Related Experiment Videos
Peripheral blood neutrophil responses in children with shigellosis
T Azim1, L N Islam, R C Halder
1International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh.
Insights
Neutrophil function, including polarization and locomotion, is altered in children with Shigella dysenteriae type 1 infection, impacting immune responses. These neutrophil alterations are linked to both uncomplicated and complicated shigellosis, suggesting a role in disease pathogenesis.
Area of Science:
- Immunology
- Pediatrics
- Infectious Diseases
Background:
- Neutrophil dysfunction in colitis can cause tissue injury.
- Neutrophil function in Shigella dysenteriae type 1 infection, particularly in children, remains understudied.
- Shigella dysenteriae type 1 infection can lead to severe colitis and life-threatening complications in young children.
Purpose of the Study:
- To investigate peripheral blood neutrophil function in children with Shigella dysenteriae type 1 infection.
- To compare neutrophil polarization, attachment, and locomotion in children with uncomplicated shigellosis, complicated shigellosis, and healthy controls.
- To assess the influence of nutritional status on neutrophil function in uninfected children.
Main Methods:
- Studied neutrophil polarization, attachment to yeast particles, and locomotion in 111 children with S. dysenteriae type 1 infection and 57 controls (aged 12-60 months).
- Assessed neutrophil responses in the absence and presence of chemoattractants like N-formylmethionyl-leucylphenylalanine (FMLP) and S. dysenteriae type 1 lipopolysaccharide (LPS).
- Categorized infected children into uncomplicated shigellosis and complicated shigellosis (including leukemoid reaction, hemolytic-uremic syndrome, or septicemia).
Main Results:
- Children with shigellosis exhibited increased neutrophil polarization compared to uninfected children.
- Complicated shigellosis cases showed higher neutrophil polarization with FMLP and LPS than uncomplicated cases.
- Neutrophil locomotion was inhibited by LPS in children with shigellosis, and polarization was negatively influenced by nutritional status in uninfected children.
Conclusions:
- Altered neutrophil polarization and locomotion are associated with Shigella dysenteriae type 1 infection in children.
- Neutrophil responses differ between uncomplicated and complicated shigellosis.
- Nutritional status impacts neutrophil polarization in healthy children, highlighting its role in immune function.
Abstract:
Alterations in peripheral blood neutrophil function are known to occur in patients with colitis and may have a role in precipitating nonspecific tissue injury. It is not known whether neutrophil function is altered in patients with Shigella dysenteriae type 1 infection, during which there is extensive colitis and which may be associated with life-threatening complications in young children. Three aspects of peripheral blood neutrophil function, polarization, attachment to yeast particles, and locomotion, were therefore studied in 111 children with S. dysenteriae type 1 infection and 57 children without any infection. All children were aged 12 to 60 months. Of the children with S. dysenteriae type 1 infection, 42 had leukemoid reaction, hemolytic-uremic syndrome, or septicemia (complicated shigellosis), while the others did not (uncomplicated shigellosis). Polarization and locomotion in the absence of chemoattractants and in response to N-formylmethionyl-leucylphenylalanine (FMLP) and the lipopolysaccharide (LPS) of S. dysenteriae type 1 were determined. Attachment to unopsonized and opsonized yeast particles was also determined. Children with shigellosis (uncomplicated or complicated) had more polarized neutrophils with and without chemoattractants than uninfected children (P < 0.05). Children with complicated shigellosis had more polarized neutrophils with FMLP at 10(-7) and 10(-6) M (P < 0.05) and with LPS than children with uncomplicated shigellosis (P < 0.05). At 3 to 5 days after enrollment, the numbers of polarized neutrophils with 10(-8), 10(-6), and 10(-5) M FMLP declined in children with uncomplicated shigellosis but not in those with complicated shigellosis. Attachment to yeast particles was similar in all three groups of children. Locomotion was inhibited by LPS in children with shigellosis (P < 0.05), whether it was uncomplicated or complicated, compared with locomotion in uninfected children. Finally, neutrophil polarization in uninfected children was negatively influenced by nutritional status. Thus, poorly nourished uninfected children had more polarized neutrophils with FMLP at 10(-9) M (P < = 0.02) and 10(-5) M (P = 0.043) than their better-nourished counterparts. In summary, altered neutrophil responses are associated with both uncomplicated and complicated shigellosis.