Evidence for selective pressure in the appearance of monoclonal immunoglobulins during aging: studies in M54 mu-transgenic mice.
Serum monoclonal immunoglobulins (M-Ig) appear during aging but little is known about the immunological factors which lead to their development. We have investigated whether such M-Ig occur as a clonally random process or result from V-region-directed selective pressures. We have analyzed a mu-transgenic mouse strain in which over 95% of all splenic B cells express the transgenic mu chain. All endogenous repertoire and mu-chain diversity are generated from the 5% of the B cells which express endogenous mu chains. Not one of the M-Ig detected in these mice were of transgene origin alone; 11 of the 14 M-Ig did not express a mu chain and none of the mu chain containing M-Ig expressed the transgene allotype alone. This observation suggests that the B cells giving rise to M-Ig are heavily selected from among the small number of B cells which express endogenous Ig. The selective factors that might act on the endogenous B cell pools are discussed.
Gueret
R
R
Division of Geriatrics, Cornell University Medical College, New York, NY 10021.
Grandien
A
A
Andersson
J
J
Coutinho
A
A
Radl
J
J
Weksler
M E
ME
D000375:Aging; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002999:Clone Cells; D007146:Immunoglobulin lambda-Chains / Q000276:immunology; D007148:Immunoglobulin mu-Chains / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic
D007146:Immunoglobulin lambda-Chains; D007148:Immunoglobulin mu-Chains