Biased usage of two restricted VH gene segments in Vh replacement

✍ Scribed by Toshihisa Komori; Yusaku Minami; Nobuo Sakato; Haruo Sugiyama

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 861 KB
• Volume: 23
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.1830230233

✦ Synopsis

Abstract

AT8‐1‐12‐5, an intracytoplasmic γ2b‐producing (μ‐γ2b^+^) pre‐B cell line transformed with Abelson murine leukemia virus continuously generated intracytoplasmic μγproducing (μ^+^μ2b^+^ cells during propagation in culture. Southern blotting, DNA cloning and sequence analysis showed that these μ. ^+^μ2b^+^ cells were generated from the μ‐ γ2b^+^ pre‐B cells by V~H~ replacement events. The gene segments involved in these replacement events were restricted to only two V~H~ gene segments, V^h^7.1 (V^h^7183 family) and V^h^6.2 (V^h^Q52 family). Cell staining using the monoclonal anti‐V^H^141 antibody 3‐5‐6f that specifically recognized the V~H~6.2 but not V~H~7.1 gene products indicated that half of the V~H~ replacement events occurring in AT8‐1‐12‐5 used the V~H~6.2 gene segment. Deletion mapping indicated that the incoming V~H~ gene segments, V~H~7.1 and V~H~6.2 were proximal to the resident V~H~ gene segment, V~H~12.5 (V~H~7183 family). These results provided direct evidence of the biased usage of VH gene segments in VH replacement and have several implications for the mechanisms of V~H~ replacement.