Staphylococcus aureus-specific skin resident memory T cells protect against bacteria colonization but exacerbate atopic dermatitis-like flares in mice.

Background: The contribution of Staphylococcus aureus to the exacerbation of atopic dermatitis (AD) is widely documented, but its role as a primary trigger of AD skin symptoms remains poorly explored.

Objectives: This study sought to reappraise the main bacterial factors and underlying immune mechanisms by which S aureus triggers AD-like inflammation.

Methods: This study capitalized on a preclinical model, in which different clinical isolates were applied in the absence of any prior experimental skin injury.

Topical corticosteroids inhibit allergic skin inflammation but are ineffective in impeding the formation and expansion of resident memory T cells.

Background: Tissue-resident memory T (T ) cells are detrimental in allergic contact dermatitis (ACD), in which they contribute to the chronicity and severity of the disease.

Methods: We assessed the impact of a standard topical corticosteroid (TCS) treatment, triamcinolone acetonide (TA), on the formation, maintenance and reactivation of epidermal T cells in a preclinical model of ACD to 2,4-dinitrofluorobenzene. TA 0.

Epicutaneous allergen immunotherapy induces a profound and selective modulation in skin dendritic-cell subsets.

Background: Epicutaneous immunotherapy (EPIT) protocols have recently been developed to restore tolerance in patients with food allergy. The mechanisms by which EPIT protocols promote desensitization rely on a profound immune deviation of pathogenic T- and B-cell responses.

Objective: To date, little is known about the contribution of skin dendritic cells (skDCs) to T-cell remodeling and EPIT efficacy.

Unique molecular signatures typify skin inflammation induced by chemical allergens and irritants.

Background: Skin exposure to chemicals may induce an inflammatory disease known as contact dermatitis (CD). Distinguishing the allergic and irritant forms of CD often proves challenging in the clinic.

Methods: To characterize the molecular signatures of chemical-induced skin inflammation, we conducted a comprehensive transcriptomic analysis on the skin lesions of 47 patients with positive patch tests to reference contact allergens and nonallergenic irritants.

Massive clonal expansion of polycytotoxic skin and blood CD8 T cells in patients with toxic epidermal necrolysis.

Toxic epidermal necrolysis (TEN) is a life-threatening cutaneous adverse drug reaction. To better understand why skin symptoms are so severe, we conducted a prospective immunophenotyping study on skin and blood. Mass cytometry results confirmed that effector memory polycytotoxic CD8 T cells (CTLs) are the main leucocytes in TEN blisters at the acute phase.

Detection of skin alterations in mild-to-moderate chronic venous disease using non-invasive techniques.

Background: Chronic venous disease (CVD) is secondary to venous hypertension, leading to vascular inflammation and tissue changes. The impact of CVD on skin structure and barrier function is not well characterized.

Objective: We aimed to assess the characteristics of skin alterations in mild-to-moderate CVD by non-invasive techniques based on a prospective exploratory study.

IFN-γ extends the immune functions of Guanylate Binding Proteins to inflammasome-independent antibacterial activities during Francisella novicida infection.

Guanylate binding proteins (GBPs) are interferon-inducible proteins involved in the cell-intrinsic immunity against numerous intracellular pathogens. The molecular mechanisms underlying the potent antibacterial activity of GBPs are still unclear. GBPs have been functionally linked to the NLRP3, the AIM2 and the caspase-11 inflammasomes.

An Co-culture Mouse Model Demonstrates Efficient Vaccine-Mediated Control of SCHU S4 and Identifies Nitric Oxide as a Predictor of Efficacy.

is a highly virulent intracellular bacterium and cell-mediated immunity is critical for protection, but mechanisms of protection against highly virulent variants, such as the prototypic strain strain SCHU S4, are poorly understood. To this end, we established a co-culture system, based on splenocytes from naïve, or immunized mice and infected bone marrow-derived macrophages that allowed assessment of mechanisms controlling infection with . We utilized the system to understand why the gene deletion mutant, ΔB, of SCHU S4 shows superior efficacy as a vaccine in the mouse model as compared to the existing human vaccine, the live vaccine strain (LVS).

Francisella tularensis IglG Belongs to a Novel Family of PAAR-Like T6SS Proteins and Harbors a Unique N-terminal Extension Required for Virulence.

The virulence of Francisella tularensis, the etiological agent of tularemia, relies on an atypical type VI secretion system (T6SS) encoded by a genomic island termed the Francisella Pathogenicity Island (FPI). While the importance of the FPI in F. tularensis virulence is clearly established, the precise role of most of the FPI-encoded proteins remains to be deciphered.

Staphylococcus aureus infective endocarditis versus bacteremia strains: Subtle genetic differences at stake.

Infective endocarditis (IE)((1)) is a severe condition complicating 10-25% of Staphylococcus aureus bacteremia. Although host-related IE risk factors have been identified, the involvement of bacterial features in IE complication is still unclear. We characterized strictly defined IE and bacteremia isolates and searched for discriminant features.

High-throughput mycobacterial interspersed repetitive-unit-variable-number tandem-repeat genotyping for Mycobacterium tuberculosis epidemiological studies.

The emergence of drug-resistant forms of tuberculosis (TB) represents a major public health concern. Understanding the transmission routes of the disease is a key factor for its control and for the implementation of efficient interventions. Mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) marker typing is a well-described method for lineage identification and transmission tracking.