Figure 3.

CD28 Tg pigs show improved specific antibody response, reducing body weight loss, clinical fever and viral load during porcine reproductive and respiratory syndrome virus (PRRSV) infection. (A) Time line of PRRSV vaccination and challenge experiments. Five male transgenic and five male wild-type pigs 4 weeks old were used in the experiments. (B) Body weight changes in WT and Tg pigs over the course of the experiment. (C) The rectal temperature of all piglets was monitored daily postvaccination and challenge. (D) PRRSV-specific antibody is expressed as S/P ratios measured by enzyme-linked immunosorbent assay (ELISA). S/P ratios < 0.4 were considered seronegative. (E) The viral loads in serum samples of WT and Tg pigs were measured by quantitative real-time PCR (WT, wild-type pigs; CD28 Tg, CD28 transgenic pigs). P < 0.05 was considered statistically significant.