Background/Purpose: , In areas where helminths infections are common, autoimmune diseases are rare. Treatment with helminthes and their ova, improved clinical findings of inflammatory bowel disease, multiple sclerosis and rheumatoid-arthritis. The immunomodulatory functions of some helminths were attributed to the phosphorylcholine (PC) moiety. We aimed to decipher the tolerogenic potential of Tuftsin-PC (TPC) compound in mice genetically prone to develop lupus when the disease was already established. In addition we analyzed the microbiota, assuming that it may be affected by TPC treatment on lupus development.

Methods: , Lupus prone NZBXW/F1 mice received subcutaneously TPC (5 mg/1 ml), 3 times a week starting at 24 weeks of age, when proteinuria showed 10 mg/dl. At this point feces were collected weekly. Autoantibodies were tested by ELISA,  cytokines secretion by splenocytes in-vitro using DuoSet ELISA, T-regulatory-cells by FACS. Glomerulonephritis was addressed by detection of proteinuria, and immunoglobulin complex deposition in the mesangium of the kidneys of the mice by immunofluorescence. Stools from the mice were collected every 3 days for microbiome analyses. DNA was extracted from the stools and then sequenced using Illumina Miseq platform.  Data analysis was performed using QIIME.

Results: Our results show that TPC treatment attenuated the development of glomerulonephritis in lupus prone mice, manifested by reduced proteinuria and immunoglobulin deposition in the kidney mesangium. TPC also increased the expression of IL-10 (p < 0.001), and inhibited the production of IFNg , IL-1b and IL-17 (p < 0.03). TPC significantly expanded  CD4⁺CD25⁺FOXP3⁺ T-regulatory cells (Tregs) phenotype in the treated mice. The microbiota analyses showed that TPC exhibited a marked depletion of Akkermansia (specifically muciniphila species) and higher abundance of Odoribacter compared to PBS treated mice, which correlated to proteinuria levels. Generally, high protein secretions correlated with an increased abundance of four bacteria genera; Akkermansia AF12, S24-7, Bacteroides, and one bacteria order Clostridiales. High protein levels were correlated also with decreased levels of thirty three additional otus, with the Odoribacter genus among them.               

Conclusion: Our data indicate that TPC treatment inhibits lupus nephritis development in genetically lupus prone mice, attenuates pro-inflammatory cytokines and enhance anti-inflammatory IL-10 expression, as well as Tregs expansion. The results propose harnessing novel natural therapy for lupus patients. In addition our results show that TPC significantly alters the microbiota composition which correlated with decreased protein levels in the urine.