In collaboration with NYU School of Medicine colleague Dr. G.J. Thorbecke, our group seeks to elucidate the function of IgD, an immunoglobulin that, while in trace amounts in serum (less than 1% of total), is present on the surface of most B lymphocytes. Although IgD's precise biological function has not been defined, considerable evidence indicates its role in humoral immunoaugmentation. In vivo and in vitro murine studies suggest that IgD's augmentation involvement applies to primary and secondary antibody responses, with helper T cells acting as mediators of the effect. This augmentation appears to result from direct contact between IgD and a specific class of T cells expressing IgD receptors on their cell surface (T-delta cells). Such contact causes up-regulation of the IgD receptors on these T cells, allowing them to bind more strongly to B cells and facilitating B-cell activation and proliferation. In microdissection studies of purified murine and human IgD to determine the minimum molecular entity that can induce IgD receptor up-regulation on T cells, we showed that IgD immune augmentation resides solely in the carbohydrate moieties on the molecule and, in murine IgD, specifically in N-linked sequences. Continuing studies examine 1) the precise oligosaccharide sequence(s) responsible for this IgD biological activity, 2) the synthesis of such sequences, 3) the nature and specificity of the IgD receptor, and 4) the use of purified IgD, or carbohydrate sequences therefrom, to stimulate various immune responses.
Our group also develops unique protocols and techniques for purifying biologically and immunologically active proteins.
Research Professor, Department of Microbiology
Professor Emeritus of Microbiology, Department of Microbiology
PhD from Loyola University
Fellowship, NYU School of Medicine, Microbiology
Annals of the New York Academy of Sciences. 2013 May; 1287:17-30
Molecular & cellular biology. 1995 Apr; 15(4):2117-2124
Biochemistry. 1994 Jun 14; 33(23):7423-7429
THE IGD RECEPTOR (IGD-R) ON HUMAN T-CELLS IS A LECTIN THAT BINDS TO A CARBOHYDRATE SEQUENCE COMMON TO IGD AND IGA1 [Meeting Abstract]
FASEB journal. 1994 Mar 18; 8(5):A749-A749
Journal of molecular biology. 1994 Jan 7; 235(1):221-230
TSG-6, AN ARTHRITIS-ASSOCIATED HYALURONAN-BINDING PROTEIN, FORMS A STABLE COMPLEX WITH INTER-ALPHA-INHIBITOR VIA A GLYCOSAMINOGLYCAN CROSS-LINK [Meeting Abstract]
Journal of cellular biochemistry. 1994 Jan 4; 269(6):338-338
Nature. 1993 Dec 09; 366(6455):585-587
International immunology. 1993 Jun; 5(6):607-614