Processing and Presentation of Exogenous HLA Class I Peptides by Dendritic Cells from Human Immunodeficiency Virus Type 1-Infected Persons

We have recently shown that human immunodeficiency virus type 1 (HIV-1) Pr55 gag virus-like particles (HIV-VLPs), produced in a baculovirus expression system and presenting a gp120 molecule from a Ugandan HIV-1 isolate of clade A, induce maturation and activation of monocyte-derived dendritic cells (MDDCs) with a production of Th1-and Th2-specific cytokines. Furthermore, HIV-VLP-loaded MDDCs are able to induce a primary and secondary response in autologous human CD4 ؉ T cells in an ex vivo immunization assay. In the present study, we show that similar data can be obtained directly with fresh peripheral blood mononuclear cells (PBMCs), and the HIV-1 seropositivity status, with either low or high viremia, does not significantly impair the immune activation status and the responsiveness of circulating monocyte CD14؉ cell populations to an immunogenic stimulus. Some HIV-1-seropositive subjects, however, show a complete lack of maturation induced by HIV-VLPs in CD14؉ circulating cells, which does not consistently correlate with an advanced status of HIV-1 infection. The established Th2 polarization in both HIV-seropositive groups is efficiently boosted by HIV-VLP induction and does not switch into a Th1 pattern, strongly suggesting that specific Th1 adjuvants would be required for therapeutic effectiveness in HIV-1-infected subjects. These results indicate the possibility of screening PBMCs for donor susceptibility to an immunogen treatment, which would greatly simplify the identification of "responsive" vaccinees as well as the understanding of eventual failures in individuals enrolled in clinical trials.

Section: Discussionsupporting

confidence: 81%

Th2 Polarization in Peripheral Blood Mononuclear Cells from Human Immunodeficiency Virus (HIV)-Infected Subjects, as Activated by HIV Virus-Like Particles

Tornesello

Gallo

Marincola

et al. 2009

“…Highresolution HLA molecular typing was done by the University of Pittsburgh Medical Center Tissue Typing Laboratory. The moDC were derived by culture of the purified blood monocytes with 1,000 U/ml recombinant GM-CSF (Amgen, Thousand Oaks, CA) and 1,000 U/ml recombinant IL-4 (R&D Systems, Minneapolis, MN) (24). Immature moDC were treated on day 5 with CD40L (0.5 g/ml; Amgen or Alexis, San Diego, CA) and gamma interferon (IFN-␥) (1,000 U/ml; R&D) (16) or with a combination of inflammatory cytokines and prostaglandin E2 (PGE2), i.e., IL-1␤ (2 ng/ml; R&D), IL-6 (1,000 IU/ml; R&D), tumor necrosis factor alpha (TNF-␣) (10 ng/ml; R&D), and PGE2 (5 M; Pfizer, Vienna, Austria), for 40 h to induce DC maturation (27).…”

Section: Methodsmentioning

confidence: 99%

Primary Human Immunodeficiency Virus Type 1-Specific CD8⁺T-Cell Responses Induced by Myeloid Dendritic Cells

Colleton

Huang

Melhem

et al. 2009

Self Cite

Induction of an antigenically broad and vigorous primary T-cell immune response by myeloid dendritic cells (DC) in blood and؉ T cells and was broadly directed to multiple regions of Gag, Env, and Nef that corresponded to known and predicted major histocompatibility complex class I epitopes. Polyfunctional CD8 ؉ T-cell responses, defined as single-cell production of more than one cytokine (IFN-␥, interleukin 2, or tumor necrosis factor alpha), chemokine (macrophage inhibitory factor 1␤), or cytotoxic degranulation marker CD107a, were primed by moDC, LC, and idDC to HIV-1 Gag and reverse transcriptase epitopes, as well as to Epstein-Barr virus and influenza A virus epitopes. Thus, three major types of blood and tissue myeloid DC targeted by HIV-1, i.e., moDC, LC, and idDC, can prime multispecific, polyfunctional CD8 ؉ T-cell responses to HIV-1 and other viral antigens.

