Under homeostatic conditions, fecal pellets from CBA mice had lower bacterial loads, and a greater proportion of the bacteria was coated with IgA. We chose the CBA/CaJ (CBA, IgA high) and C57BL/6 (B6, IgA low) strains for our study and found that the CBA strain was resistant to DSS‐colitis, unlike the B6 strain. As IgA, received either passively by neonatal mice or made actively by adults, influences host–microbe homeostasis in the gut by several mechanisms including early bacterial colonization events, immune exclusion of pathogenic bacteria, containment of inflammation through effects on regulatory T (Treg) cell generation and strengthening of the intestinal barrier, 10, 14, 15 we have tested whether IgA is necessary and sufficient to protect conventional wild‐type mice from DSS‐colitis, using mice that differ in IgA amount. Most of the studies have, however, relied on the use of gene‐deficient mice or on the colonization of germ‐free or limited flora mice with specific bacterial taxa. Treatment of mice with dextran sodium sulfate (DSS) has been used to study experimental colitis in mice, and a number of host and microbial factors have been reported to influence the induction and severity of such induced colitis. 1, 2, 3 In humans, such disruptions can lead to inflammatory bowel diseases, such as Crohn's disease or ulcerative colitis. However, intestinal homeostasis is an active and dynamic process and may be disrupted by damage to the barrier, poor wound healing, significant alterations in the resident microbial community and poor, deviant or uncontrolled immune responses. Under homeostatic conditions, a selectively permeable barrier, mucus, antimicrobial peptides (AMPs), and IgA‐mediated immune exclusion/containment of bacteria offer the first line of defense against bacterial invasion, allowing immune cells in the intestine to deal with the occasional invader without the generation of potent and tissue‐damaging inflammatory responses. Together, the data indicate that a high‐IgA response in adult life can protect against colitis and compensate for IgA deficiency in early life.Ī layer of simple epithelium separates systemic tissues from potential pathogens in the mammalian intestinal lumen.
Interestingly, B6 pups foster‐nursed on CBA dams continued to be susceptible in later life, whereas CBA pups foster‐nursed on B6 dams continued to be resistant. In F 1 mice derived separately with CBA and B6 dams and in F 1 mice backcrossed to the two parental strains, resistance segregated with the IgA response of the pups and not with barrier‐associated transcripts or bacterial loads. In support of a role for bacterial exclusion in resistance, oral administration of immunoglobulins decreased DSS‐induced disease in B6 mice. However, CBA mice continued to be resistant to colitis induction following FTs from B6 mice, indicating that they are able to contain such colitogenic members. Fecal microbial transplant (FT) experiments revealed that disease induction in B6 mice was associated with a cohort of bacteria that are not targeted by IgA. Resistance was associated with extensive IgA‐coating of fecal bacteria, lower fecal bacterial loads and greater abundance of barrier‐protective transcripts in colonic tissues under homeostatic conditions. Using wild‐type strains that differ in their IgA response but harbor a diverse gut microbiome, we found that the IgA‐high strain CBA/CaJ (CBA) is resistant to acute colitis induced with dextran sodium sulfate (DSS), unlike the IgA‐low strain C57BL/6 (B6). The quick-serve chain is offering any two select breakfast items for $2 when you mix and match.Studies with gene‐deficient and gnotobiotic mice have identified many host and microbial factors that contribute to induced colitis, but information on whether specific factors determine susceptibility under more physiological conditions is lacking. McDonald's claims that waking up is hard but you can make your morning easier with one of its breakfast favorites.
#MACDONALDS CROMWELL CT 2 FOR 5 BIG MAC TV#
There's a Better Way to Measure TV & Streaming Ad ROI Spend ? TV Impressions ? National Impressions ? Local Impressions ?
Comments Unlock These Ad Metrics Now National Airings ? First Airing ? Last Airing ? Creatives ? Recently Aired On ? Est.