Cross-reactivity between caprine arthritis-encephalitis virus and type 1 human immunodeficiency virus

• Published in: Archives of medical research 2003-09, Vol.34 (5), p.362-366
• Main Authors: Tesoro-Cruz, Emiliano, Hernández-González, Rafael, Kretschmer-Schmid, Roberto, Aguilar-Setién, Alvaro
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antigens, Viral - chemistry; Antigens, Viral - immunology; Arthritis-Encephalitis Virus, Caprine - genetics; Arthritis-Encephalitis Virus, Caprine - immunology; Arthritis-Encephalitis Virus, Caprine - metabolism; Caprine arthritis encephalitis virus; Cells, Cultured; Cross Reactions; Cross-reaction; Enzyme-Linked Immunosorbent Assay; Goats; HIV-1; HIV-1 - genetics; HIV-1 - immunology; HIV-1 - metabolism; Humans; Molecular Sequence Data; Sequence Alignment; Viral Proteins - chemistry; Viral Proteins - genetics; Viral Proteins - immunology; Viral Proteins - metabolism
• ISSN: 0188-4409; 1873-5487
• DOI: 10.1016/j.arcmed.2003.08.001

Caprine arthritis encephalitis (CAE) is caused by the lentivirus caprine arthritis-encephalitis virus (CAEV), a member of the Retroviridae family that also includes the human immunodeficiency virus (HIV). Serum of CAEV-infected goats cross-reacts with HIV-1 antigens in enzyme-linked immunosorbent assay (ELISA) tests. We attempted to identify the proteins responsible for this cross-reactivity. Fifty selected human sera (30 positive, 10 negative, and 10 indeterminate to HIV-1 by Western blot) and 50 selected goat sera (33 positive and 17 negative to CAEV by ELISA) were evaluated. Human and goat sera were tested by Western blot against HIV-1 and CAEV antigens. Cross-reactivity between surface glycoproteins gp120 (HIV-1) and gp135 (CAEV) was specific. Positive reaction of human sera to CAEV gp135 was more intense than that of goat sera to HIV-1 gp120. Surface glycoprotein sequences of the two viruses were compared by Lasergene® software (Dynex Technologies, Inc., Chantilly, VA, USA). Three homologous regions were identified: the first in the internal domain of gp120; the second in the β3 loop, and still another—with the greatest homology—in a short sequence of the proximal region of the external domain of gp120 between loops β4 and β8. Surface glycoproteins of HIV-1 and CAEV share structural regions essential for viral adsorption and for induction of neutralizing antibodies. Thus, human contact with CAEV eventually could be a possible source of HIV-1 false positive reactions and must be considered in the interpretation of HIV serologic results.