Inflammatory cytokines and their receptors in psoriatic skin : emphasis on the epidermal interleukin 1 system

Nearly two centuries have passed since the first accurate description of psoriasis by Wilan in the year 1808. Psoriasis is a common, well-defined skin disease featuring the interplay of genetic, environmental, and immunological factors. Extensive reviews on psoriasis are given elsewhere. Despite numerous reports, the exact etiology is still unknown. Moreover, 70 % of psoriatic patients are not satisfied with the currently available anti-psoriatic treatments (Gottlieb AB, oral presentation, Psoriasis Meeting, Dec 4-5 1995, Lake Buena Vista, FL), which stresses the contemporary societal interest of psoriasis research. Recent studies have identified a dysregulated crosstalk between resident skin cells and infiltrating leukocytes in psoriasis. Several lines of evidence point to the cytokine interleukin 1 (IL-l) as an integral component of the cellular immune basis of psoriasis. The regulation of cytokine activity in general, and that of epidermal IL-l in particular, is described in chapter 1.1. Skin as a site of immune responses, exemplified by the cutaneous inflammatory response, is described in chapter 1.2. Finally, the cellular immunopathogenesis of psoriasis, with special emphasis on IL-l, is reviewed in chapter 1.3

Engineering T cells for adoptive therapy: outsmarting the tumor

Adoptive transfer of T cells gene-engineered with antigen-specific receptors, whether it be chimeric antigen receptors (CARs) or T cell receptors (TCRs), has proven its feasibility and therapeutic potential in the treatment of tumors. Despite clinical successes, the majority of patients experiences no or non-sustainable clearance of solid tumors, which is attributed to local T cell evasive mechanisms. A rapidly expanding understanding of molecular and cellular events that contribute to a reduction in numbers and/or activation of intra-tumor T cells has facilitated the development of gene-engineering strategies, enabling T cells to counter immune tolerance. Here, we present an overview of gene-engineering appro

T cell retargeting with MHC class I-restricted antibodies: the CD28 costimulatory domain enhances antigen-specific cytotoxicity and cytokine production

T cells require both primary and costimulatory signals for optimal activation. The primary Ag-specific signal is delivered by engagement of the TCR. The second Ag-independent costimulatory signal is mediated by engagement of the T cell surface costimulatory molecule CD28 with its target cell ligand B7. However, many tumor cells do not express these costimulatory molecules. We previously constructed phage display derived F(AB), G8, and Hyb3, Ab-based receptors with identical specificity but distinct affinities for HLA-A1/MAGE-A1, i.e., "TCR-like" specificity. These chimeric receptors comprised the FcepsilonRI-gamma signaling element. We analyzed whether linking the CD28 costimulation structure to it (gamma + CD28) could affect the levels of MHC-restricted cytolysis and/or cytokine production. Human scFv-G8(POS) T lymphocytes comprising the gamma + CD28 vs the gamma signaling element alone produced substantially more IL-2, TNF-alpha, and IFN-gamma in response to HLA-A1/MAGE-A1(POS) melanoma cells. Also a drastic increase in cytolytic capacity of scFv-G8(POS) T cells, equipped with gamma + CD28 vs the gamma-chain alone was observed

Enhanced production of biologically active interleukin-1α and interleukin-1β by psoriatic epidermal cells ex vivo: Evidence of increased cytosolic interleukin-1β levels and facilitated interleukin-1 release

The expression of interleukin (IL)-1 is altered in psoriatic lesions. However, little is known about the actual production of IL-1α and IL-1β by psoriatic epidermal cells (EC). We monitored IL-1 in the extracellular, the membrane and the intracellular compartment of freshly isolated EC from untreated lesional psoriatic (PP) and normal healthy (NN) skin during non-stimulated short-term cultures, representing a psoriasis model ex vivo. Cytokines were measured using bioassays combined with neutralizing antibodies and enzyme-linked immunosorbent assay in parallel. PP EC released significantly increased amounts of biologically active IL-1α and IL-1β in a ratio of 3:1, whereas NN EC only released IL-1α. Also, the release of IL-6, but not of TNF-α, by PP EC was significantly increased. Membrane-associated IL-1 activity, analyzed using glutaraldehydefixed EC, was low and not unique to PP EC. The cytosol of PP EC contained significantly increased levels of immunoreactive IL-1β. Furthermore, PP EC displayed loss of membrane integrity, as determined by trypan blue exclusion and release of cytosolic lactate dehydrogenase. This facilitated release of intracellular IL-1. Depletion of CD45+ cells showed that intraepidermal leukocytes did not contribute to the production of IL-1. Our observations show that resident PP EC express enhanced IL-1 production ex vivo, which is due to an increased cytosolic IL-1β content and facilitated IL-1 release. This study provides the first evidence that PP EC can produce bioactive IL-1β

