TY - JOUR
T1 - Anti-cell antibodies in exposed seronegative individuals with HIV type 1-neutralizing activity
AU - Lopalco, Lucia
AU - Pastori, Claudia
AU - Cosma, Antonio
AU - Burastero, Samuele E.
AU - Capiluppi, Brunella
AU - Boeri, Enzo
AU - Beretta, Alberto
AU - Lazzarin, Adriano
AU - Siccardi, Antonio G.
PY - 2000
Y1 - 2000
N2 - Despite repeated exposures to HIV-1, some individuals remain seronegative. This study reports that sera from a fraction of exposed seronegative (ESN) subjects showed HIV-neutralizing activity; 5 of 17 ESN sera and none of 17 controls neutralized two different HIV-1 primary isolates (range of neutralizing titers: 1/20 to 1/60). The neutralizing activity was associated with the IgG fraction of 4 of 4 neutralizing ESN sera. Moreover, in 11 of 17 and 9 of 17 ESN sera (but none of the control sera) we found antibodies against HLA class I and CD4, respectively. One of the ESN sera (EU22) neutralized efficiently the primary virus derived from the seropositive partner and showed a good broadly cross-reactive neutralization. Immunoadsorption of two IgG fractions from EU19 and EU22 on peripheral blood mononuclear cells (PBMC) removed virus-neutralizing antibodies. The correlations between the ESN status and neutralizing activity (p < 0.05), anti-HLA antibodies (p < 0.0002), and anti-CD4 antibodies (p < 0.001) were statistically significant. However, there was no statistically significant correlation between neutralizing activity and either anti-HLA or anti-CD4 antibodies. It can therefore be said that exposure to HIV-1 without seroconversion is, in some individuals, associated with HIV-neutralizing antibodies (not directed against viral antigens) and/or with anti-cell autoantibodies, which are possibly specific for cellular antigens involved in the infection/entry process.
AB - Despite repeated exposures to HIV-1, some individuals remain seronegative. This study reports that sera from a fraction of exposed seronegative (ESN) subjects showed HIV-neutralizing activity; 5 of 17 ESN sera and none of 17 controls neutralized two different HIV-1 primary isolates (range of neutralizing titers: 1/20 to 1/60). The neutralizing activity was associated with the IgG fraction of 4 of 4 neutralizing ESN sera. Moreover, in 11 of 17 and 9 of 17 ESN sera (but none of the control sera) we found antibodies against HLA class I and CD4, respectively. One of the ESN sera (EU22) neutralized efficiently the primary virus derived from the seropositive partner and showed a good broadly cross-reactive neutralization. Immunoadsorption of two IgG fractions from EU19 and EU22 on peripheral blood mononuclear cells (PBMC) removed virus-neutralizing antibodies. The correlations between the ESN status and neutralizing activity (p < 0.05), anti-HLA antibodies (p < 0.0002), and anti-CD4 antibodies (p < 0.001) were statistically significant. However, there was no statistically significant correlation between neutralizing activity and either anti-HLA or anti-CD4 antibodies. It can therefore be said that exposure to HIV-1 without seroconversion is, in some individuals, associated with HIV-neutralizing antibodies (not directed against viral antigens) and/or with anti-cell autoantibodies, which are possibly specific for cellular antigens involved in the infection/entry process.
UR - http://www.scopus.com/inward/record.url?scp=0033972247&partnerID=8YFLogxK
U2 - 10.1089/088922200309458
DO - 10.1089/088922200309458
M3 - Article
C2 - 10659050
AN - SCOPUS:0033972247
SN - 0889-2229
VL - 16
SP - 109
EP - 115
JO - AIDS Research and Human Retroviruses
JF - AIDS Research and Human Retroviruses
IS - 2
ER -