IL-17A produced by gammadelta T cells plays a critical role in innate immunity against listeria monocytogenes infection in the liver.
IL-17A is originally identified as a proinflammatory cytokine that induces neutrophils. Although IL-17A production by CD4(+) Th17 T cells is well documented, it is not clear whether IL-17A is produced and participates in the innate immune response against infections. In the present report, we demonstrate that IL-17A is expressed in the liver of mice infected with Listeria monocytogenes from an early stage of infection. IL-17A is important in protective immunity at an early stage of listerial infection in the liver because IL-17A-deficient mice showed aggravation of the protective response. The major IL-17A-producing cells at the early stage were TCR gammadelta T cells expressing TCR Vgamma4 or Vgamma6. Interestingly, TCR gammadelta T cells expressing both IFN-gamma and IL-17A were hardly detected, indicating that the IL-17A-producing TCR gammadelta T cells are distinct from IFN-gamma-producing gammadelta T cells, similar to the distinction between Th17 and Th1 in CD4(+) T cells. All the results suggest that IL-17A is a newly discovered effector molecule produced by TCR gammadelta T cells, which is important in innate immunity in the liver.
Hamada
Satoru
S
Molecular Microbiology Group, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Umemura
Masayuki
M
Shiono
Takeru
T
Tanaka
Kensho
K
Yahagi
Ayano
A
Begum
M Dilara
MD
Oshiro
Kiyotetsu
K
Okamoto
Yuko
Y
Watanabe
Hisami
H
Kawakami
Kazuyoshi
K
Roark
Christina
C
Born
Willi K
WK
O'Brien
Rebecca
R
Ikuta
Koichi
K
Ishikawa
Hiromichi
H
Nakae
Susumu
S
Iwakura
Yoichiro
Y
Ohta
Takao
T
Matsuzaki
Goro
G
D000818:Animals; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000096:biosynthesis; D020381:Interleukin-17 / Q000096:biosynthesis / Q000276:immunology*; D008089:Listeria monocytogenes; D008088:Listeriosis / Q000276:immunology*; D008107:Liver Diseases / Q000382:microbiology*; D051379:Mice; D018345:Mice, Knockout; D016692:Receptors, Antigen, T-Cell, gamma-delta; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D020381:Interleukin-17; D016692:Receptors, Antigen, T-Cell, gamma-delta; D007371:Interferon-gamma