FIG. 1.
Design of the experiments. 129/Sv/Ev mice were infected on day 3 after birth with either 5 × 104 (HI-infected mice) or 1 to 5 (LI-infected mice) FrCasE FFU. HI-infected, but not LI-infected, mice were subjected to immunotherapy with either the 667 MAb (IgG2a/κ), the 667 F(ab′)2 MAb, or the 672 MAb (IgM/κ) under the conditions indicated in the figure. The 667 F(ab′)2 MAb was administrated every day with double injections on days 4 and 6 after birth, as indicated by double arrows. Mice were monitored from the day of infection onwards as indicated in the text. The analyzed parameters were (i) serum viremia, (ii) Env-expressing splenocytes, (iii) spleen infectious centers (SICs), (iv) endogenous anti-FrCasE IgM and IgG responses, and (v) primary and secondary CTL responses against FrCasE-infected cells. Additional treatments and experiments are indicated in the text.