Per-Oral Vaccination Induces IgA Secretion in the Female Reproductive Tract and Protection against Vaginal Chlamydia Challenge in Mice
Chlamydial infections in women cause reproductive tract pathologies and infertility. There is no effective vaccine against this pathogen. Shillova et al. (e00413-20) show that per-oral immunization with live or killed Chlamydia muridarum protects against vaginal challenge, reflected in reduced Chlamydia burden and reproductive tract pathology. Secreted IgA induced by per-oral immunization neutralizes Chlamydia, thus lowering infectivity, hindering ascension to the upper reproductive tract, and accelerating Chlamydia clearance. The authors propose that the gut-associated lymphoid tissue is the inductive site for reproductive tract B cell responses and that per-oral immunization may also be effective for developing vaccines against other sexually transmitted pathogens.
Efficient 5-OP-RU-Induced Enrichment of MAIT Cells in the Murine Lung Does Not Enhance Control against Aerosol Mycobacterium tuberculosis Infection
MAIT cells are innate lymphocytes that respond to bacterial vitamin metabolites. Because of their broad distribution, priming with MAIT stimulatory ligands could be an attractive pan-vaccination approach. In this study (e00524-20), efficient priming of MAIT cells in the lungs of mice had no effect on Mycobacterium tuberculosis infection. Despite varying kinetics of priming and the immune status of the host, M. tuberculosis was resistant to MAIT cell action, indicating that deploying this approach for TB is not viable without further insight into MAIT cell biology in M. tuberculosis infection.
A New Addition to the IL-17 Game Reveals Follistatin-Like 1 To Be a Novel Determinant of Pulmonary Host Defense
Klebsiella pneumoniae remains a prototypical antibiotic-resistant pathogen and common cause of hospital-acquired infection. Follistatin-like 1 (FSTL-1) is critical for lung homeostasis, tissue repair, and inflammation, though its role in host defense remains largely unknown. Henkel et al. (e00298-20) identify that in the murine Klebsiella pneumoniae pulmonary infection model, FSTL-1 regulates innate type-17 immunity to control infection. This study identifies FSTL-1 as a novel host factor in pulmonary host defense, while revealing a mechanism as a regulator of IL-17-mediated signaling during extracellular bacterial infection.
Methionine Metabolism Is Critical for Optimal Intestinal Colonization by Campylobacter jejuni
The activated methyl cycle and l-methionine generation are critical for optimal Campylobacter jejuni colonization in the intestinal tract. Ruddell et al. (e00542-20) identify a secondary yet important pathway encoded by MetAB that is required to maintain l-methionine production in vivo in the absence of LuxS, a primary enzyme involved in methionine metabolism. MetAB complements the l-methionine-generating function of LuxS as shown by both in vitro assay and in vivo colonization. These findings demonstrate the diverse metabolic pathways utilized by C. jejuni for successful colonization of an animal host and provide new insights into the pathophysiology of this enteric zoonotic pathogen.
- Copyright © 2020 American Society for Microbiology.
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- Per-Oral Vaccination Induces IgA Secretion in the Female Reproductive Tract and Protection against Vaginal Chlamydia Challenge in Mice
- Efficient 5-OP-RU-Induced Enrichment of MAIT Cells in the Murine Lung Does Not Enhance Control against Aerosol Mycobacterium tuberculosis Infection
- A New Addition to the IL-17 Game Reveals Follistatin-Like 1 To Be a Novel Determinant of Pulmonary Host Defense
- Methionine Metabolism Is Critical for Optimal Intestinal Colonization by Campylobacter jejuni
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