Correction to: Gene Editing Rescues in Vitro T Cell Development of RAG2-Deficient Induced Pluripotent Stem Cells in an Artificial Thymic Organoid System

Journal of Clinical Immunology - A Correction to this paper has been published: https://doi.org/10.1007/s10875-021-01030-6     

FTT0831c/FTL_0325 Contributes to Francisella tularensis Cell Division,Maintenance of Cell Shape,and Structural Integrity

The Francisella FTT0831c/FTL_0325 gene encodes amino acid motifs to suggest it is a lipoprotein and that it may interact with the bacterial cell wall as a member of the OmpA-like protein family. Previous studies have suggested that FTT0831c is surface exposed and required for virulence of Francisella tularensis by subverting the host innate immune response (M. Mahawar et al., J. Biol. Chem. 287:25216–25229, 2012). We also found that FTT0831c is required for murine pathogenesis and intramacrophage growth of Schu S4, but we propose a different model to account for the proinflammatory nature of the resultant mutants. First, inactivation of FTL_0325 from live vaccine strain (LVS) or FTT0831c from Schu S4 resulted in temperature-dependent defects in cell viability and morphology. Loss of FTT0831c was also associated with an unusual defect in lipopolysaccharide O-antigen synthesis, but loss of FTL_0325 was not. Full restoration of these properties was observed in complemented strains expressing FTT0831c in trans, but not in strains lacking the OmpA motif, suggesting that cell wall contact is required. Finally, growth of the LVS FTL_0325 mutant in Mueller-Hinton broth at 37°C resulted in the appearance of membrane blebs at the poles and midpoint, prior to the formation of enlarged round cells that showed evidence of compromised cellular membranes. Taken together, these data are more consistent with the known structural role of OmpA-like proteins in linking the OM to the cell wall and, as such, maintenance of structural integrity preventing altered surface exposure or release of Toll-like receptor 2 agonists during rapid growth of Francisella in vitro and in vivo.     

Structural polymorphism of glycophorins demonstrated by immunoblotting techniques

We have explored the polymorphism of the glycophorin system in the human erythrocyte membrane using the immunoblotting techniques and examining 52 individuals selected without prior bias as to their serologic state and ten documented serologic variants of M, N, S, s blood group system. Polyclonal antisera to alpha glycophorin and to alpha glycophorin CNBr carboxyl terminal fragment C (residues 82-131) and M and N specific monoclonal antibodies (MoAbs) were used. The first two reagents detect specific regions of the alpha glycophorin molecule and all electrophoretically resolved species of glycophorins immunologically related to alpha and delta glycophorins (delta glycophorin, [alpha-delta] hybrids and other glycophorins with an alteration in the carboxyl terminal segment); the M and N MoAbs identified the glycophorin species containing or lacking the M or N determinant in the amino terminal octapeptide structures. We find that immunoblotting confirmed in all cases the serologically determined phenotype; we also find that polymorphic forms of the glycophorin system are relatively infrequent; immunoblotting, independent from serologic testing, was capable of detecting five mutants, two most likely S-s-U-phenotypes; a new glycophorin species was detected in normal red cells with both antiglycophorin and antipeptide C sera, which is not evident with MoAbs; immunoblots of known glycophorin variants (En(a-), U-, Mg, Mi I, II, III, V, and Sta) confirmed but also extended our knowledge of the abnormal glycophorins involved; and the He+ and Wrb(-) cells showed normal patterns.