Target
SARS-CoV-2 Spike RBD
Alternative Names
SARS-CoV-2; coronavirus; SARS-CoV-2 spike RBD; SARS-CoV-2 spike protein
Storage
Store it under sterile conditions at -20°C to -80°C. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.
Introduction
The spike (S) glycoprotein of coronaviruses contains protrusions that will only bind to certain receptors on the host cell: they are essential for both host specificity and viral infectivity. The term 'peplomer' is typically used to refer to a grouping of heterologous proteins on the virus surface that function together. The spike (S) glycoprotein of coronaviruses is known to be essential in the binding of the virus to the host cell at the advent of the infection process. Most notable is severe acute respiratory syndrome (SARS). The severe acute respiratory syndrome-coronavirus (SARS-CoV) spike (S) glycoprotein alone can mediate the membrane fusion required for virus entry and cell fusion. It is also a major immunogen and a target for entry inhibitors. The SARS-CoV spike (S) protein is composed of two subunits; the S1 subunit contains a receptor-binding domain that engages with the host cell receptor angiotensin-converting enzyme 2 and the S2 subunit mediates fusion between the viral and host cell membranes. The S protein plays key parts in the induction of neutralizing-antibody and T-cell responses, as well as protective immunity, during infection with SARS-CoV.
Keywords
SARS-CoV-2; coronavirus; SARS-CoV-2 spike RBD; SARS-CoV-2 spike protein
Citations
Publication ()
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B and T Cell Responses after a Third Dose of SARS-CoV-2 Vaccine in Kidney Transplant Recipients
Schrezenmeier E, Rincon-Arevalo H, Stefanski AL, Potekhin A, Staub-Hohenbleicher H, Choi M, Bachmann F, Proβ V, Hammett C, Schrezenmeier H, Ludwig C, Jahrsdörfer B, Lino AC, Eckardt KU, Kotsch K, Dörner T, Budde K, Sattler A, Halleck F
Applications: Conjugation
Reactive species: Human
"
Abstract: Background: Accumulating evidence sugges ts solid organ transplant recipients, as opposed to the general population, show strongly impaired responsiveness toward standard SARS-CoV-2 mRNA-based vaccination, demanding alternative strategies for protectio n o f this vulnerable group."
Article snippet: Antigen-specific B cells were identified by double staining with
recombinant purified RBD (
DAGC149, Creative Diagnostics, New York, USA) conjugated to AF647 or AF488, respectively.
Figure 1. Relative frequencies (left) and absolute counts (right) of RBD-specific CD19+ B cells in all patients.
Temporary antimetabolite treatment hold boosts SARS-CoV-2 vaccination-specific humoral and cellular immunity in kidney transplant recipients
Schrezenmeier E, Rincon-Arevalo H, Jens A, Stefanski AL, Hammett C, Osmanodja B, Koch N, Zukunft B, Beck J, Oellerich M, Proß V, Stahl C, Choi M, Bachmann F, Liefeldt L, Glander P, Schütz E, Bornemann-Kolatzki K, López Del Moral C, Schrezenmeier H, Ludwig C, Jahrsdörfer B, Eckardt KU, Lachmann N, Kotsch K, Dörner T, Halleck F, Sattler A, Budde K
Applications: FC
Reactive species: Human
"
Abstract: Transplant recipients exhibit an impaired protective immunity after SARS-CoV-2 vaccination, potentially caused by mycophenolate (MPA) immunosuppression. Recent data from patients with autoimmune disorders suggest that temporary MPA hold might greatly improve booster vaccination outcomes. We applied a fourth dose of SARS-CoV-2 vaccine to 29 kidney transplant recipients during a temporary (5 weeks) MPA/azathioprine hold, who had not mounted a humoral immune response to previous vaccinations. Seroconversion until day 32 after vaccination was observed in 76% of patients, associated with acquisition of virus-neutralizing capacity. Interestingly, 21/25 (84%) calcineurin inhibitor-treated patients responded, but only 1/4 belatacept-treated patients responded. In line with humoral responses, counts and relative frequencies of spike receptor binding domain-specific (RBD-specific) B cells were markedly increased on day 7 after vaccination, with an increase in RBD-specific CD27++CD38+ plasmablasts. Whereas overall proportions of spike-reactive CD4+ T cells remained unaltered after the fourth dose, frequencies were positively correlated with specific IgG levels. Importantly, antigen-specific proliferating Ki67+ and in vivo-activated programmed cell death 1-positive T cells significantly increased after revaccination during MPA hold, whereas cytokine production and memory differentiation remained unaffected. In summary, antimetabolite hold augmented all arms of immunity during booster vaccination. These data suggest further studies of antimetabolite hold in kidney transplant recipients."
Article snippet: Antigen-specific B cells were identified by double-staining with
recombinant purified RBD (
DAGC149, Creative Diagnostics) conjugated to Alexa Fluor 647 or Alexa Fluor 488.
Figure 1. Detection of SARS-CoV2 vaccine specific B cells.
