Enhanced activation of human T cell clones specific for virus‐like particles expressing the HIV V3 loop in the presence of HIV V3 loop‐specific polyclonal antibodies

• Published in: Clinical and experimental immunology 1994-09, Vol.97 (3), p.361-366
• Main Authors: PEIFANG, S., PIRA, G. L., FENOGLIO, D., HARRIS, S., COSTA, M. G., VENTURINO, V., DESSI, V., LAYTON, G., LAMAN, J., HUISMAN, J. G., MANCA, F.
• Format: Article
• Language: English
• Subjects: AIDS; AIDS/HIV; Amino Acid Sequence; Animals; Antigen Presentation - immunology; Baculoviridae - genetics; Biological and medical sciences; CD4-Positive T-Lymphocytes - immunology; Cells, Cultured; Clone Cells; Fundamental and applied biological sciences. Psychology; HIV; HIV Antibodies - immunology; HIV Antigens - immunology; HIV Envelope Protein gp120 - genetics; HIV Envelope Protein gp120 - immunology; HIV-1 - immunology; Humans; intramolecular help; Lymphocyte Activation - immunology; Microbiology; Molecular Sequence Data; neutralizing antibodies; Peptides - immunology; Rabbits; Recombinant Fusion Proteins - immunology; Replicative cycle, interference, host-virus relations, pathogenicity, miscellaneous strains; T clones; Virology; virus‐like particles
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.1994.tb06095.x

SUMMARY Recombinant virus‐like particles (VLP), formed by the yeast Ty p1 protein, carrying the HIV gp l20 V3 loop on their surface (V3‐VLP) have been tested in vitro for immunogenicity and antigenicity by using VLP pl‐specific human CD4+ T cell lines and clones. VLP‐specific human T cell lines and clones were generated from normal individuals, indicating that VLP‐specific precursor cells present in the peripheral lymphocyte pool can be induced to expand clonally upon antigen challenge in vitro, in the absence of previous immunization. It was also shown that V3‐specific polyclonal antibodies enhance V3‐VLP‐induced activation of VLP‐specific T cell clones. Antibody‐dependent potentiation has been shown previously in other antigen systems, and it depends on enhanced uptake of complexed antigen by Fe receptor‐positive antigen‐presenting ceils. Since in this case antigen is internalized by presenting cells as a complex, it can be inferred that a similar event of antibody‐mediated antigen uptake can take place with V3‐speeific B cells, resulting in presentation by the B cells of T helper epitopes derived from processing of the VLP pi moiety. This suggests that T helper cells specific for the carrier VLP pi protein can be activated to provide help to V3‐specific B ceils in the presence of the appropriate antigen construct.