Tissue expression of TGF-β1 in uterine cervical samples from HIV/AIDS patients

Role of intestinal myofibroblasts in HIV-associated intestinal collagen deposition and immune reconstitution following combination antiretroviral therapy

OBJECTIVE

To investigate the potential role of mucosal intestinal myofibroblasts (IMFs) in HIV and associated fibrosis in gut-associated lymphoid tissue.

DESIGN

Profibrotic changes within the secondary lymphoid organs and mucosa have been implicated in failed immune reconstitution following effective combination antiretroviral therapy (cART). Microbial translocation is believed to be sustaining these systemic inflammatory pathways. IMFs are nonprofessional antigen-presenting cells with both immunoregulatory and mesenchymal functions that are ideally positioned to respond to translocating microbial antigen.

METHODS

Duodenal biopsies, obtained from patients naive to cART, underwent trichrome staining and were examined for tissue growth factor-beta (TGF-β) expression. Combined immunostaining and second harmonic generation analysis were used to determine IMF activation and collagen deposition. Confocal microscopy was performed to examine IMF activation and Toll-like receptor (TLR)4 expression. Finally, primary IMF cultures were stimulated with lipopolysaccharide to demonstrate the expression of the inflammatory biomarkers.

RESULTS

The expression of the fibrosis-promoting molecule, TGF-β1, is significantly increased in duodenal biopsies from HIV patients naïve to cART, and negatively correlated with subsequent peripheral CD4(+) recovery. The increase in TGF-β1 coincided with an increase in collagen deposition in the duodenal mucosa in the tissue area adjacent to the IMFs. We also observed that IMFs expressed TLR4 and had an activated phenotype since they were positive for fibroblast activation protein. Finally, stimulation of IMFs from HIV patients with TLR4 resulted in significantly increased expression of profibrotic molecules, TGF-β1, and interleukin-6.

CONCLUSION

Our data support the hypothesis that activated IMFs may be among the major cells contributing to the profibrotic changes, and thus, the establishment and maintenance of systemic inflammation interfering with immune reconstitution in HIV patients.

Cytokine expression in the cervical stroma of HIV-positive and HIV-negative women with cervical intraepithelial neoplasia

Cervical intraepithelial neoplasias (CINs) are a major public health issue. The prevalence of CINs is higher in women with the human immunodeficiency virus (HIV). The objective of this study was to determine whether there are differences in the immune responses in the cervical stroma of HIV-infected and -uninfected women with CIN. The responses were assessed according to the immunohistochemical expression of cytokines interleukin (IL)-4, IL-12, interferon gamma (IFN-γ), and tumor growth factor beta (TGF-β). In addition, we determined whether there were differences in the local immune responses between patients with CIN1 and CIN 2/3. A cross-sectional study was performed using material collected by cervical conization in HIV-infected and -uninfected women with CIN. The conization was performed using loop electrical excision procedure (LEEP) from January 1999 to May 2004. The evaluation of cytokines in the cervical stroma was based on immunohistochemistry. No differences were found between the two groups of women regarding HIV status. However, the associations between IL-12 expression and CIN 2/3 (p=0.016) in HIV-infected women and between IL-4 expression and CIN 1 (p=0.0456) in HIV-infected women were significant when the interaction between HIV infection and lesion grade was assessed. Additionally, a significant association between TGF-β expression and CIN 2/3 in both groups was observed regardless of HIV infection (p=0.000). An interaction between HIV infection and CIN grade was detected because IL-12 and IL-4 expression increased in the presence of HIV infection. Regarding the CIN grade, there was a high prevalence of TGF-β in CIN 2/3 lesions, which reflected the predominance of an immunoregulatory environment.