%0 Journal Article
%T The B-cell inhibitory receptor CD22 is a major factor in host resistance to Streptococcus pneumoniae infection
%A Alan B¨¦nard
%A Carolin Brandl
%A Georg F. Weber
%A Giuseppe Ercoli
%A Hannah Fahnenstiel
%A Jennifer M¨¹ller-Winkler
%A Lars Nitschke
%A Paul Denny
%A Peter W. Andrew
%A Vitor E. Fernandes
%J -
%D 2020
%R 10.1371/journal.ppat.1008464
%X Streptococcus pneumoniae is a major human pathogen, causing pneumonia and sepsis. Genetic components strongly influence host responses to pneumococcal infections, but the responsible loci are unknown. We have previously identified a locus on mouse chromosome 7 from a susceptible mouse strain, CBA/Ca, to be crucial for pneumococcal infection. Here we identify a responsible gene, Cd22, which carries a point mutation in the CBA/Ca strain, leading to loss of CD22 on B cells. CBA/Ca mice and gene-targeted CD22-deficient mice on a C57BL/6 background are both similarly susceptible to pneumococcal infection, as shown by bacterial replication in the lungs, high bacteremia and early death. After bacterial infections, CD22-deficient mice had strongly reduced B cell populations in the lung, including GM-CSF producing, IgM secreting innate response activator B cells, which are crucial for protection. This study provides striking evidence that CD22 is crucial for protection during invasive pneumococcal disease
%K B cells
%K Spleen
%K Pneumococcus
%K Escherichia coli infections
%K Respiratory infections
%K Blood
%K Genetic loci
%K Streptococcal infections
%U https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1008464