2-Chloroadenosine (2-CADO) treatment modulates the pro-inflammatory immune response to prevent acute lung inflammation in BALB/c mice suffering from Klebsiella pneumoniae B5055-induced pneumonia.

Author(s): Kumar V, Harjai K, Chhibber S

Affiliation(s): Department of Microbiology, Panjab University, Chandigarh 160014, India. vij_tox@yahoo.com

Publication date & source: 2010-06, Int J Antimicrob Agents., 35(6):599-602. Epub 2010 Mar 1.

Publication type: Research Support, Non-U.S. Gov't

Acute lung inflammation (ALI) is a life-threatening pathology and can develop during the course of several clinical conditions such as pneumonia, acid aspiration or sepsis. Adenosine plays a significant role in controlling acute inflammation via binding to A(2A) receptors on inflammatory cells, i.e. neutrophils or macrophages. The present study was designed to evaluate the anti-inflammatory and immunomodulatory effects of 2-chloroadenosine (2-CADO), alone or in combination with amoxicillin/clavulanic acid (AMC), in Klebsiella pneumoniae B5055-induced acute lung infection in mice. Acute lung infection in mice was induced by directly instilling the selected dose (10(4) colony-forming units/mL) of bacteria intranasally. Histopathological examination of the lungs was performed to reveal neutrophil infiltration into the lung alveoli. In addition to the major pro-inflammatory cytokines tumour necrosis factor-alpha (TNFalpha) and interleukin (IL)-1alpha, levels of the anti-inflammatory cytokine IL-10 were also determined. Intranasal instillation of bacteria caused profound neutrophil infiltration into the lung alveoli as well as a significant increase in the levels of pro-inflammatory mediators (i.e. TNFalpha and IL-1alpha). However, intravenous administration of 2-CADO 10 microg/kg/day, alone or in combination with an antibiotic (i.e. AMC), significantly decreased neutrophil infiltration into the lung alveoli. A significant decrease in TNFalpha and IL-1alpha along with elevation of IL-10 levels in the lung homogenate of mice with acute lung infection was observed upon treatment with 2-CADO alone, with no significant decrease in bacterial counts. Moreover, in combination with AMC, 2-CADO exhibited its immunomodulatory action in acute lung infection and prevented ALI, whilst an antibacterial action was exhibited by AMC. 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.