Envelope cross-reactivity between human immunodeficiency virus types 1 and 2 detected by different serological methods: correlation between cross-neutralization and reactivity against the main neutralizing site.
A total of 70 human immunodeficiency virus type 1 (HIV-1) and 42 HIV-2 antibody-positive serum samples, collected from groups of individuals in which only one type of HIV prevails, were tested for cross-reactivity against HIV-2 and HIV-1 proteins by Western blot (WB) (immunoblot), radioimmunoprecipitation assay (RIPA), neutralization analysis, and enzyme-linked immunosorbent assay with as antigen synthetic peptides representing selected parts of the envelope (env) glycoproteins. Cross-reactions against the env glycoproteins were observed by WB in 10% (7 of 70) and by RIPA in 40% (28 of 70) of the HIV-1 antibody-positive serum samples and by WB in 29% (12 of 42) and by RIPA in 48% (20 of 42) of the HIV-2 antibody-positive serum samples. Testing by enzyme-linked immunosorbent assay against a 36-amino-acid peptide (Cys-301-Cys-336) of the external glycoprotein of strain HTLV-IIIB of HIV-1 (HIV-1HTLV-IIIB) (known to represent a dominating, linear neutralizing site) showed type-specific reactions in 67% (38 of 57) of HIV-1 antibody-positive serum samples. Type-specific reactions against a homologous 35-amino-acid peptide of strain SBL-6669 of HIV-2 (HIV-2SBL-6669) were found in 75% (30 of 40) of HIV-2 antibody-positive serum samples, and these reactions were correlated to neutralization against HIV-2SBL-6669. Cross-reactions against these peptides were seen in 23% (13 of 57) and 33% (13 of 40) of the HIV-1 and HIV-2 antibody-positive serum samples, respectively. These cross-reactions were correlated to cross-neutralization against HIV-1HTLV-IIIB and HIV-2SBL-6669. Cross-neutralization against one heterotypic virus strain was demonstrated in 16% (9 of 57) of HIV-1 antibody-positive serum samples and in 22% (5 of 22) of HIV-2 antibody-positive serum samples, but no correlation was found between cross-neutralization and env cross-reactivity in WB or RIPA.
Department of Immunology, National Bacteriological Laboratory, Stockholm, Sweden.
B
B
Böttiger
A
A
Karlsson
P A
PA
Andreasson
A
A
Nauclér
C M
CM
Costa
E
E
Norrby
G
G
Biberfeld
D015153:Blotting, Western; D003429:Cross Reactions; D015686:Gene Products, env / Q000276:immunology*; D015483:HIV Antibodies / Q000276:immunology; D015488:HIV Antigens / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000276:immunology*; D015498:HIV-2 / Q000276:immunology*; D006801:Humans; D009500:Neutralization Tests; D011233:Precipitin Tests
D015686:Gene Products, env; D015483:HIV Antibodies; D015488:HIV Antigens; D015699:HIV Envelope Protein gp120