Abstract: Objective To study whether exogenous HA can red uce macrophage-tropic (CCR 5 -dependent, R5 )HIV infectivity. Methods In this study，first using TZM-bl cell and unstimulated CD 4⁺T cells assays to assesswhether exogenous HA can reduce R5 -HIV infectivity. Next treat the un-stimulated CD4⁺T cells with hyaluroni?dase to study endogenous HA impact on R5 -HIV infectivity. At last measures both exogenous HA, and endogenous HA effect on R5 -HIV binding on CD 4⁺T cells.Results ( 1 ) 100 μg of exogenous HA treatment can reduce R5 -HIV infectivity on TZM-bl cells and un-stimualted CD 4⁺T cells (P < 0 . 001 ). (2) Hyaluronidase treatment can enhance HIV infectivity, by adding 100 μg of exogenous HA can reverse the function of hyaluronidase treatment(P<0. 001). (3) 100 μg of exogenous HA can reduce R5-HIV binding to CD4⁺ T cells, while hyaluronidase treatment can enhance R5-HIV binding to CD4⁺ T cells (P ＜0. 001). Conclusion Exogenous HA can reduce R5 -HIV in?fectivity on un-stimulated CD 4⁺T cells, while hyaluronidase treatment can enhance R 5 -HIV binding to CD 4⁺T cells,and R5 -HIV infectivity.

Key words: hyaluronicacid(HA) , R5 -HIV, infectivity, CD4⁺Tcell