scholarly journals Monitoring anti-B cell immunotherapies in autoimmune diseases: Go with the flow. A Position Paper of the Italian Society for Clinical Cell Analysis (ISCCA)

2019 ◽  
Vol 1 (2) ◽  
pp. 52-62
Author(s):  
Bruno Brando ◽  
Arianna Gatti ◽  
Alfredo Maria Lurati ◽  
Paola M.L. Faggioli
Keyword(s):  
Monoclonal Antibodies ◽  
T Cell ◽  
B Cells ◽  
Autoimmune Diseases ◽  
B Cell ◽  
Cell Activation ◽  
Biological Effects ◽  
Individual Response ◽  
Anti Cd20

During the past decades autoimmune diseases have been usually treated with immunosuppressive drugs mostly active on T-Cell mediated responses. Only in recent years, with our extended knowledge of the pathogenic mechanisms of autoreactive disorders and the tremendous development of new therapeutic monoclonal antibodies, anti-B-Cell therapies have emerged as a new option for treating autoimmune diseases. The rationale for this changeover from T-Cell to B-Cell targeted therapies resides in the recently accumulated evidence of the role of B-Cells in the pathogenesis of autoimmune diseases and in the generation of tissue damage. Targeting memory and effector BCells may then disrupt the production of pathogenic antibodies, counteract the role of B-Cells in sustaining antigen presentation to T-Cells and block the synthesis of B-Cell activation cytokines. The anti-CD20 monoclonal antibody Rituximab was first introduced more than 20 years ago for the treatment of CD20+ chronic B-lymphoproliferative disorders, and was then successfully experimented in the treatment of an ever-increasing spectrum of autoimmune diseases. Newer anti-CD20 monoclonal antibodies have been introduced more recently, which vary in their biological effects. The need for laboratory indicators that may help the rational usage and follow-up of anti-CD20 treatments has now emerged, due to the high variability of individual response, to the markedly different outcomes in the various diseases and to the controversial role of pathogenic autoantibodies as indicators of disease activity. Flow cytometric (FCM) analyses to identify and enumerate the B-cell functional subsets in the peripheral blood have been developed in recent years. They can be used to assess the degree and the persistence of memory B-Cell depletion, the quality and the timing of B-Cell reconstitution, along with the highly sensitive FCM counting technique needed for the detection of extremely low cell levels. The long-term aim of this innovative approach is to provide clinicians with a tool for a safer and more rational usage of anti-CD20 agents.

scholarly journals Antiviral Protection and Germinal Center Formation, But Impaired B Cell Memory in the Absence of CD19

1998 ◽  
Vol 188 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Thomas Fehr ◽  
Robert C. Rickert ◽  
Bernhard Odermatt ◽  
Jürgen Roes ◽  
Klaus Rajewsky ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Antibody Responses ◽  
B Cell Activation ◽  
Protein Antigens ◽  
Cell Memory ◽  
B Cell Memory

Coligation of CD19, a molecule expressed during all stages of B cell development except plasmacytes, lowers the threshold for B cell activation with anti-IgM by a factor of 100. The cytoplasmic tail of CD19 contains nine tyrosine residues as possible phosphorylation sites and is postulated to function as the signal transducing element for complement receptor (CR)2. Generation and analysis of CD19 gene–targeted mice revealed that T cell–dependent (TD) antibody responses to proteinaceous antigens were impaired, whereas those to T cell–independent (TI) type 2 antigens were normal or even augmented. These results are compatible with earlier complement depletion studies and the postulated function of CD19. To analyze the role of CD19 in antiviral antibody responses, we immunized CD19−/− mice with viral antigens of TI-1, TI-2, and TD type. The effect of CD19 on TI responses was more dependent on antigen dose and replicative capacity than on antigen type. CR blocking experiments confirmed the role of CD19 as B cell signal transducer for complement. In contrast to immunization with protein antigens, infection of CD19−/− mice with replicating virus led to generation of specific germinal centers, which persisted for >100 d, whereas maintenance of memory antibody titers as well as circulating memory B cells was fully dependent on CD19. Thus, our study confirms a costimulatory role of CD19 on B cells under limiting antigen conditions and indicates an important role for B cell memory.

