Association between decreased CXCL12 and CCL25 expression and increased apoptosis in lymphoid tissues of cynomolgus macaques during SIV infection.
BACKGROUND
Chemokines likely play multiple roles in HIV-1 and SIV pathogenesis. To examine potential associations between chemokine expression levels and apoptosis of cells in lymphoid tissues during SIV infection, we measured chemokine and cytokine mRNA levels in multiple lymphoid tissues compartments from uninfected and SIV-infected cynomolgus macaques (Macaca fascicularis).


METHODS
Real-time RT-PCR was used to measure host mRNA levels in macaque lymphoid tissues. Proliferating or apoptotic cells were identified in lymphoid tissues by immunohistochemistry.


RESULTS
We found that CXCL12 and CCL25 mRNAs in SIV-infected lymphoid tissues were decreased and their levels were negatively correlated with the numbers of proliferating and apoptotic cells. In vitro analyses revealed that CXCL12 and CCL25 were capable of reducing apoptosis induced by SIV infection.


CONCLUSIONS
These findings suggest that increased apoptosis in lymphoid tissues due to reduced levels of anti-apoptotic chemokines might be a mechanism that contributes to loss of immune function following pathogenic SIV infection.
Qin
Shulin
S
Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA, USA.
Sui
Yongjun
Y
Murphey-Corb
Michael A
MA
Reinhart
Todd A
TA
D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D002460:Cell Line; D054377:Chemokine CXCL12 / Q000378:metabolism*; D019742:Chemokines, CC / Q000378:metabolism*; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008221:Lymphoid Tissue / Q000166:cytology* / Q000276:immunology; D008252:Macaca fascicularis; D012333:RNA, Messenger / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000378:metabolism
D054377:Chemokine CXCL12; D019742:Chemokines, CC; D012333:RNA, Messenger