VHH (nanobody) directed against human glycophorin A: A tool for autologous red cell agglutination assays

2013 ◽  
Vol 438 (1) ◽  
pp. 82-89 ◽  
Author(s):  
Ibrahim Habib ◽  
Dorota Smolarek ◽  
Claude Hattab ◽  
Magdalena Grodecka ◽  
Gholamreza Hassanzadeh-Ghassabeh ◽  
...  
2020 ◽  
Author(s):  
Alain Townsend ◽  
Pramila Rijal ◽  
Julie Xiao ◽  
Tiong Kit Tan ◽  
Kuan-Ying A Huang ◽  
...  

ABSTRACTSerological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, detection of seroconversion after vaccination, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests have a long history in blood typing, and general serology through linkage of reporter molecules to the red cell surface. They do not require special equipment, are read by eye, have short development times, low cost and can be applied as a Point of Care Test (POCT). We describe a red cell agglutination test for the detection of antibodies to the SARS-CoV-2 receptor binding domain (RBD). We show that the Haemagglutination Test (“HAT”) has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. The HAT can be titrated, detects rising titres in the first five days of hospital admission, correlates well with a commercial test that detects antibodies to the RBD, and can be applied as a point of care test. The developing reagent is composed of a previously described nanobody to a conserved glycophorin A epitope on red cells, linked to the RBD from SARS-CoV-2. It can be lyophilised for ease of shipping. We have scaled up production of this reagent to one gram, which is sufficient for ten million tests, at a cost of ∼0.27 UK pence per test well. Aliquots of this reagent are ready to be supplied to qualified groups anywhere in the world that need to detect antibodies to SARS-CoV-2, but do not have the facilities for high throughput commercial tests.


Blood ◽  
2009 ◽  
Vol 113 (22) ◽  
pp. 5624-5627 ◽  
Author(s):  
Weili Bao ◽  
Jin Yu ◽  
Susanne Heck ◽  
Karina Yazdanbakhsh

Abstract Red blood cell alloimmunization remains a major complication for transfusion-dependent patients, but immune factors governing risk for alloimmunization are unknown. We hypothesized that CD4+ regulatory T cells (Tregs), which we have shown control the rate and the frequency of red blood cell alloimmunization in mouse models, may dictate responder/nonresponder status. Using a transfusion regimen in which more than 50% of mice develop alloantibodies to human glycophorin A antigen, we found reduced in vitro and in vivo Treg-suppressive activity in responders compared with nonresponders that was the result of impaired Treg suppressor function. Moreover, responders were prone to developing additional alloantibodies to strong immunogens, whereas nonresponders were resistant to alloimmunization. Altogether, our data raise the possibility that Treg activity may be used as a marker for identifying responder/nonresponder status in transfusion recipients.


2020 ◽  
Author(s):  
Etienne Joly ◽  
Alain Townsend ◽  
Pramila Rijal ◽  
Julie Xiao ◽  
Tiong Kit Tan ◽  
...  

Abstract Serological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, detection of seroconversion after vaccination, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests have a long history in blood typing, and general serology through linkage of reporter molecules to the red cell surface. They do not require special equipment, are read by eye, have short development times, low cost and can be applied as a Point of Care Test (POCT). We describe a red cell agglutination test for the detection of antibodies to the SARS-CoV-2 receptor binding domain (RBD). We show that the Haemagglutination Test (HAT) has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. The HAT can be titrated, detects rising titres in the first five days of hospital admission, correlates well with a commercial test that detects antibodies to the RBD, and can be applied as a point of care test. The developing reagent is composed of a previously described nanobody to a conserved glycophorin A epitope on red cells, linked to the RBD from SARS-CoV-2. It can be lyophilised for ease of shipping. We have scaled up production of this reagent to one gram, which is sufficient for ten million tests, at a cost of ~0.27 UK pence per test well. Aliquots of this reagent are ready to be supplied to qualified groups anywhere in the world that need to detect antibodies to SARS-CoV-2, but do not have the facilities for high throughput commercial tests.


2020 ◽  
Author(s):  
Alain Townsend ◽  
Pramila Rijal ◽  
Julie Xiao ◽  
Tiong Kit Tan ◽  
Kuan-Ying Huang ◽  
...  

Abstract Serological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, detection of seroconversion after vaccination, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests have a long history in blood typing, and general serology through linkage of reporter molecules to the red cell surface. They do not require special equipment, are read by eye, have short development times, low cost and can be applied as a Point of Care Test (POCT). We describe a red cell agglutination test for the detection of antibodies to the SARS-CoV-2 receptor binding domain (RBD). We show that the Haemagglutination Test (HAT) has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. The HAT can be titrated, detects rising titres in the first five days of hospital admission, correlates well with a commercial test that detects antibodies to the RBD, and can be applied as a point of care test. The developing reagent is composed of a previously described nanobody to a conserved glycophorin A epitope on red cells, linked to the RBD from SARS-CoV-2. It can be lyophilised for ease of shipping. We have scaled up production of this reagent to one gram, which is sufficient for ten million tests, at a cost of ~0.27 UK pence per test well. Aliquots of this reagent are ready to be supplied to qualified groups anywhere in the world that need to detect antibodies to SARS-CoV-2, but do not have the facilities for high throughput commercial tests.


2019 ◽  
Vol 48 (11) ◽  
pp. 769-771
Author(s):  
Benjamin O Adeyemi ◽  
Edeghonghon Olayemi ◽  
Mahinath Bandara
Keyword(s):  
Red Cell ◽  

1980 ◽  
Vol 42 (1) ◽  
pp. 1-22 ◽  
Author(s):  
D. Litman ◽  
D.J. Hsu ◽  
V.T. Marchesi

Spectrin binds to a population of high-affinity sites on the exposed surface of inverted vesicles prepared from human red blood cell ghost membranes. Optimal spectrin binding requires the presence of monovalent salts but does not require calcium or magnesium. The band 2 subunit of spectrin, prepared in SDS, can also bind to vesicles, but isolated band 1 is inactive. Pre-incubation of inverted vesicles with antibodies directed against the cytoplasmic segment of band 3 or against bands 4.1-4.2 inhibits the binding of spectrin to the same vesicles. Antibodies against the cytoplasmic portion of glycophorin A have no effect. These results suggest that spectrin binds to a protein acceptor on the cytoplasmic surface of the red cell membrane which is close to the cytoplasmic segments of bands 3 and 4.1 and/or 4.2.


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