Characterization of leukocyte subpopulations in the early phase of response against Bordetella pertussis infection

GRISELDA MORENO; AGUSTINA ERREA; ROY ROBERTS; AUGUSTO GRAIEB; LAURYE VAN MAELE; JEAN CLAUDE SIRARD; DANIELA HOZBOR; MARTIN RUMBO

Viña del Mar

Congreso; Latin American Congress of Immunology; 2009

Sociedad Latinoamericana de Inmunología

Although many aspects of the respiratory disease (named whooping cough) caused by Bordetella pertussis are well known, some related to early stages of infectious process are only partially understood. Our aim was to characterize the cell populations recovered from broncoalveolar lavage at 2, 6, and 24 h after B. pertussis mice infection (1.108CFU/40μl). By flow cytometry we observed that the influx of neutrophils (PMN, CD11c-, CD11b+, GR1+) into the airways was significant, rising from less than1.103/lung to 7.105 ± 1.105 cells/lung at 6 h. While at 24 h this value was doubled, alveolar macrophages population (AM) (CD11c+,CD11b+, GR1-) was diminished. Transcriptional analysis of immunomagnetic isolated PMN and AM showed an induction of CXCL10 (Fold induction, FI 300±100), IL1β (FI 150±50), IL6 (FI 20±10) in PMN and overexpression of IL1β (FI 25±2), TNFa (FI 50±20) and Cholesterol25hydroxylase (FI 9±2) in AM. Depletion of PMN by specific monoclonal antibodies before infection,increased bacterial loads from 7.7±0.12 to 8.4±0.53 logCFU/lung at 24 hs and 7.15 ± 0.21 to 8.36 ± 0.026 log CFU/lung at 48 hs.Our results indicate that PMN participate actively in elimination of B. pertussis in the early phase of infection.