Lymphocytic infiltration in the cutaneous lymphoma microenvironment after injection of TG1042.

BACKGROUND: Primary cutaneous lymphomas (CLs), characterized by an accumulation of clonal T or B lymphocytes preferentially localized in the skin, have been successfully treated with interferons (IFNs) which counterbalance the Th2-immunosuppressive state associated with this pathology. In a phase I/II clinical trial, we correlated the local immune infiltrate and the anti-tumor effects of repeated intralesional administrations of an adenovirus vector expressing human interferon-gamma (IFN-g) termed TG1042, in patients with advanced primary cutaneous T-cell lymphomas (CTCL) or multilesional cutaneous B-cell lymphomas (CBCL). METHODS: For each patient, variation in time of specific lymphocyte populations, defined by immunohistochemical stainings, was assessed in biopsies of injected lesions. For each patient, the change in local immune response was associated with the patient's objective response at the end of the study. RESULTS: Immunohistochemical analyses of biopsies indicate that infiltration of CD8+ T lymphocytes and of TIA-1+ cytotoxic T-cells in lesions injected with TG1042 correlates with clinical benefit. CONCLUSIONS: These data suggest for the first time that a CD8+ cytotoxic infiltrate, induced by local expression of IFN-g correlates with a clinical response. TRIAL REGISTRATION: The phase I step (TG1042.01) does not have a registration number. The phase II step (TG1042.06) registration number was NCT00394693.

Robust post-translocational N-glycosylation at the extreme C-terminus of membrane and secreted proteins in Xenopus laevis oocytes and HEK293 cells.

N-Glycosylation is normally a co-translational process that occurs as soon as a nascent and unfolded polypeptide chain has emerged ~12 residues into the lumen of the endoplasmic reticulum (ER). Here, we describe the efficient utilization of an N-glycosylation site engineered within the luminal extreme C-terminal residues of distinct integral membrane glycoproteins, a native ER resident protein and an engineered secreted protein. This N-glycan addition required that the acceptor asparagine within an Asn-Trp-Ser sequon be located at least four residues away from the C-terminus of the polypeptide and, in the case of membrane proteins, at least 13 residues away from the lumenal side of the transmembrane segment. Pulse-chase assays revealed that the natural N-glycans of the proteins studied were attached co-translationally, whereas C-terminal N-glycosylation occurred post-translocationally within a time frame of hours in Xenopus laevis oocytes and minutes in human embryonic kidney 293 (HEK293) cells. In oocyte and HEK cell expression systems, affinity tag-driven C-terminal N-glycosylation may facilitate the determination of orientation of the C-terminal tail of membrane proteins relative to the membrane.

The use of thermal imaging in evaluating musculoskeletal disorders in dentists.

Musculoskeletal disorders (MSDs) caused by incorrect working positions among dentists is a serious health issue and one that leads to decreased productivity and quality of life. Muscle activity and strain is correlated with higher surface temperatures due to increased metabolic activity [2]. The main objective of this study is to evaluate, using thermal imaging, the muscular strain experienced by oral healthcare professionals during work depending on their position, and to assess whether periodic stretching exercises have an impact on preventing MSDs. The study included four subjects and used thermal imaging to evaluate the heat pattern produced by muscle strain in two different states, one while working in incorrect postures and the other after performing stretching exercises. We used a FLIRB200 thermal imaging camera to measure skin surface temperature changes of the underlining muscles in the cervical, right arm triceps, and lumbar areas. According to the imaging, all four subjects recorded a drop in temperature in evaluated muscle regions after performing stretching exercises, corresponding to a decrease in muscle strain. Thermal imaging can be effectively used to evaluate muscle strain and MSDs. Stretching exercises could be viewed as effective preventive measures to avoid MSDs caused by erroneous work postures, however, more subjects are required to draw a definite conclusion.

Trimeric architecture of homomeric P2X2 and heteromeric P2X1+2 receptor subtypes.

Of the three major classes of ligand-gated ion channels, nicotinic receptors and ionotropic glutamate receptors are known to be organized as pentamers and tetramers, respectively. The architecture of the third class, P2X receptors, is under debate, although evidence for a trimeric assembly is accumulating. Here we provide biochemical evidence that in addition to the rapidly desensitising P2X1 and P2X3 receptors, the slowly desensitising subtypes P2X2, P2X4, and P2X5 are trimers of identical subunits. Similar (heteromeric) P2X subunits also formed trimers, as shown for co-expressed P2X1 and P2X2 subunits, which assembled efficiently to a P2X1+2 receptor that was exported to the plasma membrane. In contrast, P2X6 subunits, which are incapable of forming functional homomeric channels in Xenopus oocytes, were retained in the ER as apparent tetramers and high molecular mass aggregates. Altogether, we conclude from these data that a trimeric architecture is the structural hallmark of functional homomeric and heteromeric P2X receptors.

Conditional ablation of integrin alpha-6 in mouse epidermis leads to skin fragility and inflammation.

Hemidesmosomes (HDs) are essential anchorage junctions which mediate the firm attachment of epithelia to the underlying basement membranes, of which one main component is the integrin α6ß4. These specific junctions are also able to trigger signalling pathways, via the recruitment and interactions of signalling molecules with HD components such as the cytoplasmic tail of the ß4 integrin or the plakin plectin. HDs must also assemble and disassemble depending on the tissue context for example during tissue remodelling. Alterations of HD components or their loss result in skin blistering disorders known as epidermolysis bullosa. Since mice lacking integrin α6 die at birth with severe skin blistering, we have produced a mouse line in which epidermal deletion of integrin α6 can be controlled by tamoxifen injection. We observed that the deletion was mosaic, but that hairless skin such as ears, tails and paws were affected and showed chronic inflammation associated with hyperproliferation, and expression of laminin-111. Interestingly, two cytokines, amphiregulin and epiregulin, previously found increased in integrin α6 deficient cultured keratinocytes, were also increased here in the affected skin. In detached areas, we validate clearly that the absence of integrin α6 leads to a delocalisation of plectin, and the complete disappearance of HD structures.