Commensal Microbes Affect Host Humoral Immunity to Bordetella pertussis Infection

Area of Science:

• Immunology
• Microbiology
• Infectious Diseases

Background:

• Commensal microbes and the microbiota are crucial for host defense.
• The role of the microbiota in Bordetella pertussis (whooping cough) pathogenesis is not well understood.

Purpose of the Study:

• To investigate the impact of microbiota depletion on susceptibility to B. pertussis infection.
• To elucidate the mechanisms by which the microbiota influences immune responses to B. pertussis.

Main Methods:

• Antibiotic-mediated depletion of the gut microbiota in a host model.
• Assessment of susceptibility to B. pertussis infection.
• Analysis of systemic antibody responses (IgG, IgG2a, IgG1).
• Evaluation of short-lived plasma cell and memory B cell recall responses.
• Investigation of CD4+ T cell generation and PD-1 expression.

Main Results:

• Antibiotic treatment leading to microbiota depletion increased susceptibility to early B. pertussis infection.
• This increased susceptibility correlated with impaired IgG, IgG2a, and IgG1 antibody responses.
• The microbiota influenced both short-lived plasma cell responses and memory B cell recall responses.
• Antibiotic-induced dysbiosis altered CD4+ T cell generation and PD-1 expression, disrupting plasma cell differentiation.

Conclusions:

• Commensal microbes are essential for modulating host immune responses against B. pertussis.
• Microbiota manipulation may offer a strategy to control the severity of whooping cough infections.