scholarly journals On the Key Role of Secondary Lymphoid Organs in Antiviral Immune Responses Studied in Alymphoplastic (aly/aly) and Spleenless (Hox11−/−) Mutant Mice

1997 ◽  
Vol 185 (12) ◽  
pp. 2157-2170 ◽  
Author(s):  
Urs Karrer ◽  
Alana Althage ◽  
Bernhard Odermatt ◽  
Charles W.M. Roberts ◽  
Stanley J. Korsmeyer ◽  
...  
Keyword(s):  
B Cells ◽  
Immune Responses ◽  
Critical Role ◽  
Homeobox Gene ◽  
Lymphocytic Choriomeningitis ◽  
Lymphoid Organs ◽  
Mutant Mice ◽  
Virus Infections ◽  
Secondary Lymphoid Organs

The role of the spleen and of other organized secondary lymphoid organs for the induction of protective antiviral immune responses was evaluated in orphan homeobox gene 11 knockout mice (Hox11−/−) lacking the spleen, and in homozygous alymphoplastic mutant mice (aly/aly) possessing a structurally altered spleen but lacking lymph nodes and Peyer's patches. Absence of the spleen had no major effects on the immune response, other than delaying the antibody response by 1–2 d. In aly/aly mice, the thymus-independent IgM response against vesicular stomatitis virus (VSV) was delayed and reduced, whereas the T-dependent switch to the protective IgG was absent. Therefore, aly/aly mice were highly susceptible to VSV infection. Since aly/aly spleen cells yielded neutralizing IgM and IgG after adoptive transfer into recipients with normally structured secondary lymphoid organs, these data suggest that the structural defect was mainly responsible for inefficient T–B cooperation. Although aly/aly mice generated detectable, but reduced, CTL responses after infection with vaccinia virus (VV) and lymphocytic choriomeningitis virus (LCMV), the elimination of these viruses was either delayed (VV) or virtually impossible (LCMV); irrespective of the dose or the route of infection, aly/aly mice developed life-long LCMV persistence. These results document the critical role of organized secondary lymphoid organs in the induction of naive T and B cells. These structures also provide the basis for cooperative interactions between antigen-presenting cells, T cells, and B cells, which are a prerequisite for recovery from primary virus infections via skin or via blood.

Allogeneic Environment and Tissue Damage Provide Critical Stimuli for Regulatory T Cell Expansion and Survival In Vivo after Hematopoietic Cell Transplantation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1731-1731
Author(s):  
Vu H. Nguyen ◽  
Daisy Chang ◽  
Robert S. Negrin
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Tissue Damage ◽  
Hematopoietic Cell Transplantation ◽  
Critical Role ◽  
Lymphoid Organs ◽  
Gamma Chain ◽  
Secondary Lymphoid Organs

Abstract CD4+CD25+ regulatory T cells (Treg) mediate alloresponses in murine models of bone marrow transplantation (BMT), leading to protection from graft-versus-host disease (GvHD). However, in vivo migration and tissue localization of Treg during this inflammatory response remain unclear. We previously demonstrated co-localization of Treg with effector T cells (Tcon) with initial expansion in secondary lymphoid organs prior to migration into inflamed tissues in a major MHC-mismatched BMT model. To explore the stimuli for Treg proliferation, we evaluated the role of the allogeneic environment by transferring FVB donor luciferase-expressing (luc+) Treg into lethally-irradiated syngeneic recipients. Unlike the allogeneic irradiated setting where Treg expand in the presence or absence of Tcon, adoptively transferred luc+ Treg were not detected in secondary lymphoid organs of syngeneic lethally-irradiated BMT recipients by in vivo bioluminescence imaging (BLI). Syngeneic luc+ Tcon also had significantly different in vivo dynamics, with a 4 day delay and only moderate expansion in lymph nodes. Proliferation was not detected in the spleen, unlike their allogeneic Tcon counterparts, nor in the bone marrow compartments, as seen in lymphopenic models. To assess whether irradiation induced the observed in vivo dynamics of Treg in the allogeneic setting, we transferred FVB luc+ Treg or luc+ Tcon into unirradiated Balb/c Rag2−/−gamma chain (γC) −/− recipients, which lack T, B, and NK cells. After adoptive transfer into Rag2−/−γC−/− recipients, robust Tcon proliferation was observed in secondary lymphoid organs and the bone marrow compartments; however, Treg expansion was weak, and specific localization to lymphoid or nonlymphoid tissues was not observed. Treg were stimulated to localize to and expand in secondary lymphoid organs by the co-transfer of Tcon in unirradiated Rag2−/− (γC) −/− or by conditioning Rag2−/− (γC) −/− recipients with irradiation. Exogenous IL2 administration two weeks following luc+ Treg transfer into unirradiated Rag2−/− (γC) −/− recipients similarly led to localization and expansion of Treg in secondary lymphoid organs. These studies indicate the critical role of proinflammatory cytokines, such as IL2, generated either by irradiation-induced tissue damage or donor Tcon, in the expansion and localization of Treg. Differences between Tcon and Treg expansion in syngeneic or unconditioned allogeneic Rag2−/− γC−/− hosts suggest an important role of conditioning with irradiation alone or in concert with the allogeneic environment, in providing distinct signals for Tcon versus Treg activation, proliferation, and localization.

