scholarly journals Broad, high-magnitude and multifunctional CD4+ and CD8+ T-cell responses elicited by a DNA and modified vaccinia Ankara vaccine containing human immunodeficiency virus type 1 subtype C genes in baboons

2009 ◽  
Vol 90 (2) ◽  
pp. 468-480 ◽  
Author(s):  
Wendy A. Burgers ◽  
Gerald K. Chege ◽  
Tracey L. Müller ◽  
Joanne H. van Harmelen ◽  
Greg Khoury ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
High Avidity ◽  
Subtype C ◽  
Mesenteric Lymph Nodes ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Immunodeficiency Virus

Candidate human immunodeficiency virus (HIV) vaccine regimens based on DNA boosted with recombinant modified vaccinia Ankara (MVA) have been in development for some time, and there is evidence for improved immunogenicity of newly developed constructs. This study describes immune responses to candidate DNA and MVA vaccines expressing multiple genes (gag, RT, tat, nef and env) from HIV-1 subtype C in chacma baboons (Papio ursinus). The vaccine regimen induced (i) strong T-cell responses, with a median of 4103 spot forming units per 106 peripheral blood mononuclear cells by gamma interferon (IFN-γ) ELISPOT, (ii) broad T-cell responses targeting all five vaccine-expressed genes, with a median of 12 peptides targeted per animal and without any single protein dominating the response, (iii) balanced CD4+ and CD8+ responses, which produced both IFN-γ and interleukin (IL)-2, including IL-2-only responses not detected by the ELISPOT assay, (iv) vaccine memory, which persisted 1 year after immunization and could be boosted further, despite strong anti-vector responses, and (v) mucosal T-cell responses in iliac and mesenteric lymph nodes in two animals tested. The majority of peptide responses mapped contained epitopes previously identified in human HIV infection, and two high-avidity HIV epitope responses were confirmed, indicating the utility of the baboon model for immunogenicity testing. Together, our data show that a combination of DNA and MVA immunization induced robust, durable, multifunctional CD4+ and CD8+ responses in baboons targeting multiple HIV epitopes that may home to mucosal sites. These candidate vaccines, which are immunogenic in this pre-clinical model, represent an alternative to adenoviral-based vaccines and have been approved for clinical trials.

scholarly journals JC Virus-Specific Immune Responses in Human Immunodeficiency Virus Type 1 Patients with Progressive Multifocal Leukoencephalopathy

2009 ◽  
Vol 83 (9) ◽  
pp. 4404-4411 ◽  
Author(s):  
Nina Khanna ◽  
Marcel Wolbers ◽  
Nicolas J. Mueller ◽  
Christian Garzoni ◽  
Renaud A. Du Pasquier ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Progressive Multifocal Leukoencephalopathy ◽  
Mononuclear Cells ◽  
Jc Virus ◽  
T Cell Responses ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Cell Counts ◽  
Immunodeficiency Virus

ABSTRACT Progressive multifocal leukoencephalopathy (PML) is a frequently fatal disease caused by uncontrolled polyomavirus JC (JCV) in severely immunodeficient patients. We investigated the JCV-specific cellular and humoral immunity in the Swiss HIV Cohort Study. We identified PML cases (n = 29), as well as three matched controls per case (n = 87), with prospectively cryopreserved peripheral blood mononuclear cells and plasma at diagnosis. Nested controls were matched according to age, gender, CD4+ T-cell count, and decline. Survivors (n = 18) were defined as being alive for >1 year after diagnosis. Using gamma interferon enzyme-linked immunospot assays, we found that JCV-specific T-cell responses were lower in nonsurvivors than in their matched controls (P = 0.08), which was highly significant for laboratory- and histologically confirmed PML cases (P = 0.004). No difference was found between PML survivors and controls or for cytomegalovirus-specific T-cell responses. PML survivors showed significant increases in JCV-specific T cells (P = 0.04) and immunoglobulin G (IgG) responses (P = 0.005). IgG responses in survivors were positively correlated with CD4+ T-cell counts (P = 0.049) and negatively with human immunodeficiency virus RNA loads (P = 0.03). We conclude that PML nonsurvivors had selectively impaired JCV-specific T-cell responses compared to CD4+ T-cell-matched controls and failed to mount JCV-specific antibody responses. JCV-specific T-cell and IgG responses may serve as prognostic markers for patients at risk.

scholarly journals Human CD4+ CD25+ Regulatory T Cells Control T-Cell Responses to Human Immunodeficiency Virus and Cytomegalovirus Antigens

2004 ◽  
Vol 78 (5) ◽  
pp. 2454-2459 ◽  
Author(s):  
Einar M. Aandahl ◽  
Jakob Michaëlsson ◽  
Walter J. Moretto ◽  
Frederick M. Hecht ◽  
Douglas F. Nixon
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Mononuclear Cells ◽  
Viral Infections ◽  
T Cell Responses ◽  
Peripheral Blood Mononuclear ◽  
Antiviral Immune Response ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
And Control

