Barnaba V, Franco A, Paroli M, Balsano F; International Conference on AIDS.

Int Conf AIDS. 1991 Jun 16-21; 7: 146 (abstract no. W.A.1217).

Fondazione "Andrea Cesalpino", I Clinica Medica, Universita "La Sapienza," Roma, Italy

Human T lymphocytes expressing class II molecules can process and present soluble antigens binding to their membrane molecules, as it occurs for gp120 of HIV binding CD4 molecule. In this manner, T cells can efficiently capture antigens, process them through class II major histo-compatibility complex (MHC) pathway, and present their fragments to class-II restricted T lymphocytes, as specific B cells do via their immunoglobulin receptors. Here we demonstrate that both CD4+ and CD8+ T cells can process and present hepatitis B envelope antigen (HBenvAg) with high efficiency to class-II restricted cytotoxic T lymphocytes (CTLs), which in turn kill the presenting T cells, and that the CD71-transferrin receptor (TfR) is involved in the efficient uptake of HBenvAg by T cells. Since TfR is expressed also on hepatocytes, it could play a crucial role in hepatitis B virus (HBV) infection. These results may also represent a novel mechanism of down-regulation of T cell response, since the class II-restricted CTLs reactive to HBenvAg can lyse themselves or other HLA-compatible CD4+ or CD8+ CTLs only in the presence of very low concentrations of antigen.

Publication Types:

• Meeting Abstracts

Keywords:

• Antigens
• Antigens, CD
• Antigens, CD4
• Antigens, CD8
• Antigens, Differentiation, B-Lymphocyte
• B-Lymphocytes
• CD71 antigen
• HIV Envelope Protein gp120
• Hepatitis B Antigens
• Hepatitis B Surface Antigens
• Hepatitis B virus
• Humans
• Receptors, Transferrin
• T-Lymphocytes
• T-Lymphocytes, Cytotoxic
• immunology

Other ID:

• 3121791

UI: 102192427

From Meeting Abstracts