We evaluated the proposal that during microbial infection, dendritic cells (DCs) undergo maturation and present a mixture of peptides derived from the microbe as well as harmless environmental antigens. Mice were exposed to an aerosol of endotoxin free ovalbumin (OVA) in the absence or presence of influenza virus. In its absence, OVA failed to induce B and T cell responses and even tolerized, b...

Invariant NKT cells (iNKT cells) play a pivotal role in the development of allergen-induced airway hyperresponsiveness (AHR) and inflammation. However, it is unclear what role they play in the initiation (sensitization) phase as opposed to the effector (challenge) phase. The role of iNKT cells during sensitization was examined by determining the response of mice to intratracheal transfer of OVA...

Interleukin (IL)-17 plays an important role in rhinitis and the level thereof correlates with the severity of disease. However, no mouse model for IL-17-dominant rhinitis has yet been developed. Our objective was to establish a mouse model of IL-17-dominant rhinitis via intranasal application of polyinosinic-polycytidylic acid (abbreviated as Poly(I:C)). Mice were divided into 6 groups (n=8 for...

Induction of a functional CD8(+) T-cell response is the important criterion for cancer vaccines, and it is unclear whether acute or chronic live vectors are better suited for cancer antigen delivery. We have evaluated the tumor protective ability of two recombinant vectors, Listeria monocytogenes (LM) and Salmonella typhimurium (ST), both expressing ovalbumin (OVA). Although both vectors induce...

To identify endocytic receptors that allow dendritic cells (DCs) to capture and present antigens on major histocompatibility complex (MHC) class I products in vivo, we evaluated DEC-205, which is abundant on DCs in lymphoid tissues. Ovalbumin (OVA) protein, when chemically coupled to monoclonal alphaDEC-205 antibody, was presented by CD11c+ lymph node DCs, but not by CD11c- cells, to OVA-specif...

CD4(+)CD25(high) regulatory T cells (Treg) protect the host from autoimmune diseases but are also obstacles against cancer therapies. An ideal cancer vaccine would stimulate specific cytotoxic responses and reduce/suppress Treg function. In this study, we showed that Escherichia coli expressing listeriolysin O and OVA (E. coli LLO/OVA) demonstrated remarkable levels of protection against OVA-ex...

Murine bone marrow-derived dendritic cells (DC) can phagocytose and process Salmonella enterica serovar Typhimurium for peptide presentation on major histocompatibility complex class I (MHC-I) and MHC-II molecules. To investigate if a serovar Typhimurium encounter with DC induces maturation and downregulates their ability to present antigens from subsequently encountered bacteria, DC were pulse...

The adjuvant activity of Chenopodium quinoa (quinoa) saponins on the humoral and cellular immune responses of mice subcutaneously immunized with ovalbumin (OVA) was evaluated. Two quinoa saponin fractions were obtained, FQ70 and FQ90, and 10 saponins were determined by UPLC/Q-TOF-MS. Mice were immunized subcutaneously with OVA alone or adjuvanted with Quil A (adjuvant control), FQ70, or FQ90. F...

BALB/c mice received saline (SAL groups) or ovalbumin (OVA groups) intraperitoneally (days 1, 3, 5, 7, 9, 11 and 13). After 27 days, a burst of intratracheal OVA or SAL (days 40, 43 and 46) was performed. Animals were then divided into four groups (N=8, each) and intranasally instilled with saline (SAL-SAL and OVA-SAL) or residual oil fly ash (SAL-ROFA and OVA-ROFA). 24h later, total, initial a...

We previously showed that naive CD4+ Th cells acquire peptide-MHC class I (pMHC I) and costimulatory molecules from OVA-pulsed dendritic cells (DC(OVA)), and act as Th-APCs in stimulation of CD8+ CTL responses. In this study, we further demonstrated that naive CD8+ cytotoxic T (Tc) cells also acquire pMHC I and costimulatory CD54 and CD80 molecules by DC(OVA) stimulation, and act as Tc-APC. The...