Fig. 3

Long-term cellular consequences on astrocytoma cell line monolayers following transient co-culture with HTLV-1-infected cell lines. Long-term effects (5 days post co-culture) exerted by HTLV-1-infected T cell lines on astrocytes cell lines were assessed by co-culture of astrocytoma cell lines (U251 and U87) with HTLV-1-infected (CIB) and non-infected (CEM) T cell lines. Astrocytoma cells were cultured only with RPMI for mock control (a, d and g). Under light microscopy (magnifications = ×200), no morphological alterations were observed when CEM was co-cultured with U251 (b) and U87 (e). Under light microscopy (magnifications = ×200), morphological alterations on astrocytoma cells were characterized by presence of cell shrinkage, loss of cell-cell contact, seen when CIB cells was co-cultured with U251 (c) and U87 cell lines (f). Under transmission electron microscopy, ultrastructural alterations were characterized not only by presence of cell shrinkage, loss of cell-cell contact (i), but also accumulation of secondary lysosome (j), and presence of particles compatible with HTLV-1 virions (highlighted by arrows), seen when U251 astrocytoma cells were co-cultured with CIB lymphocytes (j–l). No ultrastructural alteration were seen when U251 astrocytoma cells were co-cultured with CEM (h)