Positive selection of the peripheral B cell repertoire in gut-associated lymphoid tissues

Gut-associated lymphoid tissues (GALTs) interact with intestinal microflora to drive GALT development and diversify the primary antibody repertoire; however, the molecular mechanisms that link these events remain elusive. Alicia rabbits provide an excellent model to investigate the relationship between GALT, intestinal microflora, and modulation of the antibody repertoire. Most B cells in neonatal Alicia rabbits express VHn allotype immunoglobulin (Ig)M. Within weeks, the number of VHn B cells decreases, whereas VHa allotype B cells increase in number and become predominant. We hypothesized that the repertoire shift from VHn to VHa B cells results from interactions between GALT and intestinal microflora. To test this hypothesis, we surgically removed organized GALT from newborn Alicia pups and ligated the appendix to sequester it from intestinal microflora. Flow cytometry and nucleotide sequence analyses revealed that the VHn to VHa repertoire shift did not occur, demonstrating the requirement for interactions between GALT and intestinal microflora in the selective expansion of VHa B cells. By comparing amino acid sequences of VHn and VHa Ig, we identified a putative VH ligand binding site for a bacterial or endogenous B cell superantigen. We propose that interaction of such a superantigen with VHa B cells results in their selective expansion

Th17 Responses Are Not Induced in Dextran Sodium Sulfate Model of Acute Colitis

Dextran sodium sulfate (DSS) is a widely used chemical model for inflammatory bowel disease (IBD). It is thought that imbalances in the T helper (Th) cell subsets contribute to IBD. Recent studies suggest that the acute DSS-colitis model is polarized toward a Th1/Th17 profile based on RT-PCR analysis of colonic tissues. In the current study we determined whether colonic Th cells from DSS-colitis mice were skewed toward the Th17 profile. Mice were treated with 5% DSS for 7 days and colonic T cells isolated and examined for production of IFN-γ (Th1 cell), IL-4 (Th2 cell) and IL-17 (Th17 cell) by intracellular flow cytometry. We found that the percentage of colonic Th17 cells were similar to non-treated controls but the percentage of Th1 cells were elevated in DSS-colitis mice. These results suggest that in the acute DSS-colitis model the colonic Th cells exhibit a Th1 profile and not a Th17 profile

A novel gene mutation, c.82delC (p.Arg28 Alafs5), in a Korean family with X-linked agammaglobulinemia

X-linked agammaglobulinemia (XLA) is a hereditary humoral immunodeficiency that results from Bruton’s tyrosine kinase (BTK) gene mutations. These mutations cause defects in B-cell development, resulting in the virtual absence of these lymphocytes from the peripheral circulation. Consequently, this absence leads to a profound deficiency of lg all isotypes, and an increased susceptibility to encapsulated bacterial infections. A 15-month-old Korean boy presented with recurrent sinusitis and otitis media after 6 months of age, and had a family history of 2 maternal uncles with XLA. Laboratory tests revealed a profound deficiency of Ig isotypes, and a decreased count of CD19+ B cells in the peripheral circulation. Based on his family history and our laboratory test results, he was diagnosed with XLA. We performed BTK gene analysis of peripheral blood samples obtained from family members to confirm the diagnosis. Mutational analysis revealed a novel hemizygous frameshift mutation (c.82delC, p.Arg28Alafs*5), in the BTK gene. His mother and maternal grandmother were heterozygous carriers of this mutation and his two maternal uncles were hemizygous at the same position. After XLA diagnosis, intravenous immunoglobulin (400 mg/kg, monthly) treatment was initiated; recurrent sinusitis and otitis media were subsequently brought under control. To our knowledge, this is the first reported case of a Korean pedigree with a novel mutation in the BTK gene

Effect of volatile fatty acid concentration on anaerobic degradation rate from field anaerobic digestion facilities treating food waste leachate in

