FIG. 2.

Production of DT-specific IgG and IgM after DT vaccine rechallenge of huPBL-SCID mice treated with rhPRL. huPBL-SCID mice were created and immunized as described in Materials and Methods. Ten micrograms of rhPRL or HBSS was injected i.p. every other day for a total of 20 days. On day 28 after huPBL transfer, sera were analyzed using a DT-specific ELISA as described in Materials and Methods. There were four or five mice per group. The results are expressed in optical density units, as assessed on a spectrophotometer at 450 nm from a 1:100 dilution of each sample. rhPRL significantly (P < 0.05 for IgM production; P < 0.01 for IgG production) promoted DT-specific antibody (IgG and IgM) production after rechallenge with DT immunization.