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

2009 ◽  
Vol 83 (12) ◽  
pp. 6288-6299 ◽  
Author(s):  
Bonnie A. Colleton ◽  
Xiao-Li Huang ◽  
Nada M. Melhem ◽  
Zheng Fan ◽  
Luann Borowski ◽  
...  

ABSTRACT Induction of an antigenically broad and vigorous primary T-cell immune response by myeloid dendritic cells (DC) in blood and tissues could be important for an effective prophylactic or therapeutic vaccine to human immunodeficiency virus type 1 (HIV-1). Here we show that a primary CD8+ T-cell response can be induced by HIV-1 peptide-loaded DC derived from blood monocytes of HIV-1-negative adults and neonates (moDC) and by Langerhans cells (LC) and interstitial, dermal-intestinal DC (idDC) derived from CD34+ stem cells of neonatal cord blood. Optimal priming of single-cell gamma interferon (IFN-γ) production by CD8+ T cells required CD4+ 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-γ, interleukin 2, or tumor necrosis factor alpha), chemokine (macrophage inhibitory factor 1β), 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.

2001 ◽  
Vol 75 (5) ◽  
pp. 2142-2153 ◽  
Author(s):  
Jose Engelmayer ◽  
Marie Larsson ◽  
Andrew Lee ◽  
Marina Lee ◽  
William I. Cox ◽  
...  

ABSTRACT Recombinant canarypox virus vectors containing human immunodeficiency virus type 1 (HIV-1) sequences are promising vaccine candidates, as they replicate poorly in human cells. However, when delivered intramuscularly the vaccines have induced inconsistent and in some cases transient antigen-specific cytotoxic T-cell (CTL) responses in seronegative volunteers. An attractive way to enhance these responses would be to target canarypox virus to professional antigen-presenting cells such as dendritic cells (DCs). We studied (i) the interaction between canarypox virus and DCs and (ii) the T-cell responses induced by DCs infected with canarypox virus vectors containing HIV-1 genes. Mature and not immature DCs resisted the cytopathic effects of canarypox virus and elicited strong effector CD8+ T-cell responses from chronically infected HIV+ individuals, e.g., cytolysis, and secretion of gamma interferon (IFN-γ) and β-chemokines. Furthermore, canarypox virus-infected DCs were >30-fold more efficient than monocytes and induced responses that were comparable to those induced by vaccinia virus vectors or peptides. Addition of exogenous cytokines was not necessary to elicit CD8+ effector cells, although the presence of CD4+ T cells was required for their expansion and maintenance. Most strikingly, canarypox virus-infected DCs were directly able to stimulate HIV-specific, IFN-γ-secreting CD4 helper responses from bulk as well as purified CD4+ T cells. Therefore, these results suggest that targeting canarypox virus vectors to mature DCs could potentially elicit both anti-HIV CD8+and CD4+ helper responses in vivo.


2008 ◽  
Vol 82 (7) ◽  
pp. 3561-3573 ◽  
Author(s):  
Ellen R. Van Gulck ◽  
Guido Vanham ◽  
Leo Heyndrickx ◽  
Sandra Coppens ◽  
Katleen Vereecken ◽  
...  

ABSTRACT Developing an immunotherapy to keep human immunodeficiency virus type 1 (HIV-1) replication suppressed while discontinuing highly active antiretroviral therapy (HAART) is an important challenge. In the present work, we evaluated in vitro whether dendritic cells (DC) electroporated with gag mRNA can induce HIV-specific responses in T cells from chronically infected subjects. Monocyte-derived DC, from therapy-naïve and HAART-treated HIV-1-seropositive subjects, that were electroporated with consensus codon-optimized HxB2 gag mRNA efficiently expanded T cells, secreting gamma interferon (IFN-γ) and interleukin 2 (IL-2), as well as other cytokines and perforin, upon restimulation with a pool of overlapping Gag peptides. The functional expansion levels after 1 week of stimulation were comparable in T cells from HAART-treated and treatment-naïve patients and involved both CD4+ and CD8+ T cells, with evidence of bifunctionality in T cells. Epitope mapping of p24 showed that stimulated T cells had a broadened response toward previously nondescribed epitopes. DC, from HAART-treated subjects, that were electroporated with autologous proviral gag mRNA equally efficiently expanded HIV-specific T cells. Regulatory T cells did not prevent the induction of effector T cells in this system, whereas the blocking of PD-L1 slightly increased the induction of T-cell responses. This paper shows that DC, loaded with consensus or autologous gag mRNA, expand HIV-specific T-cell responses in vitro.


