Detection of citrate synthase autoantibodies in rats with chronic allograft nephropathy

Following Natural Autoantibodies: Further Immunoserological Evidence Regarding Their Silent Plasticity and Engagement in Immune Activation

Contradictory reports are available on vaccine-associated hyperstimulation of the immune system, provoking the formation of pathological autoantibodies. Despite being interconnected within the same network, the role of the quieter, yet important non-pathological and natural autoantibodies (nAAbs) is less defined. We hypothesize that upon a prompt immunological trigger, physiological nAAbs also exhibit a moderate plasticity. We investigated their inducibility through aged and recent antigenic triggers. Anti-viral antibodies (anti-MMR n = 1739 and anti-SARS-CoV-2 IgG n = 330) and nAAbs (anti-citrate synthase IgG, IgM n = 1739) were measured by in-house and commercial ELISAs using Croatian (Osijek) anonymous samples with documented vaccination backgrounds. The results were subsequently compared for statistical evaluation. Interestingly, the IgM isotype nAAb showed a statistically significant connection with anti-MMR IgG seropositivity (p < 0.001 in all cases), while IgG isotype nAAb levels were elevated in association with anti-SARS CoV-2 specific seropositivity (p = 0.019) and in heterogeneous vaccine regimen recipients (unvaccinated controls vector/mRNA vaccines p = 0.002). Increasing evidence supports the interplay between immune activation and the dynamic expansion of nAAbs. Consequently, further questions may emerge regarding the ability of nAAbs silently shaping the effectiveness of immunization. We suggest re-evaluating the impact of nAAbs on the complex functioning of the immunological network.

Tumor-associated and disease-associated autoantibody repertoires in healthy colostrum and maternal and newborn cord sera

In this work, we studied autoantibody repertoires and Ig isotypes in 71 mothers and their 104 healthy newborns (including twins and triplets delivered term or premature). Newborns receive maternal IgG Abs via the placenta before birth, but developing infants must produce their own IgM and IgA Abs. We used an Ag microarray analysis to detect binding to a selection of 295 self-Ags, compared with 27 standard foreign Ags. The magnitude of binding to specific self-Ags was found to be not less than that to the foreign Ags. As expected, each newborn shared with its mother a similar IgG repertoire-manifest as early as the 24th week of gestation. IgM and IgA autoantibody repertoires in cord sera were highly correlated among the newborns and differed from their mothers' repertoires; the latter differed in sera and milk. The autoantibodies bound to self-Ags known to be associated with tumors and to autoimmune diseases. Thus, autoantibody repertoires in healthy humans--the immunological homunculus--arise congenitally, differ in maternal milk and sera, and mark the potential of the immune system to attack tumors, beneficially, or healthy tissues, harmfully; regulation of the tissue site, the dynamics, and the response phenotype of homuncular autoimmunity very likely affects health.