{"title":"Regulatory T cells in pregnancy.","authors":"Ana Claudia Zenclussen","doi":"10.1007/s00281-006-0023-6","DOIUrl":"https://doi.org/10.1007/s00281-006-0023-6","url":null,"abstract":"<p><p>Tolerance mechanisms are responsible for the survival of the fetus within the maternal uterus without being attacked by the cells of the maternal immune system despite their direct contact. Regulatory T cells (Treg) were claimed to be important players in the tolerance towards the fetus bearing alloantigens. Recent evidence confirmed an augmentation in the number of Treg during pregnancy and, most importantly, diminished numbers of Treg were associated with immunological rejection of the fetus. This could be prevented by adoptively transferring CD4(+)/CD25(+) Treg cells from normal pregnant mice into abortion-prone animals. Treg prevented abortion while creating a transient tolerant microenvironment characterized by high levels of TGF-beta, LIF, and HO-1. Downregulated levels of Treg were accordingly also reported during human miscarriage. Furthermore, we have evidence suggesting that, to be protective, Treg need to be activated by male antigens during pregnancy.</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"28 1","pages":"31-9"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00281-006-0023-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26143739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The role of virus-induced regulatory T cells in immunopathology.","authors":"Shelly J Robertson, Kim J Hasenkrug","doi":"10.1007/s00281-006-0019-2","DOIUrl":"10.1007/s00281-006-0019-2","url":null,"abstract":"<p><p>In recent years, regulatory T cells have received increased attention for their role in immune responses to microbial infections. The list of microbial pathogens associated with regulatory T cell responses is growing rapidly and includes bacteria, viruses, parasites, and fungi. As the biology of regulatory T cells is revealed, we are discovering that their induction during infection is a normal aspect of immunity, necessary to limit collateral damage from inflammatory responses and aggressive immunological effectors. Thus, these cells play a critical role in maintaining the delicate balance between preventing immunopathology and allowing the immune response to clear infections. While generally successful, there are notable exceptions where regulatory T cell-mediated suppression appears to be responsible for allowing certain viruses to establish and maintain a persistent state. In this review, we will discuss our current understanding of what virus-induced regulatory T cells are, how they are induced, and what mechanisms they use to suppress immunity. The complex role of Tregs in regulating immunity to viral infections, and the consequences their activity has on disease is illustrated by a review of specific viral infections including hepatitis C virus and human immunodeficiency virus.</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"28 1","pages":"51-62"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7079961/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26144698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Regulatory T cells and innate immune regulation in tumor immunity.","authors":"Rong-Fu Wang","doi":"10.1007/s00281-006-0022-7","DOIUrl":"https://doi.org/10.1007/s00281-006-0022-7","url":null,"abstract":"<p><p>Innate and adaptive immunity play important roles in immunosurveillance and tumor destruction. However, increasing evidence suggests that tumor-infiltrating immune cells may have a dual function: inhibiting or promoting tumor growth and progression. Although regulatory T (Treg) cells induce immune tolerance by suppressing host immune responses against self- or nonself-antigens, thus playing critical roles in preventing autoimmune diseases, they might inhibit antitumor immunity and promote tumor growth. Recent studies demonstrate that elevated proportions of Treg cells are present in various types of cancers and suppress antitumor immunity. Furthermore, tumor-specific Treg cells can inhibit immune responses only when they are exposed to antigens presented by tumor cells. Therefore, Treg cells at tumor sites have detrimental effects on immunotherapy directed to cancer. This review will discuss recent progress in innate immunity, Treg cells, and their regulation through Toll-like receptor (TLR) signaling. It was generally thought that TLR-mediated recognition of specific structures of invading pathogens initiate innate and adaptive immune responses through dendritic cells. New evidence suggests that TLR signaling may directly regulate the suppressive function of Treg cells. Linking TLR signaling to the functional control of Treg cells opens intriguing opportunities to manipulate TLR signaling to control both innate and adaptive immunity against cancer.