2004 ◽  
Vol 78 (10) ◽  
pp. 5223-5232 ◽  
Author(s):  
Jean-François Fonteneau ◽  
Marie Larsson ◽  
Anne-Sophie Beignon ◽  
Kelli McKenna ◽  
Ida Dasilva ◽  
...  

ABSTRACT In this study, we analyzed the phenotypic and physiological consequences of the interaction of plasmacytoid dendritic cells (pDCs) with human immunodeficiency virus type 1 (HIV-1). pDCs are one cellular target of HIV-1 and respond to the virus by producing alpha/beta interferon (IFN-α/β) and chemokines. The outcome of this interaction, notably on the function of bystander myeloid DC (CD11c+ DCs), remains unclear. We therefore evaluated the effects of HIV-1 exposure on these two DC subsets under various conditions. Blood-purified pDCs and CD11c+ DCs were exposed in vitro to HIV-1, after which maturation markers, cytokine production, migratory capacity, and CD4 T-cell stimulatory capacity were analyzed. pDCs exposed to different strains of infectious or even chemically inactivated, nonreplicating HIV-1 strongly upregulated the expression of maturation markers, such as CD83 and functional CCR7, analogous to exposure to R-848, a synthetic agonist of toll-like receptor-7 and -8. In addition, HIV-1-activated pDCs produced cytokines (IFN-α and tumor necrosis factor alpha), migrated in response to CCL19 and, in coculture, matured CD11c+ DCs, which are not directly activated by HIV. pDCs also acquired the ability to stimulate naïve CD4+ T cells, albeit less efficiently than CD11c+ DCs. This HIV-1-induced maturation of both DC subsets may explain their disappearance from the blood of patients with high viral loads and may have important consequences on HIV-1 cellular transmission and HIV-1-specific T-cell responses.


2004 ◽  
Vol 78 (7) ◽  
pp. 3233-3243 ◽  
Author(s):  
Agatha Masemola ◽  
Tumelo Mashishi ◽  
Greg Khoury ◽  
Phineas Mohube ◽  
Pauline Mokgotho ◽  
...  

ABSTRACT An understanding of the relationship between the breadth and magnitude of T-cell epitope responses and viral loads is important for the design of effective vaccines. For this study, we screened a cohort of 46 subtype C human immunodeficiency virus type 1 (HIV-1)-infected individuals for T-cell responses against a panel of peptides corresponding to the complete subtype C genome. We used a gamma interferon ELISPOT assay to explore the hypothesis that patterns of T-cell responses across the expressed HIV-1 genome correlate with viral control. The estimated median time from seroconversion to response for the cohort was 13 months, and the order of cumulative T-cell responses against HIV proteins was as follows: Nef > Gag > Pol > Env > Vif > Rev > Vpr > Tat > Vpu. Nef was the most intensely targeted protein, with 97.5% of the epitopes being clustered within 119 amino acids, constituting almost one-third of the responses across the expressed genome. The second most targeted region was p24, comprising 17% of the responses. There was no correlation between viral load and the breadth of responses, but there was a weak positive correlation (r = 0.297; P = 0.034) between viral load and the total magnitude of responses, implying that the magnitude of T-cell recognition did not contribute to viral control. When hierarchical patterns of recognition were correlated with the viral load, preferential targeting of Gag was significantly (r = 0.445; P = 0.0025) associated with viral control. These data suggest that preferential targeting of Gag epitopes, rather than the breadth or magnitude of the response across the genome, may be an important marker of immune efficacy. These data have significance for the design of vaccines and for interpretation of vaccine-induced responses.


2008 ◽  
Vol 82 (6) ◽  
pp. 2975-2988 ◽  
Author(s):  
Petra Mooij ◽  
Sunita S. Balla-Jhagjhoorsingh ◽  
Gerrit Koopman ◽  
Niels Beenhakker ◽  
Patricia van Haaften ◽  
...  

