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Human Siglec-2/CD22 LlamabodyTM VHH His-tag Antibody

R&D Systems, part of Bio-Techne | Catalog # LMAB10732

Recombinant Monoclonal Antibody. His-tagged VHH domain.
R&D Systems, part of Bio-Techne

Key Product Details

Species Reactivity

Human

Applications

Flow Cytometry, Immunocytochemistry

Label

Unconjugated

Antibody Source

Recombinant Monoclonal Llama VHH domain Clone # L007.2.5N

Product Specifications

Clonality

Monoclonal

Host

Llama

Isotype

VHH domain

Scientific Data Images for Human Siglec-2/CD22 LlamabodyTM VHH His-tag Antibody

Detection of Siglec-2/CD22 in HEK293 Human Cell Line Transfected with Human Siglec-2/CD22 and eGFP by Flow Cytometry.

HEK293 human embryonic kidney cell line transfected with either (A) human Siglec-2/CD22 or (B) irrelevant protein and eGFP was stained with Llama Anti-Human Siglec-2/CD22 Llamabody VHH Monoclonal Antibody (Catalog # LMAB10732) followed by Goat Anti-Llama Secondary Antibody (AF011), and then Allophycocyanin-conjugated Anti-Goat IgG Tertiary Antibody (F0108). Quadrant markers were set based on secondary plus tertiary antibody staining in the absence of primary antibody. View our protocol for Staining Membrane-associated Proteins.

Detection of Siglec-2/CD22 in Transfected HEK293 Cell Line (Positive) And Wild Type HEK293Cell Line (Negative) Cells.

Siglec-2/CD22 was detected in immersion fixed Transfected HEK293 Human Embryonic Kidney Cell Line (Positive) and absent in Wild Type HEK293 Human Embryonic Kidney Cell Line (Negative) Cells using Llama Anti-Human Siglec-2/CD22 LlamabodyTM VHH His-tag Monoclonal Antibody (Catalog # LMAB10732) at 5 µg/mL for 3 hours at room temperature. Cells were stained using Anti-camelid Vhh conjugated to Rhodamine-Red X (red) and counterstained with DAPI (blue). Specific staining was localized to cytoplasm. View our protocol for Fluorescent ICC Staining of Cells on Coverslips.

Applications for Human Siglec-2/CD22 LlamabodyTM VHH His-tag Antibody

Application
Recommended Usage

Flow Cytometry

0.25 µg/106 cells
Sample: HEK293 Human Cell Line Transfected with Human Siglec-2/CD22 and eGFP

Immunocytochemistry

5-25 µg/mL
Sample: Immersion fixed Transfected HEK293 Human Embryonic Kidney Cell Line (Positive) And Wild Type HEK293 Human Embryonic Kidney Cell Line (Negative) Cells 

Formulation, Preparation, and Storage

Purification

His-tag purified from cell culture supernatant

Reconstitution

Reconstitute at 0.5 mg/mL in sterile PBS. For liquid material, refer to CoA for concentration.

Reconstitution Buffer Available:
Size / Price
Qty
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Formulation

Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied either lyophilized or as a 0.2 µm filtered solution in PBS.

Shipping

Lyophilized product is shipped at ambient temperature. Liquid small pack size (-SP) is shipped with polar packs. Upon receipt, store immediately at the temperature recommended below.

Stability & Storage

Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: Siglec-2/CD22

Siglecs are type I transmembrane proteins that belong to the immunoglobulin (Ig) superfamily and function as mammalian lectins (1). They are characterized by an extracellular domain consisting of various numbers of Ig domains with a conserved N-terminal V-set Ig ligand-binding domain. This binds species-specific sialic acid motifs on protein and lipid scaffolds to regulate intracellular signaling pathways (2). The cytoplasmic tail has signaling motifs, in most cases immunoreceptor tyrosine-based inhibitory motif (ITIM) (3). Human Siglec-2, also known as B cell antigen CD22 or B lymphocyte cell adhesion molecule (BL-CAM), is a B cell restricted glycoprotein that is expressed in the cytoplasm of progenitor B and pre B cells and on the surface of mature B cells. Two distinct human Siglec-2/CD22 cDNAs that arise from differential RNA processing of the same gene have been isolated. The predominant Siglec-2/CD22 beta encodes an 847 amino acid (aa) polypeptide with a hydrophobic signal peptide, an N-terminal Ig-like V type domain, six Ig-like C2 type domains, a transmembrane region and a cytoplasmic tail with 4 immunoreceptor tyrosine-based inhibition motifs (ITIMs) (4). The variant Siglec-2/CD22 alpha encodes a 647 aa polypeptide missing two Ig-like C2 type domains and has a truncated (23 aa) cytoplasmic tail (5). Mature human Siglec-2 beta consists of a 668 amino acid (aa) extracellular domain (ECD), a 19 aa transmembrane segment, and a 141 aa cytoplasmic domain. Within the ECD, human Siglec-2 shares 59% and 58% aa sequence identity with the mouse and rat Siglec-2, respectively. Siglec-2/CD22 is an adhesion molecule that preferentially binds alpha 2,6- linked sialic acid on the same (cis) or adjacent (trans) cells. Interaction of CD22 with trans ligands on opposing cells was found to be favored over the binding of ligands in cis (6). Besides its role as an adhesion molecule, Siglec-2/CD22 is a coreceptor that physically interacts with B-cell receptor (BCR) and is rapidly phosphorylated upon BCR ligation. It negatively regulates BCR signals by recruiting tyrosine phosphatase SHP-1 to its ITIMs. Phosphorylated Siglec-2/CD22 can also interact with other intracellular effector proteins such as Syk, PLC gamma, PI3 kinase and Grb-2, suggesting it may play a role in positive signaling (7-9). Another function of CD22 is that it mediates the anti-phagocytic effect of alpha2,6-linked sialic acid, and inhibition of CD22 promotes the clearance of myelin debris, amyloid-beta oligomers and alpha-synuclein fibrils in vivo(10). CD22 also plays a role in autoimmunity and has great potential for CD22-based immunotherapeutics for the treatment of autoimmune diseases such as systemic lupus erythematosus (SLE) (11).

References

  1. Crocker, P.R. et al. (2007) Nat. Rev. Immunol. 7:255.
  2. Poe, J.C. and T.F. Tedder (2012) Trends Immunol. 33:413.
  3. Meyer, S.J. et al. (2018) Front. Immunol. 9:2820.
  4. Wilson, G.L et al. (1991) J. Exp. Med. 173:137.
  5. Stamenkovic, I. and B. Seed (1990) Nature 345:74.
  6. Collins, B.E. et al. (2004) Proc. Natl. Acad. Sci. 101:6104.
  7. Crocker, P.R. and A. Varki (2001) Immunology 103:137.
  8. Ravetch, J.V. and L.L. Lanier (2000) Science 290:84.
  9. Wienands, Y.J. et al. (1999) J. Biol. Chem. 274:18769.
  10. Pluvinage, J.V. et al. (2019) Nature. 5568:7751.
  11. Clark, E.A. et al. (2018) Front. Immunol. 9:2235.

Long Name

Sialic Acid Binding Ig-like Lectin 2

Alternate Names

BL-CAM, CD22, Siglec2

Entrez Gene IDs

933 (Human); 12483 (Mouse); 308501 (Rat); 102130968 (Cynomolgus Monkey)

Gene Symbol

CD22

Additional Siglec-2/CD22 Products

Product Documents

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Note: Certificate of Analysis not available for kit components.

Product Specific Notices for Human Siglec-2/CD22 LlamabodyTM VHH His-tag Antibody

For research use only

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