Salivary IgA from the sublingual compartment as a novel noninvasive proxy for intestinal immune induction

Abstract

Whole-saliva IgA appears like an attractive noninvasive readout for intestinal immune induction after enteric infection or vaccination, but has failed to show consistent correlation with established invasive markers and IgA in feces or intestinal lavage. For reference, we measured antibodies in samples from 30 healthy volunteers who were orally infected with wild-type enterotoxigenic Escherichia coli. The response against these bacteria in serum, lavage, and lymphocyte supernatants (antibody-in-lymphocyte-supernatant, ALS) was compared with that in targeted parotid and sublingual/submandibular secretions. Strong correlation occurred between IgA antibody levels against the challenge bacteria in sublingual/submandibular secretions and in lavage (r=0.69, P<0.0001) and ALS (r=0.70, P<0.0001). In sublingual/submandibular secretions, 93% responded with more than a twofold increase in IgA antibodies against the challenge strain, whereas the corresponding response in parotid secretions was only 67% (P=0.039). With >twofold ALS as a reference, the sensitivity of a >twofold response for IgA in sublingual/submandibular secretion was 96%, whereas it was only 67% in the parotid fluid. To exclude that flow rate variations influenced the results, we used albumin as a marker. Our data suggested that IgA in sublingual/submandibular secretions, rather than whole saliva with its variable content of parotid fluid, is a preferential noninvasive proxy for intestinal immune induction.

Breast milk IgA to foods has different epitope specificity than serum IgA—Evidence for entero‐mammary link for food‐specific IgA?

“…It is possible that these mammary gland ASCs represent B cells that originate in the gut, similar to what has been described for the entero‐mammary link of pathogen‐specific IgA ASCs . This could be further assessed by comparing IgA epitope specificity in BM to that of the salivary IgA from the sublingual compartment, which has recently been suggested as a novel non‐invasive proxy for intestinal immune induction . Alternatively, this could result from distinct epitopes being presented to mucosal and systemic T and B cells.…”

“…13 This could be further assessed by comparing IgA epitope specificity in BM to that of the salivary IgA from the sublingual compartment, which has recently been suggested as a novel non-invasive proxy for intestinal immune induction. 36 Alternatively, this could result from distinct epitopes being presented to mucosal and systemic T and B cells. We also found that epitope-specific IgA was detectable in infants' sera as early as 3 months of age.…”

The molecular mechanism for activating IgA production by Pediococcus acidilactici K15 and the clinical impact in a randomized trial

“…Arase et al . reported that a strong correlation is observed in humans between the levels of challenge-bacteria-specific IgA Ab in sublingual/submandibular secretions and those in gut lavages 39 .…”

Analytical ultracentrifugation in saliva research: Impact of green tea astringency and its significance on the in-vivo aroma release

“…Conversely, our results are in agreement with Aase, et al . 38 , who conducted a study to determine the SIgA concentrations from 30 healthy volunteers, measured by enzyme-linked immunosorbent assay (ELISA). Their analysis has found a concentration of 555.1 μg/mL and 435.7 μg/mL in sublingual and parotid secrtions respectively, which is higher than our reported values.…”