The context of tetanus toxoid application influences the outcome of antigen‐specific and self‐directed humoral immune response

Abstract

Results are presented concerning our attempts to create a suitable model system for studying the connection between microbial antigen (micAg), autoimmunity and autoimmune disease on the basis of hyper-immunization and application of micAg in different contexts. Our research was focused on tetanus toxoid (TTd) as a model micAg. Non-pretreated and complete Freund's adjuvant pretreated BALB/c mice were immunized with high doses of TTd mixed with glycerol or aluminum hydroxide as adjuvants. The main aims of the experiments were to evaluate the properties of induced humoral immune responses, evaluate the pathological potential of induced immune responses and determine possible correlations between the properties of a humoral immune response and its pathological potential. The production of TTd-specific and self-reactive β 2 -glycoprotein I (β 2 -GP I)-specific antibodies (Abs) was detected in all groups but with specific, context-related properties. Analysis of pregnancy-related pathology (anti-β 2 -GP I Abs-associated) showed differences in the pathological potential of the induced immune response. It was demonstrated that severity of pathology is positively correlated to the abundance of IgG that recognizes β 2 -GP I adsorbed onto phosphatidylserine, and to IgG affinity. Furthermore, it was demonstrated that molecular mimicry, which results in generation of anti-β 2 -GP I Abs upon TTd immunization, is necessary but not sufficient for the development of pregnancy-related pathology.Key words adjuvant, anti-β 2 -glycoprotein I antibody, tetanus toxoid.Various data that connect exposure to micAg, during infections (1-4) and vaccinations (5-8), to autoAb production have been published in recent years. Among the possible mechanisms that contribute to autoAb generation, the most cited mechanisms are molecular mimicry (9, 10) and polyclonal cell activation (11,12). Available data show that long-term stimulation by micAg is accompanied by augmentation of self-reactivity, but not by obvious induc- tion of autoimmune diseases (13). Hence, we have tried to create a model system for studying the connection between micAg, autoimmunity and autoimmune disease on the basis of hyper-immunization and application of micAg in different contexts.With the intention of creating a suitable model system, we focused our research on TTd, a chemical derivative of tetanus toxin, as a model antigen. As a single protein

Induction of APS after TTd Hyper-Immunization has a Different Outcome in BALB/c and C57BL/6 Mice

“…In accordance with our earlier results, 7 mice were hyper‐immunized with TTd in Al or glyc adjuvants after CFA pre‐treatment, because this combination was shown to have the greatest potential to induce APS in BALB/c strain mice.…”

“…5) are in accordance with [SCN − ] 50% values calculated for NMS and sera of TTd hyper‐immunized mice after 1 hour long incubation of β 2 GPI/anti‐β 2 GPI IgG complexes with solutions containing KSCN in increasing concentrations. As already reported for BALB/c mice, the [SCN − ] 50% value for β 2 GPI‐specific IgG in NMS (3.81 m ) was significantly lower than that observed for sera of TTd hyper‐immunized mice (Al [SCN − ] 50% = 4.93 m ; glyc [SCN − ] 50% = 6.01 m ) 7 . For C57BL/6 mice sera, the following [SCN − ] 50% values were calculated: 4.1 m for NMS, 6.4 m for sera of mice immunized with Al adjuvant, and 4.7 m for sera of mice immunized with glyc adjuvant.…”

“…It has been demonstrated that molecular mimicry between common pathogens ( Haemophilus influenzae , Neisseria gonorrhoeae ) or their pathogenic products (tetanus toxoid – TTd) and β 2 GPI could be one cause for the induction of APS. This was documented for BALB/c mice hyper‐immunized 5 with TTd 6,7 . Furthermore, we showed previously that the intensity of secretion and subtle characteristics of β 2 GPI‐specific Abs in TTd hyper‐immunized BALB/c mice are highly dependent on the context of TTd application in terms of the use of pre‐treatment and suitable adjuvants [aluminum hydroxide (Al) or glycerol (glyc)] 7 .…”

“…This was documented for BALB/c mice hyper‐immunized 5 with TTd 6,7 . Furthermore, we showed previously that the intensity of secretion and subtle characteristics of β 2 GPI‐specific Abs in TTd hyper‐immunized BALB/c mice are highly dependent on the context of TTd application in terms of the use of pre‐treatment and suitable adjuvants [aluminum hydroxide (Al) or glycerol (glyc)] 7 . Stimulation of the immune system by complete Freund’s adjuvant (CFA) administration prior to TTd hyper‐immunization potentiates development of the pathogenic auto‐reactive immune response, probably by polyclonal cell stimulation 8…”

“…Commercially available mouse anti‐human β 2 GPI IgG1 (clone 5F7; ICN Biomedicals, Aurora, IL, USA) was used to identify the isolated protein 7 …”