Disease relevance of Mpmv1

• Thirty endogenous proviruses belonging to the modified polytropic (Mpmv) class of murine leukemia virus (MLV) were identified by proviral-cellular DNA junction fragment segregation in several sets of recombinant inbred mice [1].
• To determine whether one of these subclasses is associated with murine lupus, oligonucleotide probes specific for Pmv or Mpmv sequences were used in Northern analyses [2].

High impact information on Mpmv1

• In contrast to Mpmv, thymic 8.4 kb Pmv expression was poorly associated with autoimmunity: it was easily detected in nearly all strains, and was increased by polyclonal activation in control mice [2].
• Inbred mouse genomes contain two subclasses of proviruses related to mink cell focus-forming (MCF) retroviruses: polytropic (Pmv), and modified polytropic (Mpmv) [2].
• Recipients of bone marrow from nonautoimmune donors expressed neither 8.4-kb Mpmv RNA nor surface MCF gp70 in their thymuses [3].
• These studies demonstrate that lupus-associated 8.4-kb Mpmv endogenous retroviral expression is determined by bone marrow stem cells [3].
• Recent studies of thymic gene expression in murine lupus have demonstrated 8.4-kb (full-length size) modified polytropic (Mpmv) endogenous retroviral RNA [3].

Biological context of Mpmv1

• We detected highly significant marker associations for acceptance on chromosome 12 (Eif4e), for preference on chromosome 1 (D1Rti2) and chromosome 7 (D7Mit7), and for HDS on chromosome 7 (Mpmv1) [4].

Anatomical context of Mpmv1

• Thymus 8.4 kb Mpmv RNA was expressed in five of five lupus-prone strains and crosses and this expression was not affected by genes that retard or accelerate development of lupus [2].
• The present study was designed to determine whether the abnormal Mpmv expression associated with murine lupus mapped to thymic epithelium or to a marrow precursor [3].
• A phosphorothioate antisense oligonucleotide to the initiation sequence of Mpmv caused lymphocyte activation in vivo in normal mice, providing further evidence for in vivo effects of Mpmv and potential for pathological abnormalities in lupus-prone strains [5].

References