Strain differences in the humoral immune response to commensal bacterial antigens in rats

Abstract

We have investigated the immune response to commensal bacterial species in the two inbred rat strains: Dark Agouti (DA) and Albino Oxford (AO). The predominant Gram-negative aerobe in our rats' intestinal bacterial flora was Escherichia coli, while Proteus mirabilis was isolated only from DA rat strain. We report that sera from both DA and AO rat strains contain specific IgG against predominant intestinal flora. Intramuscular administration of commensal bacterial antigens provoked only Th1-type antibody response in AO rats while DA rats developed mixed Th1- and Th2-type antibody response to E. coli and Th1-type response to P. mirabilis antigens. Weaker antibody production to own E. coli and higher serum levels of natural IgG and IgA P. mirabilis-specific antibodies combined with higher CD3+ cells proliferation was found in AO rats. Strain difference in the pattern of antibody production and differential regulation of immune response to commensal bacteria may contribute to the marked differences in the immune reactivity of AO and DA rats.

Immune response to gut Escherichia coli and susceptibility to adjuvant arthritis in the rats

“…We have shown previously the presence of anti-E. coli IgG antibodies in the sera of non-immunized rats of both DA and AO strains, and this IgG priming was observed against a limited repertoire of E. coli proteins [12]. In order to monitor the immune response to E. coli during inductive phase of arthritis, the On day 14 after immunization with IFA and CFA very weak anti-E. coli IgG binding levels were detected in sera of AO rats ( Fig.…”

“…We have previously shown that these rat strains show different potential to produce reactive oxygen species [11] and specifi c antibodies [12] in response to commensal bacteria.…”

Interleukin 15 modulates the effects of poly I:C maternal immune activation on offspring behaviour

“…More specific to rats, different rat strains exhibited different extent and variability of serum Il6 response 3 hr following Poly I:C MIA ( Murray et al, 2019 ). Furthermore, strain differences have been shown to influence the antibody response to commensal bacterial antigens and the activation state of NK cells in the experimental autoimmune encephalopathy model of multiple sclerosis ( Djuretić et al, 2019 ; Kovačević-Jovanović et al, 2013 ). Therefore, it is possible that the same Poly I:C immune challenge produced different effects in each strain despite our effort to keep other experimental variables the same as our previous study.…”