Induction of Human Immunodeficiency Virus (HIV-1) Envelope Specific Cell-Mediated Immunity by a Non-Homologous Synthetic Peptide

Peer reviewed: YesNRC publication: Ye

Pleiotrophin induces expression of inflammatory cytokines in peripheral blood mononuclear cells.

Pleiotrophin (PTN) is a polypeptide that belongs to a family of heparin-binding growth factor, which displays mitogenic activity for a wide variety of cells. Since PTN induces the proliferation of immune cells the mechanism of action was investigated. In the present study, we show for the first time that PTN induces the expression of inflammatory cytokines including TNF-alpha, IL-1beta and IL-6 in quiescent human peripheral blood mononuclear cells (PBMC). These results emphasize the importance of PTN in the regulation of inflammatory processes. Elucidation of the mechanisms by which a host factor such PTN regulates cytokines production will significantly advance our understanding of endothelium-immunity interactions

Cytotoxic T Lymphocytes Specific for HIV-1 gp160 Antigen and Synthetic P18IIIB Peptide in an HLA-A11-Immunized Individual

Cytotoxic T cell determinants should be an important component of an anti-human immunodeficiency virus (HIV) vaccine. The epitopes of proteins can be defined with short synthetic peptides for class I-restricted CTLs. An immunodominant CTL epitope from the HIV-1 IIIB envelope protein gp160 comprising 15 amino acids (residues 315-329: RIQRGPGRAFVTIGK) (P18IIIB) has been identified that is recognized by class I MHC molecule H-2d-restricted murine CD8+ CTLs. We have investigated the epitope specificity of anti-HIV-1 CTLs in immunized individuals and we found that the CTL response was restricted by more than one class I MHC molecule, including HLA-A2 and HLA-A3. In the present work, we also show that the response against P18IIIB peptide is restricted by the HLA-A11 molecule in an individual immunized by vaccinia virus expressing gp160 protein. This peptide could thus be recognized in association with different HLA class I allotypes. This work has implications for vaccine strategies, using the P18 peptide. © 1994, Mary Ann Liebert, Inc. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

CTL activities derived from cell cultures of 4 HIV-infected individuals (I, II, III and IV) directed against autologous target-cells presenting cA1 peptide, control B1 peptide, or target-cells infected with either wild type vaccinia virus or recombinant vaccinia virus expressing gp160MN.

<p>The CTL cultures were generated by polyclonal activation with the irradiated autologous cells. After a 10 day incubation the effector cells were tested for CTL activity as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001214#s2" target="_blank">materials and methods</a>. The data are representative of 3 independent experiments performed in triplicates. Standard errors of the mean (s.e.m) from triplicate wells were 5% of the mean.</p

CTL activity of effector cells derived from the BI donor vaccinated with IIIB-env-recombinant protein and from the SH donor vaccinated with SIMI-env-recombinant directed against autologous target-cells presenting cA1 peptide and HIV-1 env proteins.

<p>The secondary cultures of the effector cells were generated <i>in vitro</i> after incubation with V3 loop P18 peptide ( panels I, III) and cA1 peptide (panels II, IV). The data are representative of four independent experiments performed in triplicates. Standard errors of the mean from triplicate cultures were all <7% of the means.</p

CTL activity of cA1-stimulated cell cultures of 4 HIV-infected individuals (I, II, III and IV) directed against autologous target-cells presenting cA1 peptide, control B1 peptide, or target-cells infected with either wild type vaccinia virus or recombinant vaccinia virus expressing gp160MN.

<p>The secondary cultures of the effector cells were obtained by incubating the PBMCs with the cA1 peptide and their CTL activity was tested after 10 days of incubation. The data are representative of three independent experiments performed in triplicates. Standard errors of the mean from triplicate wells were < 5% of the mean.</p

The cA1 peptide-induced T cell proliferation.

<p>(A) Proliferation response in cA1 peptide-immunized rabbits. Lymphocytes collected before and after immunization were stimulated with various concentrations of control B1 peptide, cA1 peptide or recombinant gp120 protein added to the culture media. (B) Proliferation response of PBMCs from HIV-1-infected individuals. Cells were obtained from 10 HIV-1-infected individuals (1-10) and their proliferation response was measured after stimulation with 1 µg/ml of control B1 peptide, cA1 peptide or after incubation without (-) peptide, as indicated. The incorparation of [³H]thymidine into DNA was measured 6 days after the stimulation. Tests were performed on triplicate samples.</p

Nucleotide coding sequence of A1 and cA1 peptides.

<p>The sequence designated “+” represents sense strand of DNA while the chain designated “−” corresponds to complementary antisense DNA strand, which was used as the coding sequence for the cA1 peptide amino acid sequence.</p

Phenotype of cA1 peptide-specific CTLs derived from gp160IIIB-immunized individual BI (panel I) and from gp160SIMI-immunized subject SH (panel II).

<p>Autologous B-LCLs, sensitized by cA1 peptide, were cultured with effector cells pre-treated with anti-CD8, anti-CD4 or anti-CD3 monoclonal antibodies. The control group was not treated with antibodies. Standard errors of the mean, from triplicate wells, were less than 5% of the mean.</p

The cA1 peptide-specific cytotoxicity of lymphocytes originating from gp160IIIB-immunized individual BI (HLA-A*0201, -A*6801, -B*5101, -B*1301, -CW*0501) (panel I) and from gp160SIMI-immunized subject SH (HLA-A*0201, -A*2402, -B*4402, -B41, -CW*0501, -DRB1*13, -DR-) (panel II ), both being HLA- A*0201 Class I restricted.

<p>Autologous EBV-LCL (AUTO), heterologous (HETERO) or cells sharing the HLA molecule with the donor were sensitized by cA1 peptide. Percentage of specific lysis was determined at the effector to target (E/T) ratio of 10:1. The assays were performed in triplicate with 5000 target-cells/well.</p