Inhibition of the interaction between the SARS-CoV spike protein and its cellular receptor by anti-histo-blood group antibodies.
Level 5 - mechanism / opinion, no new human data
In vitro cellular assay and mathematical modeling (no human clinical trial data).
PubMed 18818423 · doi:10.1093/glycob/cwn093
What was done
Researchers co-expressed the SARS-CoV spike (S) glycoprotein ectodomain and blood group A antigen on Chinese hamster ovary cells. They tested whether monoclonal or human natural anti-A antibodies blocked the adhesion of these cells to an ACE2-expressing cell line. They also constructed a mathematical transmission dynamics model incorporating natural ABO antibody protection to simulate population-level epidemic spread.
What was found
The abstract reports no numerical values, inhibition percentages, or statistical metrics. Qualitatively, adhesion of A-antigen-expressing S protein cells to ACE2-expressing cells was specifically inhibited by both monoclonal and human natural anti-A antibodies. The mathematical model indicated that ABO polymorphism substantially reduced viral transmission, lowering total infections and altering epidemic kinetics.
Why it matters
This paper proposes a mechanistic basis for observational reports that blood group O individuals had lower SARS-CoV infection risk, suggesting natural ABO antibodies can physically interfere with spike-ACE2 binding.
Limits
The study relies on an engineered in vitro cell adhesion model rather than live viral infection assays or primary human tissue. No quantitative effect sizes or uncertainty bounds are reported in the abstract, and population transmission conclusions depend entirely on theoretical mathematical modeling.
Cited by
- supports Type A antibodies found in individuals with blood group O or B can inhibit the interaction between SARS-CoV-1 and the ACE2 receptor.