Innate lymphoid cells regulate intestinal epithelial cell glycosylation.

Fucosylation of intestinal epithelial cells, catalyzed by fucosyltransferase 2 (Fut2), is a major glycosylation mechanism of host-microbiota symbiosis. Commensal bacteria induce epithelial fucosylation, and epithelial fucose is used as a dietary carbohydrate by many of these bacteria. However, the molecular and cellular mechanisms that regulate the induction of epithelial fucosylation are unknown. Here, we show that type 3 innate lymphoid cells (ILC3) induced intestinal epithelial Fut2 expression and fucosylation in mice. This induction required the cytokines interleukin-22 and lymphotoxin in a commensal bacteria-dependent and -independent manner, respectively. Disruption of intestinal fucosylation led to increased susceptibility to infection by Salmonella typhimurium. Our data reveal a role for ILC3 in shaping the gut microenvironment through the regulation of epithelial glycosylation.

Critical role of dendritic cells in T cell retention in the interfollicular region of Peyer's patches.

Peyer's patches (PPs) simultaneously initiate active and quiescent immune responses in the gut. The immunological function is achieved by the rigid regulation of cell distribution and trafficking, but how the cell distribution is maintained remains to be elucidated. In this study, we show that binding of stromal cell-derived lymphoid chemokines to conventional dendritic cells (cDCs) is essential for the retention of naive CD4(+) T cells in the interfollicular region (IFR) of PPs. Transitory depletion of CD11c(high) cDCs in mice rapidly impaired the IFR structure in the PPs without affecting B cell follicles or germinal centers, lymphoid chemokine production from stromal cells, or the immigration of naive T cells into the IFRs of PPs. The cDC-orchestrated retention of naive T cells was mediated by heparinase-sensitive molecules that were expressed on cDCs and bound the lymphoid chemokine CCL21 produced from stromal cells. These data collectively reveal that interactions among cDCs, stromal cells, and naive T cells are necessary for the formation of IFRs in the PPs.

Indigenous opportunistic bacteria inhabit mammalian gut-associated lymphoid tissues and share a mucosal antibody-mediated symbiosis.

The indigenous bacteria create natural cohabitation niches together with mucosal Abs in the gastrointestinal (GI) tract. Here we report that opportunistic bacteria, largely Alcaligenes species, specifically inhabit host Peyer's patches (PPs) and isolated lymphoid follicles, with the associated preferential induction of antigen-specific mucosal IgA Abs in the GI tract. Alcaligenes were identified as the dominant bacteria on the interior of PPs from naïve, specific-pathogen-free but not from germ-free mice. Oral transfer of intratissue uncultured Alcaligenes into germ-free mice resulted in the presence of Alcaligenes inside the PPs of recipients. This result was further supported by the induction of antigen-specific Ab-producing cells in the mucosal (e.g., PPs) but not systemic compartment (e.g., spleen). The preferential presence of Alcaligenes inside PPs and the associated induction of intestinal secretory IgA Abs were also observed in both monkeys and humans. Localized mucosal Ab-mediated symbiotic immune responses were supported by Alcaligenes-stimulated CD11c(+) dendritic cells (DCs) producing the Ab-enhancing cytokines TGF-beta, B-cell-activating factor belonging to the TNF family, and IL-6 in PPs. These CD11c(+) DCs did not migrate beyond the draining mesenteric lymph nodes. In the absence of antigen-specific mucosal Abs, the presence of Alcaligenes in PPs was greatly diminished. Thus, indigenous opportunistic bacteria uniquely inhabit PPs, leading to PP-DCs-initiated, local antigen-specific Ab production; this may involve the creation of an optimal symbiotic environment on the interior of the PPs.

Locoreginal radioimmunotherapy with 186Re-labeled monoclonal antibody in treating small peritoneal carcinomatosis of colon cancer in mice in comparison with 131I-counterpart.

The efficacy of locoregional radioimmunotherapy (RIT) in treating peritoneal tumors of colon cancer of <2 mm in diameter was examined at maximum tolerated doses, focusing the comparison between 186Re and 131I labeled to an anti-colorectal cancer IgG1. Estimated radiation doses to tumors were considerably higher with 186Re-RIT than with 131I-RIT. The advantage of 186Re-RIT decreased with decreasing tumor size, but 186Re-RIT delivered 1.6-times higher radiation to tumors of 1 mm. Consequently, 186Re-RIT attained better survival of mice than 131I-RIT or chemotherapy with 5-fluorouracil did. Therefore, locoregional 186Re-RIT may be an option in an adjuvant setting of colon cancer with high risk of peritoneal dissemination.

