Human milk can neutralize Coxsackievirus B4 in vitro

Abstract

The role of enteroviruses in type 1 diabetes has long been suspected. A lower risk of type 1 diabetes is associated with breastfeeding, which could be due to a protective effect against enteroviruses. The neutralizing activity of breast milk against CVB4, a representative of enteroviruses was investigated in this study in vitro. Breast milk was cytotoxic to Hep-2 cells up to a dilution of 1/32, whereas the aqueous fraction obtained after centrifugation was not cytotoxic; although it inhibited the cytopathic effect of CVB4 on Hep-2 cell monolayers. The anti-CVB4 neutralizing activity of aqueous fractions of breast milk from 49 donors living in Northern France and 15 donors living in Congo, where enteroviral infections are more prevalent, were determined. The levels of colostrum activity expressed as titre ranged from <2 to 32 in 36% of the donors from France whereas they were >128 in every donor from Congo. Pasteurized colostrum had a lower anti-CVB4 activity compared to fresh samples (P < 0.0001, n = 49). The treatment of colostrum samples with jacalin-coated beads that bind specifically to human IgA, showed that IgA plays a role in anti-CVB4 activity. There was no correlation between the neutralizing activities of breast milk and serum (P = 0.37, n = 25). The current study showed that the variations in anti-CVB4 activity in breast milk can be attributed to environmental and living conditions. Whether a low protective activity of breast milk against enteroviruses expose newborns to a higher risk of type 1 diabetes deserves further investigation.

Marker of coxsackievirus‐B4 infection in saliva of patients with type 1 diabetes

“…As shown by the present study, the salivary anti‐CV‐B4 activity in patients was found to rely on sIgA antibodies that are important players in the mucosal immune system involved in the anti‐CVB4 neutralizing activity in another compartment of mucosal immunity as previously reported by our team . The frequency and the levels of salivary anti‐CV‐B4 activity that is due to IgA1 in patients may be a result of higher levels of saliva IgA in patients with T1D as compared with controls as previously reported .…”

“…Jacalin is a plant‐based lectin isolated from jackfruit ( Artocarpus integrifolia ) seeds. Jacalin specifically binds to human secretory and serum immunoglobulin A (sIgA) . Briefly, the lectin (Invivogen ® , France) was coated on agarose beads in a 1 m NaCl saline solution containing 0.01% thiomerosal, a mercury‐containing compound used as preservative.…”

“…Jacalin specifically binds to human secretory and serum immunoglobulin A (sIgA). 22,23 Briefly, the lectin (Invivogen ® , France) was coated on agarose beads in a 1 M NaCl saline solution containing 0.01% thiomerosal, a mercury-containing compound used as preservative. To eliminate the cytotoxicity of thiomerosal, 1 volume of agarose lectin-coated beads was washed in 2 volumes of phosphate-buffered saline (PBS; Invitrogen France); the mixture was vortexed and then centrifuged at 1000g for 15 minutes, 4°C.…”

Intrafamilial spread of enterovirus infections at the clinical onset of type 1 diabetes

“…EVs are commonly spreading through the community. In developed countries, the herd immunity to these agents is reduced when compared with what documented in less developed areas (19)(20)(21). The intrafamilial transmission of EVs and the temporal/geographic clustering of cases have been reported from New York and other geographic zones (22)(23)(24)(25)(26)(27).…”

The Role of Toll‐Like Receptors and Vitamin D in Diabetes Mellitus Type 1 – A Review

“…Human milk can neutralize CV-B4 [58]. The incidence of autoantibodies associated with T1DM is 50% lower in children weaning to hydrolysed milk [59].…”