TABLE 1.

Summary of the receptors used by FIV

Cell typeSU adhesin boundaBinding receptorbEntry receptorc
Feline
    PBMCPPRFc and 34Fc43-kDa receptorCXCR4
    IL-2-dependent T cellsPPRFc and 34Fc43-kDa receptorCXCR4
    IL-2-independent T cells34Fc onlyCXCR4CXCR4
    Epithelial and glial cells34Fc onlyHSPGsCXCR4
Human
    Jurkat34Fc onlyCXCR4dCXCR4d
    HeLa34Fc onlyHSPGsCXCR4d
    U8734Fc onlyHSPGsNonee
Hamster
    CHO-K134Fc onlyHSPGsNonee
    CHO-pgsA745Nonef
  • a SU adhesins from FIV-PPR and FIV-34TF10 strains are denoted PPRFc and 34Fc, respectively.

  • b The binding receptor involved was identified by FACS, neutralization, and immunoprecipitation assays (9).

  • c The entry receptor implicated was determined by inhibition of infection by SDF1-α and AMD3100.

  • d FIV uses human CXCR4 as well for binding and entry. A block of infection occurs at a postentry level (30, 45).

  • e These cell lines are deficient in CXCR4 expression.

  • f CHO-pgsA745 cells are deficient in HSPGs, as well as in CXCR4 expression.