Human T-cell lymphotropic virus type III: immunologic characterization and primary structure analysis of the major internal protein, p24.
The major internal structural protein of human T-cell lymphotropic virus type III (HTLV-III), a virus etiologically implicated in acquired immunodeficiency syndrome (AIDS), was purified to homogeneity. This 24,000-molecular-weight protein (p24) was shown to lack immunologic cross-reacting antigenic determinants shared by other known retroviruses, including HTLV-I and HTLV-II, with the exception of equine infectious anemia virus (EIAV). A broadly reactive competition immunoassay was developed in which antiserum to EIAV was used to precipitate 125I-labeled HTLV-III p24. Although the major structural proteins of HTLV-III and EIAV competed in this assay, other type B, C, and D retroviral proteins lacked detectable reactivity. Thus, HTLV-III is more related to EIAV than to any other retroviruses. That the HTLV-III isolate is very distinct from HTLV-I and HTLV-II was further confirmed by the amino acid compositions of the major internal antigens of all three isolates. Moreover, comparison of the amino-terminal amino acid sequence of HTLV-III p24 with analogous sequences for HTLV-I and HTLV-II p24 showed that these proteins do not share significant sequence homology. In an attempt to evaluate immune response in individuals exposed to HTLV-III, sera from AIDS and lymphadenopathy syndrome patients as well as from clinically normal blood donor controls were tested for antibodies to HTLV-III p24. The results showed that sera from 93% of lymphadenopathy syndrome patients and 73% of AIDS patients exhibited high-titered antibodies to HTLV-III p24. In contrast, none of the normal control sera showed detectable reactivity to HTLV-III p24.
J M
JM
Casey
Y
Y
Kim
P R
PR
Andersen
K F
KF
Watson
J L
JL
Fox
S G
SG
Devare
D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000914:Antibodies, Viral / Q000032:analysis; D000956:Antigens, Viral / Q000276:immunology*; D001782:Blood Donors; D003429:Cross Reactions; D017977:Deltaretrovirus / Q000032:analysis / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D006801:Humans; D004860:Infectious Anemia Virus, Equine / Q000276:immunology; D008206:Lymphatic Diseases / Q000276:immunology; D008970:Molecular Weight; D012190:Retroviridae / Q000276:immunology; D013577:Syndrome; D014764:Viral Proteins / Q000032:analysis / Q000276:immunology* / Q000302:isolation & purification; D015678:Viral Structural Proteins
D000596:Amino Acids; D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D014764:Viral Proteins; D015678:Viral Structural Proteins