| 1. |
- Ekerfelt, Christina, 1957-, et al.
(författare)
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Mercury exposure as a model for deviation of cytokine responses in experimental Lyme arthritis : HgCl2 treatment decreases T helper cell type 1-like responses and arthritis severity but delays eradication of Borrelia burgdorferi in C3H/HeN mice
- 2007
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Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 150:1, s. 189-197
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Tidskriftsartikel (refereegranskat)abstract
- Lyme borreliosis is a complex infection, where some individuals develop so-called ‘chronic borreliosis’. The pathogenetic mechanisms are unknown, but the type of immune response is probably important for healing. A strong T helper cell type 1 (Th1)-like response has been suggested as crucial for eradication of Borrelia and for avoiding development of chronic disease. Many studies aimed at altering the Th1/Th2 balance in Lyme arthritis employed mice deficient in cytokine genes, but the outcome has not been clear-cut, due possibly to the high redundancy of cytokines. This study aimed at studying the importance of the Th1/Th2 balance in murine Borrelia arthritis by using the Th2-deviating effect of subtoxic doses of inorganic mercury. Ninety-eight C3H/HeN mice were divided into four groups: Borrelia-infected (Bb), Borrelia-infected exposed to HgCl2 (BbHg), controls exposed to HgCl2 alone and normal controls. Mice were killed on days 3, 16, 44 and 65 post-Borrelia inoculation. Arthritis severity was evaluated by histology, spirochaetal load determined by Borrelia culture, IgG2a- and IgE-levels analysed by enzyme-linked immunosorbemt assay (ELISA) and cytokine-secreting cells detected by enzyme-linked immunospot (ELISPOT). BbHg mice showed less severe histological arthritis, but delayed eradication of spirochaetes compared to Bb mice, associated with increased levels of IgE (Th2-induced) and decreased levels of IgG2a (Th1-induced), consistent with a Th2-deviation. Both the numbers of Th1 and Th2 cytokine-secreting cells were reduced in BbHg mice, possibly explained by the fact that numbers of cytokine-secreting cells do not correlate with cytokine concentration. In conclusion, this study supports the hypothesis that a Th1-like response is required for optimal eradication of Borrelia.
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| 2. |
- Carlsson, Hanna, 1978-
(författare)
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Laboratory methods for investigation of the immunological orchestra in response to pathogens
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Laboratory methods used for investigation of immune response often involve collection of whole blood and analysis of different biomarkers in blood components or generated from pathogen stimulation of whole blood or peripheral blood mononuclear cells (PBMC). Methods used to measure biomarkers are for example enzyme-linked immunosorbent assay (ELISA) which measures one biomarker at a time or multiplex assays for example x-unknown, multi-analyte profiling (xMAP) by Luminex or proximity extension assay (PEA), which can measure up to just over 3000 biomarkers at a time. Analysis of one biomarker at a time are time consuming, costly, and dependent of a large sample size to enable repeated measurements of different analytes. Therefore, multiplex assays that are time saving, more cost effective and measures multiple bi-omarkers at once in a small sample can be applied. The aim of this thesis was to evaluate multiplex laboratory methods for investigation of the immunological orchestra in response to Borrelia infection and influenza immunisation and if possible, further characterize individuals with different clinical outcomes or serological response, respectively. In our studies (paper I-III) we included 1113 blood donors of which 66 were found to previously have had a subclinical borreliosis (defined as presence of Borrelia-specific antibodies without recall of previous Lyme borreliosis), of the 66 individuals 60 were available for participation. We also included 22 patients previously diagnosed with Lyme neuroborreliosis (LNB). In paper IV we included in total 73 individuals consisting of healthcare workers and patients attending seasonal influenza vaccination. We applied whole blood, PBMC and plasma stimulations and measured a range of cytokines, chemokines and complement factors with ELISA, nephelometry, xMAP and PEA. Our results show that subclinical Lyme borreliosis (SB) individuals display the following pattern, low age, male sex, low amount of secreted interleukin (IL)-17, CCL20 and higher secretion of IL-10 by PBMCs stimulated three days with Borrelia garinii compared to patients with previous Lyme neuroborreliosis (LNB). The subclinical individuals also show higher activation of the complement system in response to Borrelia afzelii. We performed multiplex analysis of complement factors in attempt to further characterize our SB individuals and LNB patient but found the results to deviate largely from reference values retrieved with other standardized methods. This highlights the importance of critical review of generated results from all form of assays. To investigate immune responses after influenza immunisation and further characterize serological responders and nonresponders we included measurement of influenza-specific antibodies and total immunoglobulins (Ig) in blood serum, influenza-specific mucosal IgA (nasal-swabs) and cell-mediated immune response in supernatants from PBMCs stimulated with influenza vaccine using PEA. We found the serological responders to be characterised by lower levels of total IgM, Granzyme B (GZMB) and IL-12 together with higher levels of CXCL13 compared with nonresponders. To conclude, xMAP and PEA are two valuable methods that can be applied together with multivariate statistical methods in the investigation of both innate and adaptive immunity characteristics and association to clinical outcome or serological response after Borrelia infection and influenza immunisation, respectively.
