Increased cellular immune responses and CD4+ T-cell proliferation correlate with reduced plasma viral load in SIV challenged recombinant simian varicella virus - simian immunodeficiency virus (rSVV-SIV) vaccinated rhesus macaques.
BACKGROUND
An effective AIDS vaccine remains one of the highest priorities in HIV-research. Our recent study showed that vaccination of rhesus macaques with recombinant simian varicella virus (rSVV) vector - simian immunodeficiency virus (SIV) envelope and gag genes, induced neutralizing antibodies and cellular immune responses to SIV and also significantly reduced plasma viral loads following intravenous pathogenic challenge with SIVMAC251/CX1.


RESULTS
The purpose of this study was to define cellular immunological correlates of protection in rSVV-SIV vaccinated and SIV challenged animals. Immunofluorescent staining and multifunctional assessment of SIV-specific T-cell responses were evaluated in both Experimental and Control vaccinated animal groups. Significant increases in the proliferating CD4+ T-cell population and polyfunctional T-cell responses were observed in all Experimental-vaccinated animals compared with the Control-vaccinated animals.


CONCLUSIONS
Increased CD4+ T-cell proliferation was significantly and inversely correlated with plasma viral load. Increased SIV-specific polyfunctional cytokine responses and increased proliferation of CD4+ T-cell may be crucial to control plasma viral loads in vaccinated and SIVMAC251/CX1 challenged macaques.
Division of Microbiology, Tulane National Primate Research Center, Tulane University School of Medicine, Covington, LA 70433, USA.
Bapi
B
Pahar
Wayne L
WL
Gray
Kimberly
K
Phelps
Elizabeth S
ES
Didier
Eileen
E
deHaro
Preston A
PA
Marx
Vicki L
VL
Traina-Dorge
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D016207:Cytokines / Q000378:metabolism; D008253:Macaca mulatta; D010949:Plasma / Q000821:virology; D018449:SAIDS Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000235:genetics* / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D018140:Varicellovirus / Q000235:genetics*; D019562:Viral Load; D014766:Viremia / Q000517:prevention & control*
D016207:Cytokines; D018449:SAIDS Vaccines; D014614:Vaccines, Synthetic