TLR4 related to CXCR4 and CCR5 expression in HIV

In the present investigation, flow cytometric techniques were utilized to evaluate 20 cases of HIV for CXCR4, CCR5, and TLR4 expression in CD4 positive T cells, CD8 positive T cells, regulatory T cells, and Th17 cells, and mean fluorescence intensities (MFI) were determined. RT‐PCR was utilized to measure gene expression of CXCR4, CCR5, and TLR4. CD4+ T cells positively expressed CXCR4 in 16 cases, CCR5 in all 20, and TLR4 in 17. CD8+ T cells were positive for CXCR4 expression in 15 cases, CCR5 in all cases, and TLR4 in 18. Regulatory T cells positively expressed CXCR4 and CCR5 in 12 cases, and TLR4 in 11 cases. Th17 cells were positive for CXCR4 expression in 19 cases and TLR4 in 17. When compared to stage of disease, receptor expression by all cell types increased greatly as infection progressed from acute to chronic phase, but decreased only slightly as infection progressed from chronic phase to AIDS. Results reveal a positive correlation between CXCR4, CCR5, and TLR4 expression which may indicate that TLR4 also serves as a co‐receptor for HIV. In addition, these data suggest that TLR4 up‐regulation is not limited to gram‐negative bacterial infection nor is expression limited to myeloid cells.