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| 3. |
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| 4. |
- Ekerfelt, Christina, 1957-, et al.
(författare)
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Antibodies and T-cell reactivity to Borrelia burgdorferi in an asymptomatic population : A study of healthy blood donors in an Inland town district in the South-East of Sweden
- 2001
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 33:11, s. 806-808
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Tidskriftsartikel (refereegranskat)abstract
- To address the issue of whether Borrelia infection can be asymptomatic, blood donors with no history of borreliosis (n = 408) were screened for antibodies against Borrelia burgdorferi. Seropositive individuals (n = 17) were further investigated with respect to Borrelia-specific T-cell reactivity, using an interferon-? ELISPOT assay. Anti-Borrelia antibodies as well as Borrelia-specific T-cell responses were evident in 9 asymptomatic donors, strongly supporting a current or previous asymptomatic Borrelia infection.
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| 5. |
- Ekerfelt, Christina, 1957-, et al.
(författare)
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Detection of spontaneous and antigen-induced human interleukin-4 responses in vitro : Comparison of ELISPOT, a novel ELISA and real-time RT-PCR
- 2002
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Ingår i: JIM - Journal of Immunological Methods. - 0022-1759 .- 1872-7905. ; 260:1-2, s. 55-67
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin-4 (IL-4) is an important T-helper cell type 2 (Th2) cytokine in man, driving Th2 polarisation and exerting the most antagonistic effects to the Th1 cytokine interferon-? (IFN-?). Nevertheless, few data on spontaneous and antigen-specific secretion of IL-4 in man are available, mainly due to difficulties in the detection of IL-4. In this study, we compared three assays that can detect antigen-induced IL-4 responses, ELISPOT, ELISA after blocking the IL-4 receptor during cell culture, and real-time reverse transcription polymerase chain reaction (RT-PCR). Spontaneous, antigen- and allergen-induced responses were analysed in peripheral blood mononuclear cells from three groups with different secretion patterns for IL-4: atopic individuals, nonatopic individuals and pregnant women. ELISPOT displayed the highest sensitivity and was the only assay that could detect spontaneous secretion of IL-4 in all analysed samples. The IL-4 receptor blocking ELISA was considered best for the detection of in vitro antigen- and allergen-induced responses, since the results obtained from the ELISPOT and real-time RT-PCR displayed lower specificity, possibly because of seemingly aberrant IL-4 responses in the group of pregnant women. The real-time RT-PCR for detection of IL-4 mRNA proved to be sensitive, but expression of IL-4 mRNA was not correlated with the secretion of IL-4.
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| 6. |
- Ekerfelt, Christina, 1957-
(författare)
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Interferon-Υ and interleukin-4 in health and disease : Studies on Borrelia infection, inflammatory polyneuropathies and normal pregnancy
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The immune system needs stringent regulation in order to effectively eliminate infecting agents and, at the same time, protect the body from immunemediated tissue destruction. T cells have a major role in this regulation by secreting cytokines. Interferon-y (IFN-y) and interleukin-4 (IL-4) exert antagonistic regulatory functions and are mutually inhibitory. Thus, immune responses are generally functionally dominated by IFN-y or IL-4, a balance which is believed to be decisive for the outcome. Besides providing protection against pathogens, the immune system also has impact on several other conditions, e. g. reproduction and inflammatory diseases. Much is known about the role of IFN-y and IL-4 in animal models of these conditions, but less data are available from studies in humans. Data on IL-4 secretion are particularly rare, since this cytokine is extremely hard to detect.Material and methods: Antigen-specific secretion of IFN-y and IL-4 was detected with ELISPOT -technique in different human conditions, including Borrelia-infection, inflammatory diseases in the peripheral nerves (the Guillain-Barre syndrome [GBS] and polyneuropathy associated with monoclonal gammopathy [PNMGUS]) and normal pregnancy. A novel assay was developed for the detection of fetus-specific cytokine secretion during pregnancy. Finally, a therapeutical approach for selective redirection of inappropriate IFN-y secretion to IL-4 secretion was developed in an experimental model of GBS.Results: Predominant Borrelia-specific secretion of IFN-y and low or absent IL-4- secretion was found, both in patients with clinical Borrelia-infection and resistant individuals. A compartmentalization of this secretion to the central nervous system was evident in patients with neuro-borreliosis. There were indications that the specific IL-4 secretion increased over the disease course, and of lower numbers of Borrelia-specific IL-4 secreting cells in patients that did not fully recover compared with those who did. This suggests that Borrelia-specific IL-4 secretion might be necessary to down-regulate the inflammatory responses generated by IFN-y. Patients with a chronic disease course appeared to have a larger proportion of spontaneously IL-4 secreting cells compared with resistant individuals. Thus, individuals who develop chronic borreliosis may have limited ability to mount strong IFN-y secretion, which may be needed initially in the infection for eradication of the Borrelia bacteria.An increase in the secretion of IL-4 in response to paternal but not to unrelated anaantigen was found in the blood of pregnant women. This is an extraordinary finding, since allo-reactivity usually is predominated by IFN-y secretion. The secretion of IL-4 exclusively to paternal allo-antigen, suggests that this is primarily selective for the fehls. Thus, responses to antigens that are not present at the maternal-fetal interfaCe may well be IFN-y predominated, which is needed to combat common infections. Auto-reactive secretion of IFN-ywas found in PNMGUS, which is a chronic disease. Conversely, autoreactive secretion of IL-4, associated with recovery, was detected in the self-limiting disease GBS. This supports the hypothesis that auto-reactive IFN- )' secretion is involved in the pathogenesis of organ-specific inflammatory diseases, whereas IL-4 secretion is beneficial.Transfer of syngenic disease-specific cells, which had been ex vivo deviated to predominant secretion of IL-4, significantly ameliorated the disease in the experimental model of GBS. This may become a feasible approach for therapeutic intervention of organ-specific inflammatory diseases.Conclusions: The ELISPOT-technique successfully detected alterations in the spontaneous as well as the antigen-induced secretion of IFN-y and IL-4, which a1so in humans appears to have implications for health and disease.
