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- Rutemark, Christian, et al.
(författare)
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B cells lacking complement receptors 1 and 2 are equally efficient producers of IgG in vivo as wildtype B cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The complement system, including the complement receptors 1 and 2 (CR1/2), is crucial for the development of antibody responses against a wide range of antigens. Cr2-/- mice are deficient in both CR1 and CR2 and respond poorly upon immunization with antigen alone and with IgM-containing immune complexes. In mice, CR1/2 are expressed exclusively on B cells and follicular dendritic cells (FDC) but it is not clear which of the two cell-types that need to express the receptors for a normal antibody response. Here, bone marrow chimeras were used to distinguish between B cells and FDC. The animals were immunized with SRBC alone or with IgM anti-SRBC and SRBC. For an antibody response to SRBC alone, CR1/2 expression on FDC was crucial. When CR1/2+ FDC were present, B cells from Cr2-/- mice produced equal amounts of antibodies against SRBC as did B cells from WT. However, the response to IgM-SRBC complexes was more efficient in the presence of CR1/2+ B cells although CR1/2+ FDC still played a dominant role. In conclusion, antibody responses to antigen alone required CR1/2+ FDC, whereas CR1/2 expression on B cells was irrelevant. In contrast, in antibody responses to IgM-IC, presence of CR1/2+ B cells led to a higher and more rapid onset of the antibody response.
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| 4. |
- Kerzeli, Iliana Kyriaki, et al.
(författare)
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MALT1 inhibition suppresses T-cell dependent immune surveillance
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- MALT1 supports the development of natural regulatory T cells (Tregs), while protease-dead MALT1 (MALT1-PD) mice develop autoimmunity and an intrinsic capacity to reject syngeneic tumor transplantation. Herein, a small molecule inhibitor targeting MALT1 was developed and evaluated for potential use in Treg inhibition as part of a cancer immunotherapy strategy.In vitro, MALT1 inhibitor treatment inhibited the proteolytic cleavage of the MALT1 substrate HOIL1 in Jurkat cells and blocked IL-2 secretion by immune cells. Moreover, orally administrated MV088428 inhibited anti-CD3 induced IL-2 release in vivo. In vitro MALT1 inhibition selectively suppressed the proliferation of PBMC derived CD25+ FoxP3+ CD4+ T cells, while no direct effect was noted on the proliferation and viability of CD25- CD4+ T cells. In vivo, no evident anti-tumor effect as a monotherapy in the MB49 bladder cancer model was achieved and despite selective decrease of Treg frequencies in lymph nodes of tumor bearing animals, intratumoral Treg depletion was not observed. No synergistic anti-tumor effects were noted when MALT1 inhibitor was combined with anti-PD1 therapy, and concomitant treatment with MALT1 inhibitor abrogated the efficacy of anti-CTLA4 therapy. MALT1 inhibition had no impact on the frequencies of viable NK, lymphocyte and myeloid cells or on proliferation of conventional CD4 and CD8 T cells. However, there was a significant decrease of antigen-specific T cells in vivo upon adoptive T cell transfer and peptide vaccination. Thus, while MALT1 inhibition substantially reduced Treg populations in lymph nodes, but less so in tumors, off-target effects on antigen-experienced T cells along with the lack of impact on tumor Tregs likely abolish the compound’s efficacy. The off-target effect on antigen-experienced T cells could present implications for the use of MALT1 inhibitors for cancer indications where tumor control is likely to be mediated via T cell driven immune surveillance. Thus, dosing length and combination therapy strategies should be carefully designed and evaluated further.
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| 7. |
- Martinell, Mats, 1971-, et al.
