HIV Type 1 Infection in Women: Increased Transcription of HIV Type 1 in Ectocervical Tissue Explants

Abstract

This is, to our knowledge, the first study to compare ectocervix and endometrium in a tissue explant model of HIV-1 infection and to demonstrate greater HIV-1 transcription in the ectocervix. Our results suggest that the ectocervix is more conducive to HIV-1 replication than is the endometrium and that IL-6 enhances HIV-1 transcription at this site. Thus, the ectocervix is an important site to be considered in heterosexual transmission of HIV-1.

Nanoparticles Containing siRNA to Silence CD4 and CCR5 Reduce Expression of These Receptors and Inhibit HIV-1 Infection in Human Female Reproductive Tract Tissue Explants

“…In our previous study, we determined that the ECX has the highest level of CD45 expression in the female reproductive tract, indicating an enrichment of leukocytes at this site. 32 Moreover, we have found that the expression of CD4, CCR5, and CXCR4 varied in the ECX and in the EM on both the stromal leukocyte population as well as on epithelial cells, and the numbers and distribution of receptor-positive leukocytes also varied throughout the menstrual cycle, indicating hormonal regulation of receptor expression and leukocyte trafficking. 41,42 Thus, the varied findings among tissue sites is likely due to multiple effects including the density of receptor-positive cells, or to donor variation in age, menstrual cycle stage and/or clinical conditions.…”

“…We previously demonstrated that tissue explants prepared from the female reproductive tract of seronegative women could be infected with HIV-1, and that the level of infection among female reproductive tract sites correlated with expression of the pan-leukocyte marker, CD45. 32 In this study we exposed female reproductive tract explants to siRNA to silence CD4 and CCR5 for 48 h prior to the addition of HIV-1 to determine the efficacy of gene silencing to protect tissue explants from HIV-1 infection. We then measured the degree of gene silencing and of inhibition of HIV-1 reverse transcription on subsequent days of culture.…”

“…ECX tissues were chosen for study because this tissue type has the highest concentration of leukocytes compared to other sites within the female reproductive tract. 32 RNA isolated from siRNA-treated ECX tissue explants were subjected to stringent removal of contaminating DNA prior to amplification. IFN-α transcripts were amplified with the sense primer (5'-GCA CCG AAC TCT ACC AGC AGC-3') and anti-sense primer (5'-TCT GAC AAC CTC CCA GGC ACA-3').…”

“…12 In this study, we sought to determine the efficacy of RNAi to inhibit HIV-1 infection in human female reproductive tract tissue explants. We used a novel primary tissue explant model 32 in which explants from the human female reproductive tract were transfected with nanoparticles to deliver CD4 and CCR5-specific siRNA, and then challenged with HIV-1. The small size of these nanoparticles promoted endocytosis by phagocytic cells in the explants, thus transfecting target cells with the siRNA.…”

Inducing Immune Protection Against Trichomonas vaginalis: A Novel Vaccine Approach to Prevent HIV Transmission

“…Examination of ectocervical tissue from HIV positive women found higher levels of IL-6 than in uninfected controls. Because the ectocervix was an area where high levels of HIV replication had been detected, recombinant IL-6 was applied to tissue explants and a greater than 300-fold increase in HIV transcription was seen (Asin et al, 2009). HIV appears to be capable of not only infecting immune cells, but of using immune response to its own advantage to enhance its replication.…”