Diminished percentage of antigen bearing cells in the lymph nodes of immune aged rats

ROPOLO A; MORON VG; MALETTO B; PISTORESI-PALENCIA MC

EXPERIMENTAL GERONTOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2001 vol. 36 p. 137 - 153

0531-5565

We have demonstrated previously that during experimental autoimmune prostatitis (EAP), aged rats show a diminished humoral autoimmune response. In the present paper we have studied the transport of the autoantigen from the site of injection toward lymphatic organs in rats of different ages with or without EAP. We used as autoantigen prostatic components (rat accessory glands (RAG)) conjugated with fluorescein isothiocyanate (FITC). Studies of flow cytometry, fluorescent microscopy and confocal microscopy show no differences in the percentage of RAG-FITC positive cells or in the localization of the cells in the popliteal lymph nodes of not-immunized young and aged rats. On the other hand, in 18-month-old rats immunized with either RAG or Ovalbumin there were lower levels of specific IgG antibodies and fewer antigen containing cells in the draining lymph nodes than those of 3- or 12-month-old rats. In all groups fluorescent cells were MHC class II positive and some were IgM positive. Our results demonstrate that in immunized 18-month-old rats there is a diminished percentage of cells bearing the antigen in the draining lymph nodes after antigen injection in the skin, related to the levels of specific antibodies able to form antigen-antibody complexes in the periphery.