Kaposi sarcoma herpesvirus (KSHV) vFLIP oncoprotein induces B cell transdifferentiation and tumorigenesis in mice Academic Article uri icon


MeSH Major

  • B-Lymphocytes
  • Gene Expression Regulation, Neoplastic
  • Herpesvirus 8, Human
  • Sarcoma, Kaposi
  • Viral Proteins


  • Kaposi sarcoma herpesvirus (KSHV) is specifically associated with Kaposi sarcoma (KS) and 2 B cell lymphoproliferative diseases, namely primary effusion lymphoma (PEL) and multicentric Castleman disease (MCD). KS, PEL, and MCD are largely incurable and poorly understood diseases most common in HIV-infected individuals. Here, we have revealed the role of viral FLICE-inhibitory protein (vFLIP) in the initiation of PEL and MCD by specifically expressing vFLIP at different stages of B cell differentiation in vivo. Mice showed MCD-like abnormalities and immunological defects including lack of germinal centers (GCs), impaired Ig class switching, and affinity maturation. In addition, they showed increased numbers of cells expressing cytoplasmic IgM-λ, a thus far enigmatic feature of the KSHV-infected cells in MCD. B cell-derived tumors arose at high incidence and displayed Ig gene rearrangement with downregulated expression of B cell-associated antigens, which are features of PEL. Interestingly, these tumors exhibited characteristics of transdifferentiation and acquired expression of histiocytic/dendritic cell markers. These results define immunological functions for vFLIP in vivo and reveal what we believe to be a novel viral-mediated tumorigenic mechanism involving B cell reprogramming. Additionally, the robust recapitulation of KSHV-associated diseases in mice provides a model to test inhibitors of vFLIP as potential anticancer agents.

publication date

  • March 2011



  • Academic Article



  • eng

PubMed Central ID

  • PMC3049379

Digital Object Identifier (DOI)

  • 10.1172/JCI44417

PubMed ID

  • 21339646

Additional Document Info

start page

  • 1141

end page

  • 53


  • 121


  • 3