Feasibility of 186Re-radioimmunotherapy for treatment in an adjuvant setting of colon cancer.

PURPOSE: (186)Re displays abundant intermediate energy beta emission, and possesses an appropriate physical half-life of 3.7 days. We compared the efficacy of radioimmunotherapy (RIT) with an anti-colorectal cancer monoclonal IgG1, (186)Re-A7, with that of RIT employing (131)I in a mouse liver metastasis model. METHODS: Liver metastases were established by intrasplenic injection of LS180 human colon cancer cells. Based on the results of toxicity assessment with escalated administration doses, 21 MBq (186)Re-A7 and 7 MBq (131)I-A7 were chosen as maximum tolerated doses. In the first experiment, mice underwent RIT at 2 weeks when metastases attain a diameter of several millimeters, and were killed 2 weeks later to assess metastatic burden in the liver. In the second experiment, RIT was conducted at 1 week when metastases of several hundred micrometers in diameter were observed, and survival of mice was examined. RESULTS: (186)Re-A7 RIT inhibited the growth of liver metastases better than (131)I-A7 RIT ( P<0.02). Furthermore, (186)Re-A7 RIT induced better improvement in survival of mice than (131)I-A7 RIT ( P<0.002). (186)Re-A7 RIT caused slightly more severe myelotoxicity in mice, but they eventually recovered. Radiation dose estimation demonstrated a significant advantage of (186)Re-A7 RIT over (131)I-A7 RIT. CONCLUSION: These results support the use of RIT with (186)Re-MAb in an adjuvant setting in cases involving minimal disease.

Evaluation of engraftment by ABO genotypic analysis of erythroid burst-forming units after bone marrow transplantation.

Six patients received an allogeneic bone marrow transplant from HLA-identical ABO-mismatched donors. ABO genotype of erythroid burst-forming units (BFU-E) from peripheral blood was analyzed using polymerase chain reaction with sequence specific primers (PCR-SSP). After bone marrow transplantation (BMT), engraftment of donor cells by ABO genotypic analysis of BFU-E was compared with ABO phenotypic analysis of red blood cells (RBCs). During the early stage after BMT, ABO genotype of BFU-E in the recipients converted to that of the donors. In contrast, mixed ABO phenotype of RBCs persisted for about 3 months. In one patient, autologous hemopoietic cell recovery was detected by the ABO genotypic analysis before clinical manifestation. ABO genotypic analysis of BFU-E is relevant for enagraftment after ABO-mismatched BMT.

Radioimmunotherapy with 186Re-labeled monoclonal antibody to treat liver metastases of colon cancer cells in nude mice.

The efficacy of radioimmunotherapy (RIT) in the treatment of minimal disease has been previously shown, despite the limitation of beta-emitters suggested by a mathematical model. In the present study, the efficacy of RIT with an anti-colorectal cancer IgG1 A7 conjugated with 186Re was examined in a liver metastasis model established by intrasplenic inoculation of human colon cancer cells. In this model, small metastases of less than 1 mm in diameter can be observed 1 week after cell inoculation. Metastases attain a diameter of several millimeters at 2 weeks. 186Re-A7 accumulated exclusively in metastases, displaying a value of 24.1 +/- 8.7% ID/g 2 days after the injection. 186Re-A7 accumulation in liver metastases increased with decreasing size. RIT with 7 MBq 186Re-A7 at 2 weeks significantly suppressed the growth of metastases; weight of metastases 4 weeks after cell inoculation was 5.96 +/- 0.87 g in nontreated control mice and 1.25 +/- 0.75 g in mice receiving 186Re-A7 RIT (p < 0.0001). RIT at 1 week more effectively inhibited metastatic growth to 0.08 +/- 0.05 g (p < 0.002 vs. RIT at 2 weeks). RIT with a class-matched irrelevant MAb 186Re-HPMS-1 at 1 week after cell inoculation somewhat suppressed metastatic growth, 3.39 +/- 0.25 g at 4 weeks, as compared with the control; however, 186Re-HPMS-1 RIT was far less effective than 186Re-A7 RIT (p < 0.0001). These results support the use of RIT with 186Re-MAb in an adjuvant setting in cases involving minimal disease. Factors such as higher and homogeneous MAb accumulation in small nodules, better perfusion, and subsequent better oxygenation likely compensate for the loss of beta radiation outside small metastases.