1) We have developed two novel technologies for depletion of unwanted subsets of cells at will. The strategy is based on the nature of chemokines to deliver antigens to the cytosol of cells expressing respective chemokine receptors. One technology designated chemotoxin, a chimeric chemokine fused with toxic moieties, can specifically kill cells expressing respective chemokine receptors. TARC-chemotoxin efficiently eradicates established leukemia (CEM cells) generating almost 100% tumor- free mice . We propose that the strategy may be applied for treatment of human T cell malignant diseases when patients immune system is severely immunocompromised. The results of this study have been recently published (Baatar et al, 2007a). We have also utilized this technology to specifically deplete Tregs in mice to augment immune responses to cancer vaccines. Part one of this ongoing project demonstrates that TARC-chemotoxin-mediated depletion of Tregs enhance CD8+ T cell responses to melanoma antigen gp100. This is an encouraging result, although its clinical significance remains to be evaluated. This technology is being successfully used to understand chemokine/chemokine receptor axis in regulation of metastasis (see AG000443-02). It was also used in our recent study on the mechanism of Treg-mediated suppression of resting T cells (Baatar et al.,2009). 2) Despite significant potency and attractiveness of siRNA and shRNA-mediated gene silencing methods, the technology can not be efficiently used in vivo. The major problem is that there is almost no practical way that delivers/targets oligonucleotides to cells of interest. The inability to deliver siRNA into primary cells precludes its utilization in vivo. To solve this, we have hypothesized that this can be achieved by generating modified chemokines that contain RNA binding domains (RBD). Although this technology designated chemoarp is still under development, we have successfully demonstrated proof of principle by delivering siRNA and knocking off expression of genes in various cells, including tumor cells. To date, we have generated three different chemoarps which deliver siRNA by targeting chemokine receptors, such as CCR2, CCR4 and CCR5. However and importantly, this technology enables delivery of siRNA into primary immune cells inactivating their genes of interest. We have also established a simplified but efficient yeast production system and created chemoarp purification methods. Overall, this truly novel project, which was recently applied for patenting from NIA, is not only progressing well, but also has attracted significant interest from commercial enterprises such as ECI, Inc., Japan.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Investigator-Initiated Intramural Research Projects (ZIA)
Project #
1ZIAAG000444-03
Application #
8148261
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
3
Fiscal Year
2010
Total Cost
$273,688
Indirect Cost
Name
National Institute on Aging
Department
Type
DUNS #
City
State
Country
Zip Code
Luo, Kun; Zhang, Hong; Zavala, Fidel et al. (2014) Fusion of antigen to a dendritic cell targeting chemokine combined with adjuvant yields a malaria DNA vaccine with enhanced protective capabilities. PLoS One 9:e90413
Biragyn, Arya; Bodogai, Monica; Olkhanud, Purevdorj B et al. (2013) Inhibition of lung metastasis by chemokine CCL17-mediated in vivo silencing of genes in CCR4+ Tregs. J Immunother 36:258-67
Honjo, Akifumi; Ogawa, Hirohisa; Azuma, Masahiko et al. (2013) Targeted reduction of CCR4? cells is sufficient to suppress allergic airway inflammation. Respir Investig 51:241-9
Cervantes-Villagrana, Alberto R; Hernández-Pando, Rogelio; Biragyn, Arya et al. (2013) Prime-boost BCG vaccination with DNA vaccines based in ?-defensin-2 and mycobacterial antigens ESAT6 or Ag85B improve protection in a tuberculosis experimental model. Vaccine 31:676-84
Baatar, Dolgor; Olkhanud, Purevdorj B; Wells, Valerie et al. (2009) Tregs utilize beta-galactoside-binding protein to transiently inhibit PI3K/p21ras activity of human CD8+ T cells to block their TCR-mediated ERK activity and proliferation. Brain Behav Immun 23:1028-37
Olkhanud, Purevdorj B; Baatar, Dolgor; Bodogai, Monica et al. (2009) Breast cancer lung metastasis requires expression of chemokine receptor CCR4 and regulatory T cells. Cancer Res 69:5996-6004