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Pretreatment With Inactivated Bacillus C almette– G uerin Increases CD 4+ CD 25+ Regulatory T Cell Function and Decreases Functional and Structural Effects of Asthma Induction in a Rat Asthma Model
Author(s) -
Gong Ping,
Li Yun,
Tan YuPin,
Li Hong
Publication year - 2016
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/aor.12566
Subject(s) - ovalbumin , foxp3 , bronchoalveolar lavage , immunology , il 2 receptor , chemistry , sensitization , histamine , flow cytometry , airway resistance , medicine , pharmacology , t cell , immune system , lung , asthma
Bacillus C almette– G uerin ( BCG ) has been shown to have therapeutic effects on asthma through CD 4+ CD 25+ regulatory T cells ( T regs). We sought to assess pretreatment with inactivated BCG on CD 4+ CD 25+ T regs and its functional and structural effects in rat asthma model. The rat asthma model was established using ovalbumin ( OVA ) sensitization and challenge. Ten rats were pretreated with BCG prior to OVA and received continued BCG injections during OVA challenge ( BCG + OVA group), 10 rats were treated with OVA alone ( OVA group), and 10 rats were treated with saline (control group). After 9 weeks, histamine dihydrochloride effect on airway resistance was measured. Number of CD 4+ CD 25+ T regs was measured by flow cytometry, expression of F oxp3 and CTLA ‐4 mRNA was measured, and serum TGF ‐β levels were determined. Differential cell count in bronchoalveolar lavage fluid ( BALF ) was determined, and lung tissue was processed and stained with hematoxylin and eosin, M asson's trichrome, and alcine blue and periodic acid S chiff's reaction to evaluate inflammatory cell infiltration, collagen deposition, and presence of goblet cells, respectively. BCG treatment led to an increase in CD 4+ CD 25+ T regs, as well as an increase in F oxp3 and CTLA ‐4 expression and serum TGF ‐β levels. In addition, we observed a decrease in histamine dihydrochloride–induced airway resistance, a decrease in inflammatory leukocytes in BALF , and a decrease in airway remodeling indicators in BCG + OVA ‐treated rats compared with OVA ‐treated rats. Intradermally injected inactivated BCG has the potential to improve airway inflammation, airway resistance, and airway remodeling through a mechanism that may involve CD 4+ CD 25+ T regs.