Increased IgG secretion in Peyer’s patches of mice kept under conventional conditions.

<p>Mice were housed either under conventional (n = 6) or SPF (n = 4) conditions and actively immunized with 200 µg MP4. On days 23–30 after immunization ELISPOT assays were performed to measure the extent of total IgG secretion in the Peyer’s patches. A, Number of spots per 10⁶ plated cells derived from the Peyer’s patches, the mesenteric or inguinal lymph nodes (LN). B, Representative ELISPOT well images showing medium control and total IgG responses in SPF and conventionally housed mice.