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Quan Cai

Publications and source records attributed to Quan Cai.

4 recordsLinked to original sources
PubMed2004

alpha-type-1 polarized dendritic cells: a novel immunization tool with optimized CTL-inducing activity.

Using the principle of functional polarization of dendritic cells (DCs), we have developed a novel protocol to generate human DCs combining the three features critical for the induction of type-1 immunity: (a) fully mature status; (b) responsiveness to secondary lymphoid organ chemokines; and (c) high interleukin-12p70 (IL-12p70)-producing ability. We show that IFN-alpha and polyinosinic:polycytidylic acid (p-I:C) synergize with the "classical" type-1-polarizing cytokine cocktail [tumor necrosis factor alpha (TNFalpha)/IL-1beta/IFNgamma], allowing for serum-free generation of fully mature type-1-polarized DCs (DC1). Such "alpha-type-1-polarized DC(s)" (alphaDC1) show high migratory responses to the CCR7 ligand, 6C-kine but produce much higher levels of IL-12p70 as compared to TNFalpha/IL-1beta/IL-6/prostaglandin E2 (PGE2)-matured DCs (sDC), the current "gold standard" in DC-based cancer vaccination. A single round of in vitro sensitization with alphaDC1 (versus sDCs) induces up to 40-fold higher numbers of long-lived CTLs against melanoma-associated antigens: MART-1, gp100, and tyrosinase. Serum-free generation of alphaDC1 allows, for the first time, the clinical application of DCs that combine the key three features important for their efficacy as anticancer vaccines.

Cell Polarity↗
PubMed2002

Complementary dendritic cell-activating function of CD8+ and CD4+ T cells: helper role of CD8+ T cells in the development of T helper type 1 responses.

Dendritic cells (DCs) activated by CD40L-expressing CD4+ T cells act as mediators of "T helper (Th)" signals for CD8+ T lymphocytes, inducing their cytotoxic function and supporting their long-term activity. Here, we show that the optimal activation of DCs, their ability to produce high levels of bioactive interleukin (IL)-12p70 and to induce Th1-type CD4+ T cells, is supported by the complementary DC-activating signals from both CD4+ and CD8+ T cells. Cord blood- or peripheral blood-isolated naive CD8+ T cells do not express CD40L, but, in contrast to naive CD4+ T cells, they are efficient producers of IFN-gamma at the earliest stages of the interaction with DCs. Naive CD8+ T cells cooperate with CD40L-expressing naive CD4+ T cells in the induction of IL-12p70 in DCs, promoting the development of primary Th1-type CD4+ T cell responses. Moreover, the recognition of major histocompatibility complex class I-presented epitopes by antigen-specific CD8+ T cells results in the TNF-alpha- and IFN-gamma-dependent increase in the activation level of DCs and in the induction of type-1 polarized mature DCs capable of producing high levels of IL-12p70 upon a subsequent CD40 ligation. The ability of class I-restricted CD8+ T cells to coactivate and polarize DCs may support the induction of Th1-type responses against class I-presented epitopes of intracellular pathogens and contact allergens, and may have therapeutical implications in cancer and chronic infections.

CD40 Ligand↗
PubMedDate not supplied

Autologous glioma cell vaccine admixed with interleukin-4 gene transfected fibroblasts in the treatment of recurrent glioblastoma: preliminary observations in a patient with a favorable response to therapy.

We designed a phase I clinical trial of vaccinations with autologous glioma cells expressing transgene-derived interleukin-4 (IL-4), and treated one patient with a right temporal lobe recurrent glioblastoma. This 62-year-old man underwent craniotomy and partial tumor removal, at which time autologous tumor cells were obtained for vaccine preparation. After confirming the patient's cellular immune function by skin test, two cycles of vaccination with irradiated autologous glioma cells admixed with gene transfected fibroblasts were given intradermally. The patient demonstrated no evidence of allergic encephalitis throughout this course. Immunohistochemistry with biopsy samples taken from the vaccine sites demonstrated that the infiltration level of CD4, CD8 and CD1a positive cells increased proportionally to the amount of IL-4 produced at the each site, suggesting that there was local immune response induced at the vaccine site. While it is premature to assess effectiveness of the vaccine, this initial patient's course suggested a transient response to the vaccine, and he survived 10 months after treatment.

Antibody Formation↗