Production of Human Immunoglobulin G Reactive against Human Cancer in Tumor‐bearing Mice with Severe Combined Immunodeficiency Reconstituted with Human Splenic Tissues

Splenic tissues derived from patients with gastric cancer were implanted into mice with severe combined immunodeficiency (SCID) and then the mice were challenged with COLO‐20S, a human colon cancer cell line. Production of human immunoglobulin G (IgG) reactive against the COLO‐205 cells was detected by enzyme‐linked immunosorbent assay in sera from the reconstituted and tumor‐bearing SCID mice. The titers of the reactive IgG relative to total IgG in the sera of SCID mice began to increase from one week after implantation of the tumor cells, and became 10‐ to 100‐fold higher than that in the donor's serum by 3–4 weeks. This model using implantation of human cancer cells in SCID mice reconstituted with human splenic tissues would facilitate further studies of human cancer immunology.