Aflatoxins (AFs) are highly hazardous secondary fungal biometabolites and usually present in common feed and food. AFB1 is the most highly toxic, mutagenic, teratogenic, carcinogenic and immunotoxic in human and animals. Our most recent study on bovine innate immunity shows AFB1 is massively immunotoxic. Pattern recognition receptors (PRRs), which are highly expressed by dendritic cells (DCs), are the main part of the host innate defense; they sense pathogen-associated molecular patterns (PAMPs) against invading pathogens. PRRs also participate in many pathological processes, including, autoinflammation, autoimmunity and cancer, and their unnecessarily prolonged activation is hugely harmful for the host. To investigate the possible interaction between AFB1 and two key innate immune genes, toll-like receptor (TLR) 2 and TLR4 on human DCs, pure CD11c+ DCs were produced from harvested PBMCs of 20 healthy individuals (aged 22-23 y.). The purity of CD11c+ DCs was confirmed with FACS for expression of, especially, CD11c. To assess the expression levels of TLR2 and TLR4 in the CD11c+ DCs, the DCs were exposed with 0 and 10 ng/ml of AFB1 for 2 hours in a standard cell culture condition. Both RT-PCR and real-time qPCR was used to detect and quantify the expression levels of these genes in the CD11c+ DCs. Expression levels of both TLR2 and TLR4 in AFB1- treated DCs were significantly higher than non-treated ones (p<0.5; n=20). Considering the outcome of the upregulation of TLR2 and TLR4 genes in AFB1-exposed DCs, our novel finding would open a new door to the molecular aspects of AFB1 versus PRRs, inflammation and cancer in human and animals.

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