</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"28 1","pages":"17-23"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00281-006-0022-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26142696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Regulatory T cells in experimental autoimmune disease.","authors":"Elisabeth Suri-Payer, Benedikt Fritzsching","doi":"10.1007/s00281-006-0021-8","DOIUrl":"https://doi.org/10.1007/s00281-006-0021-8","url":null,"abstract":"<p><p>During the past 10 years, CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) have been extensively studied for their function in autoimmune disease. This review summarizes the evidence for a role of Treg in suppression of innate and adaptive immune responses in experimental models of autoimmunity including arthritis, colitis, diabetes, autoimmune encephalomyelitis, lupus, gastritis, oophoritis, prostatitis, and thyroiditis. Antigen-specific activation of Treg, but antigen-independent suppressive function, emerges as a common paradigm derived from several disease models. Treg suppress conventional T cells (Tcon) by direct cell contact in vitro. However, downmodulation of dendritic cell function and secretion of inhibitory cytokines such as IL-10 and TGF-beta might underlie Treg function in vivo. The final outcome of autoimmunity vs tolerance depends on the balance between stimulatory signals (Toll-like receptor engagement, costimulation, and antigen dose) and inhibitory signals from Treg. Whereas most experimental settings analyze the capacity of Treg to prevent onset of autoimmune disease, more recent efforts indicate successful treatment of ongoing disease. Thus, Treg are on the verge of moving from experimental animal models into clinical applications in humans.</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"28 1","pages":"3-16"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00281-006-0021-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26142697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jocelyne Demengeot, Santiago Zelenay, Maria Francisca Moraes-Fontes, Iris Caramalho, António Coutinho
{"title":"Regulatory T cells in microbial infection.","authors":"Jocelyne Demengeot, Santiago Zelenay, Maria Francisca Moraes-Fontes, Iris Caramalho, António Coutinho","doi":"10.1007/s00281-006-0024-5","DOIUrl":"https://doi.org/10.1007/s00281-006-0024-5","url":null,"abstract":"<p><p>Natural T regulatory cells (NatTReg) limit immunopathology and protective immune responses induced upon microbial infection. In addition, infection increases the number and activity of NatTReg. These findings need to be conciliated with the process of 'self-nonself' discrimination based on the function of NatTReg committed intrathymically and positively selected (and activated) on thymic epithelial cells. A review of the available evidence comforts the assumptions that, in physiological conditions, NatTReg engaged in the immune responses to microbial infections are drawn from the autoreactive repertoire even if some may appear to be microbe specific. This contention also provides a suitable explanation for the 'hygiene hypothesis': infections re-enforce the physiological mechanisms of natural dominant tolerance, through the expansion of naturally occurring regulatory T cells. Accumulating evidence demonstrates that pro-inflammatory ligands of Toll-like receptors expressed by NatTReg, both of microbial (e.g., lipopolysaccharide, flagellin, peptidoglycans) and endogenous (e.g., stress proteins and degradation products of the extracellular matrix) origin, may play a critical role in their activation and expansion. As NatTReg vigorously respond to IL-2/IL-15 locally produced by ongoing effector responses, this whole set of mechanisms provides for a robust feedback process that limits tissue damage and accounts for an 'organism-centered' quality control of immune responses. Detailed knowledge on these molecular and cellular bases should open novel opportunities for intervention in a variety of critical conditions, such as autoimmunity, allergy, chronic infections, and cancer, for which we currently lack effective therapies.</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"28 1","pages":"41-50"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00281-006-0024-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26171054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Biological therapies directed against cells in autoimmune disease.","authors":"Paul Hasler","doi":"10.1007/s00281-006-0013-8","DOIUrl":"https://doi.org/10.1007/s00281-006-0013-8","url":null,"abstract":"<p><p>Among the cells of the immune system involved in the pathogenesis of autoimmune disease, T cells have received the most attention. The central role of these cells in several animal models of autoimmune diseases and in human disease counterparts has provided the rationale for specific therapeutic targeting of T cell subsets, especially CD4 T cells. So far, the applicability of this approach has not been clearly evident in clinical trials, which was also the case when nondepleting \"coating\" anti-CD4 monoclonal antibodies was used. In the past several years, experimental evidence supporting a major role of B cells in systemic autoimmune disease has grown. This includes the pathogenicity of certain autoantibodies, the potential of B cells to present antigen in the context of MHC Class II and to signal via costimulatory molecules, and to secrete proinflammatory cytokines. In some instances, engagement of the B cell receptor and other surface receptors is sufficient to stimulate B cells to produce antibodies. The depletion of B cells by targeting the surface marker CD20 has been shown to be effective in treating rheumatoid arthritis with a good side effect profile. Series of cases with other systemic autoimmune diseases indicate that this strategy may be effective in these conditions too. The clinical data add weight to the importance of B cells in the pathogenesis of autoimmune diseases.