Since three of our MAbs (1F5A8, 6F11E1 and 8F9G7) displayed similar binding activity to SPA with regard to interaction with purified human myeloma proteins of IgG1, 2 and 4 and the IgG3 myeloma protein Goe, as well as human polyclonal IgG1, 2 and 4, but not IgG3 subclasses (Figure 1), the specificity of these MAbs resembled that of SPA.
Structural studies of a human y3 myeloma protein (Goe) that binds Staphylococcal protein A.
Fc, Fab and F (ab') 2 fragments were prepared from several purified human myeloma proteins of each of the IgG subclasses, by pepsin and papain digestion (17).
Specificity of the MAbs was determined, using a panel of purified myeloma proteins, including IgG1 (n=9), IgG2 (n=4), IgG3 (n=7) and IgG4 (n=7) subclasses.
The arrays were then washed and blocked with a 5 g/L solution of bovine serum albumin in PBS and incubated for 30 min to 24 h with 50 [micro]L of solution containing human myeloma proteins
(Sigma Chemical Co.
Richard Champlin, Head of the Leukemia and Lymphoma Transplant Section at MD Anderson Hospital (Houston, TX) and a principal investigator on the study, reported 12 of 27 patients evaluated in Phase I had achieved complete remission, defined by the absence of myeloma tumor cells in the bone marrow and the absence of the characteristic myeloma protein
in the blood and urine by the most stringent biochemical tests currently in common use.
A panel of 30 different purified human Ig myeloma proteins
of different isotypes and IgG myeloma proteins
of known IgG subclasses and light chain types was employed in this study.
EMP is a soft tissue plasma cell tumor occurring in the absence of systemic signs of multiple myeloma, such as a bone osteolytic lesion, plasma cell infiltration in bone marrow, a lytic bone lesion, and serum or urine myeloma proteins
The CAP survey materials for the immunoglobulins include pathologic as well as nondiseased serum samples, with many samples containing myeloma proteins
or M-components (MC), as detected on agarose gel electrophoresis.