Immunobiology of Stiff-Person Syndrome

The two possibilities to explain the pathogenic basis of stiff-person syndrome (SPS) are intrathecal sensitization of GAD65-reactive CD4⁺T cells and synthesis of GAD65-specific autoantibodies within the CNS [Rakocevic et al., Arch. Neurol. 61: 902–904, 2004]; and peripheral antigen sensitization followed by CNS antigen recognition by autoantibodies that cross the blood-brain barrier. Antigen-specific CD4⁺ T cells are essential for the generation of high-affinity autoantibodies [Lanzavecchia, Nature 314: 537–539, 1985], but there is no evidence of cellular infiltration in the CNS of SPS patients [Warich-Kirches et al., Clin. Neuropathol. 16: 214–219, 1997; Ishizawa et al., Acta Neuropathol.(Berl) 97: 63–70, 1999]. This review discusses the possible role of autoantibodies and autoreactive T cells specific to neuronal antigens in SPS pathogenesis.     

Cover Picture: Expansion and activation of CD4+CD25+ regulatory T cells in Heligmosomoides polygyrus infection – Eur. J. Immunol. 7/2007

The cover shows a photograph of an individual adult Heligmosomoides polygyrus, a gastrointestinal nematode parasite and was provided by Finney et al. (pp. 1874–1886). In this study authors analyse in detail the development and phenotype (CTLA‐4, GITR, CD103) of cells responsible for the suppression of the early Th2 responses during murine H. polygyrus infection. Both CD25⁺Foxp3⁺ and CD25⁺Foxp3^‐ subsets are increased during infection but, interestingly, only the latter display significant increases in TGF‐β levels.     

Cover Picture: Eur. J. Immunol. 6/11

The cover of this issue is based on microscopy images of immature dendritic cells (DCs) stained with hematoxylin‐and‐eosin (H&E) provided by Chong et al. (pp. 1639–1651). In their article, Chong et al. investigate which cell types contribute to the differentiation of TNF/iNOS‐producing dendritic cells (Tip‐DCs), a subset of DCs that has been shown to arise during inflammation and to be an important mediator of immune defense. The authors provide evidence that CD8⁺ T cells can induce the rapid development of human monocytes into Tip‐DCs that are capable of further driving Th1 responses by priming naive CD4⁺ T cells.     

Cover Picture – Eur. J. Immunol. 11/2006

The cover depicts a tissue section, stained with FITC‐conjugated anti‐CD8 antibodies, taken from the ear of a mouse after hapten challenge. It illustrates the article by Ring et al. (pp. 2981–2992) in which the authors analyze the mechanisms of Treg suppression of CHS in vivo.The staining shows infiltrating CD8⁺ T cells in the inflamed skin following treatment with conventional CD4⁺CD25^‐ T cells. In contrast, treatment with Treg decreases this infiltration leading to CHS suppression.     

CD16+ monocytes in breast cancer patients: expanded by monocyte chemoattractant protein-1 and may be useful for early diagnosis

Human peripheral blood monocytes are a heterogeneous population, including CD14⁺CD16^‐‘classical’ monocytes and CD14⁺CD16⁺‘proinflammatory’ monocytes. CD16⁺ monocytes are expanded in various inflammatory conditions. However, little is known about the CD14⁺CD16⁺ monocytes in patients with breast cancer. We detected CD14⁺CD16⁺ monocytes in 96 patients with breast cancer and 54 control subjects using flow cytometry. Receiver‐operating characteristic (ROC) curve analysis was used to determine the feasibility of CD14⁺CD16⁺ monocytes as an indicator for diagnosis of breast cancer. We found that the frequency of CD14⁺CD16⁺ monocytes showed a significantly greater increase in breast cancer patients than in controls (16·96% versus 10·84%, P < 0·0001). The area under the ROC curve for CD14⁺CD16⁺ monocytes was 0·805 [95% confidence interval (95% CI): 0·714–0·877, P = 0·0001]. Furthermore, the levels of CD16⁺ monocytes were significantly negatively associated with the tumour size and pathological staging. In vitro, we showed that CD14⁺CD16⁺ monocytes were expanded significantly when the purified CD14⁺ monocytes were exposed to Michigan Cancer Foundation (MCF)‐7 cells‐conditioned medium (MCF‐CM) or, separately, to monocyte chemotactic protein 1 (MCP‐1). Neutralizing antibodies against MCP‐1 inhibited the expansion of CD14⁺CD16⁺ monocytes by MCF‐CM. Collectively, our findings indicated that MCP‐1 can expand CD14⁺CD16⁺ monocytes in patients with breast cancer. Furthermore, the CD14⁺CD16⁺ monocyte may be a useful indicator in early diagnosis of breast cancer.     

