A bacterial extract of OM-85 Broncho-Vaxom prevents allergic rhinitis in mice.
BACKGROUND
According to the hygiene hypothesis, bacterial infections during early life contribute to a reduced incidence of asthma in animals. However, the effects of microbial products at a safe dose and within a rational time course on the prevention of allergic rhinitis (AR) have been inconclusive. This study investigated the immunomodulatory effects of oral administration of a bacterial extract, OM-85 Broncho-Vaxom (BV), with a low dose and general time course, which is currently used for respiratory infections in humans, on AR inflammation in mice.


METHODS
We developed a mouse model of ovalbumin (OVA)-induced AR allergic inflammation in the nose mucosa of mice. Low doses of OM-85 BV were orally administered for 3 months (long term) before sensitization. We evaluated nasal symptoms, pathology in the nose, inflammatory cells, and the levels of T helper 1 (Th1)/Th2 cytokines in the nasal lavage fluids, and the serum levels of specific IgE and IgG1. We also observed enhanced effects of OM-85 BV with 1 month (short term) of treatment.


RESULTS
We found that long-term pretreatment with OM-85 BV protected the mice from the majority of allergy-specific symptoms; specifically, OM-85 BV suppressed nasal symptoms, inhibited eosinophil infiltration in the nose, inhibited inflammatory infiltrates and the Th2 response by reducing cytokines (IL-4, IL-5, or IL-13) in the nasal lavage fluids, and reduced IgE and IgG1 levels. Furthermore, short-term treatment with OM-85 BV decreased the levels of Th2 cytokines and IgE.


CONCLUSIONS
Taken together, our data suggested that OM-85 BV is a low-cost alternative candidate to prevent AR with simple oral administration.
Otorhinolaryngology Hospital, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
Ling
L
Han
Chao-Pan
CP
Zheng
Yue-Qi
YQ
Sun
Geng
G
Xu
Weiping
W
Wen
Qing-Ling
QL
Fu
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000284:Administration, Oral; D000485:Allergens / Q000276:immunology; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D000942:Antigens, Bacterial / Q000008:administration & dosage*; D002457:Cell Extracts / Q000008:administration & dosage*; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004804:Eosinophils / Q000187:drug effects* / Q000276:immunology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D056747:Immunomodulation; D051379:Mice; D008807:Mice, Inbred BALB C; D009297:Nasal Mucosa / Q000187:drug effects* / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology; D065631:Rhinitis, Allergic / Q000382:microbiology / Q000517:prevention & control*; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology; D018418:Th2 Cells / Q000187:drug effects* / Q000276:immunology; D013997:Time Factors; D000095983:Bacterial Lysates
D000276:Adjuvants, Immunologic; D000485:Allergens; D000942:Antigens, Bacterial; D002457:Cell Extracts; D016207:Cytokines; D007073:Immunoglobulin E; D007074:Immunoglobulin G; D010047:Ovalbumin; C030259:Broncho-Vaxom; D000095983:Bacterial Lysates