Cross-neutralizing antibodies against cosmopolitan and Melanesian strains of human T cell leukemia/lymphotropic virus type I in sera from inhabitants of Africa and the Solomon Islands.
The so-called cosmopolitan strains of human T cell leukemia/lymphotropic virus type I (HTLV-I) from Japan, Africa, the West Indies, and the Americas differ only slightly (< 3%) in their genomic sequence. On the other hand, the Melanesian strains of HTLV-I are somewhat more divergent, exhibiting only 93% sequence similarity with the cosmopolitan strains. Despite this difference, sera from individuals infected with Melanesian strains cross-react with T cells infected with cosmopolitan strains of HTLV-I, indicating an overall conservation of the B cell immunoprevalent epitopes. Neutralizing antibodies against HTLV-I in sera from virus-infected Africans and Melanesians were assayed by determining their ability to block the formation of syncytia in cocultures of 8166 and T cell lines harboring either cosmopolitan or Melanesian HTLV-I isolates. All six African sera blocked the formation of syncytia with cells infected with HTLV-IC91-PL, a viral isolate from the United States. Similarly, all six Melanesian sera inhibited syncytium formation with cells infected with HTLV-IMEL3, a virus isolate from the Solomon Islands. Although most of these sera inhibited syncytium formation in cell cultures carrying the cosmopolitan as well as the Melanesian HTLV-I strains, neutralizing antibody titers tended to be higher against the homologous virus. All sera failed to inhibit syncytium formation when cells were infected with HTLV-II. These data indicate the involvement of one or more epitopes in syncytial formation, some of which are conserved in all strains of HTLV-I.(ABSTRACT TRUNCATED AT 250 WORDS)
Benson
J
J
Laboratory of Tumor Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Tschachler
E
E
Gessain
A
A
Yanagihara
R
R
Gallo
R C
RC
Franchini
G
G
D000349:Africa; D002460:Cell Line; D003429:Cross Reactions; D015726:Giant Cells / Q000382:microbiology; D015481:HTLV-I Antibodies / Q000276:immunology*; D015490:HTLV-I Infections / Q000276:immunology / Q000473:pathology; D015368:Human T-lymphotropic virus 1 / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D008542:Melanesia; D009500:Neutralization Tests; D013045:Species Specificity; D014759:Viral Envelope Proteins / Q000096:biosynthesis
D015481:HTLV-I Antibodies; D014759:Viral Envelope Proteins