Cell Immune Responses (cell + immune_response)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Intradermal NKT cell activation during DNA priming in heterologous prime-boost vaccination enhances T cell responses and protection against Leishmania

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2008
Blaise Dondji
Abstract Heterologous prime-boost vaccination employing DNA-vaccinia virus (VACV) modality using the Leishmania homologue of receptors for activated C,kinase (LACK) (p36) antigen has been shown to elicit protective immunity against both murine cutaneous and visceral leishmaniasis. However, DNA priming is known to have limited efficacy; therefore in the current study the effect of NKT cell activation using ,-galactosyl-ceramide (,GalCer) during intradermal DNAp36 priming was examined. Vaccinated mice receiving ,GalCer,+ DNAp36 followed by a boost with VVp36 appeared to be resolving their lesions and had at ten- to 20-fold higher reductions in parasite burdens. NKT cell activation during ,GalCer,+ DNAp36 priming resulted in higher numbers of antigen-reactive effector CD4+ and CD8+ T cells producing granzyme and IFN-,, with lower levels of IL-10. Although immunodepletion studies indicate that both CD4 and CD8 T cells provide protection in the vaccinated mice, the contribution of CD4+ T cells was significantly increased in mice primed with DNAp36 together with ,GalCer. Notably 5,months after boosting, mice vaccinated with DNAp36,+ ,GalCer continued to show sustained and heightened T cell immune responses. Thus, heterologous prime-boost vaccination using ,GalCer during priming is highly protective against murine cutaneous leishmaniasis, resulting in the heightened activation and development of CD4 and CD8 T cells (effector and memory T cells). [source]

Therapeutic human papillomavirus DNA vaccination strategies to control cervical cancer

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2007
T.-C. Wu
Abstract A persistent human papillomavirus (HPV) infection is considered causal and necessary for the continued growth of cervical cancer. Thus, vaccination against HPV represents a plausible approach to prevent and treat cervical cancer. A report in the current issue of the European Journal of Immunology describes a therapeutic HPV DNA vaccination strategy using the HPV-16 E7 antigen fused to the invariant chain to enhance the E7-specific CD8+ and CD4+ T cell immune responses, resulting in a potent anti-tumor effect against E7-expressing tumors. Continued exploration of HPV therapeutic DNA vaccines may lead to eventual clinical application. See accompanying article http://dx.doi.org/10.1002/eji.200636233 [source]

Dendritic cell-derived IL-15 controls the induction of CD8 T,cell immune responses

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2003
René Rückert
Abstract The development and the differentiation of CD8+ T,cells are dependent on IL-15. Here, we have studied the source and mechanism of how IL-15 modulates CD8+ T,cell-mediated Th1immune responses by employing two delayed-type hypersensitivity (DTH) models. IL-15-deficient (IL-15,/,) mice or mice treated with soluble IL-15R, as an IL-15 antagonist showed significantly reduced CD8+ T,cell-dependent DTH responses, while activation of CD4+ T,cell and B,cell functions remained unaffected. Injection of antigen-labeled dendritic cells (DC) fromIL-15+/+, IL-15,/, or IL-15R,,/, mice revealed that DC-derived IL-15 is an absolute requirement for the initiation of DTH response. The re-establishment of the interaction of IL-15 with the IL-15R, by incubating IL-15,/, DC with IL-15 completely restored the capacity to prime T,cells for DTH induction in vivo. Moreover, IL-15 also enhanced secretion of pro-inflammatory cytokines by DC and triggered in vitro CD8+ T,cell proliferation and IL-2 release. Taken together, the data suggest that an autocrine IL-15/IL-15R, signaling loop in DC is essential for inducing CD8+ -dependent Th1 immune responses in mice. Therefore, targeted manipulation of this loop promises to be an effective, novel strategy for therapeuticmodulation of clinically relevant DTH reactions. [source]

Suppression of allergic airway inflammation in a mouse model by Der p2 recombined BCG

IMMUNOLOGY, Issue 1pt2 2009
Hai-Feng Ou-Yang
Summary Allergic asthma is a chronic inflammatory disease mediated by T helper (Th)2 cell immune responses. Currently, immunotherapies based on both immune deviation and immune suppression, including the development of recombinant mycobacteria as immunoregulatory vaccines, are attractive treatment strategies for asthma. In our previous studies, we created a genetically recombinant form of bacille Calmette,Guerin (rBCG) that expressed Der p2 of house dust mites and established that it induced a shift from a Th2 response to a Th1 response in naive mice. However, it is unclear whether rBCG could suppress allergic airway inflammation in a mouse model. In this article we report that rBCG dramatically inhibited airway inflammation, eosinophilia, mucus production and mast cell degranulation in allergic mice. Analysis of interferon-, (IFN-,) and interleukin-4 (IL-4) levels in bronchoalveolar lavage fluid (BALF) and lung tissue revealed that the suppression was associated with a shift from a Th2 response to a Th1 response. At the same time, rBCG induced a CD4+ CD25+ Foxp3+ T-cell subtype that could suppress the proliferation of Th2 effector cells in vitro in an antigen-specific manner. Moreover, suppression of CD4+ CD25+ T cells could be adoptively transferred. Thus, our results demonstrate that rBCG induces both generic and specific immune responses. The generic immune response is associated with a shift from a Th2 to a Th1 cytokine response, whereas the specific immune response against Der p2 appears to be related to the expansion of transforming growth factor-, (TGF-,)-producing CD4+ CD25+ Foxp3+ regulatory T cells. rBCG can suppress asthmatic airway inflammation through both immune deviation and immune suppression and may be a feasible, efficient immunotherapy for asthma. [source]