Conditioned media of testicular macrophages (CMTM) from rats with experimental autoimmune orchitis (EAO) induce apoptosis of germ cells: involvement of TNF-alpha

MARÍA SUSANA THEAS; CLAUDIA RIVAL; PATRICIA JACOBO; SABRINA JARAZO DIETRICH; LIVIA LUSTIG

Rio de Janeiro

Congreso; XIII Congreso Internacional de Inmunología; 2007

Sociedad Internacional de Inmunología

We induced EAO in rats by active immunization with spermatic antigens and adjuvants. A mild interstitial lymphomononuclear cell infiltrate and apoptosis of germ cells (GC) was observed at 50 days (d) after the first immunization. At 80d, cell infiltrate and apoptotic GC expressing TNF-alpha type 1 receptor increased. The aim of this study was to evaluate the role of CMTM and TNF-alpha on GC apoptosis. Rats were immunized with testicular homogenate and adjuvants (EAO group) or with saline and adjuvants (control group, C). We analyzed the effect of CMTM on the viability of GC obtained from untreated normal and EAO rats (MTS method). CMTM from EAO rats of 50 and 80d did not affect viability of normal GC but significantly decreased the viability of EAO GC compared to CMTM from C (OD arbitrary units, CMTM-50d, C:104.60±3.36 OAE:87.80±4.49; CMTM-80d, C:73.57±3.82, OAE:58.80±5.25, p=0.01). CMTM from EAO rats of 50 and 80d significantly increased GC apoptosis compared to CMTM from C (% of TUNEL+ GC, CMTM-50d, C:20.23, OAE:60.42; CMTM-80d, C:18.34, OAE:59.78, p=0.001, X2). In the CMTM from EAO rats of 50 and 80d an increase in TNF-α content was detected compared to CMTM from C (TNF-alpha pg/ml, CMTM-50d C:83.00±6.34, EAO:100.89±17.28; CMTM-80d: C:68.23±19.53, EAO:111.45±8.79*, p=0.05). Moreover, TNF-alpha (50ng/ml) induced GC apoptosis in vitro (% of TUNEL+ GC, medium: 25.46; TNF-alpha: 55.53, p=0.001, X2). We demonstrated that in EAO testicular macrophages induce apoptosis of GC through their secretion products and that TNF-alpha released by these cells might be an important factor involved in this phenomenon.