scholarly journals Decreased Vector Gene Expression from E2b Gene-Deleted Adenovirus Serotype 5 Vaccines Intensifies Proinflammatory Immune Responses

2017 ◽  
Vol 24 (6) ◽  
Author(s):  
Dionisia Quiroga ◽  
Yasser A. Aldhamen ◽  
Sarah Godbehere ◽  
Laura Harding ◽  
Andrea Amalfitano

ABSTRACT Recombinant adenovirus serotype 5 (Ad5) vectors are promising vaccine candidates due to their intrinsic immunogenicity and potent transgene expression; however, widespread preexisting Ad5 immunity has been considered a developmental impediment to the use of traditional, or conventional, E1 and E3 gene-deleted Ad5 (Ad5[E1−]) vaccines. Even in the presence of anti-Ad5 immunity, recent murine and human studies have confirmed E2b gene-deleted Ad5 (Ad5[E1−,E2b−]) vaccines to be highly efficacious inducers of transgene-specific memory responses and significantly less toxic options than Ad5[E1−] vaccines. While these findings have been substantially confirmed, the molecular mechanisms underlying the different reactions to these vaccine platforms are unknown. Using cultures of human peripheral blood mononuclear cells (hPBMCs) derived from multiple human donors, we found that Ad5[E1−,E2b−] vaccines trigger higher levels of hPBMC proinflammatory cytokine secretion than Ad5[E1−] vaccines. Interestingly, these responses were generated regardless of the donors' preexisting anti-Ad5 humoral and cell-mediated immune response status. In vitro hPBMC infection with the Ad5[E1−,E2b−] vaccine also provoked greater Th1-dominant gene responses yet smaller amounts of Ad-derived gene expression than Ad5[E1−] vaccines. These results suggest that Ad5[E1−,E2b−] vaccines, in contrast to Ad5[E1−] vaccines, do not promote activities that suppress innate immune signaling, thereby allowing for improved vaccine efficacy and a superior safety profile independently of previous Ad5 immunity.

Blood ◽  
2008 ◽  
Vol 112 (8) ◽  
pp. 3474-3483 ◽  
Author(s):  
Rahima Zennadi ◽  
Ai Chien ◽  
Ke Xu ◽  
Milena Batchvarova ◽  
Marilyn J. Telen

Abstract Infusion of epinephrine-activated human sickle erythrocytes (SS RBCs) into nude mice promotes both SS RBC and murine leukocyte adhesion to vascular endothelium in vivo. We hypothesized that interaction of epinephrine-stimulated SS RBCs with leukocytes leads to activation of leukocytes, which then adhere to endothelial cells (ECs). In exploring the underlying molecular mechanisms, we have found that coincubation in vitro of epinephrine-treated SS RBCs with human peripheral blood mononuclear cells (PBMCs) results in robust adhesion of PBMCs to ECs. Sham-treated SS RBCs had a similar but less pronounced effect, whereas neither sham- nor epinephrine-treated normal RBCs activated PBMC adhesion. PBMC activation was induced via at least 2 RBC adhesion receptors, LW and CD44. In response to SS RBCs, leukocyte CD44 and β2 integrins mediated PBMC adhesion to ECs, a process that involved endothelial E-selectin and fibronectin. SS RBCs activated adhesion of both PBMC populations, lymphocytes and monocytes. Thus, our findings reveal a novel mechanism that may contribute to the pathogenesis of vaso-occlusion in sickle cell disease, in which SS RBCs act via LW and CD44 to stimulate leukocyte adhesion to endothelium, and suggest that RBC LW and CD44 may serve as potential targets for antiadhesive therapy designed to prevent vaso-occlusion.


2003 ◽  
Vol 31 (02) ◽  
pp. 247-257 ◽  
Author(s):  
Jiann-Jong Shen ◽  
Chun-Jing Lin ◽  
Jing-Long Huang ◽  
Kue-Hsiung Hsieh ◽  
Ming-Ling Kuo

Liu-Wei-Di-Huang Wan (LWDHW) has been used by traditional Chinese doctors to treat asthma patients. This study was to examine the potential effect of this decoction on the regulation of T helper (Th)1- and Th2-type cytokine gene expression in vitro. Peripheral blood mononuclear cells (PBMC) were activated with mitogen for 24 hours in the presence or absence of LWDHW extracts. Concentrations of different cytokines in the culture supernatants were determined with ELISA. RNA isolated from cultured cells was subjected to RT-PCR analysis. The results showed that the expression of all cytokines (Th2-type: IL-4, IL-5, IL-10, or IL-13 and Th1-type: IL-2 and IFN-γ) examined was inhibited at both RNA and protein levels by LWDHW. Since the cell viability was similar in all cultures, the reduction of cytokine production was not due to the toxicity of LWDHW. Moreover, the cells either retained or increased their capacity to respond to mitogen stimulation after incubation with the LWDHW decoction. Therefore, the data suggest that LWDHW functioned directly on cytokine gene expression from activated PBMC.


Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2516-2525 ◽  
Author(s):  
K Meszaros ◽  
S Aberle ◽  
R Dedrick ◽  
R Machovich ◽  
A Horwitz ◽  
...  

Abstract Mononuclear phagocytes, stimulated by bacterial lipopolysaccharide (LPS), have been implicated in the activation of coagulation in sepsis and endotoxemia. In monocytes LPS induces the synthesis of tissue factor (TF) which, assembled with factor VII, initiates the blood coagulation cascades. In this study we investigated the mechanism of LPS recognition by monocytes, and the consequent expression of TF mRNA and TF activity. We also studied the inhibition of these effects of LPS by rBPI23, a 23-kD recombinant fragment of bactericidal/permeability increasing protein, which has been shown to antagonize LPS in vitro and in vivo. Human peripheral blood mononuclear cells, or monocytes isolated by adherence, were stimulated with Escherichia coli O113 LPS at physiologically relevant concentrations (> or = 10 pg/mL). The effect of LPS was dependent on the presence of the serum protein LBP (lipopolysaccharide-binding protein), as shown by the potentiating effect of human recombinant LBP or serum. Furthermore, recognition of low amounts of LPS by monocytes was also dependent on CD14 receptors, because monoclonal antibodies against CD14 greatly reduced the LPS sensitivity of monocytes in the presence of serum or rLBP. Induction of TF activity and mRNA expression by LPS were inhibited by rBPI23. The expression of tumor necrosis factor showed qualitatively similar changes. Considering the involvement of LPS-induced TF in the potentially lethal intravascular coagulation in sepsis, inhibition of TF induction by rBPI23 may be of therapeutic benefit.


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