ABSTRACT Regulatory T (TR) cells maintain tolerance to self-antigens and control immune responses to alloantigens after organ transplantation. Here, we show that CD4+ CD25+ human TR cells suppress virus-specific T-cell responses. Depletion of TR cells from peripheral blood mononuclear cells enhances T-cell responses to cytomegalovirus and human immunodeficiency virus antigens. We propose that chronic viral infections lead to induction of suppressive TR cells that inhibit the antiviral immune response.

scholarly journals Hierarchical Targeting of Subtype C Human Immunodeficiency Virus Type 1 Proteins by CD8+ T Cells: Correlation with Viral Load

2004 ◽  
Vol 78 (7) ◽  
pp. 3233-3243 ◽  
Author(s):  
Agatha Masemola ◽  
Tumelo Mashishi ◽  
Greg Khoury ◽  
Phineas Mohube ◽  
Pauline Mokgotho ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Viral Load ◽  
T Cell ◽  
T Cell Responses ◽  
Subtype C ◽  
Viral Control ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Hiv 1

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.

scholarly journals Inactivated Simian Immunodeficiency Virus-Pulsed Autologous Fresh Blood Cells as an Immunotherapy Strategy

2008 ◽  
Vol 83 (3) ◽  
pp. 1501-1510 ◽  
Author(s):  
Rosemarie D. Mason ◽  
Sheilajen Alcantara ◽  
Viv Peut ◽  
Liyen Loh ◽  
Jeffrey D. Lifson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Blood Cells ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
T Cell Epitopes ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT Practical immunotherapies for human immunodeficiency virus infection are needed. We evaluated inactivated simian immunodeficiency virus (SIV) pulsed onto fresh peripheral blood mononuclear cells in 12 pigtail macaques with chronic SIVmac251 infection for T-cell immunogenicity in a randomized cross-over design study. The immunotherapy was safe and convincingly induced high levels of SIV-specific CD4+ T-cell responses (mean, 5.9% ± 1.3% of all CD4+ T cells) and to a lesser extent SIV-specific CD8+ T-cell responses (mean, 0.7% ± 0.4%). Responses were primarily directed toward Gag and less frequently toward Env but not Pol or regulatory/accessory SIV proteins. T-cell responses against Gag were generally broad and polyfunctional, with a mean of 2.7 CD4+ T-cell epitopes mapped per animal and more than half of the SIV Gag-specific CD4+ T cells expressing three or more effector molecules. The immunogenicity was comparable to that found in previous studies of peptide-pulsed blood cells. Despite the high-level immunogenicity, no reduction in viral load was observed in the chronically viremic macaques. This contrasts with our studies of immunization with peptide-pulsed blood cells during early SIV infection in macaques. Future studies of inactivated virus-pulsed blood cell immunotherapy during early infection of patients receiving antiretroviral therapy are warranted.

scholarly journals Comparison of Human Immunodeficiency Virus (HIV)-Specific T-Cell Responses in HIV-1- and HIV-2-Infected Individuals in Senegal

2004 ◽  
Vol 78 (24) ◽  
pp. 13934-13942 ◽  
Author(s):  
N. N. Zheng ◽  
N. B. Kiviat ◽  
P. S. Sow ◽  
S. E. Hawes ◽  
A. Wilson ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
T Helper ◽  
Cell Responses ◽  
Cell Immunity ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 2 (HIV-2) infection is typically less virulent than HIV-1 infection, which may permit the host to mount more effective, sustained T-cell immunity. We investigated antiviral gamma interferon-secreting T-cell responses by an ex vivo Elispot assay in 68 HIV-1- and 55 HIV-2-infected Senegalese patients to determine if differences relate to more efficient HIV-2 control. Homologous HIV-specific T cells were detected in similar frequencies (79% versus 76%, P = 0.7) and magnitude (3.12 versus 3.08 log10 spot-forming cells/106 peripheral blood mononuclear cells) in HIV-1 and HIV-2 infection, respectively. Gag-specific responses predominated in both groups (≥64%), and significantly higher Nef-specific responses occurred in HIV-1-infected (54%) than HIV-2-infected patients (22%) (P < 0.001). Heterologous responses were more frequent in HIV-1 than in HIV-2 infection (46% versus 27%, P = 0.04), but the mean magnitude was similar. Total frequencies of HIV-specific responses in both groups did not correlate with plasma viral load and CD4+ T-cell count in multivariate regression analyses. However, the magnitude of HIV-2 Gag-specific responses was significantly associated with lower plasma viremia in HIV-1-infected patients (P = 0.04). CD4+ T-helper responses, primarily recognizing HIV-2 Gag, were detected in 48% of HIV-2-infected compared to only 8% of HIV-1-infected patients. These findings indicate that improved control of HIV-2 infection may relate to the contribution of T-helper cell responses. By contrast, the superior control of HIV-1 replication associated with HIV-2 Gag responses suggests that these may represent cross-reactive, higher-avidity T cells targeting epitopes within Gag regions of functional importance in HIV replication.

