Pertussis toxin inhibits induction of human immunodeficiency virus type 1 in infected monocytes.

Tumor necrosis factor alpha (TNF-alpha) and 12-0-tetradecanoyl phorbol-13-acetate (TPA) activate human immunodeficiency virus type 1 (HIV-1) in U1 cells that are latently infected with HIV-1 to produce viral particles. Pertussis toxin, which inactivates several members of the G protein family of signaling components, including Gi, Go, and transducin, was found to inhibit either TPA or TNF-alpha induction of HIV-1 in U1 cells at the concentration of 1-10 ng/ml. Chloramphenicol acetyl transferase (CAT) assay revealed that pertussis toxin could inhibit HIV-1 gene expression.

Evaluation of anti-human immunodeficiency virus effect of recombinant CD4-immunoglobulin in vitro: a good candidate for AIDS treatment.

CD4 molecule, a surface marker of helper T lymphocytes, interacts with gp120 of human immunodeficiency virus (HIV) with a high affinity and, hence, serves as a virus receptor. Soluble chimeric CD4-immunoglobulin (Ig) possesses anti-HIV activity due to its binding activity to gp120. Furthermore, this recombinant molecule has unique Ig-like properties representing Fc receptor-binding activity and a long half-life in vivo.

Mycoplasma can enhance HIV replication in vitro: a possible cofactor responsible for the progression of AIDS.

Mycoplasma membrane protein (MMP) augmented HIV production from MOLT-4 cells chronically infected by HIV. A nearly 3-fold increase of HIV p24 antigen was detected in MMP-treated culture as compared to control culture at 100 micrograms/ml. MMP also augmented HIV production in different T cells chronically infected by HIV-1 and ARV-1.

The phorbol ester TPA strongly inhibits HIV-1-induced syncytia formation but enhances virus production: possible involvement of protein kinase C pathway.

Cocultivation of MOLT-4 and MOLT-4/HIVHTLV-IIIB cells with more than 0.01 ng/ml of 12-O-tetradecanoylphorbol-13-acetate (TPA) for 20 hr strikingly inhibited HIV-induced syncytia formation resulting from cell to cell infection. Interestingly, the production of HIV-specific p24 antigen in the culture fluid was significantly enhanced by TPA.