Immunosuppressive Activity of Florfenicol on the Immune Responses in Mice

Abstract

Florfenicol is a new type of broad-spectrum antibacterial that has been used in veterinary clinics. It shows immunosuppressive activity on the immune responses to ovalbumin (OVA) in mice. In the present study, florfenicol suppressed lipopolysaccharide (LPS)-stimulated splenocyte proliferation in a concentration-dependent manner in vitro and in vivo. BALB/c mice were immunized subcutaneously with OVA on days 1 and 4. Following the second immunization, mice were treated with a single daily oral dose of florfenicol (50, 100, and 200 mg/kg) for 10 consecutive days. On day 14, blood samples were collected to analyze OVA-specific IgG, IgG1, and IgG2b antibodies, and splenocytes were harvested to assess lymphocyte proliferation, CD3⁺ T and CD19⁺ B lymphocyte subsets. The results presented here demonstrate that florfenicol not only significantly suppressed Con A-, LPS- and OVA-induced splenocyte proliferation but also decreased the percentage of CD19⁺ B cells in a dose-dependent manner and suppressed CD3⁺ T cell at high doses. Moreover, OVA-specific IgG, IgG1 and IgG2b titers in OVA-immunized mice were reduced by florfenicol. These results suggest that florfenicol could suppress humoral and cellular immune responses in mice.

Keywords:

• Immunosuppressive
• Florfenicol
• OVA

ACKNOWLEDGMENT

This study was financed by the National Science and Technology Supporting Plan of China (No. 2006BAD31B03-4).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.