Table 1. Injection of transgenic cells from B cell-deficient (IgM -/-) mice fails to induce a proliferative response to NVDP

Donor

mice

Immunogen

Tg cells per

inoculum*

Mouse

no.

Peptide in culture

Stimulation index
       

NVDP

None

  

IgM-/-

Spleen cells

1,250

1

1,510 ± 183

1,584 ± 101

0.9
     

2

1,277 ± 222

1,133 ± 45

0.9
   

100

3

1,504 ± 150

1,287 ± 37

1.2
     

4

1,229 ± 110

1,025 ± 56

1.2

C57BL/6

Spleen cells

1,250

1

7,663 ± 959

546 ± 122

14
     

2

10,277 ± 222

1,133 ± 45

9
   

100

3

5,055 ± 58

375 ± 86

13
     

4

7,229 ± 110

879 ± 56

8

C57BL/6 mice injected i.v. with spleen cells from either IgM-/- (B cell deficient) mice or C57BL/6 mice after spontaneous transgenesis with γ1NV2NA3. The dose per group is indicated. Spleen cells from immunized mice were harvested after 14 days, and CD4 T cell proliferation after in vitro restimulation with peptide was measured per our standard procedure.

*A total of 4 × 107 spleen cells were subject to spontaneous lymphocyte transgenesis. The efficiency of transfection after magnetic column enrichment was 9% for splenocytes from C57BL/6 mice and 0.1% for splenocytes from IgM-/- mice.