Beta 2-microglobulin-, CD8+ T-cell-deficient mice survive inoculation with high doses of vaccinia virus and exhibit altered IgG responses.

AbstractNeutrophils are innate immune cells involved in the elimination of pathogens and can also induce adaptive immune responses. Nα and Nβ neutrophils have been described with distinct in vitro capacity to generate antigen-specific CD8 T-cell responses. However, how these cell types exert their role in vivo and how manipulation of Nβ/Nα ratio influences vaccine-mediated immune responses are not known. In this study, we find that these neutrophil subtypes show distinct migratory and motility patterns and different ability to interact with CD8 T cells in the spleen following vaccinia virus (VACV) infection. Moreover, after analysis of adhesion, inflammatory, and migration markers, we observe that Nβ neutrophils overexpress the α4β1 integrin compared to Nα. Finally, by inhibiting α4β1 integrin, we increase the Nβ/Nα ratio and enhance CD8 T-cell responses to HIV VACV-delivered antigens. These findings provide significant advancements in the comprehension of neutrophil-based control of adaptive immune system and their relevance in vaccine design.

Download Full-text

Stable transformation of mouse L cells for human membrane T-cell differentiation antigens, HLA and beta 2-microglobulin: selection by fluorescence-activated cell sorting.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.80.2.524 ◽

1983 ◽

Vol 80 (2) ◽

pp. 524-528 ◽

Cited By ~ 88

Author(s):

P. Kavathas ◽

L. A. Herzenberg

Keyword(s):

Cell Differentiation ◽

T Cell ◽

Cell Sorting ◽

T Cell Differentiation ◽

Stable Transformation ◽

Fluorescence Activated Cell Sorting ◽

Differentiation Antigens ◽

L Cells ◽

Beta 2 ◽

Beta 2 Microglobulin

Download Full-text

Immediate-Early Expression of a Recombinant Antigen by Modified Vaccinia Virus Ankara Breaks the Immunodominance of Strong Vector-Specific B8R Antigen in Acute and Memory CD8 T-Cell Responses

Journal of Virology ◽

10.1128/jvi.00604-10 ◽

2010 ◽

Vol 84 (17) ◽

pp. 8743-8752 ◽

Cited By ~ 33

Author(s):

Karen Baur ◽

Kay Brinkmann ◽

Marc Schweneker ◽

Juliane Pätzold ◽

Christine Meisinger-Henschel ◽

...

Keyword(s):

T Cell ◽

Vaccinia Virus ◽

T Cell Responses ◽

Cd8 T Cell ◽

Immediate Early ◽

Egfp Expression ◽

Cell Responses ◽

Modified Vaccinia Virus Ankara ◽

Memory Cd8 T Cell ◽

Early Late

ABSTRACT Efficient T-cell responses against recombinant antigens expressed by vaccinia virus vectors require expression of these antigens in the early phase of the virus replication cycle. The kinetics of recombinant gene expression in poxviruses are largely determined by the promoter chosen. We used the highly attenuated modified vaccinia virus Ankara (MVA) to determine the role of promoters in the induction of CD8 T-cell responses. We constructed MVA recombinants expressing either enhanced green fluorescent protein (EGFP) or chicken ovalbumin (OVA), each under the control of a hybrid early-late promoter (pHyb) containing five copies of a strong early element or the well-known early-late p7.5 or pS promoter for comparison. In primary or cultured cells, EGFP expression under the control of pHyb was detected within 30 min, as an immediate-early protein, and remained higher over the first 6 h of infection than p7.5- or pS-driven EGFP expression. Repeated immunizations of mice with recombinant MVA expressing OVA under the control of the pHyb promoter led to superior acute and memory CD8 T-cell responses compared to those to p7.5- and pS-driven OVA. Moreover, OVA expressed under the control of pHyb replaced the MVA-derived B8R protein as the immunodominant CD8 T-cell antigen after three or more immunizations. This is the first demonstration of an immediate-early neoantigen expressed by a poxviral vector resulting in superior induction of neoantigen-specific CD8 T-cell responses.

Download Full-text

Protection against Vaccinia Virus Challenge by CD8 Memory T Cells Resolved by Molecular Mimicry

Journal of Virology ◽

10.1128/jvi.01280-06 ◽

2006 ◽

Vol 81 (2) ◽

pp. 934-944 ◽

Cited By ~ 28

Author(s):

Markus Cornberg ◽

Brian S. Sheridan ◽

Frances M. Saccoccio ◽

Michael A. Brehm ◽

Liisa K. Selin

Keyword(s):

T Cells ◽

T Cell ◽

Vaccinia Virus ◽

Cd8 T Cells ◽

Protective Immunity ◽

Molecular Mimicry ◽

T Cell Responses ◽

Cd8 T Cell ◽

T Cell Epitopes ◽

Cell Responses

ABSTRACT Live vaccinia virus (VV) vaccination has been highly successful in eradicating smallpox. However, the mechanisms of immunity involved in mediating this protective effect are still poorly understood, and the roles of CD8 T-cell responses in primary and secondary VV infections are not clearly identified. By applying the concept of molecular mimicry to identify potential CD8 T-cell epitopes that stimulate cross-reactive T cells specific to lymphocytic choriomeningitis virus (LCMV) and VV, we identified after screening only 115 peptides two VV-specific immunogenic epitopes that mediated protective immunity against VV. An immunodominant epitope, VV-e7r130, did not generate cross-reactive T-cell responses to LCMV, and a subdominant epitope, VV-a11r198, did generate cross-reactive responses to LCMV. Infection with VV induced strong epitope-specific responses which were stable into long-term memory and peaked at the time virus was cleared, consistent with CD8 T cells assisting in the control of VV. Two different approaches, direct adoptive transfer of VV-e7r-specific CD8 T cells and prior immunization with a VV-e7r-expressing ubiquitinated minigene, demonstrated that memory CD8 T cells alone could play a significant role in protective immunity against VV. These studies suggest that exploiting cross-reactive responses between viruses may be a useful tool to complement existing technology in predicting immunogenic epitopes to large viruses, such as VV, leading to a better understanding of the role CD8 T cells play during these viral infections.