scholarly journals 702 Dual blockade of the PD-1 checkpoint pathway and the adenosinergic negative feedback signaling pathway with a PD-1/CD73 bispecific antibody for cancer immune therapy

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A744-A744
Author(s):  
Tingting Zhong ◽  
Zhaoliang Huang ◽  
Xinghua Pang ◽  
Na Chen ◽  
Xiaoping Jin ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Activation ◽  
Negative Feedback ◽  
Immune Suppression ◽  
Specific Antibody ◽  
Cell Activation ◽  
Immune Therapy ◽  
B Cell Activation

BackgroundCD73 (ecto-5’-nucleotidase) is an ecto-nucleotidase that dephosphorylate AMP to form adenosine. Activation of adenosine signaling pathway in immune cells leads to the suppression of effector functions, down-regulate macrophage phagocytosis, inhibit pro-inflammatory cytokine release, as well as yield aberrantly differentiated dendritic cells producing pro-tumorigenic molecules.1 In the tumor microenvironment, adenosinergic negative feedback signaling facilitated immune suppression is considered an important mechanism for immune evasion of cancer cells.2 3 Combination of CD73 and anti-PD-1 antibody has shown promising activity in suppressing tumor growth. Hence, we developed AK119, an anti- human CD73 monoclonal antibody, and AK123,a bi-specific antibody targeting both PD-1 and CD73 for immune therapy of cancer.MethodsAK119 is a humanized antibody against CD73 and AK123 is a tetrameric bi-specific antibody targeting PD-1 and CD73. Binding assays of AK119 and AK123 to antigens, and antigen expressing cells were performed by using ELISA, Fortebio, and FACS assays. In-vitro assays to investigate the activity of AK119 and AK123 to inhibit CD73 enzymatic activity in modified CellTiter-Glo assay, to induce endocytosis of CD73, and to activate B cells were performed. Assay to evaluate AK123 activity on T cell activation were additionally performed. Moreover, the activities of AK119 and AK123 to mediate ADCC, CDC in CD73 expressing cells were also evaluated.ResultsAK119 and AK123 could bind to its respective soluble or membrane antigens expressing on PBMCs, MDA-MB-231, and U87-MG cells with high affinity. Results from cell-based assays indicated that AK119 and AK123 effectively inhibited nucleotidase enzyme activity of CD73, mediated endocytosis of CD73, and induced B cell activation by upregulating CD69 and CD83 expression on B cells, and showed more robust CD73 blocking and B cell activation activities compared to leading clinical candidate targeting CD73. AK123 could also block PD-1/PD-L1 interaction and enhance T cell activation.ConclusionsIn summary, AK119 and AK123 represent good preclinical biological properties, which support its further development as an anti-cancer immunotherapy or treating other diseases.ReferencesDeaglio S, Dwyer KM, Gao W, Friedman D, Usheva A, Erat A, Chen JF, Enjyoji K, Linden J, Oukka M, et al. Adenosine generation catalyzed by CD39 and CD73 expressed on regulatory T cells mediates immune suppression. J Exp Med 2007; 204:1257–65.Huang S, Apasov S, Koshiba M, Sitkovsky M. Role of A2a extracellular adenosine receptor-mediated signaling in adenosine-mediated inhibition of T-cell activation and expansion. Blood. 1997; 90:1600–10.Novitskiy SV, Ryzhov S, Zaynagetdinov R, Goldstein AE, Huang Y, Tikhomirov OY, Blackburn MR, Biaggioni I,Carbone DP, Feoktistov I, et al. Adenosine receptors in regulation of dendritic cell differentiation and function. Blood 2008; 112:1822–31.

scholarly journals B cell depletion with anti-CD20 mAb exacerbates anti-donor CD4+ T cell responses in highly sensitized transplant recipients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Asuka Tanaka ◽  
Kentaro Ide ◽  
Yuka Tanaka ◽  
Masahiro Ohira ◽  
Hiroyuki Tahara ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Responses ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Transplant Recipients ◽  
Cell Responses ◽  
Anti Cd20

