Anti-inflammatory and immunomodulating effects of the bacterial lysate in the in vivo models of aseptic lymphadenitis and pneumococcal pneumonia

Bacterial lysates may produce immunoregulatory effects in the inflammatory diseases that are not directly caused by infectious agents; they may also stimulate the immune response against pathogens which are not a part of the lysate composition. Imudon® is a polyvalent bacterial lysate that is available in orodispersible tablets. However, the influence of this drug product on aseptic inflammation and immune defense against the infectious agents, the antigens of which are not contained in this preparation have not been studied so far. The aim of this study, therefore, was to determine the anti-inflammatory and immunomodulating effects of Imudon® using the models of aseptic lymphadenitis (in Wistar rats) and pneumococcal pneumonia (in Balb/c mice), i.e., the conditions not related to the specific components of the bacterial lysate. Lymphadenitis was induced in rats by administration of λ-carrageenan into a cervical lymph node via an open operative approach. Whereas pneumonia was induced in mice by administering Streptococcus pneumoniae suspension intranasally. The choice of pneumococcus was determined by the absence of pneumococcal antigens in Imudon®, i.e., it cannot be a direct inducer of adaptive immune response against pneumococcal infection. Imudon® was administered intragastrically as a crushed tablet suspension following a therapeutic-preventive regimen (for 14 days daily until the induction of inflammation and for 3 [in the lymphadenitis model] or 5 days [in the model of pneumonia] in three doses thereafter). In the lymphadenitis model, Imudon® demonstrated both local and systemic anti-inflammatory responses manifested in the reduced number of circulating leucocytes and lower TNFα levels and by ameliorated histological features of inflammation in the operated lymph node. In rats, the anti-inflammatory effect was most pronounced when the product was administered at a dose of 2.2 mg/kg (equivalent to a human therapeutic dose) and 6.6 mg/kg. In the model of pneumonia, administration of Imudon® at 4.44 mg/kg (equivalent to a human therapeutic dose) and 13.32 mg/kg demonstrated a trend towards increased survival rate as compared to the control group. On Day 5 after infection Imudon® (4.44 and 13.32 mg/kg) decreased significantly the severity of inflammation and bacterial titer in the lungs. The titer of anti-pneumococcal immunoglobulins A in the bronchoalveolar lavage fluid were found to be higher in the Imudon® treated group (13.32 mg/kg) compared to control group. The results of this study showed high antiinflammatory and immunomodulatory activities of Imudon® and provided an insight into the mechanisms that underlie the clinical effects of this drug in various inflammatory diseases.

bacterial lysates, Imudon®, immunostimulation, immunoregulation, aseptic lymphadenitis, inflammation, tumor necrosis factor, Streptococcus pneumoniae, pneumonia, immunoglobulin A

1. Blokhin B.M., Steshin V.Yu. Bacterial lysates OM-85 (Broncho-Munal) for prevention and treatment of respiratory infections in children. Prakticheskaya pulmonologiya = Practical Pulmonology, 2016, no. 2, pp. 29-34. (In Russ.)

2. Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes.

3. Kalyuzhin O.V. OM-85 in the prevention/treatment of respiratory infections and exacerbations of chronic lung diseases: selection criteria, mechanisms and evidence. Lechashchiy Vrach = Attending Physician, 2018, no. 3, pp. 77-82. (In Russ.)

4. Kalyuzhin O.V. Topical bacterial lysates in the prevention and treatment of respiratory infections. Prakticheskaya meditsina = Practical Medicine, 2016, no. 2 (94), pp. 69-74. (In Russ.)

5. Muzhikyan A.A., Makarova M.N., Gushin Ya.A. Features histological processing of organs and tissues of laboratory animals. Mezhdunarodnyy vestnik veterinarii = International Bulletin of Veterinary Medicine, 2014, no. 2, pp. 103-108. (In Russ.)