“…The resulting mature DC express high levels of the T cell costimulatory molecules CD80 and CD86 and the maturation marker CD83 and secrete the proinflammatory molecule interleukin-12p70 (IL-12p70) (15,16,19,20). These cells may be a valuable tool for analysis of the antigen recognition repertoire of CD8 ϩ T cells or in immunotherapies that strive to enhance a dysfunctional HIV-1 recall CD8 ϩ T cell response.…”

Section: H Uman Immunodeficiency Virus Type 1 (Hiv-1)-specific Cd8mentioning

confidence: 99%

“…There was an enhancing effect of DC observed early post-SC, followed by a drastic reduction late post-SC, and a restoration at the early post-cART or late post-cART time point. There are multiple mechanisms by which DC enhance recall T cell responses to HIV-1 (15,16,19), including high-level IL-12p70 production, expression of the T cell costimulatory molecules CD80 and CD86, and expression of the DC maturation marker CD83. Our current…”

Section: Fig 5 Dc-mediated Increase In Polyfunctional Cd8mentioning

confidence: 99%

“…While many aspects of the immune system become dysfunctional in chronic HIV-1 infection and remain dysfunctional even when subjects receive combination antiretroviral therapy (cART), myeloid dendritic cells (DC), the most potent antigen-presenting cells (APC), retain the ability to process and present antigen (13,14) and to stimulate HIV-1-specific gamma interferon (IFN-␥) production in CD8 ϩ (15)(16)(17) and CD4 ϩ (18) T cells. These DC require activation with proinflammatory cytokines and additional stimulation such as that provided by CD40 ligand (CD40L) on activated CD4…”

Section: H Uman Immunodeficiency Virus Type 1 (Hiv-1)-specific Cd8mentioning

confidence: 99%

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Dendritic Cells Restore CD8⁺T Cell Reactivity to Autologous HIV-1

Smith

Mailliard

Larsen

et al. 2014

Self Cite

Recall T cell responses to HIV-1 antigens are used as a surrogate for endogenous cellular immune responses generated during infection. Current methods of identifying antigen-specific T cell reactivity in HIV-1 infection use bulk peripheral blood mononuclear cells (PBMC) yet ignore professional antigen-presenting cells (APC) that could reveal otherwise hidden responses. In the present study, peptides representing autologous variants of major histocompatibility complex (MHC) class I-restricted epitopes from HIV-1 Gag and Env were used as antigens in gamma interferon (IFN-␥) enzyme-linked immunosorbent spot (ELISpot) and polyfunctional cytokine assays. Here we show that dendritic cells (DC) enhanced T cell reactivity at all stages of disease progression but specifically restored T cell reactivity after combination antiretroviral therapy (cART) to early infection levels. Type 1 cytokine secretion was also enhanced by DC and was most apparent late post-cART. We additionally show that DC reveal polyfunctional T cell responses after many years of treatment, when potential immunotherapies would be implemented. These data underscore the potential efficacy of DC immunotherapy that aims to awaken a dormant, autologous, HIV-1-specific CD8 ؉ T cell response. IMPORTANCEAssessment of endogenous HIV-1-specific T cell responses is critical for generating immunotherapies for subjects on cART. Current assays ignore the ability of dendritic cells to reveal these responses and may therefore underestimate the breadth and magnitude of T cell reactivity. As DC do not prime new responses in these assays, it can be assumed that the observed responses are not detected without appropriate stimulation. This is important because dogma states that HIV-1 mutates to evade host recognition and that CD8 ؉ cytotoxic T lymphocyte (CTL) failure is due to the inability of T cells to recognize the autologous virus. The results presented here indicate that responses to autologous virus are generated during infection but may need additional stimulation to be effective. Detecting the breadth and magnitude of HIV-1-specific T cell reactivity generated in vivo is of the utmost importance for generating effective DC immunotherapies.