Abstract: A microfluidic device is directed to sustaining a complex microbial community in direct and indirect contact with living human intestinal cells in vitro. The device includes a first microchannel having cultured cells of a human intestinal epithelium and microbiota, the first microchannel further having a first level of oxygen. The device further includes a second microchannel having cultured cells of a vascular endothelium, the second microchannel further having a second level of oxygen. The device also includes a membrane located at an interface region between the first microchannel and the second microchannel, the membrane being composed of an oxygen-permeable material or further having pores via which oxygen flows between the first microchannel and the second microchannel to form a physiologically-relevant oxygen gradient.

Abstract: Provided herein are methods and compositions for treating cancer or a tumor in a subject by administering to the subject a first agent that disrupts the interaction between PD-L2/RGMb and a second agent that disrupts the interaction between PD-1/PD-L1. The subject may have dysbiosis and/or be nonresponsive to immune checkpoint therapy.

Abstract: Provided herein are methods and compositions for treating cancer or a tumor in a subject by administering to the subject a first agent that disrupts the interaction between PD-L2/RGMb and a second agent that disrupts the interaction between PD-1/PD-L1. The subject may have dysbiosis and/or be nonresponsive to immune checkpoint therapy.

Abstract: In certain aspects, provided herein are methods and compositions for treating or preventing cancer in a subject by conjointly administering to a subject a composition comprising a bacterium (e.g., a bacterium species or strain disclosed herein) and an immunotherapeutic agent.

Abstract: In certain aspects, described herein are methods, bacteria, and compositions for the treatment of bacterial infections. Specifically, bacteria that can upregulate antimicrobial peptides, e.g., Reg3, within a subject have been identified and methods of using such bacteria to treat infections is described.

Abstract: In certain aspects, described herein are methods, bacteria, and compositions for the reduction of the amount, activity and/or proliferation of colonic group 3 innate lymphoid cells (ILC3s) and for the treatment and/or prevention of diseases associated with pathological immune responses, such as inflammatory bowel diseases.

Abstract: Provided herein are methods of modulating selected populations of immune cells by administering specific bacterial strains to a subject. Also provided herein are methods of promoting expansion and/or contraction of selected populations of immune cells following the administration of a bacterial strain to a subject.

Abstract: In certain aspects, described herein are methods, bacteria, and compositions for the reduction of the amount, activity and/or proliferation of colonic group 3 innate lymphoid cells (ILC3s) and for the treatment and/or prevention of diseases associated with pathological immune responses, such as inflammatory bowel diseases.

Abstract: Described herein are methods and compositions for the induction of the production of regulatory T cells and for the treatment and/or prevention of diseases associated with pathological immune responses, such as inflammatory bowel diseases.

Abstract: The present invention is directed to methods for producing and selecting novel mutant strains of B. fragilis that constitutively express a particular capsular polysaccharide or only selected capsular polysaccharides; compositions directed to the novel mutant strains of B. fragilis that constitutively express a particular capsular polysaccharide or only selected capsular polysaccharides; improved methods for purification of individual capsular polysaccharides; and compositions directed to novel res02 and inv19 genes and their gene products. Significantly, the present invention provides methods and compositions for overexpressing and purifying immunomodulatory capsular polysaccharide A (PSA) in high yield.

Abstract: The present invention is directed to methods for producing and selecting novel mutant strains of B. fragilis that constitutively express a particular capsular polysaccharide or only selected capsular polysaccharides; compositions directed to the novel mutant strains of B. fragilis that constitutively express a particular capsular polysaccharide or only selected capsular polysaccharides; improved methods for purification of individual capsular polysaccharides; and compositions directed to novel res02 and inv19 genes and their gene products. Significantly, the present invention provides methods and compositions for overexpressing and purifying immunomodulatory capsular polysaccharide A (PSA) in high yield.

Abstract: The present invention is directed to methods for producing and selecting novel mutant strains of B. fragilis that constitutively express a particular capsular polysaccharide or only selected capsular polysaccharides; compositions directed to the novel mutant strains of B. fragilis that constitutively express a particular capsular polysaccharide or only selected capsular polysaccharides; improved methods for purification of individual capsular polysaccharides; and compositions directed to novel res02 and inv19 genes and their gene products. Significantly, the present invention provides methods and compositions for overexpressing and purifying immunomodulatory capsular polysaccharide A (PSA) in high yield.

Abstract: Methods and products for inducing IL-2 secretion, inducing IL-10 secretion, activating T cells, suppressing IgG antibody response to specific antigen, promoting allograft survival, reducing postoperative surgical adhesion formation, and protecting against abscess formation associated with surgery, trauma or diseases that predispose the host to abscess formation are provided. The methods of the invention are accomplished using an immunomodulator which is a polymer having at least two repeating charge motifs separated by at least a certain minimum distance.

Abstract: Modified streptococcal polysaccharides and methods of using the modified polysaccharides are provided herein.