Administration of recombinant rhesus interleukin-12 during acute simian immunodeficiency virus (SIV) infection leads to decreased viral loads associated with prolonged survival in SIVmac251-infected rhesus macaques.
The ability of recombinant rhesus interleukin-12 (rMamu-IL-12) administration during acute simian immunodeficiency virus SIVmac251 infection to influence the quality of the antiviral immune responses was assessed in rhesus macaques. Group I (n = 4) was the virus-only control group. Group II and III received a conditioning regimen of rMamu-IL-12 (10 and 20 microg/kg, respectively, subcutaneously [s.c.]) on days -2 and 0. Thereafter, group II received 2 microg of IL-12 per kg and group III received 10 microg/kg s.c. twice a week for 8 weeks. On day 0 all animals were infected with SIVmac251 intravenously. While all four group I animals and three of four group II animals died by 8 and 10 months post infection (p.i.), all four group III animals remained alive for >20 months p.i. The higher IL-12 dose led to lower plasma viral loads and markedly lower peripheral blood mononuclear cell and lymph node proviral DNA loads. During the acute viremia phase, the high-IL-12-dose monkeys showed an increase in CD3(-) CD8 alpha/alpha(+) and CD3(+) CD8 alpha/alpha(+) cells and, unlike the control and low-IL-12-dose animals, did not demonstrate an increase in CD4(+) CD45RA(+) CD62L(+) naive cells. The high-IL-12-dose animals also demonstrated that both CD8 alpha/alpha(+) and CD8 alpha/beta(+) cells produced antiviral factors early p.i., whereas only CD8 alpha/beta(+) cells retained this function late p.i. Long-term survival correlated with sustained high levels of SIV gag/pol and SIV env cytotoxic T lymphocytes and retention of high memory responses against nominal antigens. This is the first study to demonstrate the capacity of IL-12 to significantly protect macaques from SIV-induced disease, and it provides a useful model to more precisely identify correlates of virus-specific disease-protective responses.
Ansari
A A
AA
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA. pathaaa@emory.edu
Mayne
A E
AE
Sundstrom
J B
JB
Bostik
P
P
Grimm
B
B
Altman
J D
JD
Villinger
F
F
D000818:Animals; D004279:DNA, Viral / Q000097:blood; D015483:HIV Antibodies / Q000097:blood; D006801:Humans; D007156:Immunologic Memory; D018664:Interleukin-12 / Q000008:administration & dosage* / Q000235:genetics* / Q000276:immunology; D008198:Lymph Nodes / Q000821:virology; D008213:Lymphocyte Activation; D008253:Macaca mulatta; D011533:Proviruses; D011995:Recombination, Genetic; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000401:mortality* / Q000517:prevention & control*; D015302:Simian Immunodeficiency Virus / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019562:Viral Load
D004279:DNA, Viral; D015483:HIV Antibodies; D018664:Interleukin-12