Decreased expression of CXCL12 and CCL25 mRNAs in LNs during SIV infection. Real-time RT-PCR was used to measure CXCL12 and CCL25 mRNA expression in LNs from uninfected macaques or macaques in the acute or AIDS stages of infection (mean ± SEM). (A–C) CXCL12 mRNA levels in ALN, MLN and HLN, respectively; (D–F) CCL25 mRNA levels in ALN, MLN and HLN, respectively; *P < 0.05 and **P < 0.01, compared with uninfected controls.