CX3CL1 and coinfection: In addition, co-infection significantly regulated the mRNA expression of several chemokine and chemokine receptor genes, including CCL3 (1.62-fold), CX3CL1 (1.7-fold), CXCL16 (0.56-fold), CCR1 (2.23-fold), and CXCR4 (1.55-fold).