Human papilloma virus-like particles, non-infectious
agents that have been used in vaccines against cervical cancer
associated with human papilloma virus (HPV), also appear to inhibit
HIV-1 replication in vitro, researchers report in the March 1st issue
of Blood.
"As with other vaccines, the HPV-like particles activate the immune
system after vaccination," senior researcher Dr. Tomozumi Imamichi told
Reuters Health. Dr. Imamichi of the National Cancer Institute,
Frederick, Maryland, and colleagues tested the effect of HPV-like
particles on HIV-1 replication in peripheral blood mononuclear cells,
CD4+ T cells and macrophages.
The team found that HIV-1 replication was suppressed by the vaccine,
but it did not affect the expression of CD4, CXCR4 and CCR5. Soluble
factors appeared to be involved and further study indicated that
cytokine IL-27 was the agent responsible for this inhibition.
"IL-27 is known to be a potent anti-cancer cytokine," continued Dr.
Imamichi. "We need further investigation to define the molecular
mechanism of the anti-viral effect by the cytokine."
In addition, he concluded, "we need to further study whether the
vaccine induces the production of IL-27 in HIV-1-negative patients."
Blood 2007;109:1841-1849.
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