SUPPRESSION OF IgE ANTIBODY RESPONSE IN MICE BY A POLYSACCHARIDE, AZ9, PRODUCED BYKLEBSIELLA OXYTOCASTRAIN TNM3

Abstract

A soil bacterium, Klebsiella oxytoca TNM3 was found to produce a polysaccharide named AZ9 that shows suppressive effects on IgE antibody response in mice. When mice were administered with 50 to approximately 100 mg/kg AZ9 subcutaneousely for 4 consecutive days after immunization with trinitrophenyl (TNP)-keyhole limpet hemocyanin, anti-TNP IgE production was significantly suppressed, while the level of anti-TNP IgM was affected marginally. In AZ9-administered mice, IL-4 secretion from splenic cells was reduced to approximately 30% of the untreated control. Thus, AZ9 suppression of IgE production may be due to attenuating effects on the Th2-type response. Although oral administration of AZ9 alone had no effects on IgE production, ovalbumin (OVA)-induced oral tolerance of anti-TNP IgE response to TNP-OVA was markedly augmented when a suboptimal dose of OVA was administered orally in combination with AZ9. Collectively, our data suggest that AZ9 has beneficial suppressive effects on IgE-dependent allergic responses.

Oral Tolerance: Therapeutic Implications for Autoimmune Diseases

“…Oral IFN-b and IFN-t (tau) synergizes with the induction of oral tolerance in SJL/PLJ mice fed low doses of MBP (Nelson et al 1996;Soos et al 2002). Other exogenous agents which have been reported to enhance oral tolerance when given orally include parasite Ag from H. polygyrus (Shi et al 2000), polysaccharide AZ9 from Klebsiella oxitoca (Sugihara et al 2002) and Schistosoma Mansoni egg antigens (SEA) (Maron et al 1998). Antibody (Ab) to chemokine monocyte chemotactic protein 1 (MCP-1) abrogates oral toleran (Karpus et al 1996).…”

Oral tolerance

“…Oral IFN‐β and IFN‐t synergize with the induction of oral tolerance in SJL/PLJ mice fed low doses of MBP (212, 213). Other exogenous agents which have been reported to enhance oral tolerance when given orally include parasite antigens from Heligmosomoides polygyrus (214), polysaccharide AZ9 from Klebsiella oxitoca (215) and S. mansoni egg antigens (216). Antibody to chemokine monocyte chemotactic protein‐1 abrogates oral tolerance (217).…”

Exopolysaccharides from Klebsiella oxytoca: anti-inflammatory activity

“…The supernatant was collected and concentrated to 100 mL in a rotary evaporator at 50 °C. Following this, the concentrated solution containing EPS was precipitated from the clear supernatant by adding three volumes of cold acetone and maintained at 4 °C for 48 h. The crude exopolysaccharides from K. oxytoca (KEPSC) were obtained by filtration, lyophilized and weighed to calculate the yield (Kazy et al, 2002;Sugihara et al, 2000;Sugihara et al, 2001;Sugihara et al, 2002). Once isolated, the KEPSC solution was deproteinized with trichloracetic acid (20%, w/v) at a ratio of 1:1, maintained at 4 °C for 2 h, and then centrifuged (12,000 × g for 20 min at 5 °C).…”