FIG. 4.

Characterization of chicken immune responses elicited by Ala95-96 peptide. (A) Inhibition of MIP-1β-induced chemotaxis of human CD4⁺ lymphocytes by anti-CCR5 chicken antibodies. Purified lymphocytes were incubated with chicken CCR5-specific IgY antibodies at concentrations ranging from 0.45 to 30 ng/ml. Lymphocytes from two healthy blood donors were used. Negative control included lymphocytes treated with IgY fractions from chicken antibodies to human Ig. Data are representative of the three assays performed. (B to H) Dose-response curves of the neutralization of the infectivity of HIV-1 strains by anti-CCR5 chicken antibodies. (B and C) Neutralization curves of SOS pseudoviruses JRFL and VSV. IgY fractions of the WT and Ala95-96 peptides were employed. As positive controls, SIM4 (anti-CD4 neutralizing monoclonal antibody) and 2D7 (anti-CCR5 neutralizing monoclonal antibody, tested at 30 μg/ml only) were used. As a negative control, IgY fractions of human Ig were tested. (D to H) HIV inhibition curves of a number of HIV-1 primary isolates. Primary isolates HIV #40 and #36 were subtype B and R5 tropic. HIV #92TH007, #92TH008, and #92BR025 were subtypes A, E, and C, respectively, and were R5 tropic, and they were provided by the AIDS Reference Research and Reagent Program. Antibodies were tested from 6 to 200 ng/ml. 2D7 (at 30 μg) and SIM4 were used as positive controls, and a chicken antibody to human Ig was used as a negative control. All data are representative of at least three of the independent assays performed.