Publications

Journal Articles


  • Spatial organization of dendritic cells within tumor draining lymph nodes impacts clinical outcome in breast cancer patients JOURNAL OF TRANSLATIONAL MEDICINE Chang, A. Y., Bhattacharya, N., Mu, J., Setiadi, A. F., Carcamo-Cavazos, V., Lee, G. H., Simons, D. L., Yadegarynia, S., Hemati, K., Kapelner, A., Ming, Z., Krag, D. N., Schwartz, E. J., Chen, D. Z., Lee, P. P. 2013; 11

    Abstract

    Dendritic cells (DCs) are important mediators of anti-tumor immune responses. We hypothesized that an in-depth analysis of dendritic cells and their spatial relationships to each other as well as to other immune cells within tumor draining lymph nodes (TDLNs) could provide a better understanding of immune function and dysregulation in cancer.We analyzed immune cells within TDLNs from 59 breast cancer patients with at least 5 years of clinical follow-up using immunohistochemical staining with a novel quantitative image analysis system. We developed algorithms to analyze spatial distribution patterns of immune cells in cancer versus healthy intra-mammary lymph nodes (HLNs) to derive information about possible mechanisms underlying immune-dysregulation in breast cancer. We used the non-parametric Mann-Whitney test for inter-group comparisons, Wilcoxon Matched-Pairs Signed Ranks test for intra-group comparisons and log-rank (Mantel-Cox) test for Kaplan Maier analyses.Degree of clustering of DCs (in terms of spatial proximity of the cells to each other) was reduced in TDLNs compared to HLNs. While there were more numerous DC clusters in TDLNs compared to HLNs,DC clusters within TDLNs tended to have fewer member DCs and also consisted of fewer cells displaying the DC maturity marker CD83. The average number of T cells within a standardized radius of a clustered DC was increased compared to that of an unclustered DC, suggesting that DC clustering was associated with T cell interaction. Furthermore, the number of T cells within the radius of a clustered DC was reduced in tumor-positive TDLNs compared to HLNs. Importantly, clinical outcome analysis revealed that DC clustering in tumor-positive TDLNs correlated with the duration of disease-free survival in breast cancer patients.These findings are the first to describe the spatial organization of DCs within TDLNs and their association with survival outcome. In addition, we characterized specific changes in number, size, maturity, and T cell co-localization of such clusters. Strategies to enhance DC function in-vivo, including maturation and clustering, may provide additional tools for developing more efficacious DC cancer vaccines.

    View details for DOI 10.1186/1479-5876-11-242

    View details for Web of Science ID 000326447100001

    View details for PubMedID 24088396

  • Center-surround vs. distance-independent lateral connectivity in the olfactory bulb FRONTIERS IN NEURAL CIRCUITS Kim, D. H., Chang, A. Y., McTavish, T. S., Pateland, H. K., Willhite, D. C. 2012; 6

    Abstract

    Lateral neuronal interactions are known to play important roles in sensory information processing. A center-on surround-off local circuit arrangement has been shown to play a role in mediating contrast enhancement in the visual, auditory, and somatosensory systems. The lateral connectivity and the influence of those connections have been less clear for the olfactory system. A critical question is whether the synaptic connections between the primary projection neurons, mitral and tufted (M/T) cells, and their main inhibitory interneurons, the granule cells (GCs), can support a center-surround motif. Here, we study this question by injecting a "center" in the glomerular layer of the olfactory bulb (OB) with a marker of synaptic connectivity, the pseudorabies virus (PRV), then examines the distribution of labeling in the "surround" of GCs. We use a novel method to score the degree to which the data fits a center-surround model vs. distance-independent connectivity. Data from 22 injections show that M/T cells generally form lateral connections with GCs in patterns that lie between the two extremes.

    View details for DOI 10.3389/fncir.2012.00034

    View details for Web of Science ID 000304625700001

    View details for PubMedID 22666190

  • Learning to live together: harnessing regulatory T cells to induce organ transplant tolerance. Yale journal of biology and medicine Chang, A. Y., Bhattacharya, N. 2011; 84 (4): 345-351

    Abstract

    The discovery of immune cells with regulatory effects has created considerable excitement for their potential use in inducing tolerance to transplanted tissues. Despite the fact that these cells possess essential functions in vivo, attempts to translate them into effective clinical therapies has proved challenging due to a number of unanticipated complexities in their behavior. This article provides a broad summary of research done to understand the largest of the regulatory cell subtypes, namely CD4+Foxp3+ Regulatory T cells (T(Regs)). Special attention will be paid to current and future difficulties in using T(Regs) clinically, as well as room for improvement and innovation in this field.

    View details for PubMedID 22180672

  • Lateral connectivity in the olfactory bulb is sparse and segregated FRONTIERS IN NEURAL CIRCUITS Kim, D. H., Phillips, M. E., Chang, A. Y., Patel, H. K., Nguyen, K. T., Willhite, D. C. 2011; 5

    Abstract

    Lateral connections in the olfactory bulb were previously thought to be organized for center-surround inhibition. However, recent anatomical and physiological studies showed sparse and distributed interactions of inhibitory granule cells (GCs) which tended to be organized in columnar clusters. Little is known about how these distributed clusters are interconnected. In this study, we use transsynaptic tracing viruses bearing green or red fluorescent proteins to further elucidate mitral- and tufted-to-GC connectivity. Separate sites in the glomerular layer were injected with each virus. Columns with labeling from both viruses after transsynaptic spread show sparse red or green GCs which tended to be segregated. However, there was a higher incidence of co-labeled cells than chance would predict. Similar segregation of labeling is observed from dual injections into olfactory cortex. Collectively, these results suggest that neighboring mitral and tufted cells receive inhibitory inputs from segregated subsets of GCs, enabling inhibition of a center by specific and discontinuous lateral elements.

    View details for DOI 10.3389/fncir.2011.00005

    View details for Web of Science ID 000290153700001

    View details for PubMedID 21559072

  • Hydrophilic Graft Modification of a Commercial Crystalline Polyolefin J. Polym. Sci. Part A: Polym. Chem. Andrew Y. Chang, Lacie V. Brownell, Ira O. Racoma, Coreen H. Ozawa, Ho-Yong Chung, Shufu Peng, Chulsung Bae, Jihoon Shin 2008; 46: 3533-3545
  • Regioselective functionalization of high-molecular-weight crystalline polyolefins via C-H activation of methyl side group Polymer Preprints Hoyong Chung, Andrew Y. Chang, Ira O. Racoma, Coreen H. Ozawa, Chulsung Bae 2006; 47: 247-248

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