Brucella abortus conjugated with a peptide derived from the V3 loop of human immunodeficiency virus (HIV) type 1 induces HIV-specific cytotoxic T-cell responses in normal and in CD4+ cell-depleted BALB/c mice
Autor: | P Highet, J Inman, R Blackburn, Basil Golding, Cheryl K. Lapham, Jody Manischewitz, Hana Golding |
---|---|
Rok vydání: | 1996 |
Předmět: |
CD4-Positive T-Lymphocytes
Cytotoxicity Immunologic Molecular Sequence Data Immunology Brucella abortus Enzyme-Linked Immunosorbent Assay chemical and pharmacologic phenomena CD8-Positive T-Lymphocytes HIV Antibodies HIV Envelope Protein gp120 V3 loop Major histocompatibility complex Microbiology Lymphocyte Depletion Immunoglobulin G HIV Envelope Protein gp160 Mice Immune system Virology Animals Humans Cytotoxic T cell Amino Acid Sequence Protein Precursors Cells Cultured AIDS Vaccines B-Lymphocytes Mice Inbred BALB C Vaccines Synthetic biology Gene Products env Molecular biology Peptide Fragments Immunoglobulin Isotypes Bacterial vaccine CTL Vaccines Inactivated Insect Science Bacterial Vaccines HIV-1 biology.protein Immunologic Memory CD8 T-Lymphocytes Cytotoxic Research Article |
Zdroj: | Journal of Virology. 70:3084-3092 |
ISSN: | 1098-5514 0022-538X |
DOI: | 10.1128/jvi.70.5.3084-3092.1996 |
Popis: | We have previously shown that immunization of mice with human immunodeficiency virus (HIV)-derived proteins or peptides conjugated to inactivated Brucella abortus induces the secretion of virus-neutralizing antibodies, predominantly of the immunoglobulin G2a (IgG2a) isotype. In addition, B. abortus activates human CD4+ and CD8+ cells to secrete gamma interferon. Since these are both characteristics of a Th1-type immune response, which is associated with the development of cell-mediated immunity, it was important to determine if B. abortus conjugates would also act as a carrier to induce a cytotoxic T-lymphocyte (CTL) response. To test this hypothesis, we conjugated an 18-amino-acid peptide from the V3 loop of the MN strain of HIV-1 gp120 that contains both B- and cytotoxic T-cell epitopes to B. abortus (B. abortus-MN 18-mer). A 10-amino-acid fragment of this peptide has been shown to be the minimal CTL determinant presented by murine H-2Dd. It was found that two in vivo immunizations with 10(8) organisms of B. abortus-MN 18-mer followed by in vitro stimulation with peptide induced a virus-specific CTL response. Conjugation to B. abortus was required for in vivo priming, since there was no induction of memory CTLs when B. abortus was only mixed with peptide. Targets pulsed with peptide as well as those infected with a vaccinia virus encoding HIV gp160 were killed, demonstrating recognition of naturally processed envelope. Also, major histocompatibility complex-incompatible L cells which were infected with vaccinia viruses that encoded H-2Dd, but not H-2Kd, and pulsed with peptide were lysed. This demonstrated the appropriate major histocompatibility complex class I restriction. Treatment of the mice with anti-L3T4 prior to immunization caused a severe depletion of CD4+ lymphocytes, yet it did not decrease the CTL priming. Thus, inactivated B. abortus can induce non-CD4+ cells to produce the cytokines required for CTL induction. We conclude that B. abortus stimulates a cellular as well as a humoral immune response, even in the relative absence of CD4+ helper cells. It may be a particularly useful vaccine carrier in HIV-1-infected individuals or others with impaired CD4+ T-cell function. |
Databáze: | OpenAIRE |
Externí odkaz: |