Impaired germinal center formation and recall T-cell–dependent immune responses in mice lacking the costimulatory ligand B7-H2

Blood ◽  
2003 ◽  
Vol 102 (4) ◽  
pp. 1381-1388 ◽  
Author(s):  
Siew-Cheng Wong ◽  
Edwin Oh ◽  
Chee-Hoe Ng ◽  
Kong-Peng Lam
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Immune Responses ◽  
Heavy Chain ◽  
Germinal Center ◽  
Critical Role ◽  
Mutant Mice ◽  
Type Ii ◽  
Germinal Center Formation

Abstract B7-H2, which is expressed constitutively on B cells and binds the inducible costimulator (ICOS) on antigen-activated T cells, is a member of the B7 family of costimulatory ligands. We have inactivated B7-H2 in the mouse. B7-H2–/– mice generate normal populations of B and T cells in their various lymphoid organs but have lower basal levels of heavy chain class–switched antibodies in their sera. These mice are able to mount normal immune responses to both type I and type II T-cell–independent antigens. However, their pattern of responses to a T-cell–dependent antigen is altered, with greatly reduced production of antigen-specific heavy chain class–switched antibodies, the levels of which could not be elevated even with repeated immunizations. This suggests a critical role for B7-H2 in the recall phases of the immune response. Germinal center formation is also impaired in the mutant mice. While B cells from the mutant mice could response normally to anti-IgM, anti-CD40, and lipopolysaccharide stimulation, the production of T-helper–type II cytokines such as interleukin-4 (IL-4) and IL-10 by primed CD4+ T cells from mutant mice were reduced. This indicated that the defects in humoral responses and germinal center formation in B7-H2–deficient mice are due to the lack of T-cell–mediated help to the B cells. Hence, B7-H2 on B cells is important for recruiting T-cell help via its interaction with ICOS and plays a critical role in costimulating humoral immune responses.

scholarly journals α4-integrin deficiency in B cells does not affect disease in a T-cell–mediated EAE disease model

2019 ◽  
Vol 6 (4) ◽  
pp. e563
Author(s):  
Rehana Z. Hussain ◽  
Petra D. Cravens ◽  
William A. Miller-Little ◽  
Richard Doelger ◽  
Valerie Granados ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Adoptive Transfer ◽  
Lymphoid Organs ◽  
Pathogenic Role ◽  
Genetic Ablation ◽  
Secondary Lymphoid Organs ◽  
The Brain

ObjectiveThe goal of this study was to investigate the role of CD 19+ B cells within the brain and spinal cord during CNS autoimmunity in a peptide-induced, primarily T-cell–mediated experimental autoimmune encephalomyelitis (EAE) model of MS. We hypothesized that CD19+ B cells outside the CNS drive inflammation in EAE.MethodsWe generated CD19.Cre+/− α4-integrinfl/fl mice. EAE was induced by active immunization with myelin oligodendrocyte glycoprotein peptide (MOGp35-55). Multiparameter flow cytometry was used to phenotype leukocyte subsets in primary and secondary lymphoid organs and the CNS. Serum cytokine levels and Ig levels were assessed by bead array. B-cell adoptive transfer was used to determine the compartment-specific pathogenic role of antigen-specific and non–antigen-specific B cells.ResultsA genetic ablation of α4-integrin in CD19+/− B cells significantly reduced the number of CD19+ B cells in the CNS but does not affect EAE disease activity in active MOGp35-55-induced disease. The composition of B-cell subsets in the brain, primary lymphoid organs, and secondary lymphoid organs of CD19.Cre+/− α4-integrinfl/fl mice was unchanged during MOGp35-55-induced EAE. Adoptive transfer of purified CD19+ B cells from CD19.Cre+/− α4-integrinfl/fl mice or C57BL/6 wild-type (WT) control mice immunized with recombinant rMOG1-125 or ovalbumin323-339 into MOGp35-55-immunized CD19.Cre+/− α4-integrinfl/fl mice caused worse clinical EAE than was observed in MOGp35-55-immunized C57BL/6 WT control mice that did not receive adoptively transferred CD19+ B cells.ConclusionsObservations made in CD19.Cre+/− α4-integrinfl/fl mice in active MOGp35-55-induced EAE suggest a compartment-specific pathogenic role of CD19+ B cells mostly outside of the CNS that is not necessarily antigen specific.

