scholarly journals Different Levels of Immunogenicity of Two Strains of Fowlpox Virus as Recombinant Vaccine Vectors Eliciting T-Cell Responses in Heterologous Prime-Boost Vaccination Strategies

2006 ◽  
Vol 13 (7) ◽  
pp. 747-757 ◽  
Author(s):  
Matthew G. Cottingham ◽  
Andre van Maurik ◽  
Manola Zago ◽  
Angela T. Newton ◽  
Richard J. Anderson ◽  
...  

ABSTRACT The FP9 strain of Fowlpox virus has been described as a more immunogenic recombinant vaccine vector than the Webster FPV-M (FPW) strain (R. J. Anderson et al., J. Immunol. 172:3094-3100, 2004). This study expands the comparison to include two separate recombinant antigens and multiple, rather than single, independent viral clones derived from the two strains. Dual-poxvirus heterologous prime-boost vaccination regimens using individual clones of recombinant FP9 or FPW in combination with recombinant modified Vaccinia virus Ankara expressing the same antigen were evaluated for their ability to elicit T-cell responses against recombinant antigens from Plasmodium berghei (circumsporozoite protein) or human immunodeficiency virus type 1 (a Gag-Pol-Nef fusion protein). Gamma interferon enzyme-linked immunospot assay and fluorescence-activated cell sorting assays of the responses to specific epitopes confirmed the approximately twofold-greater cellular immunogenicity of FP9 compared to FPW, when given as the priming or boosting immunization. Equality of transgene expression in mouse cells infected with the two strains in vitro was verified by Western blotting. Directed partial sequence analysis and PCR analysis of FPW and comparison to available whole-genome sequences revealed that many loci that are mutated in the highly attenuated and culture-adapted FP9 strain are wild type in FPW, including the seven multikilobase deletions. These “passage-specific” alterations are hypothesized to be involved in determining the immunogenicity of Fowlpox virus as a recombinant vaccine vector.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4821-4821
Author(s):  
Hakan Mellstedt ◽  
Parviz Kokhaei ◽  
Anders Osterborg ◽  
Aniruddha Choudhury

Abstract The slow indolent nature of B-CLL makes it eminently suitable for immune-based treatment strategies. Currently, there exist very few CLL-associated, defined antigen which can be used in vaccination approaches. The use of whole tumor preparations in conjunction with dendritic cells (DC) as cellular adjuvants presents an alternative method for generating therapeutic T-cell responses in CLL patients. We have examined various strategies of loading DC with whole tumor antigens; viz. tumor-DC hybrids, endocytosed apoptotic bodies, RNA or lysate from B-CLL cells. Dendritic cells were generated in vitro, using GM-CSF and IL-4 from immunomagnetically purified, CD14+ monocyte precursors obtained from the peripheral blood of B-CLL patients. The immature DC were loaded with whole tumor antigen using the above methods and matured using TNFα. The tumor antigen-loaded DC were compared for their ability to stimulate autologous T-cell responses. Among all the antigen-loading methods tested, DC that had endocytosed apoptotic bodies (Apo-DC) consistently generated the greatest numbers and magnitude of reactive T-cells as quantified in proliferation and ELISPOT assays. RT-PCR analysis for cytokine mRNA revealed that T-cells stimulated by Apo-DC resulted in an immune response that was almost entirely of the TH1 type as manifested by the production of mRNA for IFN-γ and TNFα. In contrast, other methods of loading antigen resulted in a mixed TH1-TH2 population with varying amounts of TH2 cytokines like IL-4 and IL-10. In a separate series of experiments we compared the T-cell stimulatory capacities of cryopreserved and thawed, with fresh antigen-loaded DC. The results of these studies are essential for the development of a protocol for clinical therapy of B-CLL patients using Apo-DC. Our results indicated that cryopreserved DC could be recovered with high viability. A comparison of functional abilities demonstrated that no significant differences in T-cell stimulatory capacity between cryopreserved and fresh Apo-DC could be noted over a wide variety of immunological assays. Cumulatively, our results suggest that Apo-DC may be a suitable vaccine candidate for immunotherapy of B-CLL patients.


npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mauro Di Pilato ◽  
Miguel Palomino-Segura ◽  
Ernesto Mejías-Pérez ◽  
Carmen E. Gómez ◽  
Andrea Rubio-Ponce ◽  
...  