ABSTRACT Poxvirus vectors have proven to be highly effective for boosting immune responses in diverse vaccine settings. Recent reports reveal marked differences in the gene expression of human dendritic cells infected with two leading poxvirus-based human immunodeficiency virus (HIV) vaccine candidates, New York vaccinia virus (NYVAC) and modified vaccinia virus Ankara (MVA). To understand how complex genomic changes in these two vaccine vectors translate into antigen-specific systemic immune responses, we undertook a head-to-head vaccine immunogenicity and efficacy study in the pathogenic HIV type 1 (HIV-1) model of AIDS in Indian rhesus macaques. Differences in the immune responses in outbred animals were not distinguished by enzyme-linked immunospot assays, but differences were distinguished by multiparameter fluorescence-activated cell sorter analysis, revealing a difference between the number of animals with both CD4+ and CD8+ T-cell responses to vaccine inserts (MVA) and those that elicit a dominant CD4+ T-cell response (NYVAC). Remarkably, vector-induced differences in CD4+/CD8+ T-cell immune responses persisted for more than a year after challenge and even accompanied antigenic modulation throughout the control of chronic infection. Importantly, strong preexposure HIV-1/simian immunodeficiency virus-specific CD4+ T-cell responses did not prove deleterious with respect to accelerated disease progression. In contrast, in this setting, animals with strong vaccine-induced polyfunctional CD4+ T-cell responses showed efficacies similar to those with stronger CD8+ T-cell responses.


2002 ◽  
Vol 76 (5) ◽  
pp. 2298-2305 ◽  
Author(s):  
Bradley H. Edwards ◽  
Anju Bansal ◽  
Steffanie Sabbaj ◽  
Janna Bakari ◽  
Mark J. Mulligan ◽  
...  

ABSTRACT The importance of CD8+ T-cell responses in the control of human immunodeficiency virus type 1 (HIV-1) infection has been demonstrated, yet few studies have been able to correlate these responses with markers of HIV-1 disease progression. This study measured cell-mediated immune responses using peripheral blood mononuclear cells (PBMC) obtained from 27 patients with chronic HIV-1 infection, the majority of whom were off antiretroviral therapy. The ELISPOT assay was used to detect gamma interferon-secreting PBMC after stimulation with overlapping HIV-1 peptides spanning the Gag, Pol, Env, and Nef proteins in addition to the baculovirus-derived p24 and gp160 proteins. All volunteers had responses to at least one HIV-1-specific peptide. All but one of the subjects (96%) responded to the Gag peptide pool, and 86% responded to the Pol and/or Nef peptide pools. The magnitude and the breadth of T-cell responses directed to either the Gag or p24 peptide pools correlated inversely with viral load in plasma (r = −0.60, P < 0.001 and r = −0.52, P < 0.005, respectively) and directly with absolute CD4+ T-cell counts (r = 0.54, P < 0.01 and r = 0.39, P < 0.05, respectively) using the Spearman rank correlation test. Responses to the Pol and integrase peptide pools also correlated with absolute CD4+ T-cell counts (r = 0.45, P < 0.05 and r = 0.49, P < 0.01, respectively). No correlation with markers of disease progression was seen with specific T-cell responses directed toward the Env or Nef peptides. These data serve as strong evidence that major histocompatibility complex class I presentation of Gag peptides is an essential feature for any HIV-1 vaccine designed to elicit optimal CD8+ T-cell responses.


2003 ◽  
Vol 77 (20) ◽  
pp. 11220-11231 ◽  
Author(s):  
Hanne Gahéry-Ségard ◽  
Gilles Pialoux ◽  
Suzanne Figueiredo ◽  
Céline Igéa ◽  
Mathieu Surenaud ◽  
...  

ABSTRACT We studied the effect of booster injections and the long-term immune response after injections of an anti-human immunodeficiency virus type 1 (HIV-1) lipopeptide vaccine. This vaccine was injected alone or with QS21 adjuvant to 28 HIV-uninfected volunteers. One month later, after a fourth injection of the vaccine, B- and T-cell anti-HIV responses were detected in >85% of the vaccinated volunteers. One year after this injection, a long-term immune response was observed in >50% of the volunteers. At this point, a positive QS21 effect was observed only in the sustained B-cell and CD4+-T-cell responses. To better characterize the CD8+-T-cell response, we used a gamma interferon enzyme-linked immunospot method and a bank of 59 HIV-1 epitopes. For the six most common HLA molecules (HLA-A2, -A3, -A11, -A24, -B7 superfamily, and -B8), an average of 10 (range, 3 to 15) HIV-1 epitopes were tested. CD8+-T-cell responses were evaluated according to the HLA class I molecules of the volunteers. Each assessment was based on 18 HIV-1 epitopes in average. We showed that 31 HIV-1 epitopes elicited specific CD8+-T-cell responses after vaccination. The most frequently recognized peptides were Nef 68-76 (-B7), Nef 71-79 (-B7), Nef 84-92 (-A11), Nef 135-143 (-B7), Nef 136-145 (-A2), Nef 137-145 (-A2), Gag 259-267 (-B8), Gag 260-268 (-A2), Gag 267-274 (-A2), Gag 267-277 (-B7), and Gag 276-283 (A24). We found that CD8+-T-cell epitopes were induced at a higher number after a fourth injection (P < 0.05 compared to three injections), which indicates an increase in the breadth of HIV CD8+-T-cell epitope recognition after the boost.


