Abstract
Recombinant soluble CD134 (sCD134) facilitated feline immunodeficiency virus (FIV) entry into CXCR4-positive, cell surface CD134-negative target cells. sCD134-activated entry was dose dependent and CXCR4 dependent. We used the sCD134 activation system to explore the neutralization by four anti-V3 monoclonal antibodies (MAbs). V3 MAbs weakly neutralized FIV infection using target cells expressing both CD134 and CXCR4 but potently inhibited sCD134-activated entry into target cells expressing CXCR4 alone. These findings provide direct evidence for a sequential interaction of FIV Env with CD134 and CXCR4 and reveal the presence of a cryptic epitope in V3 that is masked in the mature envelope oligomers.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Amino Acid Sequence
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Animals
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Cats
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Epitopes / chemistry
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Epitopes / genetics
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Epitopes / immunology
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Gene Expression Regulation, Viral
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Gene Products, env / chemistry
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Gene Products, env / genetics
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Gene Products, env / metabolism*
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Genes, env
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HIV Envelope Protein gp120 / chemistry
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Immunodeficiency Virus, Feline / metabolism
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Immunodeficiency Virus, Feline / pathogenicity*
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Molecular Sequence Data
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Neutralization Tests
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Peptide Fragments / chemistry
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Peptide Fragments / genetics
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Peptide Fragments / immunology
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Receptors, CXCR4 / metabolism*
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Receptors, OX40
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Receptors, Tumor Necrosis Factor / metabolism*
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Solubility
Substances
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Epitopes
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Gene Products, env
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HIV Envelope Protein gp120
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HIV envelope protein gp120 (305-321)
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Peptide Fragments
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Receptors, CXCR4
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Receptors, OX40
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Receptors, Tumor Necrosis Factor