Clinical and experimental immunology
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Clin. Exp. Immunol. · Aug 2011
Modulation of CD4⁺ T cell responses following splenectomy in hepatitis C virus-related liver cirrhosis.
Dysfunction of T cells is a common feature in chronic persistent viral infections, including hepatitis C virus (HCV), and although hepatic and peripheral T cells have been studied extensively in chronic HCV hepatitis, the role of splenic T cell responses in such patients is poorly defined. This is an important issue, as thrombocytopenia is a complication of HCV-related liver cirrhosis (LC), due to splenic platelet sequestration and bone marrow suppression; splenectomy has been proposed to treat such patients. Herein, we studied peripheral blood mononuclear cells (PBMC) and splenic lymphoid subpopulations from a total of 22 patients, including 15 with HCV-related LC with marked thrombocytopenia treated with splenectomy, and seven controls. ⋯ Blocking of PD-1/PD-1 ligand interaction reconstituted proliferative and cytokine responses of splenic mononuclear cells (SMC) from patients with LC. Splenectomy was followed by an increase in the ratio of interferon (IFN)-γ to interleukin (IL)-10 and a reduction of PD-1-expressing CD4(+) T cells in peripheral blood. Our data suggest that peripheral tolerance is promoted by the spleen in LC via the up-regulated expression of PD-1 ligands.
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Clin. Exp. Immunol. · May 2011
Review Historical ArticleWhat does the future hold for clinical studies in vasculitis?
The era prior to 1990 was a time of careful observation of disease presentation, course, outcomes and meticulous pathology studies. These mainly single-centre studies introduced new life-saving therapies for drugs still used effectively today. In the 1970-1980s, cyclophosphamide (CyP) added to glucocorticosteroids (GCS) was shown to be life-saving. ⋯ Unmet needs and strategies are as follows: (1) to increase the numbers of vasculitis-trained physicians; (2) to define risk-benefit formulae for chronic maintenance therapy versus discontinuation of treatment after remission; (3) to define risk- and cost-benefit formulae for laboratory monitoring; (4) large-scale studies with longer follow-up that explore inhibition of interleukin-5 in CSS; (5) to explore the value of anti-interferon-γ for GCA, Takayasu's and other granulomatous vasculitides; and (6) identification of aetiological factors: cures will probably be linked to knowledge of the antigen driving the disease, plus vulnerabilities of the patient that prepare them to develop an illness phenotype. Improved outcomes using anti-inflammatory/immunosuppressive agents do not rule out infection as a driver for autoimmunity. Techniques that can facilitate pathogen discovery have never been more sophisticated.
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Clin. Exp. Immunol. · Apr 2011
Induction of β-defensins by l-isoleucine as novel immunotherapy in experimental murine tuberculosis.
Tuberculosis is a worldwide health problem, and multidrug-resistant (MDR) and extensively multidrug-resistant (XMDR) strains are rapidly emerging and threatening the control of this disease. These problems motivate the search for new treatment strategies. One potential strategy is immunotherapy using cationic anti-microbial peptides. ⋯ Administration of l-isoleucine induced a significant increase of beta-defensins 3 and 4 which was associated with decreased bacillary loads and tissue damage. This was seen in animals infected with the antibiotic-sensitive strain H37Rv and with the MDR clinical isolate. Thus, induction of beta-defensins might be a potential therapy that can aid in the control of this significant infectious disease.
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Clin. Exp. Immunol. · Apr 2011
Elevated blood levels of inflammatory monocytes (CD14+ CD16+ ) in patients with complex regional pain syndrome.
Complex regional pain syndrome (CRPS) is a chronic pain disorder. Although its pathophysiology is not completely understood, neurogenic inflammation is thought to play a significant role. Microglia and astrocytes are activated following tissue injury or inflammation and have been reported to be both necessary and sufficient for enhanced nociception. ⋯ Our data cannot determine whether CD14(+) CD16(+) monocytes became elevated prior to or after developing CRPS. In either case, the elevation of blood proinflammatoty monocytes prior to the initiating event may predispose individuals for developing the syndrome whereas the elevation of blood proinflammatory monocytes following the development of CRPS may be relevant for its maintenance. Further evaluation of the role the immune system plays in the pathogenesis of CRPS may aid in elucidating disease mechanisms as well as the development of novel therapies for its treatment.
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Clin. Exp. Immunol. · Mar 2011
Selective expansion of merocytic dendritic cells and CD8DCs confers anti-tumour effect of Fms-like tyrosine kinase 3-ligand treatment in vivo.
Vaccination with autologous cancer cells aims to enhance adaptive immune responses to tumour-associated antigens. The incorporation of Fms-like tyrosine kinase 3-ligand (FLT3L) treatment to the vaccination scheme has been shown previously to increase the immunogenicity of cancer vaccines, thereby enhancing their therapeutic potential. While evidence has been provided that FLT3L confers its effect through the increase of absolute dendritic cell (DC) numbers, it is currently unknown which DC populations are responsive to FLT3L and which effect FLT3L treatment has on DC functions. ⋯ While both DC populations effectively primed CD8(+) T cell responses to cell-associated antigens, only mcDC were capable to prime CD4(+) T cells to cell-associated antigens. Consequentially, the transfer of tumour vaccine-pulsed mcDC, but not of CD8 DCs, protected mice from subsequent tumour challenge in a vaccination model and resulted in eradication of established tumours in a therapeutic approach. These results show that the beneficial effect of FLT3L is associated with the induction of mcDC and suggests that selective targeting to mcDC or instilling mcDC 'characteristics' into conventional DC populations could significantly enhance the efficacy of tumour vaccines.