors
  • Interferon-gamma* / immunology
  • Interleukin-4 / immunology*
  • Leishmania donovani / immunology*
  • Leishmaniasis, Visceral / drug therapy
  • Leishmaniasis, Visceral / immunology*
  • Leishmaniasis, Visceral / pathology
  • Male
  • Middle Aged
  • Models, Biological
  • Organ Culture Techniques
  • Spleen / parasitology
  • Spleen / pathology
  • Tumor Necrosis Factor-alpha* / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha* / immunology

Substances

  • Antibodies, Monoclonal, Murine-Derived
  • IFNG protein, human
  • IL4 protein, human
  • Tumor Necrosis Factor-alpha
  • Interleukin-4
  • Interferon-gamma