Limited role of polymorphonuclear neutrophils in a pregnant mouse model of secondary infection by Chlamydophila abortus (Chlamydia psittaci serotype 1)

• Published in: Microbial pathogenesis Vol. 29; no. 6; pp. 319 - 327
• Main Authors: Montes de Oca, Roberto, Buendı́a, Antonio J, Sánchez, Joaquı́n, Del Rı́o, Laura, Seva, Juan, Navarro, Jose A, Salinas, Jesús
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2000; Elsevier
• Subjects: Animals; Antibodies, Monoclonal; Bacterial diseases; Biological and medical sciences; Chlamydia psittaci; Chlamydophila - immunology; Chlamydophila - pathogenicity; Chlamydophila abortus; Chlamydophila abortus, neutrophils, secondary infection, abortion; Chlamydophila Infections - immunology; Experimental bacterial diseases and models; Female; Fluorescent Antibody Technique, Indirect; Immunohistochemistry; Infectious diseases; Interferon-gamma - analysis; Interleukin-4 - blood; Litter Size; Liver - immunology; Liver - microbiology; Liver - pathology; Male; Medical sciences; Mice; Neutrophils - immunology; Placenta - immunology; Placenta - pathology; Pregnancy; Pregnancy Complications, Infectious - immunology; Specific Pathogen-Free Organisms; Statistics, Nonparametric; Tumor Necrosis Factor-alpha - analysis; Chlamydophila abortus, neutrophils, secondary infection, abortion; Animal model; Immune response; Chlamydiaceae; Rodentia; Chlamydia psittaci; Cellular immunity; Reinfection; Infection; Pregnancy; Vertebrata; Experimental disease; Mammalia; Mouse; Bacteriosis; Chlamydiales; Bacteria; Chlamydiosis; Neutrophil
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1006/mpat.2000.0396

The aim of this work was to study the role of polymorphonuclear neutrophils (PMNs) in the clearance of infection, and in the development of specific immunity against Chlamydophila abortus (Chlamydia psittaci serotype 1) secondary infection. A pregnant mouse model depleted of neutrophils by the RB6-8C5 monoclonal antibody was used. No clinical signs were observed in depleted or non-depleted mice after secondary infection and no significant differences were observed in the litter size between the infected and control groups. In PMN-depleted mice C. abortus was not detected in the materno-fetal unit but merely produced low, persistent levels of infection in spleen and liver. In the non-depleted mice the level of infection was significantly lower, being resolved during the first few days post-reinfection. In both infected mice groups the immune response in the liver was quickly established and was seen to be composed mainly of CD4+T lymphocytes and macrophages. A Th1 response characterized by the presence of IFN-γ and TNF-α in serum was observed during early infection, with significantly higher levels in the non-depleted animals. Our results suggest that PMNs have little influence on the control ofC. abortus secondary infection, although they are a first line of defense and may influence the early production of TNF-α and IFN-γ.