Selective depletion of CD14+ CD16+ monocytes by glucocorticoid therapy

Glucocorticoids (GC) are potent anti-inflammatory and immunosuppressive agents that act on many cells of the body, including monocytes. Here we show that a 5-day course of high dose GC therapy differentially affected the CD14⁺⁺ and the CD14⁺ CD16⁺ monocyte subpopulations in 10 patients treated for multiple sclerosis. While the classical (CD14⁺⁺) monocytes exhibited a substantial increase from 495 ± 132 to 755 ± 337 cells/μl, the CD14⁺ CD16⁺ monocytes responded with a pronounced decrease from 36 ± 15 to 2 ± 3 cells/μl (P < 0.001). In 4/10 patients the CD14⁺ CD16⁺ monocytes fell below detection limits (< 0.2 cells/μl). This observation was confirmed when the CD14⁺ CD16⁺ monocytes were identified by virtue of their low CD33 expression as these cells decreased as well. After discontinuation of GC therapy the CD14⁺ CD16⁺ monocytes reappeared and reached normal levels after 1 week. The profound depletion of CD14⁺ CD16⁺ monocytes by GC as described here is a novel effect of GC action in vivo and may contribute to GC-mediated immunosuppression. Determination of the number of this monocyte subset may also serve to monitor the effectiveness of GC therapy in patients requiring immunosuppressive treatment.     

Application of central immunologic concepts to cancer: Helping T cells and B cells become intolerant of tumors

CD4‐mediated T‐cell help in the activation of CD8⁺ T cells and B cells, through linked‐recognition of antigenic determinants, is a long‐standing concept foundational to our understanding of immunity (presence of help) versus tolerance (lack of help). Surprisingly, this function of CD4⁺ T cells has not been extensively examined as a means to overcome immune tolerance of the self‐antigens made by tumor cells. Hesitation to employ this powerful mechanism may be due to the potential to cause unwanted autoimmune pathology. In this issue of the European Journal of Immunology, Snook et al. [Eur. J. Immunol. 2014. 44: 1956–1966] identify a state of split tolerance, showing that CD4⁺ T cells specific for a number of tumor‐associated self‐antigens are robustly tolerant, while their CD8⁺ T‐cell and B‐cell counterparts are far less tolerant. Furthermore, the authors demonstrate that provision of linked foreign helper epitopes, such as influenza hemagglutinin, substantially enhances both CD8⁺ T‐cell and B‐cell responses to tumor self‐antigens without causing any overt autoimmune pathology. These findings provide a strong rationale to employ foreign helper epitopes in cancer vaccines and highlight the need to fully explore therapeutic strategies that are based on well‐established immunologic concepts.     

The Efficiency of Viscum album ssp. album and Hypericum perforatum on Human Immune Cells In Vitro

Viscum album L. ssp. album and Hypericum perforatum L. are used for the treatment of different diseases. In this study, the effects of these herbals on immune cells were assessed in vitro. The phagocytosis, candidacidal activity of neutrophils and adhesion function of epithelial cells were investigated. Also, the expression of the surface markers of lymphocytes was analyzed by flow cytometry. It was observed that V. album ssp. album increased phagocytic activity and candidacidal activity of neutrophils and decreased adhesion function of epithelial cells. We also observed that in human peripheral blood mononuclear cells stimulated by Viscum album L. ssp. album the levels of CD4⁺CD25⁺ and CD8⁺CD25⁺ T cells, CD69 expressions in the activated T lymphocytes and CD3^-CD16⁺CD56⁺ NK cells increased compared to the cells that were not stimulated by this herbal. Whereas CD4⁺CD25⁺, CD8⁺CD25⁺ T cells, CD 69 expression and CD3^-CD16⁺CD56⁺ Natural killer cells did not show any significant differences with the presence of Hypericum perforatum L. compared to the control group. Hypericum perforatum L. increased candidacidal activity of neutrophils and decreased adhesion function of epithelial cells. In the light of these findings, it is considered that these extracts may be used as an adjuvant treatment option for immune activation in immunosuppressed patients.     

