Immunoglobulins (Ig) of pooled healthy human sera were purified by affinity chromatography based on their reactivity with human IgG. This Ig fraction represent connected, natural antibodies (NAbs) and here are denoted as anti- IgG antibodies. The data revealed that IgG, IgA and IgM isotypes are constituents of anti-IgG fraction. The ability of anti- IgG antibodies to prevent infection of PBMC by HIV-1 was demonstrated. They exhibited different neutralizing activity depending on the phenotype of the tested virus. The efficacy of neutralization was comparable to monoclonal antibodies (MAbs) IgG1b12 at least for the HIV-1 92HT593B strain. These studies suggest that connected antibodies thus, constituents of immune network, could prevent infection by HIV-1. NAbs as essential components of therapeutic molecules of intravenous Ig (IVIg) have a beneficial effect on variety of immunological disorders by affecting the structure, function and dynamics of the immune network. Since, hallmark of HIV-1 infection are immunological disorders we hypothesizes that they might be corrected to some extend by anti-IgG antibodies.