Fig 1.

Anti-SIV humoral (IgA) responses in secretions during immunization. (A to C) IgA antibodies to SIV gp140 Env and SIV lysate Gag and Pol proteins were measured by an ELISA performed on rectal secretions (A), vaginal secretions (B), and salivary secretions (C) collected at intervals after immunization by each mucosal route. To compare the magnitude of the mucosal IgA responses generated in animals, the SIV antibody concentration in each secretion was normalized against the total IgA concentration and is expressed as specific activity (nanogram of SIV-specific IgA per microgram of total IgA). Graphs on the left depict the specific activity in individual animals at time points corresponding to 2 and 4 weeks after the third DNA immunization (weeks 26 and 28), 2 weeks after the MVA immunization (week 34), and 2 and 5 weeks after the second viral particle immunization (weeks 52 and 54). The specific activity had to fall outside the shaded portion in the graphs to be considered statistically significant. Symbols in the shaded region may be overlapping, but all symbols above this have been separated to permit visualization of positive responders. Peak IgA responses measured during this phase of the study are illustrated in the Tukey graphs on the right. P values were obtained using the Mann-Whitney rank sum test. Int, intestinal; Nas, nasal; Vag, vaginal. (D) The percentage of animals in each group that were found to have significant IgA responses to both Env and Gag/Pol at the mucosal site is shown. (E) The number of animals that demonstrated a significant Env or Gag/Pol IgA response at all three or fewer mucosal sites is presented for each immunization group. Animal identification (ID) numbers for the four immunization groups were as follows: oral, animals 153, 247, 248, 249, 253, 255, and 256; intestinal, animals 146, 155, 246, 257, 258, 259, and 260; nasal, animals 145, 147, 148, 149, 150, 156, and 250; and vaginal, animals 151, 152, 154, 157, 158, 254, and 265.