These transgenic mice express the human interleukin 6 (IL6) gene under the direction of the mouse histocompatibility 2, D region (H-2LD) promoter. The transgenic insert is located on Chromosome 9. Human IL6 protein is detected in serum by ELISA and mRNA is detected in the spleen, lymph nodes, thymus, heart, lung, liver, kidney, and intestine, but not in brain tissue. As early as three to four months of age, transgenic mice develop up to 10-fold enlarged lymph nodes (due to plasma cell accumulation), plasma cell tumors, splenomegaly, and glomerulonephritis. Although homozygotes for this transgenic insert are viable and fertile, due to the early onset of plasma cell tumors, this strain is maintained as a hemizygote.
