Entry inhibitors SCH-C, RANTES, and T-20 block HIV type 1 replication in multiple cell types

Area of Science:

• Virology
• Immunology
• Pharmacology

Background:

• Human Immunodeficiency Virus type 1 (HIV-1) entry into host cells is a critical target for antiviral therapies.
• CCR5 is a key co-receptor utilized by many primary HIV-1 strains for cellular entry.

Purpose of the Study:

• To evaluate the efficacy of the CCR5 antagonist SCH-C in inhibiting HIV-1 replication in various human immune cells.
• To compare the activity of SCH-C with other entry inhibitors like T-20 and RANTES.
• To assess the potential of SCH-C as a microbicide or for preventing mother-to-infant transmission.

Main Methods:

• Testing SCH-C, T-20, and RANTES against CCR5-using HIV-1 primary isolates.
• Assessing inhibition in peripheral blood mononuclear cells (PBMCs), cord blood mononuclear cells, immature dendritic cells (DCs), and macrophages.
• Investigating inhibition of PBMC infection by mature DC-associated virus in trans.

Main Results:

• SCH-C demonstrated potent inhibition of HIV-1 replication across all tested cell types, with some cell-dependent variations in potency.
• All three entry inhibitors (SCH-C, T-20, RANTES) were effective against different CCR5-using primary HIV-1 isolates.
• CCR5-dependent HIV-1 infectivity, including DC-associated virus, was susceptible to blockade by different entry inhibition mechanisms.

Conclusions:

• The CCR5 antagonist SCH-C is a viable candidate for further clinical evaluation against HIV-1 replication.
• Entry inhibitors targeting the CCR5 co-receptor show broad potential for HIV-1 prevention strategies.
• SCH-C and similar agents warrant investigation for microbicide development and prevention of vertical HIV transmission.