Higher levels of IL-18 circulate during primary infection of monkeys with a pathogenic SHIV than with a nonpathogenic SHIV.
We have monitored kinetics of peripheral blood Interleukin (IL)-18 level, viral RNA load, and CD4(+) T cell counts in cynomolgus and rhesus macaques following infections of various simian/human immunodeficiency viruses (SHIVs) causing differential pathogenicity. Infections of cynomolgus and rhesus macaques with pathogenic SHIVs-C2/1 and -89.6PD, respectively, induced high levels of plasma IL-18 (0.1-1 ng/ml) and enhanced apoptosis of peripheral blood T cells during primary viremia, along with a rapid decline of CD4(+) T cells and a high level of set point viral load after primary viremia (six of six cases). In contrast, infections of cynomolgus macaques with nonpathogenic SHIVs-TH09V3 and -MD14 did not cause such IL-18 elevation, showing no decline of CD4(+) T cells and no or low viral set point level following primary viremia (three of three cases). Thus, the elevation of circulating IL-18 level during primary viral infection can be a good indicator of an active pathogenic viral infection. However, the role of increased IL-18 remains to be elucidated and needs further investigation.
Kaizu
Masahiko
M
AIDS Research Center, National Institute of Infectious Diseases, Shinjuku, Tokyo 162-8640, Japan.
Ami
Yasushi
Y
Nakasone
Tadashi
T
Sasaki
Yuko
Y
Izumi
Yasuyuki
Y
Sato
Hironori
H
Takahashi
Eiji
E
Sakai
Koji
K
Shinohara
Katsuaki
K
Nakanishi
Kenji
K
Honda
Mitsuo
M
D000818:Animals; D017209:Apoptosis; D015415:Biomarkers / Q000097:blood; D018791:CD4 Lymphocyte Count; D004195:Disease Models, Animal; D006678:HIV / Q000472:pathogenicity; D020382:Interleukin-18 / Q000097:blood*; D008252:Macaca fascicularis; D008253:Macaca mulatta; D016097:Simian Acquired Immunodeficiency Syndrome / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000472:pathogenicity; D013601:T-Lymphocytes / Q000502:physiology; D019562:Viral Load
D015415:Biomarkers; D020382:Interleukin-18