Bcl-2 rescues the germinal center response but does not alter the V gene somatic hypermutation spectrum in MSH2-deficient mice.

J Immunol

Kimmel Cancer Center and Department of Microbiology and Immunology, Jefferson Medical College, Thomas Jefferson University Philadelphia, PA 19107, USA.

Published: October 2002

Ab V genes in mice deficient for the postreplication mismatch repair factor MutS homolog (MSH2) have been reported to display an abnormal bias for hypermutations at G and C nucleotides and hotspots. We previously showed that the germinal center (GC) response is severely attenuated in MSH2-deficient mice. This suggested that premature death of GC B cells might preclude multiple rounds of hypermutation necessary to generate a normal spectrum of base changes. To test this hypothesis, we created MSH2-deficient mice in which Bcl-2 expression was driven in B cells from a transgene. In such mice, the elevated levels of intra-GC apoptosis and untimely GC dissolution characteristic of MSH2-deficient mice are suppressed. However, the spectrum of hypermutation is unchanged. These data indicate that the effects of MSH2 deficiency on GC B cell viability and the hypermutation process are distinct.

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http://dx.doi.org/10.4049/jimmunol.169.7.3819DOI Listing

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