Search results for "TOLL-LIKE RECEPTORS"

Toll-like receptor 2 is dispensable for acquired host immune resistance to Candida albicans in a murine model of disseminated candidiasis

2004

Previous work by our group showed that Toll-like receptor 2 (TLR2) is essential for activation of innate immunity, playing a major role in the response of macrophages to Candida albicans, triggering cytokine and chemokine expression, and therefore TLR2 -/- mice are more susceptible to systemic primary candidiasis. In this work, we used a murine model of systemic C. albicans infection, in which resistance to reinfection with virulent wild-type cells is induced by prior exposure of mice to a low-virulence agerminative strain of C. albicans (primary sublethal infection), to study the influence of TLR2 gene deletion on (i) the ability to develop an acquired resistance upon vaccination; (ii) the…

Toll-like receptor-2 is essential in murine defenses against Candida albicans infections

2004

In this work, we studied the role of toll-like receptor-2 (TLR2) in murine defenses against Candida albicans. TLR2-deficient mice experimentally infected intraperitoneally (i.p.) or intravenously (i.v.) in vivo had very significant impaired survival compared with that of control mice. In vitro production of TNF-alpha and macrophage inhibitory protein-2 (MIP-2) by macrophages from TLR2-/- mice in response to yeasts and hyphae of C. albicans were significantly lower (80% and 40%, respectively; P <0.05) than production by macrophages from wild-type mice. This impaired production of TNF-alpha and MIP-2 probably contributed to the 41% decreased recruitment of neutrophils to the peritoneal cavity…

TLR3-induced activation of mast cells modulates CD8+ T-cell recruitment.

2005

AbstractMast cells play an important role in host defense against various pathogens, but their role in viral infection has not been clarified in detail. dsRNA, synthesized by various types of viruses and mimicked by polyinosinic-polycytidylic acid (poly(I:C)) is recognized by Toll-like receptor 3 (TLR3). In this study, we demonstrate that poly(I:C) injection in vivo potently stimulates peritoneal mast cells to up-regulate a number of different costimulatory molecules. Therefore, we examined the expression and the functional significance of TLR3 activation in mast cells. Mast cells express TLR3 on the cell surface and intracellularly. After stimulation of mast cells with poly(I:C) and Newcas…

Toll-like receptors are part of the innate immune defense system of sponges (demospongiae: Porifera).

2006

During evolution and with the emergence of multicellular animals, the need arose to ward off foreign organisms that threaten the integrity of the animal body. Among many different receptors that participate in the recognition of microbial invaders, toll-like receptors (TLRs) play an essential role in mediating the innate immune response. After binding distinct microbial components, TLRs activate intracellular signaling cascades that result in an induced expression of diverse antimicrobial molecules. Because sponges (phylum Porifera) are filter feeders, they are abundantly exposed to microorganisms that represent a potential threat. Here, we describe the identification, cloning, and deduced …

Activation of the human immune system via toll-like receptors by the oncolytic parvovirus H-1.

2012

This study aimed to investigate the function of toll-like receptors (TLRs) during oncolytic parvovirus H-1 (H-1PV)-induced human immune responses. First, the role of TLRs in the activation of the NFκB transcription factor was characterized; second, the immunologic effects of H-1PV-induced tumor cell lysates (TCL) on human antitumor immune responses were evaluated. A human ex vivo model was used to study immune responses with dendritic cells (DCs). Human embryonic kidney cells (HEK293) transfected to stably express TLRs were used as potential human DC equivalents to further investigate the role of specific TLRs during immune activation. TLR3 and TLR9 were activated by H-1PV infection, which …

RNA mediated toll-like receptor stimulation in health and disease

2012

Besides their well known functions in storage and translation of information nucleic acids have emerged as a target of pattern recognition receptors that drive activation of innate immunity. Due to the paucity of building block monomers used in nucleic acids, discrimination of host and microbial nucleic acids as a means of self/foreign discrimination is a complicated task. Pattern recognition receptors rely on discrimination by sequence, structural features and spatial compartmentalization to differentiate microbial derived nucleic acids from host ones. Microbial nucleic acid detection is important for the sensing of infectious danger and initiating an immune response to microbial attack. F…

Genetics of Inflammation in Age-Related Atherosclerosis: Its Relevance to Pharmacogenomics

2007

In response to tissue injury elicited by trauma or infection, the inflammatory response, as a complex network of molecular and cellular interactions, sets an answer directed to facilitate a return to physiological homeostasis and tissue repair. The role of the genetic background and the subsequent predisposition toward the extent of the inflammatory response is determined by gene variability encoding endogenous mediators involved in the inflammatory pathway. Due to its clinical relevance, the genetics of inflammation in aging will be studied using an inflammatory disease like atherosclerosis as an example. Several studies have reported a significant difference in distribution, between patie…

Aging Successfully: The Role of Genetics and Environment in the Era of the Aging-Boom. Potential Therapeutic Implications

2019

Aging is one of the main health-related challenges in the world. The average life expectancy of the global population at birth is increasing up to 72 years, in 2016 and it increases about two years every decade. The healthcare costs in many countries are very high because of the increased number of unhealthy populations, and the consequent increase of severe age-related disabilities [1]. Therefore, the goal of the future should be the achievement of the so-called “health-span” (healthy-life-span), more than the treatment of age-related disease to prevent the collapse of the health system. In order to achieve this objective, it is necessary to identify new targets and biomarkers and to addre…

The many roads to inflammatory bowel diseases.

2006

Two independent studies by Rakoff-Nahoum et al. (2006) and Uhlig et al. (2006) in this issue of Immunity have illuminated a unique pathogenic role of innate immunity via Toll-like receptor and interleukin-23 signaling, respectively, in intestinal inflammation. These data define new roads to gut inflammation and future avenues for therapy.

Molecular approaches in autoimmunity and ageing: potential implications for future therapies.

My researches during my PhD were mainly focused on two aspects. The first one, was to study molecular aspects potentially implicated in autoimmunity pathogenesis, in order to identify new potential risk factors useful as therapeutic target. To this end, we focused on two severe and wasting systemic autoimmune diseases: systemic lupus erythematosus and systemic sclerosis. Pathogenesis of these diseases has still not clear and early diagnosis is difficult to identify because of complex and heterogeneous presentation of symptoms. A strong genetic association between HLA and disease susceptibility is well accept, nevertheless, other factors as oxidative stress, KIR and inflammatory cytokines ha…