IL-17 and [gamma][d] T-lymphocytes play a critical role in innate immunity against Nocardia asteroides GUH-2

• Published in: Microbes and infection 2012-11, Vol.14 (13), p.1133-1143
• Main Authors: Tam, Stanley, Maksaereekul, Saipiroon, Hyde, Dallas M, Godinez, Ivan, Beaman, Blaine L
• Format: Article
• Language: English
• Subjects: Antibodies; CD4 antigen; Data processing; Flow cytometry; Immunity; Inoculation; Interleukin 17; Leukocytes (neutrophilic); Lung; Lymphocytes T; Nocardia asteroides; Nocardiosis; T-cell receptor
• ISSN: 1286-4579
• DOI: 10.1016/j.micinf.2012.05.008

The early host response during pulmonary nocardiosis is highly dependent on neutrophils and the successful clearance of bacteria in tissue. The data presented in this study showed that IL-17 mediated the neutrophil response following intranasal inoculation with Nocardia asteroides strain GUH-2. Flow cytometry revealed that neutrophil levels in C57BL/6 mice were increased by day 1 post inoculation and remained elevated until day 3, during which time the majority of bacterial clearance occurred. Intracellular cytokine staining for IL-17 showed a 3.5- to 5-fold increase in IL-17 producing T-lymphocytes that were predominately comprised by CD4-CD8- [gamma][d] T-lymphocytes. The importance of IL-17 and [gamma][d] T-cells was determined by the inANBvivo administration of antibody, capable of blocking IL-17 binding or TCR [d], respectively. Neutralization of either IL-17 or [gamma][d] T-cells in Nocardia treated mice resulted in attenuated neutrophil infiltration. Paralleling this impaired neutrophil recruitment, nearly a 10-fold increase in bacterial burden was observed in both anti-IL-17 and anti-TCR [d] treated animals. Together, these data indicate a protective role for IL-17 and suggest that IL-17 producing [gamma][d] T-lymphocytes contribute to neutrophil infiltration during pulmonary nocardiosis.