(författare)
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Characterization of Cellular Immunology in LADA Patients
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Objective: Patients with latent autoimmune diabetes mellitus in adults (LADA) have antibodies against the insulin-producing b-cells but at disease onset they are not insulin-dependent. This study presents cellular immunological differences between LADA, type 1, type 2 diabetes and healthy controls.Research Design and Methods: All patients and matched (by age, gender and body mass index) healthy controls were recruited from the County of Uppsala, Sweden. Peripheral blood mononuclear cells were isolated from freshly collected blood to determine proportions of innate, adaptive and regulatory immune cells by using flow cytometry. Results: Included were 14 patients with LADA, 16 with type 1 diabetes, 16 with type 2 diabetes and 13 healthy controls. The proportion of CD11c+CD123- antigen presenting cells (APCs) was lower, whilst proportions of CD11c+CD123+ APCs and Interleukin (IL)-35+ tolerogenic APCs were higher in LADA patients compared to patients with type 1 diabetes. The proportion of CD3-CD56highCD16+ Natural Killer (NK) cells was higher in LADA patients than in both healthy controls and type 2 diabetes patients. IL-35+ Treg cell numbers were similar to those observed in both type 1 diabetes and type 2 diabetes patients, but a lower frequency of IL-35+ regulatory T (Treg) cells was observed in LADA patients than in healthy controls. The proportion of regulatory B (Breg) cells in LADA patients was higher than in healthy controls, type 1 and type 2 diabetes patients and IL-35+ Breg cell numbers were higher than in type 1 diabetes patients. Conclusions: LADA patients present a mixed cellular immunological pattern compared to type 1 and type 2 diabetes patients. Numbers of APCs, IL-35+ tolerogenic APCs and IL-35+ Breg cells in LADA patients are similar to those observed in type 2 diabetes patients, whereas the changes in NK cells are similar to those observed in type 1 diabetes patients.
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| 8. |
- Åhlin, Erik, 1980-, et al.
(författare)
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Occurrence of rheumatoid arthritis-associated autoantibodies in Sudanese patients with Leishmania donovani infection
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Objective Our aim with this investigation was to evaluate the occurrence of anti-cyclic citrullinated peptide antibodies (anti-CCP), rheumatoid factor (RF) and circulating immune complexes (IC) in Sudanese patients infected with Leishmania donovani parasite. Methods Serum samples were collected from Leishmania infected patients and healthy Sudanese controls. Sudanese anti-CCP positive RA patients were included as positive controls. Data from all analyses were also compared with Swedish healthy control cohorts. Levels of circulating IC and anti-CCP were measured using ELISA and RF using nephelometry. A control plate with cyclic control peptides containing arginine instead of citrulline was used to evaluate citrulline specific reactivity. Results We demonstrate that sera from Leishmania infected patients are often RF positive, have elevated IC levels and that a substantial number exhibit antibody reactivity towards CCP. However, contrary to what was evident the in Sudanese RA sera, the CCP reactivity was not restricted to citrulline but reacted equally well with the arginine control peptide. Conclusions Our findings stress the importance to interpret a positive CCP test carefully when evaluated in non-rheumatic conditions.
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- Mullazehi, Mohammed, 1966-, et al.
(författare)
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Anti-type II collagen-IC-induced production of IL-1β and TNF-α, stimulate production of matrix met-alloproteinases from monocytes/rheumatoid arthritis synovial fibroblast co-cultures
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Objective: To establish an in vitro model that might explain the association between early joint destruction and the appearance of collagen type II (CII) antibodies in early Rheumatoid Arthritis (RA) patients. This RA pannus tissue model utilizes immune complexes (IC) containing CII-antibodies as stimulus and monocytes and synovial fibroblastsas responder cells. Methods: Peripheral blood mononuclear cells (PBMC) and RA synovial fibroblasts (RASF) were stimulated with IC individually as well in co-cultures. Monocytes were depleted to define the responder cells, and TNF-α and IL-1β were neutralized to study the effect on MMP production. TNF-α, IL-1β, MMP-1, MMP-8 and MMP-13 were measured in cell culture super-natants using ELISA.Results: Anti-CII-containing IC induced production of TNF-α, IL-1β and MMP-1 in PBMC cultures, and TNF-α, IL-1β, MMP-1 and MMP-8 in PBMC/fibroblast co-cultures, in a dose-dependent manner. IC-induced MMP-1 responses were stronger and more associated with induced produc-tion of IL-1β as compared to MMP-8 responses. Baseline production of IL-1β and MMP-1 increased significantly in co-cultures as compared to indi-vidual cultures, whereas this was not the effect for TNF-α and MMP-8. Monocyte depletion decreased TNF-α, IL-1β and MMP-1 production, while the effect on MMP-8 production was variable. Cytokine neutralization re-vealed that IL-1β was a stronger inducer of MMP-1 than was TNF-α.Conclusion:Synergistic actions between RASF and PBMC result in enhanced anti-CII IC-induced production of IL-1β and MMP-1. IL-1β and MMP-1 are regu-lated in parallel as anti-CII IC-induced IL-1β supports the production of MMP-1. MMP-8 seems to be regulated by other means. Anti-CII IC-induced TNF-α seems to be inferior to IL-1β concerning MMP-1 induction. The fact that IC stimulated synovial macrophages and fibroblasts to produce MMP, which are the first enzymes to cleave the interstitial collagens may explain the anti-CII-associated joint destruction apparent in early RA.
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