scholarly journals Enhanced Cellular Immunity in Macaques following a Novel Peptide Immunotherapy

2005 ◽  
Vol 79 (6) ◽  
pp. 3748-3757 ◽  
Author(s):  
S. Chea ◽  
C. J. Dale ◽  
R. De Rose ◽  
I. A. Ramshaw ◽  
S. J. Kent
Keyword(s):  
T Cell ◽  
Mononuclear Cells ◽  
De Novo ◽  
T Cell Responses ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Cell Immunity ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Advances in treating and preventing AIDS depend on understanding how human immunodeficiency virus (HIV) is eliminated in vivo and on the manipulation of effective immune responses to HIV. During the development of assays quantifying the elimination of fluorescent autologous cells coated with overlapping 15-mer simian immunodeficiency virus (SIV) or HIV-1 peptides, we made a remarkable observation: the reinfusion of macaque peripheral blood mononuclear cells, or even whole blood, pulsed with SIV and/or HIV peptides generated sharply enhanced SIV- and HIV-1-specific T-cell immunity. Strong, broad CD4+- and CD8+-T-cell responses could be enhanced simultaneously against peptide pools spanning 87% of all SIV- and HIV-1-expressed proteins—highly desirable characteristics of HIV-specific immunity. De novo hepatitis C virus-specific CD4+- and CD8+-T-cell responses were generated in macaques by the same method. This simple technique holds promise for the immunotherapy of HIV and other chronic viral infections.

scholarly journals Maintenance of Viral Suppression in Human Immunodeficiency Virus Controllers Despite Waning T-Cell Responses During Antiretroviral Therapy

2020 ◽  
Vol 222 (11) ◽  
pp. 1837-1842 ◽  
Author(s):  
Nikolaus Jilg ◽  
Pilar Garcia-Broncano ◽  
Michael Peluso ◽  
Florencia P Segal ◽  
Ronald J Bosch ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Responses ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Undetectable Viremia ◽  
Hiv Controllers

Abstract AIDS Clinical Trials Group study A5308 found reduced T-cell activation and exhaustion in human immunodeficiency virus (HIV) controllers start antiretroviral therapy (ART). We further assessed HIV-specific T-cell responses and post-ART viral loads. Before ART, the 31% of participants with persistently undetectable viremia had more robust HIV-specific T-cell responses. During ART, significant decreases were observed in a broad range of T-cell responses. Eight controllers in A5308 and the Study of the Consequences of the Protease Inhibitor Era (SCOPE) cohort showed no viremia above the level of quantification in the first 12 weeks after ART discontinuation. ART significantly reduced HIV-specific T-cell responses in HIV controllers but did not adversely affect controller status after ART discontinuation.

scholarly journals Analysis of CD4+ T-Cell Responses to Human Papillomavirus (HPV) Type 11 L1 in Healthy Adults Reveals a High Degree of Responsiveness and Cross-Reactivity with Other HPV Types

2002 ◽  
Vol 76 (15) ◽  
pp. 7418-7429 ◽  
Author(s):  
O. Martin Williams ◽  
Keith W. Hart ◽  
Eddie C. Y. Wang ◽  
Colin M. Gelder
Keyword(s):  
Human Papillomavirus ◽  
T Cell ◽  
In Vitro Selection ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
T Cell Responses ◽  
Cross Reactivity ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Hpv Types

ABSTRACT Human papillomavirus type 11 (HPV-11) infection causes genital warts and recurrent respiratory papillomatosis. While there is compelling evidence that CD4+ T cells play an important role in immune surveillance of HPV-associated diseases, little is known about human CD4+ T-cell recognition of HPV-11. We have investigated the CD4+ T-cell responses of 25 unrelated healthy donors to HPV-11 L1 virus-like particles (VLP). CD4+ T-cell lines from 21 of 25 donors were established. Cell sorting experiments carried out on cells from six donors demonstrated that the response was located in the CD45RAlow CD45ROhigh memory T-cell population. To determine the peptide specificity of these responses, epitope selection was analyzed by using 95 15-mer peptides spanning the entire HPV-11 L1 protein. No single region of L1 was immunodominant; responders recognized between 1 and 10 peptides, located throughout the protein, and peptide responses fell into clear HLA class II restricted patterns. Panels of L1 peptides specific for skin and genital HPV were used to show that the L1 CD4+ T-cell responses were cross-reactive. The degree of cross-reactivity was inversely related to the degree of L1 sequence diversity between these viruses. Finally, responses to HPV-11 L1 peptides were elicited from ex vivo CD45RO+ peripheral blood mononuclear cells, demonstrating that recognition of HPV-11 was a specific memory response and not due to in vitro selection during tissue culture. This is the first study of CD4+ T-cell responses to HPV-11 in healthy subjects and demonstrates marked cross-reactivity with other skin and genital HPV types. This cross-reactivity may be of significance for vaccine strategies against HPV-associated clinical diseases.

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