</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"27 4","pages":"443-56"},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00281-006-0013-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26057415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Biologics in the prevention and treatment of graft rejection.","authors":"Reinhard Marks, Jürgen Finke","doi":"10.1007/s00281-006-0014-7","DOIUrl":"https://doi.org/10.1007/s00281-006-0014-7","url":null,"abstract":"<p><p>Biologics are used in solid organ allografting and hematopoietic stem cell transplantation (HSCT) for the induction and maintenance of immunosuppression. In solid organ transplantation, antibodies targeting T cells are part of induction protocols administered for initiation of immunosuppression during organ transfer and during sustained post transplant periods for prevention of graft rejection. Several clinical trials in renal allografting provide data for the efficacy and safety of biologics in this clinical setting. Application of biologics also allows the reduction of calcineurin inhibitors, thereby reducing toxicity and improving long-term graft function. In acute rejection periods, anti T cell antibodies are established in steroid-resistant cases. Strategies interfering with the activity of soluble cytokines are less frequently applied for solid organ transplantation. In HSCT, T cell directed antibodies as part of conditioning protocols improve engraftment and reduce the incidence of detrimental graft vs host disease (GvHD). In acute GvHD, both antibodies targeting T cells and cytokines like TNF-alpha are established therapeutics for remission induction.</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"27 4","pages":"457-76"},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00281-006-0014-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26057416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leigh D Church, Sarah M Churchman, Philip N Hawkins, Michael F McDermott
{"title":"Hereditary auto-inflammatory disorders and biologics.","authors":"Leigh D Church, Sarah M Churchman, Philip N Hawkins, Michael F McDermott","doi":"10.1007/s00281-006-0015-6","DOIUrl":"10.1007/s00281-006-0015-6","url":null,"abstract":"<p><p>The term auto-inflammatory disorders has been coined to describe a group of conditions characterized by spontaneously relapsing and remitting bouts of systemic inflammation without apparent involvement of antigen-specific T cells or significant production of auto-antibodies. The hereditary periodic fever syndromes are considered as the prototypic auto-inflammatory diseases, and genetic studies have yielded important new insights into innate immunity. DNA analysis has greatly enhanced the clinical characterization of these conditions, and elucidation of their molecular aetiopathogenesis has suggested that therapies may be aimed at specific targets within the immune cascade. The availability of biologic response modifiers such as inhibitors of tumour necrosis factor (TNF) and interleukin-1beta has greatly improved the outlook for some of these disorders, although effective therapies remain elusive in patients with certain conditions, including hyperimmunoglobulinaemia-D with periodic fever syndrome (HIDS) and a proportion of those with TNF-receptor associated periodic syndrome (TRAPS). Indeed, outstanding challenges and the unique potential to further elucidate molecular mechanisms in innate immunity are illustrated by the dashed early hope that TNF blockade would be a panacea for TRAPS: not only is etanercept (Enbrel) ineffective in some cases, but there are anecdotal reports of this condition being greatly exacerbated by infliximab (Remicade).</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"27 4","pages":"494-508"},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26057421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Disturbances in placental immunology: ready for therapeutic interventions?","authors":"Sinuhe Hahn, Anurag Kumar Gupta, Carolyn Troeger, Corinne Rusterholz, Wolfgang Holzgreve","doi":"10.1007/s00281-006-0016-5","DOIUrl":"https://doi.org/10.1007/s00281-006-0016-5","url":null,"abstract":"<p><p>Recent studies have provided new insight into aberrations in the immunological interplay between mother and fetus and their potential role in the development of recurrent fetal loss and preeclampsia. The action of anti-phospholipid antibodies in recurrent fetal loss is now proposed to involve the complement system, neutrophil activation and the production of TNFalpha by immune bystander cells. A clear involvement of the immune system is emerging in preeclampsia, involving mainly the innate arm, especially neutrophils. The activation of peripheral neutrophils by placentally released inflammatory debris triggers the induction of neutrophil extracellular traps (NETs), which may lead to an occlusion of the intervillous space, thereby further promoting a condition of placental hypoxia. It has, hence, been suggested that new therapeutic strategies be developed, including the possible use of TNFalpha antagonists in cases of recurrent miscarriage. These strategies need to be addressed with caution due to the possible induction of fetal congenital abnormalities.</p>","PeriodicalId":74860,"journal":{"name":"Springer seminars in immunopathology","volume":"27 4","pages":"477-93"},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00281-006-0016-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26057418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}