T Cell Maturation Stage Prior to and During GMP Processing Informs on CAR T Cell Expansion in Patients

textabstractAutologous T cells were genetically modified to express a chimeric antigen receptor (CAR) directed toward carboxy-anhydrase-IX (CAIX) and used to treat patients with CAIX-positive metastatic renal cell carcinoma. In this study, we questioned whether the T cell maturation stage in the pre-infusion product affected CAIX CAR expression and function in vitro as well as in vivo CAR T cell numbers and expansion. During the 14 days expansion of CAR T cells prior to administration, we observed shifts from a predominant CD4 to a CD8 T cell phenotype and from a significant fraction of naïve to central effector T cells. Surface expression of the CAR was equally distributed among different T cell subsets and T cell maturation stages. During T cell culture days 14-18 (which covered patient treatment days 1-5), T cells demonstrated a decline in CAR expression level per cell irrespective of T cell maturation stage, although the proportion of CAR-positive T cells and CAR-mediated T cell effector functions remained similar for both CD4 and CD8 T cell populations. Notably, patients with a higher fraction of naïve CD8 T cells at baseline (prior to genetic modification) or central effector CD8 T cells at 2 weeks of CAR T cell culture demonstrated a higher fold expansion and absolute numbers of circulating CAR T cells at 1 month after start of therapy. We conclude that the T cell maturation stage prior to and during CAR T cell expansion culture is related to in vivo CAR T cell expansion

T cell receptor fused to CD3ζ: Transmembrane domain of CD3ζ prevents TCR mis-pairing, whereas complete CD3ζ directs functional TCR expression

TCR gene therapy represents a feasible and promising treatment for patients with cancer and virus infections. Currently, this treatment rationale is hampered by diluted surface expression of the TCR transgene and generation of potentially self reactive T-cells, both a direct consequence of mis-pairing with endogenous TCR chains. As we reported previously (Gene Ther 16:1369, 2000; J Immunol 180:7736, 2008), TCR mis-pairing can be successfully addressed by a TCR:CD3ζ fusion protein (i.e., TCR:ζ). Here, we set out to minimize the content of CD3ζ in TCR:ζ, specific for MAGEA1/ HLA-A1, without compromising TCR pairing and function. Domain-exchange and 3D-modeling strategies defined a set of minimal TCR:ζ variants, which, together with a murinized and cysteine-modified TCR (TCR:mu+cys), were tested for functional TCR expression and TCR pairing. Our data with Jurkat T cells show that the CD3ζ transmembrane domain is important for cell-surface expression, whereas the CD3ζ intracellular domain is crucial for T-cell activation. Notably, inability of TCR:ζ to mis-pair was not observed for TCR:mu+cys, which depended exclusivel

Enhanced recruitment of genetically modified CX3CR1-positive human T cells into Fractalkine/CX3CL1 expressing tumors: Importance of the chemokine gradient

Background: Adoptive T-cell based immunotherapies constitute a promising approach to treat cancer, however, a major problem is to obtain effective and long-lasting anti-tumor responses. Lack of response may be due to insufficient trafficking of specific T cells to tumors. A key requirement for efficient migration of cytotoxic T cells is that they express chemokine receptors that match the chemokines produced by tumor or tumor-associated cells. Methods: In this study, we investigated whether the in vivo tumor trafficking of activated T cells could be enhanced by the expression of the chemokine receptor CX3CR1. Two human colorectal cancer cell lines were used to set up a xenograft tumor model in immunodeficient mice; the NCI-H630, constitutively expressing the chemokine ligand CX3CL1 (Fractalkine), and the RKO cell line, transduced to express CX3CL1. Results: Human primary T cells were transduced with the receptor CX3CR1-eGFP. Upon in vivo adoptive transfer of genetically modified CX3CR1-T cells in mice bearing NCI-H630 tumors, enhanced lymphocyte migration and tumor trafficking were observed, compared to mice receiving Mock-T cells, indicating improved homing ability towards ligand-expressing tumor cells. Furthermore, significant inhibition of tumor growth was found in mice receiving modified CX3CR1-T cells. In contrast, tumors formed by RKO cells transduced with the ligand (RKO-CX3CL1) were not affected, nor more infiltrated upon transfer of CX3CR1-T lymphocytes, likely because high levels of the chemokine were shed by tumor cells in the systemic circulation, thus nullifying the blood-tissue chemokine gradient. Conclusions: This study demonstrates that ectopic express