B Cell Numbers Predict Humoral and Cellular Response Upon SARS-CoV-2 Vaccination Among Patients Treated With Rituximab
Stefanski AL, Rincon-Arevalo H, Schrezenmeier E, Karberg K, Szelinski F, Ritter J, Jahrsdörfer B, Schrezenmeier H, Ludwig C, Sattler A, Kotsch K, Chen Y, Claußnitzer A, Haibel H, Proft F, Guerra G, Durek P, Heinrich F, Ferreira-Gomes M, Burmester GR, Radbruch A, Mashreghi MF, Lino AC, Dörner T
Applications: FCM
Reactive species: SARS-CoV-2
"
Abstract: Objective: Patients with autoimmune inflammatory rheumatic diseases receiving rituximab (RTX) therapy are at higher risk of poor COVID-19 outcomes and show substantially impaired humoral immune response to anti-SARS-CoV-2 vaccine. However, the complex relationship between antigen-specific B cells and T cells and the level of B cell repopulation necessary to achieve anti-vaccine responses remain largely unknown.
Methods: Antibody responses to SARS-CoV-2 vaccines and induction of antigen-specific B and CD4/CD8 T cell subsets were studied in 19 patients with rheumatoid arthritis (RA) or antineutrophil cytoplasmic antibody-associated vasculitis receiving RTX, 12 patients with RA receiving other therapies, and 30 healthy controls after SARS-CoV-2 vaccination with either messenger RNA or vector-based vaccines.
Results: A minimum of 10 B cells per microliter (0.4% of lymphocytes) in the peripheral circulation appeared to be required for RTX-treated patients to mount seroconversion to anti-S1 IgG upon SARS-CoV-2 vaccination. RTX-treated patients who lacked IgG seroconversion showed reduced receptor-binding domain-positive B cells (P = 0.0005), a lower frequency of Tfh-like cells (P = 0.0481), as well as fewer activated CD4 (P = 0.0036) and CD8 T cells (P = 0.0308) compared to RTX-treated patients who achieved IgG seroconversion. Functionally relevant B cell depletion resulted in impaired interferon-γ secretion by spike-specific CD4 T cells (P = 0.0112, r = 0.5342). In contrast, antigen-specific CD8 T cells were reduced in both RA patients and RTX-treated patients, independently of IgG formation"
Article snippet: Staining of antigen-specific B cells. To identify receptor-binding domain (RBD)–specific B cells,
recombinant purified RBD (
DAGC149; Creative Diagnostics) was labeled with either Alexa Fluor 647 or Alexa Fluor 488 as previously described.
Figure 1. Reduction in the frequencies and numbers of total B cells and antigen-specific B cells in RTX-treated patients, and correlation of B cell numbers with humoral immune response.
Recruitment of plasma cells from IL-21-dependent and IL-21-independent immune reactions to the bone marrow
Ferreira-Gomes M, Chen Y, Durek P, Rincon-Arevalo H, Heinrich F, Bauer L, Szelinski F, Guerra GM, Stefanski AL, Niedobitek A, Wiedemann A, Bondareva M, Ritter J, Lehmann K, Hardt S, Hipfl C, Hein S, Hildt E, Matz M, Mei HE, Cheng Q, Dang VD, Witkowski M, Lino AC, Kruglov A, Melchers F, Perka C, Schrezenmeier EV, Hutloff A, Radbruch A, Dörner T, Mashreghi MF
Applications: FCM
Reactive species: SARS-CoV-2
"
Abstract: Bone marrow plasma cells (BMPC) are the correlate of humoral immunity, consistently releasing antibodies into the bloodstream. It remains unclear if BMPC reflect different activation environments or maturation of their precursors. Here we define human BMPC heterogeneity and track the recruitment of antibody-secreting cells (ASC) from SARS-CoV-2 vaccine immune reactions to the bone marrow (BM). Trajectories based on single-cell transcriptomes and repertoires of peripheral and BM ASC reveal sequential colonisation of BMPC compartments. In activated B cells, IL-21 suppresses CD19 expression, indicating that CD19
low-BMPC are derived from follicular, while CD19
high-BMPC originate from extrafollicular immune reactions. In primary immune reactions, both CD19low- and CD19high-BMPC compartments are populated. In secondary immune reactions, most BMPC are recruited to CD19high-BMPC compartments, reflecting their origin from extrafollicular reactivations of memory B cells. A pattern also observable in vaccinated-convalescent individuals and upon diphtheria/tetanus/pertussis recall-vaccination. Thus, BMPC diversity reflects the evolution of a given humoral immune response."
Article snippet: Cells were then stained intracellularly for 30 min 4 °C with
recombinant purified RBD (
DAGC149, Creative Diagnostics, New York, USA) and TT (***), which were coupled with either Alexa Fluor 647 or Alexa Fluor 488 to identify antigenspecific cells as described above and in ref. 72,73, and with anti-human antibodies to detect expressed isotypes: IgA-biotin (****), IgG-PE-Cy7 (****), IgM-BV421 (***).
Figure 1. Antigen-specific BMPC are sequentially recruited to both CD19high and CD19low BMPC compartments.
COA
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