Table 1.

IgG does not abolish T helper cell induction

Donor*	Recipient*	2° IgG anti-NIP†	P vs. c‡	2° IgG anti-SRBC†	P vs. c‡
Nil	SRBC-NIP	3.75  ±  0.09 (5,605)	c	3.22  ±  0.17 (1.655)	c
SRBC	SRBC-NIP	4.75  ±  0.08 (56,245)	0.001 vs. c	5.46  ±  0.05 (288,606)	0.001 vs. c
IgG + SRBC	SRBC-NIP	4.54  ±  0.06 (34,445)	0.001 vs. 0.005	4.42  ±  0.05 (26,104)	0.001 vs. 0.001

^*CBA donor mice were primed with 50 μg polyclonal SRBC-specific IgG and 4 × 10⁷ SRBC, or 4 × 10⁷ SRBC alone, or were left unprimed. Five months later, groups of eight irradiated, syngeneic recipients received 6 × 10⁷ spleen cells from the different groups of donors and were secondary-immunized with 4 × 10⁷ SRBC-NIP immediately after transfer. Five days after adoptive transfers, the antibody response in recipient mice was tested in an ELISPOT assay. This experiment was repeated once with similar results (not shown). 

^†Mean of the log₁₀ value of IgG anti-NIP/SRBC (SFC/spleen) ± SD (geometrical mean) in recipients 5 days after transfer/secondary immunization. 

^‡P value vs. control value (c).