Volume 8, Number 8, August 2002

Research

DNA Vaccine Expressing Conserved Influenza Virus Proteins Protective against H5N1 Challenge Infection in Mice

Suzanne L. Epstein,* Terrence M. Tumpey,† Julia A. Misplon,* Chia-Yun Lo,* Lynn A. Cooper, ‡ Kanta Subbarao,‡ Mary Renshaw,‡ Suryaprakash Sambhara,‡ and Jacqueline M. Katz‡
*Food and Drug Administration Rockville, Maryland, USA; †United States Department of Agriculture, Athens, Georgia, USA; and ‡Centers for Disease Control and Prevention, Atlanta, Georgia, USA

Figure 1. DNA vaccination induces T-cell responses. a. Enzyme-linked immuno spot (ELISPOT) assay for interferon-g (IFN-g) secreting cells. Mice were immunized three times with A/NP+A/M or influenza B nucleoprotein DNA (B/NP DNA) intramuscularly. Spleen cells were analyzed by ELISPOT, using peptides at 1 µg/mL or A/PR/8 live virus. Results are the mean of three experiments. No response to A/PR/8 virus occurred in one experiment. Concanavalin A (Con A) responses: A/NP+A/M groups, >274 for all experiments; B/NP groups, >329 for all experiments. b. Cytotoxic T-cell assay. Mice were vaccinated as above or with live A/PR/8 virus given on the day of the second DNA injection. Spleens were harvested 2½ weeks after the third DNA injection. Spleen cells were restimulated in vitro with live A/PR/8 or B/AA. After 7 days of culture, restimulated effector cells at various ratios were mixed with P815 target cells infected with A/PR/8 or B/AA, and lactate dehydrogenase (LDH) release measured.

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This page last reviewed July 9, 2002

Emerging Infectious Diseases Journal
National Center for Infectious Diseases
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