In:
Infection and Immunity, American Society for Microbiology, Vol. 78, No. 4 ( 2010-04), p. 1750-1759
Abstract:
A human Campylobacter jejuni infection model provided controlled exposure to assess vaccine efficacy and investigate protective immunity for this important diarrheal pathogen. A well-characterized outbreak strain, C. jejuni 81-176, was investigated using a volunteer experimental infection model to evaluate the dose range and duration of protection. Healthy Campylobacter -seronegative adults received C. jejuni strain 81-176 via oral inoculation of 10 5 , 10 7 , or 10 9 CFU (5 adults/dose), which was followed by clinical and immunological monitoring. Based on dose range clinical outcomes, the 10 9 -CFU dose ( n = 31) was used to assess homologous protection at 28 to 49 days (short-term veterans [STV]; n = 8) or 1 year (long-term veterans [LTV]; n = 7) after primary infection. An illness dose effect was observed for naïve subjects (with lower doses, 40 to 60% of the subjects were ill; with the 10 9 -CFU dose, 92% of the subjects were ill) along with complete protection for the STV group and attenuated illness for the LTV group (57%). Partial resistance to colonization was seen in STV (25% of the subjects were not infected; 3-log-lower maximum excretion level). Systemic and mucosal immune responses were robust in naïve subjects irrespective of the dose or the severity of illness. In contrast, in STV there was a lack of circulating antibody-secreting cells (ASC), reflecting the local mucosal effector responses. LTV exhibited comparable ASC responses to primary infection, and anamnestic fecal IgA responses likely contributed to self-resolving illness prior to antibiotic treatment. Campylobacter antigen-dependent production of gamma interferon by peripheral blood mononuclear cells was strongly associated with protection from illness, supporting the hypothesis that TH1 polarization has a primary role in acquired immunity to C. jejuni . This study revealed a C. jejuni dose-related increase in campylobacteriosis rates, evidence of complete short-term protection that waned with time, and immune response patterns associated with protection.
Type of Medium:
Online Resource
ISSN:
0019-9567
,
1098-5522
DOI:
10.1128/IAI.01021-09
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2010
detail.hit.zdb_id:
1483247-1
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