The purpose of this study was to investigate the effect of volatile fatty acid concentration on anaerobic degradation rate of food waste leachate in the anaerobic digestion facilities. The anaerobic digestion facilities treating food waste leachate (FWL), codigestion with food leachate and animal manure (A-MIX), and codigestion with food waste leachate and sewage sludge (S-MIX) were selected for this study. In accordance with the regulation under Wastes Control Act in South Korea, the guideline of volatile solid removal rate for anaerobic digestion facility is set as 65% for anaerobic degradation efficiency. Highest volatile solids removal rates were achieved from FWL (63.5%) than A-MIX (56.4%) and S-MIX (41.2%). Four out of eight FWLs met the guidelines. The concentration of volatile fatty acids, therefore, was analyzed to determine the relationship with volatile solid removal rate. The results showed that, in order to meet the Korean guideline of 65% volatile solid removal rate, volatile fatty acid concentrations should remain below 4,000 mg/L on the field anaerobic digestion facilities treating FWL. Volatile fatty acid concentrations should be used along with others as an operational parameter to control and manage the anaerobic digestion process

Composite scoring system and optimal tumor budding cut-off number for estimating lymph node metastasis in submucosal colorectal cancer

Background Tumor budding is associated with lymph node (LN) metastasis in submucosal colorectal cancer (CRC). However, the rate of LN metastasis associated with the number of tumor buds is unknown. Here, we determined the optimal tumor budding cut-off number and developed a composite scoring system (CSS) for estimating LN metastasis of submucosal CRC. Methods In total, 395 patients with histologically confirmed T1N0–2M0 CRC were evaluated. The clinicopathological characteristics were subjected to univariate and multivariate analyses. The Akaike information criterion (AIC) values of the multivariate models were evaluated to identify the optimal cut-off number. A CSS for LN metastasis was developed using independent risk factors. Results The prevalence of LN metastasis was 13.2%. Histological differentiation, lymphatic or venous invasion, and tumor budding were associated with LN metastasis in univariate analyses. In multivariate models adjusted for histological differentiation and lymphatic or venous invasion, the AIC value was lowest for five tumor buds. Unfavorable differentiation (odds ratio [OR], 8.16; 95% confidence interval [CI], 1.80–36.89), lymphatic or venous invasion (OR, 5.91; 95% CI, 2.91–11.97), and five or more tumor buds (OR, 3.01; 95% CI, 1.21–7.69) were independent risk factors. In a CSS using these three risk factors, the rates of LN metastasis were 5.6%, 15.5%, 31.0%, and 52.4% for total composite scores of 0, 1, 2, and ≥ 3, respectively. Conclusions For the estimation of LN metastasis in submucosal CRC, the optimal tumor budding cut-off number was five. Our CSS can be utilized to estimate LN metastasis.This work was supported by the Korean government (MSIT) Grant No. 2021R1F1A1063000 from the National Research Foundation of Korea (NRF)

Fimasartan versus perindopril with and without diuretics in the treatment of elderly patients with essential hypertension (Fimasartan in the Senior Subjects (FITNESS)): study protocol for a randomized controlled trial

Background Hypertension is an important risk factor for cardiovascular disease, even in the elderly. Fimasartan is a new non-peptide angiotensin II receptor blocker with a selective type I receptor blocking effect. The objective of this study is to confirm the safety and the non-inferiority of the blood pressure–lowering effect of fimasartan compared with those of perindopril, which has been proven safe and effective in elderly patients with hypertension. Methods This is a randomized, double-blind, active-controlled, two-parallel group, optional-titration, multicenter, phase 3 study comparing the efficacy and safety of fimasartan and perindopril arginine. The study population consists of individuals 70 years old or older with essential hypertension. The primary outcome will be a change in sitting systolic blood pressure from baseline after the administration of the investigational product for 8 weeks. The secondary outcomes will be a change in sitting diastolic blood pressure from baseline and changes in sitting systolic blood pressure and diastolic blood pressure from baseline after the administration of the investigational product for 4, 16, and 24 weeks. The sample size will be 119 subjects for each group to confer enough power to test for the primary outcome. Discussion Research to confirm the efficacy and safety of a new medicine compared with those of previously proven anti-hypertensive drugs is beneficial to guide physicians in the selection of therapeutic agents. If it is confirmed that the new drug is not inferior to the existing drug, the drug will be considered as an option in the treatment of hypertension in elderly patients. Trial registration ClinicalTrials.gov Identifier: NCT03246555, registered on July 25, 2017.The study is funded by Boryung Pharmaceutical Co., Ltd. The company was involved in all stages of the study conduct and design. Boryung also took responsibility for all costs associated with the development and publishing of the manuscript