High level expression of functional human IgMs in human PER.C6 cells.
Natural IgM antibodies play an important role in the body's defense mechanisms against transformed cells in the human body and are currently being exploited both in prognoses of malignant lesions and in the therapy of cancer patients. However, despite growing interest and clinical promise, thus far the IgM class of antibodies has failed to gain widespread commercial interest as these are considered to be difficult to produce recombinantly. IgMs are polymeric and have a relatively large mass. In addition, IgM molecules are heavily glycosylated and, when produced in non-human cell lines, they may contain non-human glycan structures which may be potentially immunogenic. Clearly, production systems capable of expressing human recombinant IgM antibodies are needed. We have successfully used PER.C6 cells-a human cell line-to generate three separate human recombinant monoclonal IgMs in suspension cultures in protein-free medium. All three of the IgMs were constructed with joining (J) chain and were expressed in the pentameric form. One of the IgMs was also expressed as a hexamer without J chain. Clones with cell specific productivities greater than 20 pg/cell/day were generated, which led to yields of 0.5 g/L to 2g/L in fed-batch production. All the IgMs expressed were biologically active as shown in binding and cytotoxicity assays. These studies demonstrate the potential of PER.C6 cells for the production of high levels of functional recombinant IgM and other polymeric molecules, using a straightforward and rapid stable cell line generation method.
Tchoudakova
Anna
A
Percivia LLC, Cambridge, MA 02135, USA.
Hensel
Frank
F
Murillo
Alec
A
Eng
Bernie
B
Foley
Marketa
M
Smith
Lakee
L
Schoenen
Frank
F
Hildebrand
Antonia
A
Kelter
Arndt-René
AR
Ilag
Leodevico L
LL
Vollmers
H Peter
HP
Brandlein
Stephanie
S
McIninch
Jane
J
Chon
John
J
Lee
Gene
G
Cacciuttolo
Marco
M
D000230:Adenocarcinoma; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000235:genetics; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D002277:Carcinoma; D018929:Cell Culture Techniques; D002460:Cell Line; D045744:Cell Line, Tumor / Q000276:immunology; D016895:Culture Media, Serum-Free; D005786:Gene Expression Regulation; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis* / Q000235:genetics; D008175:Lung Neoplasms; D010190:Pancreatic Neoplasms; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics
D000911:Antibodies, Monoclonal; D016895:Culture Media, Serum-Free; D007075:Immunoglobulin M; D011994:Recombinant Proteins