scholarly journals CellCelector™ as a platform in isolating primary B cells for antibody discovery

2022 ◽  
Author(s):  
Wadim L Matochko ◽  
Constantin Nelep ◽  
Weihsu C Chen ◽  
Stephanie Grauer ◽  
Karyn McFadden ◽  
...  

Abstract Background The most robust strategy in antibody discovery is the use of immunized animals and the ability to isolate and immortalize immune B-cells to hybridoma for further interrogation. However, capturing the full repertoire of an immunized animal is labor intensive, time consuming, and limited in throughput. Therefore, techniques to directly mine the antibody repertoire of primary B-cells are of great importance in antibody discovery. Methods In the current study, we present a method to isolate individual antigen specific primary B-cells using the CellCellector™ single-cell isolation platform from XenoMouse® (XM) immunized with a recombinant therapeutic protein, EGFR. We screened a subset of CD138+ B-cells and identified 238 potential EGFR specific B-cells from 1,189 antibody secreting cells (ASCs) and isolated 94 by CellCellector. Results We identified a diverse set of heavy chain CDR sequences and cloned and expressed 20 into a standard human IgG1 antibody format. We further characterized and identified 13 recombinant antibodies that engage soluble and native forms of EGFR. By extrapolating the method to all 400,000 CD138+ B-cells extracted from one EGFR immunized XM, a potential 1,196 unique EGFR-specific antibodies could be discovered. Conclusions CellCelector allows for interrogating the B-cell pool directly and isolating B-cells specific to the therapeutic target of interest. Furthermore, antibody sequences recovered from isolated B-cells engage the native and recombinant target, demonstrating the CellCellector can serve as a platform in antibody discovery.

Blood ◽  
1998 ◽  
Vol 91 (1) ◽  
pp. 173-180 ◽  
Author(s):  
Kazunaga Agematsu ◽  
Haruo Nagumo ◽  
Yumiko Oguchi ◽  
Takayuki Nakazawa ◽  
Keitaro Fukushima ◽  
...  

B cells can differentiate into the antibody-secreting cells, plasma cells, whereas the crucial signals that positively control the entry into the pathway to plasma cells have been unclear. Triggering via CD27 by CD27 ligand (CD70) on purified peripheral blood B cells yielded an increase in the number of plasma cells in the presence of interleukin-10 (IL-10). Differentiation into plasma cells by a combination of IL-10 and CD70 transfectants occurred in CD27+ B cells but not in CD27− B cells. Moreover, addition of IL-2 to the IL-10 and CD70-transfect activation system greatly induced differentiation into plasma cells. In the presence of only IL-2, IL-4, or IL-6, CD70 transfectants did not promote differentiation into plasma cells. On the other hand, CD40 signaling increased the expansion of a B-cell pool from peripheral blood B cells primarily activated by IL-2, IL-10, and anti-CD40 monoclonal antibody (MoAb). Finally, CD27 signaling also rescued B cells from IL-10–mediated apoptosis. These data demonstrate that CD27 ligand (CD70) is a key molecule to prevent the IL-10–mediated promotion of apoptosis and to direct the differentiation of CD27+ memory B cells toward plasma cells in cooperation with IL-10.


Blood ◽  
1998 ◽  
Vol 91 (1) ◽  
pp. 173-180 ◽  
Author(s):  
Kazunaga Agematsu ◽  
Haruo Nagumo ◽  
Yumiko Oguchi ◽  
Takayuki Nakazawa ◽  
Keitaro Fukushima ◽  
...  

Abstract B cells can differentiate into the antibody-secreting cells, plasma cells, whereas the crucial signals that positively control the entry into the pathway to plasma cells have been unclear. Triggering via CD27 by CD27 ligand (CD70) on purified peripheral blood B cells yielded an increase in the number of plasma cells in the presence of interleukin-10 (IL-10). Differentiation into plasma cells by a combination of IL-10 and CD70 transfectants occurred in CD27+ B cells but not in CD27− B cells. Moreover, addition of IL-2 to the IL-10 and CD70-transfect activation system greatly induced differentiation into plasma cells. In the presence of only IL-2, IL-4, or IL-6, CD70 transfectants did not promote differentiation into plasma cells. On the other hand, CD40 signaling increased the expansion of a B-cell pool from peripheral blood B cells primarily activated by IL-2, IL-10, and anti-CD40 monoclonal antibody (MoAb). Finally, CD27 signaling also rescued B cells from IL-10–mediated apoptosis. These data demonstrate that CD27 ligand (CD70) is a key molecule to prevent the IL-10–mediated promotion of apoptosis and to direct the differentiation of CD27+ memory B cells toward plasma cells in cooperation with IL-10.


1992 ◽  
Vol 176 (2) ◽  
pp. 427-438 ◽  
Author(s):  
B Schittek ◽  
K Rajewsky

While most murine peripheral B cells express germline-encoded antibodies of classes M and D (mu+ delta+ cells), small numbers of memory B cells expressing somatically mutated immunoglobulin G antibodies are generated upon T cell-dependent immunization. Analyzing the antibody repertoire of the mu-delta- B cell pool in unimmunized mice, we show that these cells express somatically mutated VH genes and that most of these genes derive from a set of germline VH genes dominantly expressed by mu+delta+ B cells. Thus, class-switched memory B cells are generated in the absence of intentional immunization, presumably in response to environmental antigens. These cells are either recruited from mu+delta+ B cells or selected from newly arising B cells in parallel to the latter, by the same antigens.


2020 ◽  
Author(s):  
Emily S. Ford ◽  
Anton M. Sholukh ◽  
RuthMabel Boytz ◽  
Savanna S. Carmack ◽  
Alexis Klock ◽  
...  

