Lipopolysaccharide augments IgG and IgE responses of mice to the latex allergen Hev b 5.

Abstract

LPS is a common contaminant in the health care environment and in latex examination gloves. We sought to investigate the role of LPS in enhancing the immune responses of mice to inhaled latex allergen. As our model allergen, we used a fusion protein containing the potent latex allergen Hev b 5. BALB/c mice were lightly anesthetized and given repeated intranasal doses of saline, LPS, and/or Hev b 5. The doses were given in 2 courses separated by a 6-week period, with the first course consisting of 6 doses and the second consisting of 3 doses. After the first set of immunizations, mice given Hev b 5 alone had no detectable IgG1 or IgE responses to Hev b 5, whereas mice given the antigen along with LPS had significant responses (IgG1, 0.73 U +/- 0.05; IgE, 0.88 U +/- 0.2). No enhancement of specific IgG2a was observed. A stimulatory effect of LPS on all 3 immunoglobulin types was apparent after the second course. Lymphocytes from mice immunized with LPS and Hev b 5 had increased proliferation to Hev b 5 and its fusion partner. LPS may be an important immunoadjuvant for the development of allergic reactions to latex protein allergens.