Search results for "Acquired Immune System"

2019

Dendritic cells (DC) fulfill an essential sentinel function within the immune system, acting at the interface of innate and adaptive immunity. The DC family, both in mouse and man, shows high functional heterogeneity in order to orchestrate immune responses toward the immense variety of pathogens and other immunological threats. In this review, we focus on the Langerin+CD8+ DC subpopulation in the spleen. Langerin+CD8+ DC exhibit a high ability to take up apoptotic/dying cells, and therefore they are essential to prime and shape CD8+ T cell responses. Next to the induction of immunity toward blood-borne pathogens, i.e., viruses, these DC are important for the regulation of tolerance toward …

Plasma phospholipid transfer protein (PLTP) modulates adaptive immune functions through alternation of T helper cell polarization

2016

International audience; Objective: Plasma phospholipid transfer protein (PLTP) is a key determinant of lipoprotein metabolism, and both animal and human studies converge to indicate that PLTP promotes atherogenesis and its thromboembolic complications. Moreover, it has recently been reported that PLTP modulates inflammation and immune responses. Although earlier studies from our group demonstrated that PLTP can modify macrophage activation, the implication of PLTP in the modulation of T-cell-mediated immune responses has never been investigated and was therefore addressed in the present study. Approach and results: In the present study, we demonstrated that PLTP deficiency in mice has a pro…

Increased PD-1 Expression and Altered T Cell Repertoire Diversity Predict Mortality in Patients with Septic Shock: A Preliminary Study

2017

Sepsis causes impairment of innate and adaptive immunity by multiple mechanisms, including depletion of immune effector cells and T cell exhaustion. Although lymphocyte dysfunction is associated with increased mortality and potential reactivation of latent viral infection in patients with septic shock, the relation between viral reactivation and lymphocyte dysfunction is obscure. The objectives of this study were 1) to determine the relation of lymphocyte dysfunction to viral reactivation and mortality, and 2) to evaluate recovery of lymphocyte function during septic shock, including T cell receptor (TCR) diversity and the expression of programmed death 1 (PD-1). In 18 patients with septic …

The Anti-apoptotic Murine Cytomegalovirus Protein vMIA-m38.5 Induces Mast Cell Degranulation.

2020

Mast cells (MC) represent "inbetweeners" of the immune system in that they are part of innate immunity by acting as first-line sentinels for environmental antigens but also provide a link to adaptive immunity by secretion of chemokines that recruit CD8 T cells to organ sites of infection. An interrelationship between MC and cytomegalovirus (CMV) has been a blank area in science until recently when the murine model revealed a role for MC in the resolution of pulmonary infection by murine CMV (mCMV). As to the mechanism, MC were identified as a target cell type of mCMV. Infected MC degranulate and synthesize the CC-chemokine ligand-5 (CCL-5), which is released to attract protective virus-spec…

Gut dysbiosis and adaptive immune response in diet-induced obesity vs. Systemic inflammation

2017

A mutual interplay exists between adaptive immune system and gut microbiota. Altered gut microbial ecosystems are associated with the metabolic syndrome, occurring in most obese individuals. However, it is unknown why 10-25% of obese individuals are metabolically healthy, while normal weight individuals can develop inflammation and atherosclerosis. We modelled these specific metabolic conditions in mice fed with a chow diet, an obesogenic but not inflammatory diet - mimicking healthy obesity, or Paigen diet - mimicking inflammation in the lean subjects. We analysed a range of markers and cytokines in the aorta, heart, abdominal fat, liver and spleen, and metagenomics analyses were performed…

Identification of responders to immune checkpoint therapy: which biomarkers have the highest value?

2019

Evasion of immune recognition by the innate and acquired immune system is a major principle of tumour cells and belongs to the hallmarks of cancer. Immune checkpoint inhibitor-based cancer therapies targeting the co-inhibitory receptors CTLA-4 or PD-1 have received enormous scientific and clinical attention during the last few years, because of promising clinical results observed in the treatment of different cancer entities including melanoma and cutaneous squamous cell carcinoma. However, the enthusiasm about the effects of the immune checkpoint inhibitors is muted as only a subfraction of patients shows a stable clinical response. To predefine the patient cohorts that may benefit from im…

Distribution of macrophages and plasma cells in apical periodontitis and their relationship with clinical and image data

2017

BACKGROUND Macrophages and plasma cells play a key role in the regulation of innate and adaptive immunity. The aim of this study was to assess the presence of these cells in apical periodontitis and their distribution comparing with clinical and image data. MATERIAL AND METHODS Thirty-three lesions were selected and divided in two groups (17 periapical cysts and 16 periapical granulomas). Immunoreactions using anti-CD68 and anti-CD138 antibodies were carried out; image analysis was performed with an optical microscope and 5 high-power fields from each slide were evaluated leading to an average score of immunoexpression. This mean score was compared between the two groups and correlated with…

2021

BackgroundMultiple synergistic combination approaches with cancer drugs are developed to overcome primary resistance to immunotherapy; however, the mechanistic rationale to combine chemoradiotherapy (CRT) with immune checkpoint inhibitors remains elusive.MethodsThis study described the immunological landscape of tumor microenvironment (TME) exposed to CRT. Tumor samples from patients with rectal cancer (n=43) treated with neoadjuvant CRT or radiotherapy were analyzed by nanostring and immunohistochemistry. Studies in mice were performed using three syngeneic tumors (TC1, CT26 and MC38). Tumor-bearing mice were treated either with platinum-based CRT, radiotherapy or chemotherapy. Anti-CTLA-4…

BAX inhibitor-1 is a Ca(2+) channel critically important for immune cell function and survival.

2015

The endoplasmic reticulum (ER) serves as the major intracellular Ca(2+) store and has a role in the synthesis and folding of proteins. BAX (BCL2-associated X protein) inhibitor-1 (BI-1) is a Ca(2+) leak channel also implicated in the response against protein misfolding, thereby connecting the Ca(2+) store and protein-folding functions of the ER. We found that BI-1-deficient mice suffer from leukopenia and erythrocytosis, have an increased number of splenic marginal zone B cells and higher abundance and nuclear translocation of NF-κB (nuclear factor-κ light-chain enhancer of activated B cells) proteins, correlating with increased cytosolic and ER Ca(2+) levels. When put into culture, purifie…

Cnidarian Immunity and the Repertoire of Defense Mechanisms in Anthozoans

2020

Anthozoa is the most specious class of the phylum Cnidaria that is phylogenetically basal within the Metazoa. It is an interesting group for studying the evolution of mutualisms and immunity, for despite their morphological simplicity, Anthozoans are unexpectedly immunologically complex, with large genomes and gene families similar to those of the Bilateria. Evidence indicates that the Anthozoan innate immune system is not only involved in the disruption of harmful microorganisms, but is also crucial in structuring tissue-associated microbial communities that are essential components of the cnidarian holobiont and useful to the animal’s health for several functions including metabolism, imm…