scholarly journals Lymphoid Tissue Mesenchymal Stromal Cells in Development and Tissue Remodeling

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Luca Genovese ◽  
Andrea Brendolan
Keyword(s):  
Immune Responses ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Cell Activation ◽  
Critical Role ◽  
Tissue Remodeling ◽  
Stromal Microenvironment ◽  
Inflammatory Conditions ◽  
Secondary Lymphoid Organs

Secondary lymphoid organs (SLOs) are sites that facilitate cell-cell interactions required for generating adaptive immune responses. Nonhematopoietic mesenchymal stromal cells have been shown to play a critical role in SLO function, organization, and tissue homeostasis. The stromal microenvironment undergoes profound remodeling to support immune responses. However, chronic inflammatory conditions can promote uncontrolled stromal cell activation and aberrant tissue remodeling including fibrosis, thus leading to tissue damage. Despite recent advancements, the origin and role of mesenchymal stromal cells involved in SLO development and remodeling remain unclear.

scholarly journals Sphingosine-1-Phosphate Receptor Type 4 (S1P4) Is Differentially Regulated in Peritoneal B1 B Cells upon TLR4 Stimulation and Facilitates the Egress of Peritoneal B1a B Cells and Subsequent Accumulation of Splenic IRA B Cells under Inflammatory Conditions

2021 ◽  
Vol 22 (7) ◽  
pp. 3465
Author(s):  
Janik Riese ◽  
Alina Gromann ◽  
Felix Lührs ◽  
Annabel Kleinwort ◽  
Tobias Schulze
Keyword(s):  
B Cells ◽  
B Cell ◽  
Peritoneal Cavity ◽  
Lymphoid Organs ◽  
Receptor Expression ◽  
Inflammatory Conditions ◽  
Sphingosine 1 Phosphate ◽  
Secondary Lymphoid Organs

Background: Gram-negative infections of the peritoneal cavity result in profound modifications of peritoneal B cell populations and induce the migration of peritoneal B cells to distant secondary lymphoid organs. However, mechanisms controlling the egress of peritoneal B cells from the peritoneal cavity and their subsequent trafficking remain incompletely understood. Sphingosine-1-phosphate (S1P)-mediated signaling controls migratory processes in numerous immune cells. The present work investigates the role of S1P-mediated signaling in peritoneal B cell trafficking under inflammatory conditions. Methods: Differential S1P receptor expression after peritoneal B cell activation was assessed semi‑quantitatively using RT-PCR in vitro. The functional implications of differential S1P1 and S1P4 expression were assessed by transwell migration in vitro, by adoptive peritoneal B cell transfer in a model of sterile lipopolysaccharide (LPS)‑induced peritonitis and in the polymicrobial colon ascendens stent peritonitis (CASP) model. Results: The two sphingosine-1-phosphate receptors (S1PRs) expressed in peritoneal B cell subsets S1P1 and S1P4 are differentially regulated upon stimulation with the TLR4 agonist LPS, but not upon PMA/ionomycin or B cell receptor (BCR) crosslinking. S1P4 deficiency affects both the trafficking of activated peritoneal B cells to secondary lymphoid organs and the positioning of these cells within the functional compartments of the targeted organ. S1P4 deficiency in LPS-activated peritoneal B cells results in significantly reduced numbers of splenic innate response activator B cells. Conclusions: The S1P-S1PR system is implicated in the trafficking of LPS-activated peritoneal B cells. Given the protective role of peritoneal B1a B cells in peritoneal sepsis, further experiments to investigate the impact of S1P4-mediated signaling on the severity and mortality of peritoneal sepsis are warranted.

scholarly journals THU0053 CONTRIBUTION OF DEFECTIVE NON-APOPTOTIC FAS SIGNALING TO IMMUNE DYSREGULATION IN AUTOIMMUNE LYMPHOPROLIFERATIVE SYNDROME (ALPS)

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 238.3-238
Author(s):  
J. Staniek ◽  
T. Kalina ◽  
G. Andrieux ◽  
M. Boerries ◽  
I. Janowska ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Signaling Pathway ◽  
Germinal Center ◽  
Lymphoid Organs ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
Fas Signaling ◽  
Secondary Lymphoid Organs