AbstractTissue-based T cells increasingly have been shown to be important effectors in the control and prevention of mucosal viral infections – less is known about tissue-based B cells. We demonstrate that B cells and antibody-secreting cells (ASCs) are present in skin biopsies of persons with symptomatic HSV-2 reactivation. CD20+ B cells are observed in inflammatory infiltrates at greatest density at the time of symptomatic reactivation; HSV-2-specific antibodies to HSV-2 surface antigens are also detected. The concentrations of HSV-2-specific antibodies in tissue biopsies vary over the course of HSV-2 reactivation and healing, unlike serum where concentrations remain static over time. B cells and HSV-specific antibody were rarely present in biopsies of unaffected skin. Investigation of serial biopsies over the course of lesion healing suggests that B cells follow a more migratory than resident pattern of infiltration in HSV-affected genital skin, in contrast to T cells. Together, these observations may suggest a functional and distinct role of tissue-based B cells in the local immune response to HSV-2.


2020 ◽  
Vol 11 ◽  
Author(s):  
Tatsuya Yamazaki ◽  
Mrityunjoy Biswas ◽  
Kouyu Kosugi ◽  
Maria Nagashima ◽  
Masanori Inui ◽  
...  

Radioprotective 105 (RP105) (also termed CD180) is an orphan and unconventional Toll-like receptor (TLR) that lacks an intracellular signaling domain. The agonistic anti-RP105 monoclonal antibody (mAb) can cross-link RP105 on B cells, resulting in the proliferation and activation of B cells. Anti-RP105 mAb also has a potent adjuvant effect, providing higher levels of antigen-specific antibodies compared to alum. However, adjuvanticity is required for the covalent link between anti-RP105 mAb and the antigen. This is a possible obstacle to immunization due to the link between anti-RP105 mAb and some antigens, especially multi-transmembrane proteins. We have previously succeeded in inducing rapid and potent recombinant mAbs in mice using antibody gene-based delivery. To simplify the covalent link between anti-RP105 mAb and antigens, we generated genetic constructs of recombinant anti-RP105 mAb (αRP105) bound to the transmembrane domain of the IgG-B cell receptor (TM) (αRP105-TM), which could enable the anti-RP105 mAb to link the antigen via the cell membrane. We confirmed the expression of αRP105-TM and the antigen hemagglutinin, which is a membrane protein of the influenza virus, on the same cell. We also found that αRP105-TM could activate splenic B cells, including both mature and immature cells, depending on the cell surface RP105 in vitro. To evaluate the adjuvanticity of αRP105-TM, we conducted DNA immunization in mice with the plasmids encoding αRP105-TM and hemagglutinin, followed by challenge with an infection of a lethal dose of an influenza virus. We then obtained partially but significantly hemagglutinin-specific antibodies and observed protective effects against a lethal dose of influenza virus infection. The current αRP105-TM might provide adjuvanticity for a vaccine via a simple preparation of the expression plasmids encoding αRP105-TM and of that encoding the target antigen.


2022 ◽  
Vol 11 (1) ◽  
pp. 270
Author(s):  
Martina Hinterleitner ◽  
Clemens Hinterleitner ◽  
Elke Malenke ◽  
Birgit Federmann ◽  
Ursula Holzer ◽  
...  

Immune cell reconstitution after stem cell transplantation is allocated over several stages. Whereas cells mediating innate immunity recover rapidly, adaptive immune cells, including T and B cells, recover slowly over several months. In this study we investigated kinetics and reconstitution of de novo B cell formation in patients receiving CD3 and CD19 depleted haploidentical stem cell transplantation with additional in vivo T cell depletion with monoclonal anti-CD3 antibody. This model enables a detailed in vivo evaluation of hierarchy and attribution of defined lymphocyte populations without skewing by mTOR- or NFAT-inhibitors. As expected CD3+ T cells and their subsets had delayed reconstitution (<100 cells/μL at day +90). Well defined CD19+ B lymphocytes of naïve and memory phenotype were detected at day +60. Remarkably, we observed a very early reconstitution of antibody-secreting cells (ASC) at day +14. These ASC carried the HLA-haplotype of the donor and secreted the isotypes IgM and IgA more prevalent than IgG. They correlated with a population of CD19− CD27− CD38low/+ CD138− cells. Of note, reconstitution of this ASC occurred without detectable circulating T cells and before increase of BAFF or other B cell stimulating factors. In summary, we describe a rapid reconstitution of peripheral blood ASC after CD3 and CD19 depleted haploidentical stem cell transplantation, far preceding detection of naïve and memory type B cells. Incidence before T cell reconstitution and spontaneous secretion of immunoglobulins allocate these early ASC to innate immunity, eventually maintaining natural antibody levels.


2020 ◽  
Author(s):  
Hector Cordero ◽  
Rodney King ◽  
Pranay Dogra ◽  
Chloe Dufeu ◽  
Sarah See ◽  
...  

Abstract The thymus is a central lymphoid organ responsible for the development of T cells. Here, we show that the thymus of human neonates also contains a consistent contingent of CD138+ plasma cells, producing all classes and subclasses of immunoglobulins with the exception of IgD. These antibody-secreting cells (ASC) are comprised within a larger subset of B cells lacking expression of the complement receptors CD21 and CD35 and sharing the expression of signature genes defining mouse B1 B cells. Single-cell transcriptomic analyses supported the intrathymic differentiation of CD138+ plasma cells alongside other B cell subsets with distinctive molecular phenotypes. Neonatal thymic plasma cells also included clones reactive to pathogenic bacteria that commonly infect children born with antibody deficiency. Thus, our findings point to the thymus as a source of innate humoral immunity in human neonates.


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