Related Experiment Video

Updated: Jul 9, 2026

Quantification of Intracellular Growth Inside Macrophages is a Fast and Reliable Method for Assessing the Virulence of Leishmania Parasites
10:01

Quantification of Intracellular Growth Inside Macrophages is a Fast and Reliable Method for Assessing the Virulence of Leishmania Parasites

Published on: March 16, 2018

Interleukin-15 increases Paracoccidioides brasiliensis killing by human neutrophils

Elisandra Garcia Tavian1, Luciane Alarcão Dias-Melicio, Michele Janegitz Acorci

  • 1Department of Microbiology and Immunology, Biosciences Institute, São Paulo State University (UNESP), Botucatu, CEP 18618-000, S.P., Brazil.

Cytokine
|December 19, 2007
PubMed

Insights

Interleukin-15 (IL-15) enhances human neutrophil antifungal activity against Paracoccidioides brasiliensis. This cytokine boosts neutrophil oxidative burst, crucial for pathogen killing, without affecting IL-8 or TNF-alpha levels.

Area of Science:

  • Immunology
  • Cell Biology
  • Infectious Diseases

Background:

  • Interleukin-15 (IL-15) is a cytokine produced by various cells, including macrophages.
  • IL-15 plays a role in innate immune responses and phagocytic cell activation against pathogens.
  • The specific impact of IL-15 on human neutrophil fungicidal activity was not fully elucidated.

Purpose of the Study:

  • To investigate the effects of IL-15 on human polymorphonuclear leukocyte (neutrophil) fungicidal activity.
  • To determine if IL-15 influences the oxidative burst of neutrophils.
  • To explore the mechanism underlying IL-15's effect on neutrophil antifungal capacity.

Main Methods:

  • Human neutrophils from healthy donors were pretreated with varying doses of IL-15.
  • Fungicidal activity against a virulent strain of Paracoccidioides brasiliensis was assessed.
  • Neutrophil oxidative burst was measured via superoxide anion and hydrogen peroxide (H2O2) release.
  • The role of H2O2 was examined using catalase inhibition.
  • Levels of IL-8 and TNF-alpha were monitored.

Main Results:

  • Pretreatment with IL-15 significantly increased neutrophil fungicidal activity in a dose-dependent manner.
  • IL-15 exposure led to enhanced neutrophil oxidative burst, evidenced by increased superoxide anion and H2O2 release.
  • Catalase treatment inhibited the fungicidal activity, confirming the role of H2O2 in killing Paracoccidioides brasiliensis.
  • IL-15 did not affect the levels of IL-8 and TNF-alpha.

Conclusions:

  • Interleukin-15 is a potent stimulant of antifungal activity in human neutrophils.
  • The mechanism involves, at least partly, an enhancement of the oxidative metabolism and H2O2 production.
  • IL-15's effects are not mediated through increased IL-8 or TNF-alpha.

Related Concept Videos

Leishmaniasis01:30

Leishmaniasis

Leishmaniasis is a protozoal disease caused by species of the genus Leishmania and transmitted through the bite of infected female sandflies. The parasite exists in two principal morphological forms during its life cycle. A sandfly acquires intracellular amastigotes from an infected reservoir host, such as a dog. Within the sandfly, these forms differentiate into motile, flagellated promastigotes. During a subsequent blood meal, promastigotes are injected into the human host, where they...
Cytotoxic T Cells-mediated Immune Response01:27

Cytotoxic T Cells-mediated Immune Response

Cytotoxic T cells are a vital component of the immune system. They have the remarkable ability to identify and target antigens on infected or abnormal cells. These antigens often originate from intracellular pathogens such as viruses or abnormal proteins cancer cells produce.
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
Cryptococcal Meningitis01:27

Cryptococcal Meningitis

Cryptococcal meningitis is a life-threatening opportunistic infection predominantly associated with HIV/AIDS, accounting for over 100,000 deaths annually worldwide. However, it also affects individuals with other forms of immunosuppression, including those undergoing immunosuppressive therapy, organ transplant recipients, patients with innate immunodeficiencies, and individuals with hematological disorders. The infection is caused mainly by Cryptococcus neoformans and Cryptococcus gattii,...
Antiprotozoal Agents01:21

Antiprotozoal Agents

Leishmaniasis is a widespread parasitic disease caused by several Leishmania species. It affects millions of people each year and remains a major public health problem in endemic regions. First-line treatment relies on pentavalent antimonials, including meglumine antimoniate and sodium stibogluconate. Even so, how these drugs work has not been fully clear, especially their interaction with parasite-specific biochemical pathways. One key target is trypanothione reductase (TR), an enzyme that...