AbstractPretransplant desensitization with rituximab has been applied to preformed donor-specific anti-human leukocyte antigen antibody (DSA)-positive recipients for elimination of preformed DSA. We investigated the impact of pretransplant desensitization with rituximab on anti-donor T cell responses in DSA-positive transplant recipients. To monitor the patients’ immune status, mixed lymphocyte reaction (MLR) assays were performed before and after desensitization with rituximab. Two weeks after rituximab administration, the stimulation index (SI) of anti-donor CD4+ T cells was significantly higher in the DSA-positive recipients than in the DSA-negative recipients. To investigate the mechanisms of anti-donor hyper responses of CD4+ T cells after B cell depletion, highly sensitized mice models were injected with anti-CD20 mAb to eliminate B cells. Consistent with clinical observations, the SI values of anti-donor CD4+ T cells were significantly increased after anti-CD20 mAb injection in the sensitized mice models. Adding B cells isolated from untreated sensitized mice to MLR significantly inhibited the enhancement of anti-donor CD4+ T cell response. The depletion of the CD5+ B cell subset, which exclusively included IL-10-positive cells, from the additive B cells abrogated such inhibitory effects. These findings demonstrate that IL-10+ CD5+ B cells suppress the excessive response of anti-donor CD4+ T cells responses in sensitized recipients.

scholarly journals Germinal center B cell development has distinctly regulated stages completed by disengagement from T cell help

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Ting-ting Zhang ◽  
David G Gonzalez ◽  
Christine M Cote ◽  
Steven M Kerfoot ◽  
Shaoli Deng ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
B Cell Differentiation ◽  
B Cell Maturation ◽  
Germinal Center B Cell ◽  
T Cell Help ◽  
Dose Dependent

To reconcile conflicting reports on the role of CD40 signaling in germinal center (GC) formation, we examined the earliest stages of murine GC B cell differentiation. Peri-follicular GC precursors first expressed intermediate levels of BCL6 while co-expressing the transcription factors RelB and IRF4, the latter known to repress Bcl6 transcription. Transition of GC precursors to the BCL6hi follicular state was associated with cell division, although the number of required cell divisions was immunogen dose dependent. Potentiating T cell help or CD40 signaling in these GC precursors actively repressed GC B cell maturation and diverted their fate towards plasmablast differentiation, whereas depletion of CD4+ T cells promoted this initial transition. Thus while CD40 signaling in B cells is necessary to generate the immediate precursors of GC B cells, transition to the BCL6hi follicular state is promoted by a regional and transient diminution of T cell help.

Cellular side of acquired immunity (B cells)

2013 ◽  
pp. 371-378
Author(s):  
Thomas Dörner ◽  
Peter E. Lipsky
Keyword(s):  
B Cells ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Plasma Cells ◽  
Adaptive Immune System ◽  
Adaptive Immune ◽  
B Cell Homeostasis ◽  
Anti Cd20 ◽  
Antigen Presenting

B cells have gained interest in rheumatoid arthritis (RA) beyond being the precursors of antibody-producing plasma cells since they are also a broader component of the adaptive immune system. They are capable of functioning as antigen-presenting cells for T-cell activation and can produce an array of cytokines. Disturbances of peripheral B-cell homeostasis together with the formation of ectopic lymphoid neogenesis within the inflamed synovium appears to be a characteristic of patients with RA. Enhanced generation of memory B cells and autoreactive plasma cells producing IgM-RF and ACPA-IgG antibodies together with formation of immune complexes contribute to the maintenance of RA, whereas treatment with B-cell-directed anti-CD20 and CLTA4-Ig therapy provides clinical benefit.

scholarly journals Inhibition of T cell activation in vivo with mixtures of monoclonal antibodies specific for I-A and I-A/E molecules.

1981 ◽  
Vol 154 (1) ◽  
pp. 188-192 ◽  
Author(s):  
J Sprent ◽  
E A Lerner ◽  
J Bruce ◽  
F W Symington
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
T Cell ◽  
B Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Marked Contrast ◽  
Sheep Erythrocytes

