Prvky imunitní způsobilosti

1 Charles University in Prague Faculty of Medicine in Hradec Kralove Elements of Immune Fitness Mouhammed O. Abuattieh Abstract of the thesis Doctoral study programme Medical Immunology Hradec Kralove 2013 2 Dissertation thesis was written during combined doctoral study (PhD) study programme Medical Immunology at the Department of Immunology and Allergy, Faculty of Medicine in Hradec Králové, Charles University in Prague and Transplantation Biology Programme, Department of Surgery, Mayo Clinic in Rochester, MN, USA. Author: Mouhammed O. Abuattieh M.D Department of Ophthalmology, Washington University Saint Louis MO, USA. Supervisor: Prof. Jan Krejsek, Ph.D. Chairperson, Department of Immunology and Allergy, Faculty of Medicine in Hradec Králové, Charles University in Prague, Faculty Hospital Hradec Králové, Czech Republic Consultant-Supervisor: Assoc. Prof. Marilia Cascalho M.D., Ph.D. Transplantation Biology Program, University of Michigan, Ann Arbor MI, USA Opponents: Assoc. Prof. Milan Raška, MD., Ph.D. University Palacky, Faculty of Medicine, Institute of Immunology, Olomouc, Czech Republic Assoc. Prof. Zuzana Kročová, Ph.D. University of Defence, Faculty of Military Medicine, Institute of Molecular Pathology Hradec Králové, Czech Republic This thesis will be defended at September 2013 at Department of...Prvky imunitní způsobilosti Cílem disertační práce bylo definovat podíl diverzity receptorů pro antigen na funkcích, které určují adaptivní imunitu. Obvykle se předpokládá, že imunologická způsobilost vyžaduje diverzitu lymfocytárních receptorů. My jsme tuto hypotézu ověřili na modelu omezené lymfocytární diverzity. Byla testována způsobilost buňkami zprostředkované imunity myší s omezenou diverzitou receptorů TCR. Byl ověřen vliv omezené diverzity receptorů TCR na vznik B lymfocytární odpovědi indukované modelovými antigeny. Koncept způsobilosti buňkami zprostředkované imunity ve vazbě na diverzitu receptorů PCR byl ověřen na myších experimentálních modelech, který zahrnovaly myši JH-/- , u kterých nejsou vyvinuty B lymfocyty a mají diverzitu receptorů TCR 99 % a projevují známky defektní organogeneze lymfoidních orgánů. Myši JH-/- reagují aktivací T lymfocytů po stimulaci peptidem a vykazují opožděný typ hypersenzitivity, přestože intenzita těchto reakcí je...Department of Clinical Immunology and AllergologyÚstav klinické imunologie a alergologieLékařská fakulta v Hradci KrálovéFaculty of Medicine in Hradec Králov

B cell depletion reduces the development of atherosclerosis in mice

B cell depletion significantly reduces the burden of several immune-mediated diseases. However, B cell activation has been until now associated with a protection against atherosclerosis, suggesting that B cell–depleting therapies would enhance cardiovascular risk. We unexpectedly show that mature B cell depletion using a CD20-specific monoclonal antibody induces a significant reduction of atherosclerosis in various mouse models of the disease. This treatment preserves the production of natural and potentially protective anti–oxidized low-density lipoprotein (oxLDL) IgM autoantibodies over IgG type anti-oxLDL antibodies, and markedly reduces pathogenic T cell activation. B cell depletion diminished T cell–derived IFN-γ secretion and enhanced production of IL-17; neutralization of the latter abrogated CD20 antibody–mediated atheroprotection. These results challenge the current paradigm that B cell activation plays an overall protective role in atherogenesis and identify new antiatherogenic strategies based on B cell modulation

Tolerance has its limits: how the thymus copes with infection

The thymus is required for T cell differentiation; a process that depends on which antigens are encountered by thymocytes, the environment surrounding the differentiating cells, and the thymic architecture. These features are altered by local infection of the thymus and by the inflammatory mediators that accompany systemic infection. Although once believed to be an immune privileged site, it is now known that antimicrobial responses are recruited to the thymus. Resolving infection in the thymus is important because chronic persistence of microbes impairs the differentiation of pathogen-specific T cells and diminishes resistance to infection. Understanding how these mechanisms contribute to disease susceptibility, particularly in infants with developing T cell repertoires, requires further investigation.We thank Joana Neves and Nadine Santos for critical reading of the manuscript. This work was supported by Portuguese Foundation for Science and Technology (FCT) grant PTDC/SAU-MII/101663/2008 and individual fellowships to CN-A and CN. SMB was supported by National Institutes of Health Grant R01 R56 AI067731

Elements of Immune Fitness

1 Charles University in Prague Faculty of Medicine in Hradec Kralove Elements of Immune Fitness Mouhammed O. Abuattieh Abstract of the thesis Doctoral study programme Medical Immunology Hradec Kralove 2013 2 Dissertation thesis was written during combined doctoral study (PhD) study programme Medical Immunology at the Department of Immunology and Allergy, Faculty of Medicine in Hradec Králové, Charles University in Prague and Transplantation Biology Programme, Department of Surgery, Mayo Clinic in Rochester, MN, USA. Author: Mouhammed O. Abuattieh M.D Department of Ophthalmology, Washington University Saint Louis MO, USA. Supervisor: Prof. Jan Krejsek, Ph.D. Chairperson, Department of Immunology and Allergy, Faculty of Medicine in Hradec Králové, Charles University in Prague, Faculty Hospital Hradec Králové, Czech Republic Consultant-Supervisor: Assoc. Prof. Marilia Cascalho M.D., Ph.D. Transplantation Biology Program, University of Michigan, Ann Arbor MI, USA Opponents: Assoc. Prof. Milan Raška, MD., Ph.D. University Palacky, Faculty of Medicine, Institute of Immunology, Olomouc, Czech Republic Assoc. Prof. Zuzana Kročová, Ph.D. University of Defence, Faculty of Military Medicine, Institute of Molecular Pathology Hradec Králové, Czech Republic This thesis will be defended at September 2013 at Department of..

