Highlights d DSB repair, but not NER, coevolves with maximum lifespan (MLS) in rodents d The activity of SIRT6 in stimulating DSB repair coevolves with MLS in rodent species d Five amino acids determine the differential activities of mouse and beaver SIRT6 d Stronger SIRT6 leads to a longer lifespan

Background As there is limited data on the sustainability of desensitization of multifood-oral immunotherapy (multifood-OIT), we conducted a multisite multifood-OIT study to compare the efficacy of successful desensitization with sustained dosing vs discontinued dosing after multifood-OIT. Methods We enrolled 70 participants, aged 5–22 years with multiple food allergies confirmed by double-blind placebo-controlled food challenges (DBPCFCs). In the open-label phase of the study, all participants received omalizumab (weeks 1–16) and multi-OIT (2–5 allergens; weeks 8–30) and eligible participants (on maintenance dose of each allergen by weeks 28–29) were randomized 1:1:1 to 1 g, 300 mg, or 0 mg arms (blinded, weeks 30–36) and then tested by food challenge at week 36. Success was defined as passing 2 g food challenge to at least 2 foods in week 36. Findings Most participants were able to reach a dose of 2 g or higher of each of 2, 3, 4, and 5 food allergens (as applicable to the participant's food allergens in OIT) in week 36 food challenges. Using an intent-to-treat analysis, we did not find evidence that a 300 mg dose was effectively different than a 1 g dose in maintaining desensitization, and both together were more effective than OIT discontinuation (0 mg dose) (85% vs 55%, P = 0.03). Fifty-five percent of the intent-to-treat participants and 69% of per protocol participants randomized to the 0 mg arm showed no objective reactivity after 6 weeks of discontinuation. Cross-desensitization was found between cashew/pistachio and walnut/pecan when only one of the foods was part of OIT. No statistically significant safety differences were found between the three arms. Interpretation These results suggest that sustained desensitization after omalizumab-facilitated multi-OIT best occurs through continued maintenance OIT dosing of either 300 mg or 1 g of each food allergen as opposed to discontinuation of multi-OIT. Funding Sean N. Parker Center for Allergy and Asthma Research at , , AADCRC U19AI104209. Trial Registration Number ClinicalTrials.gov number, NCT02626611 .

Children with multiple food allergies have a higher risk of impaired growth and may have a higher risk of inadequate nutrient intake than children without food allergies. Until more research is available, we recommend monitoring of nutrition and growth of children with multiple food allergies to prevent possible nutrient deficiencies and to optimize growth.

FOXN1 is the master regulatory gene of thymic epithelium development. FOXN1 deficiency leads to thymic aplasia, alopecia, and nail dystrophy, accounting for the nude/severe combined immunodeficiency (nu/SCID) phenotype in humans and mice. We identified several newborns with low levels of T cell receptor excision circles (TRECs) and T cell lymphopenia at birth, who carried heterozygous loss-of-function FOXN1 variants. Longitudinal analysis showed persistent T cell lymphopenia during infancy, often associated with nail dystrophy. Adult individuals with heterozygous FOXN1 variants had in most cases normal CD4 þ but lower than normal CD8 þ cell counts. We hypothesized a FOXN1 gene dosage effect on the function of thymic epithelial cells (TECs) and thymopoiesis and postulated that these effects would be more prominent early in life. To test this hypothesis, we analyzed TEC subset frequency and phenotype, early thymic progenitor (ETP) cell count, and expression of FOXN1 target genes (Ccl25, Cxcl12, Dll4, Scf, Psmb11, Prss16, and Cd83) in Foxn1 nu/þ (nu/þ) mice and age-matched wild-type (þ/þ) littermate controls. Both the frequency and the absolute count of ETP were significantly reduced in nu/þ mice up to 3 weeks of age. Analysis of the TEC compartment showed reduced expression of FOXN1 target genes and delayed maturation of the medullary TEC compartment in nu/þ mice. These observations establish a FOXN1 gene dosage effect on thymic function and identify FOXN1 haploinsufficiency as an important genetic determinant of T cell lymphopenia at birth.

Common variable immunodeficiency (CVID) is a common primary immunodeficiency characterized by a failure in B-