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| 7. |
- Ekerfelt, Christina, 1957-, et al.
(författare)
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Lyme borreliosis in Sweden - Diagnostic performance of five commercial Borrelia serology kits using sera from well-defined patient groups
- 2004
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 112:1, s. 74-78
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Tidskriftsartikel (refereegranskat)abstract
- Five commercial Borrelia serology kits available in Sweden were evaluated and compared for their diagnostic performance in sera from clinically well-characterized patient groups. With the clinically defined groups as the gold standard, i.e. without knowledge of antibody status in serum and cerebrospinal fluid, the diagnostic performance of the kits was compared and important differences in diagnostic usefulness were found. The kits from Abbot and DAKO, that often predict clinically relevant Borrelia infection and do not detect antibodies in sera from patients without strong suspicion of Borrelia infection, were considered the most useful in the population studied. This kind of validation study is an important part of good laboratory practice and should be performed by laboratories serving patient populations with varying endemicity of Borrelia.
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| 8. |
- Ekerfelt, Christina, 1957-, et al.
(författare)
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Phenotypes indicating cytolytic properties of Borrelia-specific interferon-? secreting cells in chronic Lyme neuroborreliosis
- 2003
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Ingår i: Journal of Neuroimmunology. - : Elsevier BV. - 0165-5728 .- 1872-8421. ; 145:1-2, s. 115-126
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Tidskriftsartikel (refereegranskat)abstract
- The immuno-pathogenetic mechanisms underlying chronic Lyme neuroborreliosis are mainly unknown. Human Borrelia burgdorferi (Bb) infection is associated with Bb-specific secretion of interferon-? (IFN-?), which may be important for the elimination of Bb, but this may also cause tissue injury. In order to increase the understanding of the pathogenic mechanisms in chronic neuroborreliosis, we investigated which cell types that secrete IFN-?. Blood mononuclear cells from 13 patients with neuroborreliosis and/or acrodermatitis chronicum atrophicans were stimulated with Bb antigen and the phenotypes of the induced IFN-?-secreting cells were analyzed with three different approaches. Cells expressing CD8 or TCR?d, which both have cytolytic properties, were the main phenotypes of IFN-?-secreting cells, indicating that tissue injury in chronic neuroborreliosis may be mediated by cytotoxic cells.
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| 9. |
- Ekerfelt, Christina, 1957-, et al.
(författare)
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Th2-deviation of fetus-specific T cells
- 1999
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Ingår i: Immunology today (Amsterdam. Regular ed.). - 0167-5699 .- 1355-8242. ; 20, s. 534-534
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Tidskriftsartikel (refereegranskat)
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| 10. |
- Ekerfelt, Christina, 1957-, et al.
(författare)
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Transfer of myelin-specific cells deviated in vitro towards IL-4 production ameliorates ongoing experimental allergic neuritis
- 2001
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Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 123:1, s. 112-118
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Tidskriftsartikel (refereegranskat)abstract
- A causal role of IL-4 (Th2) production for recovery in experimental allergic neuritis (EAN) was indicated by experiments where Th1-like autoreactive cell populations, taken from the induction phase of the disease, were deviated to extensive secretion of IL-4 in a selective fashion, by ex vivo stimulation with autoantigen in the presence of IL-4. The deviated cells were adoptively transferred to EAN rats at a time just prior to the onset of clinical signs. This treatment ameliorated EAN compared with sham treatment. This therapeutic approach, with generation of autoreactive IL-4-secreting cells ex vivo followed by subsequent adoptive transfer, may become a new selective treatment of organ-specific autoimmune diseases since, in contrast to previous attempts, it is done in a physiological and technically easy way.
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