TLR2 and TLR4 expression on blood monocytes and granulocytes of cardiac surgical patients is not affected by the use of cardiopulmonary bypass.

Cardiac surgery is inseparably linked to the activation of innate immunity cells recognizing danger signals of both endogenous and exogenous origin via pattern recognition receptors such as TLR receptors. Therefore, we followed by flow cytometry TLR2 and TLR4 expression on blood monocytes and granulocytes of patients who underwent coronary artery bypass grafting using beating heart surgery (off-pump, n = 34), with use of standard cardiopulmonary bypass (CPB), (on-pump, n = 30), and miniinvasive CPB (mini on-pump, n = 25), respectively, before, during surgery, and up to 7th postoperative day. TLR2 and TLR4 expression both on monocytes and granulocytes was significantly diminished already at the end of CPB being highly significantly decreased at the end of surgery in all patients\u27 groups. TLR2 and TLR4 expression reached preoperative value at the 1st postoperative day being significantly higher at the 3rd postoperative day. Using intracellular staining we found the peak of TLR2 and TLR4 expression inside of monocytes and granulocytes at the first postoperative day in a subgroup of on-pump patients. In conclusion, TLR2 and TLR4 expression is significantly modulated in patients undergoing coronary artery bypass grafting as a part of adaptive homeostatic mechanisms induced by major surgery. The very surgical trauma is responsible for TLR2 and TLR4 modulation. Surprisingly, cardiopulmonary bypass itself was little contributing to the modulation of TLR2 and TLR4 expression

TLR2 AND TLR4 EXPRESSION ON BLOOD MONOCYTES AND GRANULOCYTES OF CARDIAC SURGICAL PATIENTS IS NOT AFFECTED BY THE USE OF CARDIOPULMONARY BYPASS

Cardiac surgery is inseparably linked to the activation of innate immunity cells recognizing danger signals of both endogenous and exogenous origin via pattern recognition receptors such as TLR receptors. Therefore, we followed by flow cytometry TLR2 and TLR4 expression on blood monocytes and granulocytes of patients who underwent coronary artery bypass grafting using beating heart surgery (off-pump, n = 34), with use of standard cardiopulmonary bypass (CPB), (on-pump, n = 30), and miniinvasive CPB (mini on-pump, n = 25), respectively, before, during surgery, and up to 7th postoperative day. TLR2 and TLR4 expression both on monocytes and granulocytes was significantly diminished already at the end of CPB being highly significantly decreased at the end of surgery in all patients’ groups. TLR2 and TLR4 expression reached preoperative value at the 1st postoperative day being significantly higher at the 3rd postoperative day. Using intracellular staining we found the peak of TLR2 and TLR4 expression inside of monocytes and granulocytes at the first postoperative day in a subgroup of on-pump patients. In conclusion, TLR2 and TLR4 expression is significantly modulated in patients undergoing coronary artery bypass grafting as a part of adaptive homeostatic mechanisms induced by major surgery. The very surgical trauma is responsible for TLR2 and TLR4 modulation. Surprisingly, cardiopulmonary bypass itself was little contributing to the modulation of TLR2 and TLR4 expression

Fitness of cell-mediated immunity independent of repertoire diversity.

Fitness of cell-mediated immunity is thought to depend on TCR diversity; however, this concept has not been tested formally. We tested the concept using JH(-/-) mice that lack B cells and have TCR Vbeta diversity99% and defective lymphoid organogenesis, JH(-/-) mice rejected H-Y-incompatible skin grafts as rapidly as wild-type mice. JH(-/-) mice exhibited T cell priming by peptide and delayed-type hypersensitivity, although these responses were less than normal owing either to TCR repertoire contraction or defective lymphoid organogenesis. QM mice with TCR diversity contracted \u3e90%, and normal lymphoid organs rejected H-Y incompatible skin grafts as rapidly as wild type mice and exhibited normal T cell priming and normal delayed-type hypersensitivity reactions. QM mice also resisted Pneumocystis murina like wild-type mice. Thus, cell-mediated immunity can function normally despite contractions of TCR diversity \u3e90% and possibly \u3e99%

Regulatory B cells inhibit EAE initiation in mice while other B cells promote disease progression

EAE is a mouse T cell–mediated autoimmune disease of the CNS used to model the human condition MS. The contributions of B cells to EAE initiation and progression are unclear. In this study, we have shown that EAE disease initiation and progression are differentially influenced by the depletion of B cells from mice with otherwise intact immune systems. CD20 antibody–mediated B cell depletion before EAE induction substantially exacerbated disease symptoms and increased encephalitogenic T cell influx into the CNS. Increased symptom severity resulted from the depletion of a rare IL-10–producing CD1dhiCD5+ regulatory B cell subset (B10 cells), since the adoptive transfer of splenic B10 cells before EAE induction normalized EAE in B cell–depleted mice. While transfer of regulatory B10 cells was maximally effective during early EAE initiation, they had no obvious role during disease progression. Rather, B cell depletion during EAE disease progression dramatically suppressed symptoms. Specifically, B cells were required for the generation of CD4+ T cells specific for CNS autoantigen and the entry of encephalitogenic T cells into the CNS during disease progression. These results demonstrate reciprocal regulatory roles for B cells during EAE immunopathogenesis. The therapeutic effect of B cell depletion for the treatment of autoimmunity may therefore depend on the relative contributions and the timing of these opposing B cell activities during the course of disease initiation and pathogenesis