ThGM-CSF cells contribute to the protective immune response against Listeria monocytogenes

Abstract

Abstract Aim To investigate the functions of ThGM-CSF cells in the host defense against L. monocytogenes infection. Material 168 Wild-type (WT, C57BL/6J) mice and 18 GM-CSF deficient (Csf2−/−) mice were used in this study. In vitro bone marrow-derived macrophages (BMDMs) and ThGM-CSF cells were respectively derived from bone marrow and spleen. Methods A protective immune mouse model was established with L. monocytogenes. Flow cytometry, enzyme-linked immunosorbent assay, and quantitative RT-PCR were used to detect the expression of related immune cells and proteins at cellular, protein and mRNA levels. Plate counts and immunofluorescence were used to determine bacterial colonization. Results ThGM-CSF cells contribute to the protective immune response against L. monocytogenes infection. The induction of GM-CSF is significantly increased in both primary and secondary infection. Csf2−/− mice are more susceptible to L. monocytogenes infection and transfer of ThGM-CSF cells enhanced the clearance of L. monocytogenes. Anti-GM-CSF neutralizing antibody impaired the elimination of L. monocytogenes and the generation of protective immune response. Depletion of macrophages and neutrophils decreased ThGM-CSF cells development. GM-CSF promotes phagocytosis of macrophages and neutrophils to clear L. monocytogenes. Conclusion The results suggest that ThGM-CSF cells are significantly involved in the generation of protective immune responses against bacterial infection.