Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are chronic autoimmune diseases that result from the combined influence of genetic and environmental factors that promotes the loss of tolerance to cellular components. The complexity of these diseases converts them into a major challenge at the diagnostic and treatment level. Therefore, it is convenient to implement the use of tools for a better understanding of the physiopathology of these diseases to propose reliable biomarkers. The “omics” disciplines like metabolomics and lipidomics allow to study RA and SLE in a higher degree of detail since they evaluate the metabolites and metabolic pathways involved in disease pathogenesis. This review has compiled the information of metabolomics and lipidomics studies where samples obtained from RA and SLE patients were evaluated to find the metabolites and pathways differences between patients and healthy controls. In both diseases, there is a decrease in several amino acids and oxidative stress-related metabolites like glutathione. These findings may be useful for functional metabolomics studies aiming to reprogram the metabolism in a disease setting to recover normal immune cell homeostasis and function.

Rotavirus (RV) predominantly replicates in intestinal epithelial cells (IEC), and “danger signals” released by these cells may modulate viral immunity. We have recently shown that human model IEC (Caco-2 cells) infected with rhesus-RV release a non-inflammatory group of immunomodulators that includes heat shock proteins (HSPs) and TGF-β1. Here we show that both proteins are released in part in association with membrane vesicles (MV) obtained from filtrated Caco-2 supernatants concentrated by ultracentrifugation. These MV express markers of exosomes (CD63 and others), but not of the endoplasmic reticulum (ER) or nuclei. Larger quantities of proteins associated with MV were released by RV-infected cells than by non-infected cells. VP6 co-immunoprecipitated with CD63 present in these MV, and VP6 co-localized with CD63 in RV-infected cells, suggesting that this viral protein is associated with the MV, and that this association occurs intracellularly. CD63 present in MV preparations from stool samples from 36 children with gastroenteritis due or not due to RV were analyzed. VP6 co-immunoprecipitated with CD63 in 3/8 stool samples from RV-infected children, suggesting that these MV are released by RV-infected cells in vivo . Moreover, fractions that contained MV from RV-infected cells induced death and inhibited proliferation of CD4 ⁺ T cells to a greater extent than fractions from non-infected cells. These effects were in part due to TGF-β, because they were reversed by treatment of the T cells with the TGF-β-receptor inhibitor ALK5i. MV from RV-infected and non-infected cells were heterogeneous, with morphologies and typical flotation densities described for exosomes (between 1.10 and 1.18 g/mL), and denser vesicles (>1.24 g/mL). Both types of MV from RV-infected cells were more efficient at inhibiting T-cell function than were those from non-infected cells. We propose that RV infection of IEC releases MV that modulate viral immunity.

The abnormal biological activity of cytokines and their imbalance are implicated in developing rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Cytokine levels were measured in RA and SLE patients and compared to healthy controls using the Wilcoxon rank sum test and Kruskal–Wallis test. The relationship between cytokine levels and blood and clinical parameters was assessed using Spearman's correlation test. Compared to healthy controls, both RA and SLE patients exhibited elevated levels of GM-CSF, CX3CL1, IFN-α2, IL-12p70, IL-17A, TNF-α, IL-1β, and IFN-γ, which is evidence of their shared inflammatory signature. IL-2 levels were elevated exclusively in RA patients, while MCP-1 and IL-10 were uniquely increased in SLE patients. Notably, TNF-α showed the most significant increase in SLE patients. IL-4 was elevated in SLE patients with nephritis, correlating with IL-6, IL-10, sCD40L, and IL-8, suggesting B cell involvement in lupus nephritis. The negative correlation between CX3CL1 and TNF-α with HDL in RA and SLE respectively, highlights the potential association of these inflammatory markers with cardiovascular risk. These findings underscore the complex cytokine interplay in RA and SLE. CX3CL1 emerges as a potential therapeutic target for RA, while TNF-α and IL-4 show promise as therapeutic targets for SLE.

In a double blind trial, 319 fully immunized children received two doses of either placebo or 10^6.7 focus-forming units of the attenuated RIX4414 human rotavirus (RV) vaccine (“all-in-one” formulation). Plasma RV-specific IgA (RV IgA), stool RV IgA, and circulating total and RV memory B cells (CD19 ⁺ IgD^+/− CD27⁺) with an intestinal homing phenotype (α₄β₇ ⁺ CCR9^+/−) were measured, after the first and second doses, as potential correlates of protection. After the first and/or second dose, 54% of vaccinees and 13% of placebo recipients had plasma RV IgA. Before vaccination, most (95%) of the children (of both study groups) were breast-fed and had stool RV IgA (68.64%). Co-proconversion (4-fold increase) after the first and/or second dose was observed in 32.7% of vaccinees and 17.4% of placebo recipients. No significant difference was seen when comparing the frequencies of any subset of memory B cells between vaccinees and placebo recipients. Statistically significant weak correlations were found between plasma RV IgA titers and coproconversion, and several subsets of memory B cells. The vaccine provided 74.8% protection (95% confidence interval, 30.93–92.62) against any RV gastroenteritis and 100% protection (95% confidence interval, 14.53–100) against severe RV gastroenteritis. When vaccinees and placebo recipients were considered together, a correlation was found between protection from disease and plasma RV IgA measured after dose 2 and RV memory (IgD⁻ CD27⁺ α₄β₇ ⁺ CCR9⁺) circulating B cells measured after dose 1. However, the correlation coefficients for both tests were low (<0.2), suggesting that other factors are important in explaining protection from disease.