Evaluation of sublethal and transgenerational effects of sulfoxaflor on Aphis gossypii via life table parameters and 16S rRNA sequencing.

BACKGROUND: Aphis gossypii, a polyphagous and recurrent pest induced by pesticides, causes tremendous loss crop yields each year. Previous studies on the mechanism of pesticide-induced sublethal effects mainly focus on the gene level. The symbiotic bacteria are also important participants of this mechanism, but their roles in hormesis are still unclear. RESULTS: In this study, life table parameters and 16S rRNA sequencing were applied to evaluate the sublethal and transgenerational effects of sulfoxaflor on adult A. gossypii after 24-h LC20 (6.96 mg L-1 ) concentration exposure. The results indicated that the LC20 of sulfoxaflor significantly reduced the finite rate of increase (λ) and net reproductive rate (R0 ) of parent generation (G0), and significantly increased mean generation time (T) of G1 and G2, but not of G3 and G4. Both reproductive period and fecundity of G1 and G2 were significantly higher than those of the control. Furthermore, our sequencing data revealed that more than 95% bacterial communities were dominated by the phylum Proteobacteria, in which the maximum proportion genus was the primary symbiont Buchnera and the facultative symbiont Arsenophonus. Compared to those of the control, the abundance and composition of symbiotic bacteria of A. gossypii for three successive generations (G0-G2) were changed after G0 A. gossypii was exposed to sulfoxaflor: the diversity of the bacterial community was decreased, but the abundance of Buchnera was increased (G0), while the abundance of Arsenophonus was decreased. Contrary to G0, G1 and G2 cotton aphid exhibited an increased relative abundance of Arsenophonus in the sublethal treatment group. CONCLUSION: Taken together, our results provide an insight into the interactions among pesticide resistance, aphids, and symbionts, which will eventually help to better manage the resurgence of A. gossypii. © 2021 Society of Chemical Industry.

Modification of chemokine receptor expression to enhance levels of trafficking receptors on autologous cytokine-induced killer cells derived from patients with colorectal cancer.

Cytokine-induced killer (CIK) cells have achieved therapeutic benefit in treatment of solid tumors in clinic. However, some patients show no response after CIK treatment. Animal assays have shown that successful infiltration of CIK cells to the tumor sites could affect the outcome. Chemokines play important roles in lymphocyte trafficking. Understanding the molecular mechanism of chemokines in the process of CIK cell homing is important for further modification of CIK therapy. In this study, we investigated the spectrum of chemokine ligands in the colorectal cancer sites and observed that chemokine ligands CCL20 and CXCL10 were overexpressed in the CRC tumor tissues compared with adjacent tissues. Although the corresponding receptors CCR6 and CXCR3 increased on CIK cells compared with PBMCs, their expression on CIK cells derived from CRC patients had lower levels than healthy donors, which might be a limited factor for autologous-CIK cells trafficking to tumor site. Importantly, stimulation with chemokines CCL20 and CXCL10 promotes the expression levels of CCR6 and CXCR3 on CIK cells, thus augmenting the relative migration of CIK cells in vitro. Our results suggest that modification of surface chemokine receptors may enhance the homing ability of CIK cells for better therapeutic achievements.