Replication of dengue-2 virus in cultured human lymphoblastoid cells and subpopulations of human peripheral leukocytes.

We studied the susceptibility of four human lymphoblastoid cell lines (HCL) and of subpopulations of circulating peripheral human leukocytes to dengue-2 virus infection. HCL with B cell characteristics (Raji, Wil 2WT, 8866), B-type peripheral lymphocytes, and macrophages were productively infected by dengue-2 virus. In contrast, an HCL with T cell characteristics (MOLT-4), T type peripheral lymphocytes, and polymorphonuclear (PMN) cells did not become infected and replicate dengue-2 virus. PMN cells did not adsorb dengue-2 virus, suggesting lack of viral receptors. However, T-type cultured lymphoblasts and T-type peripheral lymphocytes adsorbed dengue-2 virus, suggesting that the block in viral replication involves some stage of infection occurring after adsorption. Permissiveness of B-type HCL to dengue-2 virus infection was dependent on the virus seed used but the virus titers obtained among the susceptible HCL varied. HCL infected persistently with dengue-2 virus have been established. Human peripheral lymphocytes inoculated after cultivation for 3 days in complete medium alone or complete medium supplemented with mitogens replicated dengue-2 virus. In contrast, unstimulated peripheral lymphocytes inoculated immediately after isolation adsorbed dengue-2 but did not support its replication. Mitogen-treated and untreated macrophages replicated dengue-2 virus equally well. The efficiency of dengue-2 virus replication by macrophages was higher than that of peripheral lymphocytes but lower than that of HCL.