EFFECT OF RESPIRATORY VIRAL INFECTION ON THE UPTAKE AND IMMUNE RESPONE TO DIETARY ANTIGENS: POSSIBLE ROLE IN POTENTIATION OF ALLERGY

Abstract

Groups of Balb/c-mice were sham infected or infected intranasally (I/N) with respiratory syncytial virus (RSV). The animals were repeatedly exposed I/N to ovalbumin (OVA), with or without adjuvant (Alum). At different intervals, levels of anti-OVA antibody and OVA concentrations were determined in serum and pulmonary lavage fluid (PLF) employing the techniques of Elisa (for IgG, IgA, IgM) and passive cutaneous anaphylaxis (for IgE). In all mice, anti-OVA IgG in the serum reached peak liters after 24 days, with statistically significant higher titers in the infected mice compared to uninfected controls. OVA-specific IgA and IgM could be detected in low concentrations in both groups. Antigen-specific IgA in PLF was detectable from 17 to 31 days after exposure, with higher titers for the RSV-infected animals. OVA-specific IgE response in serum and PLF was demonstrable in 20% of the infected mice and in none of the controls. OVA concentration in serum peaked at 2 hours after administration and appeared to be higher in RSV infected animals as well as non infected animals treated with adjuvant, when compared to uninfected animals without adjuvant treatment. These observations suggest that acute bronchopulmonary infection with RSV is associated with significant increase in the development of IgG and IgE immune response to other concurrently inhaled antigens. These findings may explain the observed nonspecific increase in allergic reactions to dietary antigens during viral infection.