C5a receptor expression in T lymphocytes

Abstract

Connelly et al. [1] have published in a recent paper that C5a receptor expression in murine T lymphocytes is inducible under certain experimental conditions. Their conclusions rely exclusively on immunophenotyping by flow cytometry using a single mAb (20/70). In Acknowledgments, it is declared that “We are grateful to Dr. Jorg Zwirner (Georg-August-University Gottingen) for the mAb against C5a receptor.” I had originally provided mAb 20/70 against murine C5a receptor to the senior author of that paper, Dr. Jagannath, on a collaborative basis. However, I felt obliged to suggest withdrawal of coauthorship in the genuine belief that more experiments were required to verify expression of a functional C5a receptor on T lymphocytes. Specifically, I had asked for: 1) investigation of antibody binding after preincubation of lymphocytes with C5a, as reduced 20/70 binding might be expected through ligand-specific receptor blockade and/or internalization; and 2) investigation of C5a-induced calcium fluxes in C5a receptor-expressing T lymphocytes, as C3ainduced calcium fluxes in activated T cells have been observed previously [2]. Unfortunately, Dr. Jagannath felt unable to perform these experiments.