The DATK32 monoclonal antibody reacts with mouse LPAM-1 also known as integrin alpha 4 beta 7. The 130 kDa integrin β7 chain associates with the 150 kDa integrin α4 (CD49d) chain to form LPAM-1, a member of the Ig superfamily. LPAM-1 is expressed by peripheral lymphocytes, small subsets of thymocytes, and bone marrow progenitors. LPAM-1 binds VCAM-1 (CD106), MAdCAM-1, and fibronectin and facilitates lymphocyte adhesion and migration to the intestine and associated lymphoid tissues. The DATK32 antibody has been reported to block LPAM-1-mediated cell adhesion in vivo.

INVIVOMAB ANTI-MOUSE LPAM-1 (INTEGRIN Α4Β7) (CLONE: DATK32)

Rosser, E. C., et al. (2014). “Regulatory B cells are induced by gut microbiota-driven interleukin-1beta and interleukin-6 production.” Nat Med 20(11): 1334-1339. PubMed

Regulatory B cells (Breg cells) differentiate in response to inflammation and subsequently restrain excessive immune responses via the release of interleukin-10 (IL-10). However, the precise inflammatory signals governing their differentiation remain to be elucidated. Here we show that the gut microbiota promotes the differentiation of Breg cells in the spleen as well as in the mesenteric lymph nodes. Perturbation of the gut microbiome imposed either by antibiotic treatment or by changes in the sterility of housing conditions reduces the number and function of Breg cells. Following the induction of arthritis, IL-1beta and IL-6 are produced only in conventionally housed mice and both cytokines directly promote Breg cell differentiation and IL-10 production. Mice lacking IL-6 receptor (IL-6R) or IL-1 receptor 1 (IL-1R1) specifically on B cells have a reduced number of IL-10-producing B cells and develop exacerbated arthritis compared to control animals. Thus, in response to inflammatory signals induced by both the gut flora and arthritis, Breg cells increase in number and restrain excessive inflammation.

 

Sheridan, B. S., et al. (2014). “Oral infection drives a distinct population of intestinal resident memory CD8(+) T cells with enhanced protective function.” Immunity 40(5): 747-757. PubMed

The intestinal mucosa promotes T cell responses that might be beneficial for effective mucosal vaccines. However, intestinal resident memory T (Trm) cell formation and function are poorly understood. We found that oral infection with Listeria monocytogenes induced a robust intestinal CD8 T cell response and blocking effector T cell migration showed that intestinal Trm cells were critical for secondary protection. Intestinal effector CD8 T cells were predominately composed of memory precursor effector cells (MPECs) that rapidly upregulated CD103, which was needed for T cell accumulation in the intestinal epithelium. CD103 expression, rapid MPEC formation, and maintenance in intestinal tissues were dependent on T cell intrinsic transforming growth factor beta signals. Moreover, intestinal Trm cells generated after intranasal or intravenous infection were less robust and phenotypically distinct from Trm cells generated after oral infection, demonstrating the critical contribution of infection route for directing the generation of protective intestinal Trm cells.

 

Lindebo Holm, T., et al. (2012). “Pharmacological Evaluation of the SCID T Cell Transfer Model of Colitis: As a Model of Crohn’s Disease.” Int J Inflam 2012: 412178. PubMed

Animal models are important tools in the development of new drug candidates against the inflammatory bowel diseases (IBDs) Crohn’s disease and ulcerative colitis. In order to increase the translational value of these models, it is important to increase knowledge relating to standard drugs. Using the SCID adoptive transfer colitis model, we have evaluated the effect of currently used IBD drugs and IBD drug candidates, that is, anti-TNF-alpha, TNFR-Fc, anti-IL-12p40, anti-IL-6, CTLA4-Ig, anti-alpha4beta7 integrin, enrofloxacin/metronidazole, and cyclosporine. We found that anti-TNF-alpha, antibiotics, anti-IL-12p40, anti-alpha4beta7 integrin, CTLA4-Ig, and anti-IL-6 effectively prevented onset of colitis, whereas TNFR-Fc and cyclosporine did not. In intervention studies, antibiotics, anti-IL-12p40, and CTLA4-Ig induced remission, whereas the other compounds did not. The data suggest that the adoptive transfer model and the inflammatory bowel diseases have some main inflammatory pathways in common. The finding that some well-established IBD therapeutics do not have any effect in the model highlights important differences between the experimental model and the human disease.