2009 ◽  
Vol 83 (11) ◽  
pp. 5881-5889 ◽  
Author(s):  
Petra Mooij ◽  
Sunita S. Balla-Jhagjhoorsingh ◽  
Niels Beenhakker ◽  
Patricia van Haaften ◽  
Ilona Baak ◽  
...  

ABSTRACT Rhesus macaques (Macaca mulatta) have played a valuable role in the development of human immunodeficiency virus (HIV) vaccine candidates prior to human clinical trials. However, changes and/or improvements in immunogen quality in the good manufacturing practice (GMP) process or changes in adjuvants, schedule, route, dose, or readouts have compromised the direct comparison of T-cell responses between species. Here we report a comparative study in which T-cell responses from humans and macaques to HIV type 1 antigens (Gag, Pol, Nef, and Env) were induced by the same vaccine batches prepared under GMP and administered according to the same schedules in the absence and presence of priming. Priming with DNA (humans and macaques) or alphavirus (macaques) and boosting with NYVAC induced robust and broad antigen-specific responses, with highly similar Env-specific gamma interferon (IFN-γ) enzyme-linked immunospot assay responses in rhesus monkeys and human volunteers. Persistent cytokine responses of antigen-specific CD4+ and CD8+ T cells of the central memory as well as the effector memory phenotype, capable of simultaneously eliciting multiple cytokines (IFN-γ, interleukin 2, and tumor necrosis factor alpha), were induced. Responses were highly similar in humans and primates, confirming earlier data indicating that priming is essential for inducing robust NYVAC-boosted IFN-γ T-cell responses. While significant similarities were observed in Env-specific responses in both species, differences were also observed with respect to responses to other HIV antigens. Future studies with other vaccines using identical lots, immunization schedules, and readouts will establish a broader data set of species similarities and differences with which increased confidence in predicting human responses may be achieved.


2006 ◽  
Vol 80 (19) ◽  
pp. 9779-9788 ◽  
Author(s):  
Helen Horton ◽  
Colin Havenar-Daughton ◽  
Deborah Lee ◽  
Erin Moore ◽  
Jianhong Cao ◽  
...  

ABSTRACT Candidate human immunodeficiency virus type 1 (HIV-1) vaccines designed to elicit T-cell immunity in HIV-1-uninfected persons are under investigation in phase I to III clinical trials. Little is known about how these vaccines impact the immunologic response postinfection in persons who break through despite vaccination. Here, we describe the first comprehensive characterization of HIV-specific T-cell immunity in vaccine study participants following breakthrough HIV-1 infection in comparison to 16 nonvaccinated subjects with primary HIV-1 infection. Whereas none of the 16 breakthrough infections possessed vaccine-induced HIV-1-specific T-cell responses preinfection, 85% of vaccinees and 86% of nonvaccinees with primary HIV-1 infection developed HIV-specific T-cell responses postinfection. Breakthrough subjects' T cells recognized 43 unique HIV-1 T-cell epitopes, of which 8 are newly described, and 25% were present in the vaccine. The frequencies of gamma interferon (IFN-γ)-secreting cells recognizing epitopes within gene products that were and were not encoded by the vaccine were not different (P = 0.64), which suggests that responses were not anamnestic. Epitopes within Nef and Gag proteins were the most commonly recognized in both vaccinated and nonvaccinated infected subjects. One individual controlled viral replication without antiretroviral therapy and, notably, mounted a novel HIV-specific HLA-C14-restricted Gag LYNTVATL-specific T-cell response. Longitudinally, HIV-specific T cells in this individual were able to secrete IFN-γ and tumor necrosis factor alpha, as well as proliferate and degranulate in response to their cognate antigenic peptides up to 5 years postinfection. In conclusion, a vaccinee's ability to mount an HIV-specific T-cell response postinfection is not compromised by previous immunization, since the CD8+ T-cell responses postinfection are similar to those seen in vaccine-naïve individuals. Finding an individual who is controlling infection highlights the importance of comprehensive studies of breakthrough infections in vaccine trials to determine whether host genetics/immune responses and/or viral characteristics are responsible for controlling viral replication.


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