(CBA x B6)F1 (Iak x Iab) T cells were activated to sheep erythrocytes in irradiated F1 mice in the presence of various monoclonal anti-Ia reagents and then tested for their capacity to collaborate with B cells from B10.BR (I-Ak, I-Ek) (kk), B10.A(4R) (kb), and B10 (bb) mice. Anti-I-Ak antibodies blocked the generation of help for B10.A(4R) B cells, but not B10.BR or B10 B cells. An anti-I-Ab antibody blocked help for B10 B cells, but not for B10.BR or B10.A(4R) B cells. An antibody (Y-17) specific for I-Ak/Ek and I-Ab/Ek molecules, but not for I-Ak or I-Ab molecules, failed to impair the generation of help for B10.BR, B10.A (4R), or B10 B cells. In marked contrast to injecting each antibody separately, a mixture of anti-I-Ak and anti-I-Ak,b/Ek (Y-17) antibodies virtually abolished the generation of help for B10.BR B cells. A mixture of anti-I-Ak and anti-I-Ab antibodies effectively blocked help for (4R x B10)F1 B cells, i.e., cells expressing hybrid I-A molecules. These two antibodies only marginally impaired help for (CBA x B6)F1 B cells. To block help for (CBA x B6)F1 B cells required selection in the presence of a cocktail of anti-I-Ak, anti-I-Ab, and anti-I-Ak,b/Ek antibodies. The implications of these findings are discussed.

scholarly journals Human leukemic B cell activation: functional consequence of membrane IgM interaction with anti-IgM ligand is an alterable cell characteristic

Blood ◽  
1987 ◽  
Vol 70 (4) ◽  
pp. 1193-1202 ◽  
Author(s):  
P Mongini ◽  
C Blessinger ◽  
S Seremetis ◽  
R Winchester ◽  
S Rudich
Keyword(s):  
Signal Transduction ◽  
T Cell ◽  
B Cells ◽  
Dna Synthesis ◽  
B Cell ◽  
Cell Activation ◽  
Functional Study ◽  
Normal Peripheral Blood ◽  
Activated T Cell ◽  
Cell Supernatant

Abstract A functional study of several human malignant B cell populations has indicated that occasional leukemic clones are extraordinarily sensitive to signal transduction through membrane IgM. One isolated hairy cell leukemia (HCL) with low background DNA synthesis was stimulated to significant levels of DNA synthesis when cultured with high (100 micrograms/mL) concentrations of soluble anti-IgM ligands. In contrast to the activation of normal peripheral blood polyclonal B cells, this DNA synthesis was completely independent of accessory T cell factors. Although the HCL clone could also be induced to enter S phase by incubation in media supplemented with only activated T cell supernatant, culture of the clone with activated T cell supernatant plus anti-IgM Ab resulted in DNA synthesis that was significantly less than that induced by either activator alone. Factor(s) in T cell supernatant appear to modulate the leukemic clone so that the binding of ligand to membrane IgM is perceived as an inhibitory rather than a stimulatory signal for DNA synthesis. In terms of Ig Fc independence and low ligand dose requirements, anti-IgM-mediated inhibitory signal transduction in the T cell supernatant-activated HCL clone was found to mimic anti-IgM mediated suppression of the spontaneous DNA synthesis of an alternative HCL clone. The functional results suggest that the type of signal transduced anti-Ig ligands may reflect differences in the activation state of receptive leukemic B cells.

scholarly journals T Cell Accumulation in B Cell Follicles Is Regulated by Dendritic Cells and Is Independent of B Cell Activation

2003 ◽  
Vol 197 (2) ◽  
pp. 195-206 ◽  
Author(s):  
Simon Fillatreau ◽  
David Gray
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
B Cell Activation ◽  
Cell Accumulation ◽  
Antigen Presenting ◽  
Deficient Mice

We investigated the mechanism of CD4 T cell accumulation in B cell follicles after immunization. Follicular T cell numbers were correlated with the number of B cells, indicating B cell control of the niche that T cells occupy. Despite this, we found no role for B cells in the follicular migration of T cells. Instead, T cells are induced to migrate into B cell follicles entirely as a result of interaction with dendritic cells (DCs). Migration relies on CD40-dependent maturation of DCs, as it did not occur in CD40-deficient mice but was reconstituted with CD40+ DCs. Restoration was not achieved by the activation of DCs with bacterial activators (e.g., lipopolysaccharide, CpG), but was by the injection of OX40L–huIgG1 fusion protein. Crucially, the up-regulation of OX40L (on antigen-presenting cells) and CXCR-5 (on T cells) are CD40-dependent events and we show that T cells do not migrate to follicles in immunized OX40-deficient mice.

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