Expansion of CD14+CD16+ peripheral monocytes among patients with aseptic loosening

Objective and design  In this study, we have investigated the relevance of peripheral blood inflammatory CD14⁺CD16⁺ monocytes phenotype to patients with aseptic loosening (AL). Material and treatment  Immunophenotypes of monocytes were examined among patients with AL (n = 43), patients with mechanical loosening (ML, n = 30), patients with stable implant (SI, n = 16), and patients with osteoarthritis (OA, n = 17) using flow cytometry. Methods  Immunological assay was used to measure TNF-α and IL-1β levels in both sera and culture media of implant wear stimulated CD14⁺CD16⁺ and CD14⁺⁺CD16⁻ monocytes. Periprosthetic tissues were collected during surgery for histological assessment. Results  The frequency of CD14⁺CD16⁺ monocytes showed significant increase in AL patients than in ML, SI, and OA patients. A positive association was found between the subpopulation of CD14⁺CD16⁺ monocytes and plasma TNF-α and IL-1β level in AL patients. Furthermore, a positive correlation existed between the subpopulation of CD14⁺CD16⁺ monocytes and the total histopathology score. Conclusion  The results indicate that CD14⁺CD16⁺ monocytes represent a sensitive marker for the disease activity of AL, and may serve as an effective prognostic index to identify total joint replacement recipients who are at increased risk for osteolysis and progression of AL.     

Impaired dendritic cell differentiation of CD16‐positive monocytes in tuberculosis: Role of p38 MAPK

Tuberculosis (TB) is one of the world's most pernicious diseases mainly due to immune evasion strategies displayed by its causative agent Mycobacterium tuberculosis (Mtb). Blood monocytes (Mos) represent an important source of DCs during chronic infections; consequently, the alteration of their differentiation constitutes an escape mechanism leading to mycobacterial persistence. We evaluated whether the CD16⁺/CD16^? Mo ratio could be associated with the impaired Mo differentiation into DCs found in TB patients. The phenotype and ability to stimulate Mtb‐specific memory clones DCs from isolated Mo subsets were assessed. We found that CD16^? Mos differentiated into CD1a⁺DC‐SIGN^high cells achieving an efficient recall response, while CD16⁺ Mos differentiated into a CD1a^?DC‐SIGN^low population characterized by a poor mycobacterial Ag‐presenting capacity. The high and sustained phosphorylated p38 expression observed in CD16⁺ Mos was involved in the altered DC profile given that its blockage restored DC phenotype and its activation impaired CD16^? Mo differentiation. Furthermore, depletion of CD16⁺ Mos indeed improved the differentiation of Mos from TB patients toward CD1a⁺DC‐SIGN^high DCs. Therefore, Mos from TB patients are less prone to differentiate into DCs due to their increased proportion of CD16⁺ Mos, suggesting that during Mtb infection Mo subsets may have different fates after entering the lungs.     

Role of Prolactin in the Recovered T-Cell Development of Early Partially Decapitated Chicken Embryo

Although different experimental approaches have suggested certain regulation of the mammalian immune system by the neuroendocrine system, the precise factors involved in the process are largely unknown. In previous reports, we demonstrated important changes in the thymic development of chickens deprived of the major neuroendocrine centers by the removal of embryonic prosencephalon at 33-38 hr of incubation (DCx embryos) (Herradón et al., 1991; Moreno et al., 1995). In these embryos, there was a stopping of T-cell maturation that resulted in an accumulation of the most immature T-cell subsets (CD4^-CD8^- cells and CD4^-CD8^1o cells) and, accordingly, in decreased numbers of DP (CD4⁺CD8⁺) thymocytes and mature CD3⁺TcRαβ ⁺ cells, but not CD3⁺TcRγδ lymphocytes. In the present work, we restore the thymic histology as well as the percentage of distinct T-cell subsets of DCx embryos by supplying recombinant chicken prolactin, grafting of embryonic pituitary gland, or making cephalic chick-quail chimeras. The recovery was not, however, whole and the percentage of CD3⁺TcRαβ thymocytes did not reach the normal values observed in 17-day-old control Sham-DCx embryos. The results are discussed on the basis of a key role for prolactin in chicken T-cell maturation. This hormone could regulate the transition of DN (CD4^-CD8^-) thymocytes to the DP (CD4⁺CD8⁺) cell compartment through its capacity for inducing IL-2 receptor expression on the former.     

