A new infectious mammary tumor virus in the milk of mice implanted with C4 hyperplastic alveolar nodules

摘要

AbstractWe have previously characterized an infectious mouse mammary tumor virus (MMTV(SW) which induces a strong superantigen responsein vivo. Here we describe the isolation and characterization of MMTV(C4) which was derived from milk of mice implanted with hyperplastic alveolar nodules. MMTV(C4) stimulates Vβ2 expressing T cells after local injectionin vivo. Comparison with known open reading frame (orf) sequences revealed high homology to Mtv‐6, an endogenous virus interacting with Vβ3‐expressing T cells. The carboxyl‐terminal amino acids were, however, altered. High homology including the carboxyl‐terminal orf amino acids were found with MMTV(C3H‐K). We show here that MMTV(C3H‐K) has lost its superantigen function. Sequence comparisons permitted the characterization of few key amino acids which could be important for T cell receptor interaction and superantig