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Background: Cromer antigens are carried on decay accelerating factor (DAF, CD55), for which the crystal structure is available. We investigated two samples with an unidentified antibody to a high prevalence antigen and evaluate the location and characteristics of amino acids associated with antigens on the CD55 by 3D modelling.
Materials And Methods: Antigen typing and antibody identification were by standard methods. CD55 was sequenced, and Cromer variants were generated using the protein's crystal structure (1OK3, chain A). Antigen-associated residues and intraprotein interactions were investigated in 3D (Naccess, Protein Interactions Calculator).
Results: The antibody in the sample from a woman of Kashmiri descent was identified as anti-IFC (anti-CROM7). Her RBCs were negative for high-prevalence Cromer antigens including IFC. CD55 sequencing revealed a silent c.147G>A (p.Leu49=) and c.148G>T (p.Glu50Ter) changes, designated CROM*01N.05. The antibody in the sample from a woman of Greek ancestry was only compatible with IFC- RBCs but her RBCs were positive for known high-prevalence Cromer antigens. CD55 sequencing found she was homozygous for c.173A>G (p.Asp58Gly). The high prevalence antigen was named CRAG (ISBT CROM18 or 021018) and the allele designated CROM*01.-18. By 3D analysis, all known antigen-associated residues, including the new CRAG antigen, were exposed at the protein surface. Interactions between antigen-associated residues within the same CD55 domains were identified.
Discussion: Identification of antibodies to high prevalence Cromer antigens can be challenging. The surface exposure of antigen-associated residues likely accounts for their immunogenicity. 3D analysis of CD55 provides insight into previous serologic observations regarding the influence of some Cromer antigens on the expression of others.
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http://dx.doi.org/10.2450/2022.0285-21 | DOI Listing |
J Orthop Case Rep
August 2025
Department of Health Informatics, Rutgers - School of Health Professions, Piscataway, New Jersey, United States.
Introduction: Bilateral displaced femoral neck fractures are uncommon in adults without significant trauma, especially in the absence of high-energy impact. This case highlights the importance of considering underlying metabolic disorders such as end-stage renal disease (ESRD) as significant contributing factors. It is one of the few reported cases demonstrating the interplay between ESRD, renal osteodystrophy, anemia of chronic disease, and the presence of rare Cromer blood group antibodies, adding a unique dimension to orthopedic and hematological literature.
View Article and Find Full Text PDFCell
June 2025
Precision Immunology Program, Garvan Institute of Medical Research, Sydney, NSW, Australia; St. Vincent's Healthcare Clinical Campus, School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Kensington, Sydney, NSW, Australia. Electronic address:
Vaccines generate long-lived plasma cells and memory B cells (Bmems) that may re-enter secondary germinal centers (GCs) to further mutate their B cell receptor upon boosting and re-exposure to antigen. We show in mouse models that lymph nodes draining the site of primary vaccination harbor a subset of Bmems that reside in the subcapsular niche, generate larger recall responses, and are more likely to re-enter GCs compared with circulating Bmems in non-draining lymph nodes. This location-dependent recall of Bmems into the GC in the draining lymph node was dependent on CD169 subcapsular sinus macrophages (SSMs) in the subcapsular niche.
View Article and Find Full Text PDFNPJ Vaccines
April 2025
Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
The ongoing rollout of SARS-CoV-2 vaccines lags behind rapid viral evolution. Updated vaccine immunogens elicit neutralising antibodies against the component strain. However, protection against future SARS-CoV-2 variants is unclear.
View Article and Find Full Text PDFJCI Insight
January 2025
Department of Microbiology and Immunology and.
BACKGROUNDThe immunogenicity of current influenza vaccines needs improvement. Inactivated influenza and COVID-19 mRNA vaccines can be coadministered, but randomized controlled trial data are lacking on whether the 2 vaccines are more immunogenic if given in the same arm or opposite arms. Murine studies suggest mRNA vaccines can adjuvant influenza vaccines when coformulated and codelivered.
View Article and Find Full Text PDFActa Trop
December 2024
Department of Laboratory medicine, Lund University, Lund, Sweden; Clinical Chemistry and Pharmacology, Office for Medical Services, Region Skåne, Lund, Sweden. Electronic address:
Malaria caused by Plasmodium falciparum leads to the destruction of red blood cells (RBCs). A better understanding of how naturally immune individuals control infections should be valuable for future vaccine studies. Antibodies against RBCs and RBC surface antigens were measured together with different inflammatory markers in healthy adults living in a malaria endemic area of Uganda and compared to Swedish healthy adults.
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