Activation of cord blood myeloid dendritic cells by Trypanosoma cruzi and parasite-specific antibodies,proliferation of CD8+ T cells,and production of IFN-γ

We previously reported that Trypanosoma cruzi, the agent of Chagas disease, induces in congenitally infected fetuses a strong, adult-like parasite-specific CD8⁺ T cell response producing IFN-γ (Hermann et al. in Blood 100:2153–2158, 2002). This suggests that the parasite is able to overcome the immaturity of neonatal antigen presenting cells, an issue which has not been previously addressed. We therefore investigated in vitro the ability of T. cruzi to activate cord blood DCs and compared its effect to that on adult cells. We show that T. cruzi induces phenotypic maturation of cord blood CD11c⁺ myeloid DCs (mDCs), by enhancing surface expression of CD40, CD80, and CD83, and that parasite-specific IgG purified from cord blood of neonates born to T. cruzi-infected mothers amplify such expression. CD83, considered as the best marker of mature DCs, reaches higher level on cord blood than on adult mDCs. Allo-stimulation experiments showed that T. cruzi-activated cord blood mononuclear cells enriched in DCs (eDCs) stimulate proliferation of cord blood and adult CD3⁺ T cells to a similar extent. Of note, T. cruzi-activated eDCs from cord blood trigger more potent proliferation of CD8⁺ than CD8⁻ (mainly CD4⁺) adult T cells, a feature not observed with adult eDCs. T cell proliferation is associated with IFN-γ release and down-regulation of IL-13 production. These data show that T. cruzi potently activates human cord blood mDCs and endows eDCs to trigger CD8⁺ T cell proliferation and favor type 1 immune response. Interestingly, maternal antibodies can strengthen the development of mature DCs that might contribute to overcome the immunological immaturity associated with early life.     

A LARGE QUANTITY OF CD3− /CD19− /CD16− LYMPHOCYTES IN MALIGNANT PLEURAL EFFUSION FROM A PATIENT WITH RECURRENT CHOLANGIO CELL CARCINOMA

Tumor infiltrating lymphocytes (TILs) are candidates for adoptive cellular immunotherapy. Here we report on a patient whose TILs presented unusual lymphocyte antigens. Pleural effusions were collected from a 47-year-old man with recurrent cholangio cell carcinoma and malignant effusion. Effusion- associated lymphocytes (EALs) were separated by Ficoll-Hypaque gradient, and the EAL phenotype was determined by flow cytometry. The percentage of positive cells was determined for each lymphocyte-related differentiation antigen. The percentages of CD3⁺, CD19⁺, and CD16⁺ lymphocyte subpopulations among EALs were 20%, 7%, and 3%, respectively. Nearly 70% of EALs were CD3^? /CD19^? /CD56^? /CD16^?cells. The phenotypes of peripheral blood lymphocytes (PBLs) collected simultaneously from the patient's peripheral blood were CD3⁺ (52%), CD19⁺ (20%), and CD16⁺ (20%).When EALs were cultured in medium without pleural effusion, T cell-related antigens, but not B cell- or natural killer (NK) cell-related antigens, were newly expressed on EALs, and this expression reached a plateau after 48 h in culture. The proportions of CD3⁺, CD19⁺, and CD16⁺ cells were 69%, 7%, and 3%, respectively. However, when EALs were cultured in medium with pleural effusion, increased expression of T cell-related antigens was not observed; the proportions of CD3⁺, CD19⁺, and CD16⁺ cells were 16%, 6%, and 1%, respectively. Neither total cell numbers nor cellular viability of EALs changed significantly after in-vitro culture, suggesting that significant proliferation or death of EALs did not occur during the culture period. Co-culture of the patient's PBLs with autologous pleural effusion for 96 h did not alter the expression of lymphocyte-related antigens on the PBLs. These results indicate that expression of T cell-related antigens, but not B cell- or NK cell-related antigens, on EALs was blocked temporarily by the malignant pleural effusion. This is the first report concerning the existence of a large quantity of unclassified lymphocytes in which the T cell-related antigens were reversibly masked in the malignant pleural effusion.     

