Non-Infectious Papilloma virus–like Particles (VLPs) inhibit HIV-1 replication: Implications for immune control of HIV-1 replication by IL-27. Laboratory of Human Retrovirology CSP / NIAID-Frederick J.Mohamad Fakruddin

BACKGROUND Immune system uses a range of soluble molecules to suppress viral infections. Action of non-cytolytic antiviral factors to control HIV-1 replication. Some viral infections elicit the secretion of soluble HIV-1 suppressor factors.

HPV-like particles(VLPs) bind to dendritic cells and induce the expression of anti-viral cytokines such as IFN- , IL-10 and IFN- . VLPs have been used as a vaccine to prevent HPV infection. BACKGROUND

VLP Structure

To study the potential of VLP induced soluble HIV-1 suppressive factors.AIM

Cells+PHA 3-days + HIV-1 X4(NL4.3) or R5(AD8) 2hr/37 0 C/CO 2 Cultured with VLP 7 or 10 days HIV-1 replication evaluated by p24 ELISAMETHODS

VLP inhibits HIV-1 replication in PBMCs X4 virusR5 virus VLP suppresses HIV-1 replication regardless of the virus tropism

HIV-1 inhibition is Papilloma virus specific SV40 VLP has no effect on replication of HIV

Pretreatment of PBMC with VLP inhibits HIV-1 24 hr pretreatment is sufficient for inhibition

VLP does not alter the expression of HIV receptors Effect of VLP on HIV-1 receptors

VLP does not inhibits HIV in CD4 + T cells and CD8 + cells not required Effect of VLP on subset of PBMCs Media VLP

VLP binds strongly to Monocytes

VLP exerted its inhibitory activity on PBMCs, but not on CD4 + cells. VLP inhibitory effect is due to anti-HIV soluble factors or by cell to cell interaction. To study the mechanism- The effect of conditioned medium(CM) derived from VLP treated PBMCs on HIV infected CD4 + T-cells was investigated. Is there a role for soluble factors?

Effect of VLP treated CM on CD4 + T cells VLP induces soluble anti-HIV factor(s) from both PBMCs and MDMs

Global gene response by microarray Global gene response by microarray One point study to examine transcriptional changes. MDMs and PBMCs at 24h or 36h after exposure to VLP.

Fold Increase Gene ID Gene name PBMC MDM IL MCP TNSF13B IL-10 NS TNSF IL-15 NS CXCL CXCL MCP NS 3469 INF-  NS 3456 IFN-  NS Expression of cytokine genes

Detection of of anti-HIV cytokines and IL-27 in CM Significant increase of IL-27 in both PBMCs and MDMs

Blocking the activity of anti-HIV factors VLP stimulated anti-HIV activity is partially blocked by  -IL-27

IL-27 expression is specific for HPV-VLP SV40 VLP has no effect on IL-27 expression

IL-27 is key factor of VLP mediated HIV inhibition - many fold increase of IL-27 by VLP was observed at both RNA and protein levels. - in neutralization experiments only IL-27 blocked VLP inhibition.

IL-27 is a member of the IL-6/IL-12 family of cytokines. IL-27 produced by dendritic cells and monocytes. Expression of IL-27R can be detected in NK, B cells and T cells. Nature of the IL-27/IL-27R interaction is pleiotropic. IL-27 is an immunomodulator as it promotes pro- and anti- inflammatory response. Biology of IL-27

IL-27 suppresses X4 replication in CD4 + T cells

IL-27 suppresses X4 replication in PBMCs

IL-27 suppresses R5 replication in MDMs

Conclusions VLP displayed anti-HIV activity in PBMCs and MDMs. This inhibitory effect was lost in the enriched CD4 + T-cells. Soluble factors play a major role in VLP mediated anti-HIV effect.

Neutralization experiments implicated IL-27 to be one of the mediator anti-HIV VLP effect. Further studies identified IL-27 as a novel anti-HIV cytokine. Elucidation of the molecular mechanism of action of IL-27 may lead to HIV therapeutics.Conclusions

Tomozumi Imamichi Cliff Lane Ligia Pinto Alfonso Pineres Richard Lempicki Joseph Adelsberger Jun Yang Catherine Watkins Cathi YeagerAcknowledgements