S or IgG fraction with about 20 inhibition of transactivation ability, which is similar to the percent inhibition from HIV+Tat- and HIV- plasma samples (Table 1). These demonstrated that anti-Tat antibodies are specifically responsible for the neutralization activity and IgG fraction contributes to most of this neutralization activity. Statistical analyses revealed that the neutralizing activity of the group that exhibited strong binding reactivity (OD values above 1.0) to 370-86-5 full-length Tat was significantly higher than the group that exhibited weak binding reactivity (OD values between 0.2?,3) (Fig. 5a). Correlation analyses between the antibody reactivity of each antigen and Tat-neutralizing activity were carried out for the 48 samples from these six profiles. We found that the reactivity with Tat(1?6), Tat(1?8), full-length Tat, Tat(38?1), Tat(38?100) and Tat(1?1) was significantly correlated with Tat-neutralizing activity (Fig. 5b).Characterization of 22948146 Tat-antibody-response profiles in HIV1-infected individualsAs described above, both the C and N antigens showed complementary but different reactivity patterns; based on these differences, the anti-Tat responses could be easily classified into one of the following five order 69-25-0 Profile classes (Fig. 3a). Profile 1) full potential response: Three of the 42 Tatseropositive samples fell into this category, which was characterized by reactivity, usually strong or moderate, against all of the N and C antigens. All the plasma samples from this profile reacted with full-length Tat at a strong or moderate level. Profile 2) combined response: Twelve of 42 Tat-seropositive samples fell into this category, which was characterized by reactivity against both N and C antigens. This profile could be further divided into two distinct reaction types: (1) N-preferred reaction, which reacted with both the Tat(1?8) and Tat(1?6) (and possibly more) N antigens as well as with at least one of the C antigens, usually at strong or moderate level. Six of seven plasma samples of this type reacted with full-length Tat at a strong or moderate level. (2) Common reaction, which reacted with one or two of C antigens and only the Tat(1?8) of N antigens at weak or moderate level. All five plasma samples of this type only weakly reacted with full-length Tat. Profile 3) N-specific response: Ten of 42 Tat-seropositive samples represented the response of this profile which was only characteristically against one, Tat(1?8), or more, Tat(1?6), of the N antigens usually at weak level. The plasma samples with this profile reacted with full-length Tat usually at weak level. Profile 4) C-specific response: Fourteen of 42 Tat-seropositive samples fell into this category, which was only reactive against the C antigens. This profile, could be further divided into two distinct reaction types: (1) full C reaction, which reacted with all four C antigens, mostly at moderate levels; three of the four plasma samples of this 12926553 type reacted with full-length Tat at weak level. (2) Common reaction, which reacted with one or more, but not all, of the C antigens at weak level. All ten plasma samples of this type reacted with full-length Tat at weak level. Profile 5) full-length Tat-specific response: Only three of 42 Tatseropositive samples fell into this response profile, which was characterized by weak reactivity against full-length Tat, but no reactivity against the N and C antigens. Considering the nonimmunodominant nature of Tat, we screened out 6 sa.S or IgG fraction with about 20 inhibition of transactivation ability, which is similar to the percent inhibition from HIV+Tat- and HIV- plasma samples (Table 1). These demonstrated that anti-Tat antibodies are specifically responsible for the neutralization activity and IgG fraction contributes to most of this neutralization activity. Statistical analyses revealed that the neutralizing activity of the group that exhibited strong binding reactivity (OD values above 1.0) to full-length Tat was significantly higher than the group that exhibited weak binding reactivity (OD values between 0.2?,3) (Fig. 5a). Correlation analyses between the antibody reactivity of each antigen and Tat-neutralizing activity were carried out for the 48 samples from these six profiles. We found that the reactivity with Tat(1?6), Tat(1?8), full-length Tat, Tat(38?1), Tat(38?100) and Tat(1?1) was significantly correlated with Tat-neutralizing activity (Fig. 5b).Characterization of 22948146 Tat-antibody-response profiles in HIV1-infected individualsAs described above, both the C and N antigens showed complementary but different reactivity patterns; based on these differences, the anti-Tat responses could be easily classified into one of the following five profile classes (Fig. 3a). Profile 1) full potential response: Three of the 42 Tatseropositive samples fell into this category, which was characterized by reactivity, usually strong or moderate, against all of the N and C antigens. All the plasma samples from this profile reacted with full-length Tat at a strong or moderate level. Profile 2) combined response: Twelve of 42 Tat-seropositive samples fell into this category, which was characterized by reactivity against both N and C antigens. This profile could be further divided into two distinct reaction types: (1) N-preferred reaction, which reacted with both the Tat(1?8) and Tat(1?6) (and possibly more) N antigens as well as with at least one of the C antigens, usually at strong or moderate level. Six of seven plasma samples of this type reacted with full-length Tat at a strong or moderate level. (2) Common reaction, which reacted with one or two of C antigens and only the Tat(1?8) of N antigens at weak or moderate level. All five plasma samples of this type only weakly reacted with full-length Tat. Profile 3) N-specific response: Ten of 42 Tat-seropositive samples represented the response of this profile which was only characteristically against one, Tat(1?8), or more, Tat(1?6), of the N antigens usually at weak level. The plasma samples with this profile reacted with full-length Tat usually at weak level. Profile 4) C-specific response: Fourteen of 42 Tat-seropositive samples fell into this category, which was only reactive against the C antigens. This profile, could be further divided into two distinct reaction types: (1) full C reaction, which reacted with all four C antigens, mostly at moderate levels; three of the four plasma samples of this 12926553 type reacted with full-length Tat at weak level. (2) Common reaction, which reacted with one or more, but not all, of the C antigens at weak level. All ten plasma samples of this type reacted with full-length Tat at weak level. Profile 5) full-length Tat-specific response: Only three of 42 Tatseropositive samples fell into this response profile, which was characterized by weak reactivity against full-length Tat, but no reactivity against the N and C antigens. Considering the nonimmunodominant nature of Tat, we screened out 6 sa.