Multiparametric flow cytometric analysis of whole blood reveals changes in minor lymphocyte subpopulations of multiple sclerosis patients

Objective: The objective of this study is to characterise the functionally relevant minor lymphocyte subpopulations in whole blood of multiple sclerosis (MS) patients and their potential utility as biomarkers for treatment follow up. Material and methods: Peripheral blood from 40 healthy donors (HD) and 66 MS patients [23 relapsing–remitting (RRMS) without treatment, 27 RRMS undergoing treatment (16 IFN-β, 11 natalizumab), and 16 progressive forms (eight secondary progressive and eight primary progressive)] was analysed by multiparametric flow cytometry. Results: Untreated MS patients showed a decrease in early effector memory (CD45RA^?CCR7^?CD27⁺) CD4⁺ and CD8⁺ T cells and an increase in Th17 lymphocytes in peripheral blood compared with HD. Regarding the effect of treatment, whereas no differences in relative percentages of cellular subpopulations were observed in patients under IFN-β treatment, those under treatment with natalizumab had an increased percentage of early effector memory CD4⁺ (CD45RA^?CCR7^?CD27⁺), central memory CD8⁺ (CD45RA^?CCR7⁺CD27⁺) T cells, recent thymic emigrants (CD4⁺ CD45RA⁺CCR7⁺CD27⁺CD31⁺PTK7⁺) and transitional B cells (CD19⁺CD27^?CD24^hiCD38^hi). Conclusions: Multiparametric flow cytometry analysis of whole blood is a robust, reproducible, and sensitive technology to monitor the effect of MS treatments even in minor lymphocyte subpopulations that might represent useful biomarkers of treatment response.     

Cover Picture: Eur. J. Immunol. 4'13

The cover features a histology image of a lung section from a C57BL/6 mouse intranasally infected with influenza virus. The hematoxylin and eosin‐stained section shows substantial cellular influx into airways 6 days after exposure to influenza virus, which is confirmed by flow cytometry to include CD3^?NKp46⁺NK1.1⁺CD127^? NK cells. The image is taken from the article by Zhou et al. (pp. 929–938) in which the authors show that NK cells may exacerbate lung pathology during influenza infection in mice. Zhou et al. also show that NK‐cellinduced pathology occurs with high‐dose, but not low‐dose influenza challenge, indicating that with severe influenza infections, NK cells may induce pathology that promote morbidity and mortality.     

Immunophenotype of peripheral blood natural killer cells and IL‐10 serum levels in relation to Helicobacter pylori status

Recent findings suggest that NK (Natural Killer) cells may directly modulate the antimicrobial immune responses. In this study, we performed immunophenotypic analysis of peripheral blood NK cells with regard to CD56, CD16, Nkp46, and CD25 markers, as well as IL‐10 levels quantification in the sera samples of asymptomatic, H. pylori (Hp)‐infected or uninfected individuals, and combined these results with our previous findings on lymphocyte cytotoxic activity. Twenty healthy volunteers [10 Hp(?);10 Hp(+)] were included in the study. The percentages of classic lymphocytes (CD3⁺) and NK cells (CD3^?CD56⁺, CD3^?Nkp46⁺, CD3^?CD16⁺) with or without CD25 receptor were evaluated by fluorochrome‐conjugated monoclonal antibody staining and flow cytometry analysis. IL‐10 quantification was performed by enzyme‐linked immunosorbent assay‐ELISA. Our study showed elevated levels of IL‐10 and higher NK cell numbers of both CD3^?CD56⁺CD25⁺ and CD3^?Nkp46⁺CD25⁺ phenotypes, as well as CD3⁺CD25⁺ classic lymphocytes in Hp(+) compared with Hp(?) individuals. No differences between Hp(?) and Hp(+) individuals were found either in total number of classic lymphocytes or NK cell subtypes. Our data suggest that in Hp(+) donors, there is a domination of lymphocytes and NK cells co‐expressing CD25 marker, which might be influenced by the regulatory IL‐10. This phenomenon may be a result of H. pylori adaptation to a changing environment in vivo leading to a chronic infection and lack of severe gastric pathologies.     

Vitamin A notches up CD11bhi DC development

Vitamin A and its metabolite retinoic acid influence various aspects of immunity. Although the capacity of vitamin A to condition intestinal CD103⁺ DCs to imprint tissue‐specific homing programs onto activated lymphocytes is well documented, it is unclear whether vitamin A also regulates DC populations in other tissues. A study published in this issue of the European Journal of Immunology, Beijer et al. [Eur. J. Immunol. 2013. 43: 1608–1616] now demonstrates that vitamin A exerts profound effects on the subset composition of splenic DCs. By resolving that splenic ESAM^hi CD11b^hi DCs are preferentially responsive to regulation by vitamin A, these novel insights not only further support the notion that ESAM expression marks two distinct lineages of splenic CD11b^hi DCs, but also provide an important extension to our understanding of how vitamin A influences the immune system.