Figure 2

A. The number of 5T33 MMM cells in the spleen was estimated by the area of the IgH CDR3 mRNA peak with the length and sequence analysis of cDNA of 5T33 MMM cells using ImageJ Version 1.37 (NIH, Bethesda, MD). Splenic samples were obtained by partial splenectomy, 1, 2, or, at sacrifice, 21 days after injection after injection of 5T33 MMM cells. Splenic 5T33 cell number in young wild type C57BL/6 mice decreased by nearly 50% between day 1 and 2 and by 70% between day 2 and 21 following the injection of 5T33 MMM cells. In contrast, in old mice decreased only 30% and less than 5% between day 1 and 2 and less than 5% between day 2 and 21. After 21 days the index of 5T33 MMM cells remaining in the spleen was 4 fold greater in old than in young mice (p=0.036, Mann-Whitney Rank Sum Test). B. The average growth of 10 million luciferase-transfected 5T33 MMM (5T33L) cells injected into 3 young wild-type C57BL/6 mice or into 5 C57BL/6 Rag1-deficient mice by the average photon flux during the 7 weeks following the injection of 10 million 5T33L MMM cells. The average photon flux was measured using an IVIS optical imaging system after 20 minutes, 2 days, and at weekly intervals following 5T33L MMM cell infection for 7 weeks. Within 14 days the difference in the average photon flux of the C57BL/6-Rag-1-deficient and C57BL/6 wildtype mice was significantly different (p < 0.036 Wilcoxin-Mann-Whitney rank sum test) and increased progressively thereafter.