Download Full-text

Novel Recombinant Mycobacterium bovis BCG, Ovine Atadenovirus, and Modified Vaccinia Virus Ankara Vaccines Combine To Induce Robust Human Immunodeficiency Virus-Specific CD4 and CD8 T-Cell Responses in Rhesus Macaques

Journal of Virology ◽

10.1128/jvi.02607-09 ◽

2010 ◽

Vol 84 (12) ◽

pp. 5898-5908 ◽

Cited By ~ 19

Author(s):

Maximillian Rosario ◽

Richard Hopkins ◽

John Fulkerson ◽

Nicola Borthwick ◽

Máire F. Quigley ◽

...

Keyword(s):

T Cell ◽

Vaccinia Virus ◽

Mycobacterium Bovis ◽

Ex Vivo ◽

Rhesus Macaques ◽

T Cell Responses ◽

Cd8 T Cell ◽

Cell Responses ◽

Modified Vaccinia Virus Ankara ◽

Hiv 1

ABSTRACT Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity against tuberculosis, is the most widely used vaccine in the world. Due to its persistence and immunogenicity, BCG has been proposed as a vector for vaccines against other infections, including HIV-1. BCG has a very good safety record, although it can cause disseminated disease in immunocompromised individuals. Here, we constructed a recombinant BCG vector expressing HIV-1 clade A-derived immunogen HIVA using the recently described safer and more immunogenic BCG strain AERAS-401 as the parental mycobacterium. Using routine ex vivo T-cell assays, BCG.HIVA401 as a stand-alone vaccine induced undetectable and weak CD8 T-cell responses in BALB/c mice and rhesus macaques, respectively. However, when BCG.HIVA401 was used as a priming component in heterologous vaccination regimens together with recombinant modified vaccinia virus Ankara-vectored MVA.HIVA and ovine atadenovirus-vectored OAdV.HIVA vaccines, robust HIV-1-specific T-cell responses were elicited. These high-frequency T-cell responses were broadly directed and capable of proliferation in response to recall antigen. Furthermore, multiple antigen-specific T-cell clonotypes were efficiently recruited into the memory pool. These desirable features are thought to be associated with good control of HIV-1 infection. In addition, strong and persistent T-cell responses specific for the BCG-derived purified protein derivative (PPD) antigen were induced. This work is the first demonstration of immunogenicity for two novel vaccine vectors and the corresponding candidate HIV-1 vaccines BCG.HIVA401 and OAdV.HIVA in nonhuman primates. These results strongly support their further exploration.

Download Full-text

Removal of the C6 Vaccinia Virus Interferon-β Inhibitor in the Hepatitis C Vaccine Candidate MVA-HCV Elicited in Mice High Immunogenicity in Spite of Reduced Host Gene Expression

Viruses ◽

10.3390/v10080414 ◽

2018 ◽

Vol 10 (8) ◽

pp. 414 ◽

Cited By ~ 7

Author(s):

María Q. Marín ◽

Patricia Pérez ◽

Carmen E. Gómez ◽

Carlos Óscar S. Sorzano ◽

Mariano Esteban ◽

...

Keyword(s):

Gene Expression ◽

Hepatitis C ◽

T Cell ◽

Vaccinia Virus ◽

Vaccine Candidate ◽

Human Monocyte ◽

Cd8 T Cell ◽

Inhibitory Effect ◽

Effector Memory ◽

Modified Vaccinia Virus Ankara

Hepatitis C virus (HCV) represents a major global health problem for which a vaccine is not available. Modified vaccinia virus Ankara (MVA)-HCV is a unique HCV vaccine candidate based in the modified vaccinia virus Ankara (MVA) vector expressing the nearly full-length genome of HCV genotype 1a that elicits CD8+ T-cell responses in mice. With the aim to improve the immune response of MVA-HCV and because of the importance of interferon (IFN) in HCV infection, we deleted in MVA-HCV the vaccinia virus (VACV) C6L gene, encoding an inhibitor of IFN-β that prevents activation of the interferon regulatory factors 3 and 7 (IRF3 and IRF7). The resulting vaccine candidate (MVA-HCV ΔC6L) expresses all HCV antigens and deletion of C6L had no effect on viral growth in permissive chicken cells. In human monocyte-derived dendritic cells, infection with MVA-HCV ΔC6L triggered severe down-regulation of IFN-β, IFN-β-induced genes, and cytokines in a manner similar to MVA-HCV, as defined by real-time polymerase chain reaction (PCR) and microarray analysis. In infected mice, both vectors had a similar profile of recruited immune cells and induced comparable levels of adaptive and memory HCV-specific CD8+ T-cells, mainly against p7 + NS2 and NS3 HCV proteins, with a T cell effector memory (TEM) phenotype. Furthermore, antibodies against E2 were also induced. Overall, our findings showed that while these vectors had a profound inhibitory effect on gene expression of the host, they strongly elicited CD8+ T cell and humoral responses against HCV antigens and to the virus vector. These observations add support to the consideration of these vectors as potential vaccine candidates against HCV.

Download Full-text