Cervical carcinoma is the second leading cancer in women in Malaysia, after breast cancer. Human papillomavirus (HPV) has been implicated in the development of dysplasia or cervical intraepithelial neoplasia and progression to squamous cell carcinoma. Because of the confinement of the human papillomavirus infection within the epithelial layer, the presence of dentritic cells or Langerhans cells in epithelial layer of the ectocervix is paramount in producing immune response. The mature dentritic cells express CD83 and high CD40/80/86, whereas the immature cells express CD1a and low CD40/80/86. By identifying CD1a and CD83, theoretically, both immature and mature dentritic cell populations can be studied. In view of the facts, we investigated the infiltrating cell density of mature and immature dentritic cells in cervical neoplasia.
Dendritic cells (DC) are specialized antigen presenting cells (APC) that have important roles in host defenses and in generating anti-tumour immune response. Altered frequency and maturation of DC have been reported in malignant tumours. We studied the distribution and maturation status of DC by immunohistochemistry, on the formalin-fixed, paraffin-embedded lymph node tissues of 32 histologically diagnosed lymphomas and 40 inflammatory conditions that were retrieved from the Department of Pathology, UKM Medical Centre, Kuala Lumpur. Our study showed a significant reduction in the total DC counts in the lymphoma tissues compared to the inflammatory conditions. The mature and immature DC counts were both significantly reduced (p = 0.008 and 0.001 respectively), although a greater reduction was observed in mature DC numbers. We also observed compartmentalization of DC where the immature DC were seen within the tumour tissues and the mature DC were more in peri-tumoural areas. Our findings were similar to other reports, suggesting that reduced numbers of DC appears to be a factor contributing to lack of tumour surveillance in these cases.
Methods that allow expansion of myeloid dendritic cells (MDCs) from CD34(+) cells are potentially important for boosting anti-leukemic responses after cord blood (CB) hematopoietic stem cell transplantation (HSCT). We showed that the combination of early-acting cytokines FLT3-ligand (FL), stem cell factor (SCF), interleukin (IL)-3, and IL-6 supported the generation of CD11c(+)CD16() CD1a()/c() MDCs from CB CD34(+) cells or CB myeloid precursors. Early-acting cytokine-derived MDCs were maintained within the myeloid CD33(+)CD14()CD15() precursors with a mean of 4 x 10(6) cells generated from 1-4 x 10(4) CB CD34(+) cells or myeloid precursors after 2 weeks. After 8-12 days of culture the MDCs expressed higher levels of HLA-DR antigen but lower levels of CD40 and CD86 antigen, compared to adult blood MDCs. At this stage of differentiation, the early-acting cytokine-derived MDCs had acquired the ability to induce greater allogeneic T cell proliferation than monocytes or granulocytes derived from same culture. Early-acting cytokine-derived MDCs exposed to the cytokine cocktail (CC) comprising IL-1beta, IL-6, tumor necrosis factor (TNF)-alpha, and prostaglandin E (PGE)-2, upregulated the surface co-stimulatory molecules CD40 and CD86 and enhanced allogeneic T cell proliferation, as is characteristic of MDCs maturation. The reliable production of MDCs from CB CD34(+) cells provides a novel way to study their lineage commitment pathway(s) and also a potential means of enriching CB with MDCs to improve prospects for DC immunotherapy following CB HSCT.