Background:ALPS patients show impaired generation of humoral memory for T independent antigens whereas they generate memory for self-antigens due to impaired FAS-dependent removal of autoreactive germinal center B cells. It is known that FAS signaling via caspase activation results in cell apoptosis. However, FAS ligation may also initiate or modulate non-apoptotic signaling as shown for example by its ability to activate NF-κB. Recent data implicate a regulatory role of FAS in the modulation of mTOR signaling in ALPS double-negative T cells. Moreover, a recently described C194V FAS mutation disturbs its post-translational modification leading to impaired apoptosis induction while non-apoptotic signalling is still intact. Consequently, C194V FAS protects from the autoimmune phenotype in the murine ALPS system. This supports the view that FAS may prevent autoimmunity with other mechanisms than inducing apoptosis.Objectives:We hypothesize that FAS mutations impair this modulatory signaling, leading to hyper-activation of B cells. Therefore we aim to investigate non apoptotic FAS signaling in B cells derived from healthy individuals and ALPS patients.Methods:We studied resting and activated B cells in ALPS patients in presence or absence of FAS ligand by flow cytometry analysing relevant molecules to the CD40 signaling pathway. We used mass cytometry to perform functional phenotyping of B cells isolated from secondary lymphoid organs. Proteomic studies were performed to identify potential signaling circuits and RNA sequencing to study the consequences of FAS signaling on B cell fate.Results:In CD40L activated B cells, FAS signaling results in specific modulation of the mTOR signaling pathway. This modulation is absent in ALPS derived B cells. In line with these data germinal center B cells and plasmablast from secondary lymphoid organs of ALPS patients show hyperactive mTOR signaling pathway. Proteomic studies identify a circuit that links FAS to the phosphatase PTEN via DAXX and the deubiquitinase USP7.Conclusion:We describe a new role of FAS in the regulation of B cell activation. Defects in FAS signaling in ALPS contribute to dysregulation of the mTOR signaling pathway and disturbed B cell development.Disclosure of Interests:None declared

scholarly journals Critical role of the IgM Fc receptor in IgM homeostasis, B-cell survival, and humoral immune responses

2012 ◽  
Vol 109 (40) ◽  
pp. E2699-E2706 ◽  
Author(s):  
R. Ouchida ◽  
H. Mori ◽  
K. Hase ◽  
H. Takatsu ◽  
T. Kurosaki ◽  
...  
Keyword(s):  
Immune Responses ◽  
B Cell ◽  
Cell Survival ◽  
Critical Role ◽  
Fc Receptor ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
B Cell Survival

scholarly journals Role of ChemR23 in directing the migration of myeloid and plasmacytoid dendritic cells to lymphoid organs and inflamed skin

2005 ◽  
Vol 201 (4) ◽  
pp. 509-515 ◽  
Author(s):  
William Vermi ◽  
Elena Riboldi ◽  
Valerie Wittamer ◽  
Francesca Gentili ◽  
Walter Luini ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Lupus Erythematosus ◽  
Normal Skin ◽  
Cell Monolayer ◽  
Lymphoid Organs ◽  
High Endothelial Venules ◽  
Luminal Side ◽  
Plasmacytoid Dcs ◽  
Secondary Lymphoid Organs

Chemerin is a chemotactic agent that was recently identified as the ligand of ChemR23, a serpentine receptor expressed by activated macrophages and monocyte-derived dendritic cells (DCs). This paper shows that blood plasmacytoid and myeloid DCs express functional ChemR23. Recombinant chemerin induced the transmigration of plasmacytoid and myeloid DCs across an endothelial cell monolayer. In secondary lymphoid organs (lymph nodes and tonsils), ChemR23 is expressed by CD123+ plasmacytoid DCs and by CD1a+ DC-SIGN+ DCs in the interfollicular T cell area. ChemR23+ DCs were also observed in dermis from normal skin, whereas Langerhans cells were negative. Chemerin expression was selectively detected on the luminal side of high endothelial venules in secondary lymphoid organs and in dermal endothelial vessels of lupus erythematosus skin lesions. Chemerin+ endothelial cells were surrounded by ChemR23+ plasmacytoid DCs. Thus, ChemR23 is expressed and functional in plasmacytoid DCs, a property shared only by CXCR4 among chemotactic receptors. This finding, together with the selective expression of the cognate ligand on the luminal side of high endothelial venules and inflamed endothelium, suggests a key role of the ChemR23/chemerin axis in directing plasmacytoid DC trafficking.

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