Studies in macaques on cross-clade T cell responses elicited by a DNA/MVA AIDS vaccine, better conservation of CD8 than CD4 T cell responses.
One of the unknowns faced by an HIV/AIDS vaccine is the ability of a single clade vaccine to protect against the multiple genetic subtypes and recombinant forms of HIV-1 present in the current pandemic. Here, we use a macaque model to investigate the ability of our clade B vaccine that consists of DNA priming and modified vaccinia Ankara (MVA) virus boosting to elicit T cell responses that recognize an A/G recombinant of HIV-1. To test for cross-reactive T cells, intracellular cytokine staining was conducted using five pools of Gag and six pools of Env peptides representing B or A/G sequences. Studies using the peptide pools revealed essentially complete conservation of the CD8 response but only approximately 50% conservation of the CD4 response. Thus, the ability of an HIV vaccine for one clade to protect against other clades may be more limited by the ability to provide CD4 T cell help than the ability to elicit CD8 effector functions.
Smith
James M
JM
Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia 30329, USA.
Amara
Rama Rao
RR
Wyatt
Linda S
LS
Ellenberger
Dennis L
DL
Li
Bin
B
Herndon
James G
JG
Patel
Milloni
M
Sharma
Sunita
S
Chennareddi
Lakshmi
L
Butera
Sal
S
McNicholl
Janet
J
McClure
Harold M
HM
Moss
Bernard
B
Robinson
Harriet L
HL
D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003429:Cross Reactions; D015497:HIV-1 / Q000276:immunology*; D008251:Macaca; D019444:Vaccines, DNA / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology*; D014616:Vaccinia virus / Q000276:immunology
D016915:AIDS Vaccines; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic