Cytoskeletal organization and functional changes in monocytes from patients with chronic hepatitis B: relationship with viral replication

Monocytes play an important role in the initiation and regulation of the antiviral immune response. These cells have a dense framework of intermediate filaments composed of vimentin monomers. In 35 patients with chronic hepatitis B, 26 healthy controls, seven patients with acute liver damage and eight patients with inactive HBsAg-negative cirrhosis, we investigated the expression of vimentin filaments, C3b and IgGFc receptors, HLA-DR molecules and the phagocytic activity in monocytes purified from venous blood. In the same subjects, we also studied the display of CD2, CD3 and CD5 on lymphocytes. In patients with chronic hepatitis B manifesting viral replication (n = 21; Group 1), the expression of vimentin filaments and the other functional monocyte parameters were decreased, whereas in patients in the nonreplicative phase of the disease (n = 14; Group 2) and in control cases with various forms of acute liver damage or inactive HBsAg-negative cirrhosis, they were similar to those found in healthy subjects. In Group 1, there was also a selective defect in the display of CD3 on lymphocytes. The expression of this molecule correlated with the functional state of monocytes. In three patients with chronic hepatitis B that changed from the replicative to the nonreplicative phase of the disease, the expression of vimentin filaments in monocytes and of CD3 on lymphocytes increased to normal levels. On the other hand, the incubation of patients' monocytes with gamma-interferon corrected the diminished expression of vimentin filaments and the other decreased functional parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppressor T-cell activity in chronic hepatitis B-virus infection: relationship with the presence of HBV-DNA in serum

Suppressor T-cell activity and allogeneic T-cell response to concanavalin A (ConA) were investigated in 46 patients chronically infected with hepatitis B virus (HBV). Thirty-eight patients had chronic active hepatitis, seven of whom were superinfected with Delta virus, and eight were healthy chronic HBV carriers. T-cell suppressor activity was in the normal range in healthy carriers and in patients negative for serum HBV-DNA, independent of the e antigen status. In contrast, the group of patients positive for HBV-DNA exhibited a significant reduction in suppressor activity. Longitudinal studies in patients who cleared serum HBV-DNA demonstrated that suppressor T-cell activity became normal thereafter. These results suggest a relationship between suppressor T-cell function and the stage of viral replication in individuals with chronic HBV infection.

Inhibition of acquired immunodeficiency syndrome virus by oligodeoxynucleoside methylphosphonates

Antisense oligodeoxynucleotides containing internucleoside methylphosphonate linkages were examined for their ability to inhibit human immunodeficiency virus (HIV)-induced syncytium formation and virus expression. HIV inhibitory activity was found to be dependent on both chain length and the number of phosphonate residues. Introduction of 18 phosphonate groups in an oligomer of chain length 20 significantly increased HIV inhibitory activity relative to the parent oligonucleotide, whereas 5 such groups showed little or no increase in the HIV inhibition capacity. Methylphosphonate-linked oligomers are more stable to nuclease degradation and hence could be potentially useful in the treatment of acquired immunodeficiency syndrome.

Oligodeoxynucleoside phosphoramidates and phosphorothioates as inhibitors of human immunodeficiency virus

Modified oligodeoxynucleotides complementary to RNA of human immunodeficiency virus 1 (HIV-1) were tested for their ability to inhibit virally induced syncytium formation and expression of viral p24 protein. The modifications of oligomers include replacement of backbone phosphodiester groups with phosphorothioates and various phosphoramidates. All oligomers were found to be active. Oligomers with complete replacement of phosphodiesters with phosphoramidate or phosphorothioate groups were more active at the micromolar range than were unmodified oligomers of the same sequence. In addition, modified and unmodified homooligonucleotides also showed inhibition of HIV-1 replication. It is suggested that different classes of oligonucleotides may inhibit HIV replication by different mechanisms.

Inhibition of human immunodeficiency virus replication by antisense oligodeoxynucleotides

Twenty different target sites within human immunodeficiency virus (HIV) RNA were selected for studies of inhibition of HIV replication by antisense oligonucleotides. Target sites were selected based on their potential capacity to block recognition functions during viral replication. Antisense oligomers complementary to sites within or near the sequence repeated at the ends of retrovirus RNA (R region) and to certain splice sites were most effective. The effect of antisense oligomer length on inhibiting virus replication was also investigated, and preliminary toxicity studies in mice show that these compounds are toxic only at high levels. The results indicate potential usefulness for these oligomers in the treatment of patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex either alone or in combination with other drugs.