Protection against Cutaneous Leishmaniasis in Outbred Vervet Monkeys, Using a Recombinant Histone H1 Antigen

Infection with Leishmania major parasites results in the development of cutaneous ulcerative lesions on the skin. We investigated the protective potential of a single, recombinant histone H1 antigen against cutaneous leishmaniasis in an outbred population of vervet monkeys, using Montanide adjuvant. Protection was assessed by challenging the animals with a mixture of vector sand fly salivary-gland lysate and a low dose of in vitro-derived parasites, thus more closely mimicking natural infection induced by L. major. The course of infection in immunized monkeys was compared with that of animals that had healed from a primary infection and were immune. The monkeys immunized with recombinant histone H1 showed a reduced development of lesion size, compared with controls. Our study therefore illustrates the potential use of histone H1 as a vaccine candidate against cutaneous leishmaniasis in human

Biological activity of ectodysplasin A is conditioned by its collagen and heparan sulfate proteoglycan-binding domains.

Mutations in the TNF family ligand EDA1 cause X-linked hypohidrotic ectodermal dysplasia (XLHED), a condition characterized by defective development of skin appendages. The EDA1 protein displays a proteolytic processing site responsible for its conversion to a soluble form, a collagen domain, and a trimeric TNF homology domain (THD) that binds the receptor EDAR. In-frame deletions in the collagen domain reduced the thermal stability of EDA1. Removal of the collagen domain decreased its activity about 100-fold, as measured with natural and engineered EDA1-responsive cell lines. The collagen domain could be functionally replaced by multimerization domains or by cross-linking antibodies, suggesting that it functions as an oligomerization unit. Surprisingly, mature soluble EDA1 containing the collagen domain was poorly active when administered in newborn, EDA-deficient (Tabby) mice. This was due to a short stretch of basic amino acids located at the N terminus of the collagen domain that confers EDA1 with proteoglycan binding ability. In contrast to wild-type EDA1, EDA1 with mutations in this basic sequence was a potent inducer of tail hair development in vivo. Thus, the collagen domain activates EDA1 by multimerization, whereas the proteoglycan-binding domain may restrict the distribution of endogeneous EDA1 in vivo

High-throughput sequencing of the T-cell receptor repertoire: pitfalls and opportunities.

T-cell specificity is determined by the T-cell receptor, a heterodimeric protein coded for by an extremely diverse set of genes produced by imprecise somatic gene recombination. Massively parallel high-throughput sequencing allows millions of different T-cell receptor genes to be characterized from a single sample of blood or tissue. However, the extraordinary heterogeneity of the immune repertoire poses significant challenges for subsequent analysis of the data. We outline the major steps in processing of repertoire data, considering low-level processing of raw sequence files and high-level algorithms, which seek to extract biological or pathological information. The latest generation of bioinformatics tools allows millions of DNA sequences to be accurately and rapidly assigned to their respective variable V and J gene segments, and to reconstruct an almost error-free representation of the non-templated additions and deletions that occur. High-level processing can measure the diversity of the repertoire in different samples, quantify V and J usage and identify private and public T-cell receptors. Finally, we discuss the major challenge of linking T-cell receptor sequence to function, and specifically to antigen recognition. Sophisticated machine learning algorithms are being developed that can combine the paradoxical degeneracy and cross-reactivity of individual T-cell receptors with the specificity of the overall T-cell immune response. Computational analysis will provide the key to unlock the potential of the T-cell receptor repertoire to give insight into the fundamental biology of the adaptive immune system and to provide powerful biomarkers of disease

Variability of CD3 membrane expression and T cell activation capacity

αβT cells have a wide distribution of their CD3 membrane density. The aim of this paper was to evaluate the significance of the CD3 differential expression on T cell subsets. Analysis was performed on healthy donors and renal transplant patients by flowcytometry The results obtained are : 1-CD3 expression was widely distributed (CV =38.3±3.1 to (43±2.3%). 2-The CD4, CD8,CD45 and forward scatter were similarly distributed. 3-The diversity of CD3 expression was direcly related to the clonotypes: γ9, non γ9 from γδT cells and Vβ clonotype from αβT cells (e.g.: Vβ3FITC 7980±1628 Vβ8PE: Vβ20-FITC 11768±1510). 4-Using a computer simulation, we could confirm differential kinetics of T cell activation according to the initial parameters. Finally, in vitro activation was significantly higher on Vβ8 and Vβ9 (high CD3) compared to Vβ2 and Vβ3 (low CD3, P=0.040 to 0.0003). In conclusion: T cells have highly heterogeneous CD3 expression, possibly predetermined and with clear functional significance

Le processus seigneurial en zone royale bourguignonne : l’exemple des Mont (ixe-xie siècle)

Mieux documentée que d’autres puissantes parentèles, les Mont permettent d’étudier les modalités de la transformation des élites rodolphiennes et paraissent vérifier tous les critères de la seigneurialisation avec une nette spatialisation : l’émergence d’une catégorie, qui, non seulement cumule la supériorité foncière, sociale et militaire – ce en quoi elle ne diffère pas des élites carolingiennes –, mais de façon limitée dans l’espace, plus ou moins exclusive, permanente sur la longue durée et indépendante de la fonction distributrice du souverain.Toutefois, cet apparent cas d’école de l’émergence de lignages seigneuriaux au tournant des xe et xie siècles entre en contradiction avec la perception (nouvelle) d’un royaume de Bourgogne solidement organisé, surtout dans la zone royale où vivent les Mont. Ceux-ci illustrent alors les ambiguïtés et les spécificités de la Transjurane des années 1000 : une transition inaboutie, dans un monde toujours dominé par des hiérarchies issues du modèle royal

Class II MHC Self-Antigen Presentation in Human B and T Lymphocytes

Human CD4[superscript +] T cells process and present functional class II MHC-peptide complexes, but the endogenous peptide repertoire of these non-classical antigen presenting cells remains unknown. We eluted and sequenced HLA-DR-bound self-peptides presented by CD4[superscript +] T cells in order to compare the T cell-derived peptide repertoire to sequences derived from genetically identical B cells. We identified several novel epitopes derived from the T cell-specific proteome, including fragments of CD4 and IL-2. While these data confirm that T cells can present peptides derived from the T-cell specific proteome, the vast majority of peptides sequenced after elution from MHC were derived from the common proteome. From this pool, we identified several identical peptide epitopes in the T and B cell repertoire derived from common endogenous proteins as well as novel endogenous epitopes with promiscuous binding. These findings indicate that the endogenous HLA-DR-bound peptide repertoire, regardless of APC type and across MHC isotype, is largely derived from the same pool of self-protein.National Institutes of Health (U.S.) (grant P01AI039671)National Institutes of Health (U.S.) (P01AI045757

Protection against cutaneous leishmaniasis in outbred vervet monkeys using a recombinant histone H1 antigen.

Infection with Leishmania major parasites results in the development of cutaneous ulcerative lesions on the skin. We investigated the protective potential of a single, recombinant histone H1 antigen against cutaneous leishmaniasis in an outbred population of vervet monkeys, using Montanide adjuvant. Protection was assessed by challenging the animals with a mixture of vector sand fly salivary-gland lysate and a low dose of in vitro-derived parasites, thus more closely mimicking natural infection induced by L. major. The course of infection in immunized monkeys was compared with that of animals that had healed from a primary infection and were immune. The monkeys immunized with recombinant histone H1 showed a reduced development of lesion size, compared with controls. Our study therefore illustrates the potential use of histone H1 as a vaccine candidate against cutaneous leishmaniasis in humans