The enhanced immune response to the HIV gp160/LAMP chimeric gene product targeted to the lysosome membrane protein trafficking pathway.
The lysosome-associated membrane proteins (LAMP), found in the outer membrane of lysosomes and also in a multilaminar compartment that contains major histocompatibility complex class II (MHC II) proteins, are directed to their localization by a cytoplasmic carboxyl-terminal sequence. Our studies of the immune response to LAMP-targeted proteins has led to the application of a HIV-1 gp160/LAMP chimeric gene as a novel means to enhance the MHC II presentation of gp160. Immunofluorescence microscopy confirmed that the gp160/LAMP protein had a cellular localization corresponding to that of lysosomes. Pulse-chase analysis confirmed that the rates of synthesis of gp160/LAMP and wild type gp160 were comparable and that both proteins were processed to gp120 at similar rates. However, the gp160/LAMP was degraded more rapidly than the wild type gp160. MHC II-mediated T cell proliferation assays performed with cloned human cell lines showed that gp160/LAMP stimulated greater responses than did the wild type gp160. Moreover, mice vaccinated with recombinant vaccinia expressing gp160/LAMP had greater gp160-specific lymphoproliferation responses and higher titers of anti-V3 loop antibodies than mice vaccinated with recombinant vaccinia expressing wild type gp160.
Ruff
A L
AL
Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Guarnieri
F G
FG
Staveley-O'Carroll
K
K
Siliciano
R F
RF
August
J T
JT
D000818:Animals; D000917:Antibody Formation; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival; D002999:Clone Cells / Q000378:metabolism; D019302:HIV Envelope Protein gp160 / Q000235:genetics / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D051907:Lysosomal Membrane Proteins; D008247:Lysosomes / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D008715:Methionine / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D014176:Protein Biosynthesis; D011993:Recombinant Fusion Proteins / Q000276:immunology*; D014611:Vaccination
D015703:Antigens, CD; D019302:HIV Envelope Protein gp160; D000949:Histocompatibility Antigens Class II; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D008715:Methionine