6. Muzhikyan A.A., Khodko S.V., Gushin Ya.A., Makarova M.N., Makarov V.G. Histological changes in the lymph nodes of rats in modeling acute cervical lymphadenitis .Mezhdunarodnyy vestnik veterinarii = International Bulletin of Veterinary Medicine, 2017, no. 1, pp. 75-83. (In Russ.)

7. Tesakova S.V., Samusenko I.A., Karachinskaya I.V., Kryshen K.L., Abrashova T.V., Makarova M.N., Makarov V.G. Experimental model of cervical lymphadenitis in rats to evaluate the efficacy of anti-inflammatory medicines. Profilakticheskaya i klinicheskaya meditsina = Preventive and Clinical Medicine, 2011, no. 1 (38), pp. 57-62. (In Russ.)

8. Cheliabin E.A., Zavyalov A.E., Kurinsky V.V., Vazhzhov I.V. Cervical lymphadenitis as interdisciplinary problem. Nauchnyy almanakh = Scientific Almanac, 2017, no. 1-3, pp. 256-260. (In Russ.)

9. Bessler W.G., vor dem Esche U., Masihi N. The bacterial extract OM-85 BV protects mice against influenza and Salmonella infection. Int. Immunopharmacol., 2010, Vol. 10, no. 9, pp. 1086-1090.

10. Bodemer C., Guillet G., Cambazard F., Boralevi F., Ballarini S., Milliet C., Bertuccio P., la Vecchia C., Bach J.F., de Prost Y. Adjuvant treatment with the bacterial lysate (OM-85) improves management of atopic dermatitis: A randomized study. PloS ONE, 2017, Vol. 12, no. 3, e0161555. doi: 10.1371/journal.pone.0161555.

11. Cazzola M. A new bacterial lysate protects by reducing infectious exacerbations in moderate to very severe COPD: A double-blind, randomized, placebo-controlled trial. Trends in Medicine, 2006, Vol. 6, no. 3, pp. 191-199.

12. Guidance for Industry. Estimating the maximum safe starting dose in initial clinical trials for therapeutics in adult healthy volunteers: Pharmacology and toxicology. 2005. 30 p.

13. Han L., Zheng C.P., Sun Y.Q., Xu G., Wen W., Fu Q.L. A bacterial extract of OM-85 Broncho-Vaxom prevents allergic rhinitis in mice. Am. J. Rhinol. Allergy, 2014, Vol. 28, no. 2, pp. 110-116.

14. Hvalbye B.K., Aaberge I.S., Løvik M., Haneberg B. Intranasal immunization with heat-inactivated Streptococcus pneumoniae protects mice against systemic pneumococcal infection. Infect. Immun., 1999, Vol. 67, no. 9, pp. 4320-4325.

15. Lewandowski A., Christine M.D., Myers М.J. λ-Carrageenan initiates inflammation via activation of heterodimers TLR2/6 and TLR4/6. J. Immunol., 2018, Vol. 200, Suppl. 1, 42.12.

16. Orcel B., Delclaux B., Baud M., Derenne J.P. Oral immunization with bacterial extracts for protection against acute bronchitis in elderly institutionalized patients with chronic bronchitis. Eur. Respir J., 1994, Vol. 7, pp. 446-452.

17. Roїy A., Chorostowska-Wynimko J. Bacterial immunostimulants-mechanism of action and clinical application in respiratory diseases. Pneumonol. Alergol. Pol., 2008, Vol. 76, no. 5, pp. 353-359.

18. Tao Y., Yuan T., Li X., Yang S., Zhang F., Shi L. Bacterial extract OM-85 BV protects mice against experimental chronic rhinosinusitis. Int. J. Clin. Exp. Pathol., 2015, Vol. 8, no. 6, pp. 6800-6806.

19. Zhong H., Wei J., Yao Y., Fu R., Li H., Fu Q., Wen W. A bacterial extract of OM-85 Broncho-Vaxom suppresses ovalbumin-induced airway inflammation and remodeling in a mouse chronic allergic asthma model. Int. J. Clin. Exp. Pathol., 2017, Vol. 10, no. 2, pp. 1149-1157.