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.


2017 ◽  
Vol 142 (7) ◽  
pp. 1467-1479 ◽  
Author(s):  
Nicolas Çuburu ◽  
Selina Khan ◽  
Cynthia D. Thompson ◽  
Rina Kim ◽  
Jort Vellinga ◽  
...  

2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.


Author(s):  
Maud Wilhelm ◽  
Amandeep Kaur ◽  
Marion Wernli ◽  
Hans H Hirsch

Abstract Background BK polyomavirus (BKPyV) remains a significant cause of premature kidney transplant failure. In the absence of effective antivirals, current treatments rely on reducing immunosuppression to regain immune control over BKPyV replication. Increasing BKPyV-specific CD8 T cells correlate with clearance of BKPyV DNAemia in kidney transplant patients. We characterized a novel approach for expanding BKPyV-specific CD8 T cells in vitro using 27mer-long synthetic BKPyV peptides, different types of antigen-presenting cells, and CD4 T cells. Methods Langerhans cells and immature or mature monocyte-derived dendritic cells (Mo-DCs) were generated from peripheral blood mononuclear cells of healthy blood donors, pulsed with synthetic peptide pools consisting of 36 overlapping 27mers (27mP) or 180 15mers (15mP). BKPyV-specific CD8 T-cell responses were assessed by cytokine release assays using 15mP or immunodominant 9mers. Results BKPyV-specific CD8 T cells expanded using 27mP and required mature Mo-DCs (P = .0312) and CD4 T cells (P = .0156) for highest responses. The resulting BKPyV-specific CD8 T cells proliferated, secreted multiple cytokines including interferon γ and tumor necrosis factor α, and were functional (CD107a+/PD1–) and cytotoxic. Conclusions Synthetic 27mP permit expanding BKPyV-specific CD8 T-cell responses when pulsing mature Mo-DCs in presence of CD4 T cells, suggesting novel and safe approaches to vaccination and adoptive T-cell therapies for patients before and after kidney transplantation.


2001 ◽  
Vol 75 (20) ◽  
pp. 9665-9670 ◽  
Author(s):  
Mohamed T. Shata ◽  
David M. Hone

ABSTRACT A prototype Shigella human immunodeficiency virus type 1 (HIV-1) gp120 DNA vaccine vector was constructed and evaluated for immunogenicity in a murine model. For comparative purposes, mice were also vaccinated with a vaccinia virus-env(vaccinia-env) vector or the gp120 DNA vaccine alone. Enumeration of the CD8+-T-cell responses to gp120 after vaccination using a gamma interferon enzyme-linked spot assay revealed that a single intranasal dose of the Shigella HIV-1 gp120 DNA vaccine vector elicited a CD8+ T-cell response to gp120, the magnitude of which was comparable to the sizes of the analogous responses to gp120 that developed in mice vaccinated intraperitoneally with the vaccinia-env vector or intramuscularly with the gp120 DNA vaccine. In addition, a single dose of the Shigella gp120 DNA vaccine vector afforded significant protection against a vaccinia-env challenge. Moreover, the number of vaccinia-env PFU recovered in mice vaccinated intranasally with the Shigella vector was about fivefold less than the number recovered from mice vaccinated intramuscularly with the gp120 DNA vaccine. Since theShigella vector did not express detectable levels of gp120, this report confirms that Shigella vectors are capable of delivering passenger DNA vaccines to host cells and inducing robust CD8+ T-cell responses to antigens expressed by the DNA vaccines. Furthermore, to our knowledge, this is the first documentation of antiviral protective immunity following vaccination with a live Shigella DNA vaccine vector.


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