Interleukin-5 expressed by a recombinant virus vector enhances specific mucosal IgA responses in vivo.
Several in vitro studies have shown that murine interleukin-5 (mIL-5) enhances IgA production by activated mucosal B cells. To date, however, there is no evidence that this factor significantly up-regulates mucosal IgA responses in vivo. Here, we show that expression of the gene for mIL-5 in a recombinant vaccinia virus vector markedly increases IgA responses to co-expressed heterologous antigen in the lungs of mice given intranasal inocula of the virus. The elevated local IgA responses to vectors expressing mIL-5 peaked at a fourfold higher level than those elicited by control virus at 14 days after infection and were sustained for at least 4 weeks. Increased IgA responses were abrogated in mice treated with monoclonal antibody against mIL-5 and were not detected in systemic lymphoid tissue. No enhancement of specific IgG levels was found either locally or systemically. Our results indicate that mIL-5 selectively enhances the development of mucosal IgA responses in vivo and suggest that expression of this factor in mucosal vaccine vectors may stimulate local immune reactivity.
Ramsay
A J
AJ
Viral Engineering and Cytokine Research Group, John Curtin School of Medical Research, Australian National University, Canberra.
Kohonen-Corish
M
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D005822:Genetic Vectors; D007114:Immunization; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis*; D015848:Interleukin-5 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D008168:Lung / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA; D009092:Mucous Membrane / Q000276:immunology; D011994:Recombinant Proteins / Q000494:pharmacology; D014616:Vaccinia virus / Q000235:genetics* / Q000254:growth & development
D000911:Antibodies, Monoclonal; D007071:Immunoglobulin A, Secretory; D015848:Interleukin-5; D011994:Recombinant Proteins