FoxP3 overexpression and CD1a+ and CD3+ depletion in anal tissue as possible mechanisms for increased risk of human papillomavirus-related anal carcinoma in HIV infection.

AIM: We analysed local cellular and humoral immunity factors in the anal mucosa in an attempt to explain how HIV infection increases the risk of anal cancer in HPV-infected patients. METHOD: HIV-positive cases and matched HIV-negative controls with more than one recurrence of condylomas were included in a prospective study following treatment of the initial lesions. Patients were followed every 3 to 6 months for the development of anal intraepithelial neoplasia (AIN3) and cancer for up to 60 months. Tissue CD1a(+), CD3(+), CD4(+), CD8(+) cells and mRNAs of selected cytokines and chemokines were quantified and compared in patients with or without AIN3 or cancer using morphometric or immunohistochemistry analysis and qRT-PCR. RESULTS: Sixty-six individuals (22 patients and 44 controls) were included. In the case group, CD1a(+) and CD3(+) cell counts were significantly lower in biopsies from AIN3 and cancer specimens compared with those from AIN 1-2 or normal biopsies (P < 0.0001). A CD1a(+) count of < 10/mm was predictive of AIN3 and cancer (Odds ratio = 9.4, 95% CI: 5.4-18.3, P < 0.0001). IL-8 and IL23 levels were significantly higher in cancer than in non-cancer tissues regardless of HIV status (P = 0.02). FoxP3 expression was significantly higher in HIV-infected cases than in controls with AIN3/cancer (P < 0.04). CONCLUSION: Depletion of CD1a(+) and CD3(+) cells and overexpression of FoxP3 in the anal mucosa appear likely to contribute to the risk of HPV-related anal cancer in HIV-infected patients. Furthermore, overexpression of IL-8 and IL-23 in the anal mucosa might be responsible for the development of this cancer regardless of HIV status.

High prevalence of Foxp3 and IL17 in MMR-proficient colorectal carcinomas.

BACKGROUND AND AIMS: Colorectal cancer (CRC) harbours different types of DNA alterations, including microsatellite instability (MSI). Cancers with high levels of MSI (MSI-H) are considered to have a good prognosis, probably related to lymphocyte infiltration within tumours. The aim of the present study was to characterise the intratumoural expression of markers associated with the antitumour immune response in mismatch repair (MMR)-proficient (MSS) colon cancers. METHODS: Ninety human colon cancers (T) and autologous normal colon mucosa (NT) were quantified for the expression of 15 markers of the immune response with quantitiative reverse transcription-PCR (qRT-PCR). mRNA expression levels were correlated with MMR status. Immunohistochemistry (IHC) was performed using both interleukin 17 (IL17) and CD3 antibodies. RESULTS: Expression of cytotoxic markers (FasL, granzyme B and perforin), inflammatory cytokines (IL1beta, IL6, IL8, IL17 and transforming growth factor beta (TGFbeta)) and a marker of regulatory T cells (forkhead box P3 (Foxp3)) was significantly higher in tumours than in autologous normal tissues. Adjusting for MMR status, higher tumoural expression of both granzyme B and perforin was associated with the MSI-H phenotype, and the perforin T/NT ratio was higher in MSI-H tissues than in MSS tissues. Higher tumoural expression of Foxp3, IL17, IL1beta, IL6 and TGFbeta was associated with the MSS phenotype, and the IL17 T/NT ratio was higher in MSS tissues than in MSI-H tissues as assessed by both qRT-PCR and IHC. CONCLUSIONS: Immune gene expression profiling in CRC displayed different patterns according to MMR status. Higher Foxp3, IL6, TGFbeta and IL17 expression is a particular determinant in MMR-proficient CRC. These may be potential biomarkers for a new prognostic "test set" in sporadic CRCs.