Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
Add more filters










Database
Language
Publication year range
1.
Virology ; 265(1): 1-9, 1999 Dec 05.
Article in English | MEDLINE | ID: mdl-10603312

ABSTRACT

Recombinant envelope glycoproteins prepared from a subtype B (MN) strain and a subtype E (CM244) strain of HIV-1 were combined to create a bivalent vaccine (B/E) effective against viruses circulating in the United States and Asia. Combining the two antigens resulted in formulations that increased the breadth and potency of the inter-subtype neutralizing response. Antibodies to the bivalent vaccine formulation neutralized viruses possessing diverse phenotypes, including syncytia-inducing and non-syncytia-inducing primary isolates, viruses using either the CCR5 or the CXCR4 chemokine receptors, and viruses differing in their sensitivity to soluble CD4. These studies demonstrate for the first time that the magnitude and quality of the immune response to HIV-1 can be improved by combining recombinant envelope glycoproteins from different genetic subtypes.


Subject(s)
AIDS Vaccines , HIV-1/classification , HIV-1/immunology , Receptors, CCR5 , Animals , Gene Products, env/immunology , HIV Antibodies/biosynthesis , HIV Antigens/immunology , HIV Envelope Protein gp120/metabolism , HIV Infections/prevention & control , HIV Infections/virology , Humans , In Vitro Techniques , Macrophages/virology , Neutralization Tests , Phenotype , Rabbits , Receptors, CXCR4/metabolism , Recombinant Proteins/immunology , Thailand , United States
2.
J Biol Chem ; 271(3): 1343-8, 1996 Jan 19.
Article in English | MEDLINE | ID: mdl-8576122

ABSTRACT

The Ras-related GTP-binding protein, Rab6, is localized in late Golgi compartments where it mediates intra-Golgi vesicular trafficking. Herein we report that coexpression of Alzheimer's beta-amyloid precursor protein (beta APP751) with a dominant-negative Rab6 mutant (Rab6N126I) in human embryonal kidney 293 cells causes an increase in secretion of the soluble amino-terminal exodomain (s-APP alpha) derived from non-amyloidogenic processing of beta-APP751 by alpha-secretase. The effect was specific to Rab6N126I, since the corresponding mutation in Rab8 (i.e. Rab8N121I), which has been implicated in protein transport to the plasma membrane, caused a modest reduction in s-APP alpha secretion. While Rab6N126I stimulated secretion of APP alpha, the accumulation of amyloid beta peptide (A beta) in the medium was either moderately reduced or unaffected. Similar differential effects of Rab6N126I on secretion of s-APP alpha versus A beta were observed in cell cultures that were overproducing A beta after transfection with a plasmid encoding Swedish variant of beta APP751. Moreover, assays of medium from the latter cultures revealed a marked increase in secretion of s-APP alpha relative to s-APP beta (the immediate product derived from cleavage of beta APP by beta-secretase). The results indicate that vesicular transport events controlled by Rab6 occur at or near a critical juncture in the trans-Golgi network where beta APP is sorted into either the constitutive alpha-secretase pathway or the amyloidogenic beta-secretase pathway.


Subject(s)
Amyloid beta-Peptides/biosynthesis , Amyloid beta-Protein Precursor/metabolism , Carrier Proteins/metabolism , Protein Processing, Post-Translational , rab GTP-Binding Proteins , ras Proteins/metabolism , Amyloid/metabolism , Amyloid Precursor Protein Secretases , Amyloid beta-Peptides/genetics , Amyloid beta-Protein Precursor/genetics , Aspartic Acid Endopeptidases , Base Sequence , DNA Primers , Endopeptidases/metabolism , Gene Expression , Genetic Variation , HeLa Cells , Humans , Molecular Sequence Data , Mutagenesis, Site-Directed , Polymerase Chain Reaction , RNA, Messenger/biosynthesis , RNA, Messenger/metabolism , Recombinant Proteins/metabolism , Restriction Mapping , Sweden , Transcription, Genetic , Transfection
3.
J Biol Chem ; 270(18): 10982-9, 1995 May 05.
Article in English | MEDLINE | ID: mdl-7738040

ABSTRACT

The role of the Ras-related GTP-binding protein, Rab1B, in intracellular trafficking of beta-amyloid precursor protein (beta APP) was studied in cultured 293 cells. beta APP is processed via one of two alternative routes. In the major secretory pathway, beta APP is cleaved by alpha-secretase within the region comprising the beta-amyloid peptide (A beta), resulting in release of a soluble NH2-terminal exodomain (APP alpha) and a 3-kDa peptide (p3) derived from the carboxyl-terminal tail. In the alternative amyloidogenic pathway, beta APP is cleaved by beta-secretase, with the release of a truncated exodomain (APP beta) and an intact A beta peptide. When beta APP751 was coexpressed with Rab1B(wt) or dominant-negative Rab1B mutants (Rab1BN121I or Rab1BS22N) there was a marked decrease in conversion of the immature Endo-H sensitive form of beta APP751 (108 kDa) to the mature O-glycosylated form of beta APP751 (130 kDa) in cells expressing the mutant forms of Rab1B. The block in Golgi-dependent processing of beta APP was accompanied by inhibition of secretion of APPS (APP alpha). A similar decrease in secretion of APPS (APP alpha+APP beta) was observed in cells that were coexpressing Rab1BN121I with the "Swedish" variant of beta APP751 (i.e. beta APPSW751), which undergoes increased amyloidogenic processing. Coincident with the decline in APPS secretion, the cells coexpressing beta APPSW751 with Rab1BN121I showed a 90% decrease in A beta secretion. The data indicate that Rab1B plays a key role in endoplasmic reticulum-->Golgi transport of beta APP, and that beta APP must pass through a late Golgi compartment before entering either the alpha-secretase or the amyloidogenic beta-secretase pathway. The results also suggest that mutant versions of other Rab proteins that function in different parts of the exocytic and endocytic pathways may be useful in defining the specific routes of beta APP transport involved in the biogenesis of A beta.


Subject(s)
Amyloid beta-Protein Precursor/metabolism , GTP-Binding Proteins/metabolism , rab1 GTP-Binding Proteins , Base Sequence , Cell Line , DNA Primers/chemistry , Exocytosis , Golgi Apparatus/metabolism , Hexosaminidases/pharmacology , Humans , In Vitro Techniques , Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase , Molecular Sequence Data , Mutagenesis, Site-Directed , Protein Precursors/metabolism , Protein Processing, Post-Translational , Structure-Activity Relationship
SELECTION OF CITATIONS
SEARCH DETAIL