Campylobacter is a worldwide foodborne pathogen, associated with human gastroenteritis. The efficient translocation of Campylobacter and its ability to secrete toxins into host cells are the 2 key features of Campylobacter pathophysiology which trigger inflammation in intestinal cells and contribute to the development of gastrointestinal symptoms, particularly diarrhoea, in humans. The purpose of conducting this literature review is to summarise the current understanding of: i) the human immune responses involved in the elimination of Campylobacter infection and ii) the resistance potential in Campylobacter against these immune responses. This review has highlighted that the intestinal epithelial cells are the preliminary cells which sense Campylobacter cells by means of their cell-surface and cytosolic receptors, activate various receptors-dependent signalling pathways, and recruit the innate immune cells to the site of inflammation. The innate immune system, adaptive immune system, and networking between these systems play a crucial role in bacterial clearance. Different cellular constituents of Campylobacter, mainly cell membrane lipooligosaccharides, capsule, and toxins, provide protection to Campylobacter against the human immune system mediated killing. This review has also identified gaps in knowledge, which are related to the activation of following during Campylobacter infection: i) cathelicidins, bactericidal permeability-increasing proteins, chemokines, and inflammasomes in intestinal epithelial cells; ii) siglec-7 receptors in dendritic cell; iii) acute phase proteins in serum; and iv) T-cell subsets in lymphoid nodules. This review evaluates the existing literature to improve the understanding of human immunity against Campylobacter infection and identify some of the knowledge gaps for future research.
Acute-Phase Proteins ; Antigen-Presenting Cells ; Campylobacter Infections ; Campylobacter ; Cathelicidins ; Cell Membrane ; Chemokines ; Cytosol ; Dendritic Cells ; Epithelial Cells ; Gastroenteritis ; Guillain-Barre Syndrome ; Homicide ; Humans ; Immune System ; Inflammasomes ; Inflammation ; T-Lymphocyte Subsets ; Toll-Like Receptors

The active form of vitamin D3, 1,25-dihydroxyvitamin D₃ (aVD₃), is known to exert beneficial effects in the treatment of autoimmune diseases because of its immunosuppressive effects. However, clinical application of aVD₃ remains limited because of the potential side effects, particularly hypercalcemia. Encapsulation of aVD₃ within biodegradable nanoparticles (NPs) would enhance the delivery of aVD₃ to antigen presenting cells, while preventing the potential systemic side effects of aVD₃. In the present study, polymeric NPs containing ovalbumin (OVA) and aVD₃ (NP[OVA+aVD₃]) were prepared via the water-in-oil-in-water double emulsion solvent evaporation method, after which their immunomodulatory effects were examined. Bone marrow-derived immature dendritic cells (DCs) treated with NP(OVA+aVD₃) did not mature into immunogenic DCs but were converted into tolerogenic DCs, which express low levels of co-stimulatory molecules and MHC class II molecules, produce lower levels of pro-inflammatory cytokines while increasing the production of IL-10 and TGF-β, and induce the generation of Tregs. Intravenous injection with NP(OVA+aVD₃) markedly suppressed the generation of OVA-specific CTLs in mice. Furthermore, OVA-specific immune tolerance was induced in mice orally administered with NP(OVA+aVD₃). These results show that biodegradable NPs encapsulating both antigen and aVD₃ can effectively induce antigen-specific immune suppression.
Animals ; Antigen-Presenting Cells ; Autoimmune Diseases ; Cholecalciferol ; Cytokines ; Dendritic Cells ; Hypercalcemia ; Immune Tolerance ; Injections, Intravenous ; Interleukin-10 ; Methods ; Mice ; Nanoparticles ; Ovalbumin ; Polymers ; T-Lymphocytes, Regulatory ; Vitamins

Myeloid-derived suppressor cells (MDSCs) that are able to suppress T cell function are a heterogeneous cell population frequently observed in cancer, infection, and autoimmune disease. Immune checkpoint molecules, such as programmed death 1 (PD-1) expressed on T cells and its ligand (PD-L1) expressed on tumor cells or antigen-presenting cells, have received extensive attention in the past decade due to the dramatic effects of their inhibitors in patients with various types of cancer. In the present study, we investigated the expression of PD-1 on MDSCs in bone marrow, spleen, and tumor tissue derived from breast tumor-bearing mice. Our studies demonstrate that PD-1 expression is markedly increased in tumor-infiltrating MDSCs compared to expression in bone marrow and spleens and that it can be induced by LPS that is able to mediate NF-κB signaling. Moreover, expression of PD-L1 and CD80 on PD-1+ MDSCs was higher than on PD-1− MDSCs and proliferation of MDSCs in a tumor microenvironment was more strongly induced in PD-1+ MDSCs than in PD-1− MDSCs. Although we could not characterize the inducer of PD-1 expression derived from cancer cells, our findings indicate that the study on the mechanism of PD-1 induction in MDSCs is important and necessary for the control of MDSC activity; our results suggest that PD-1+ MDSCs in a tumor microenvironment may induce tumor development and relapse through the modulation of their proliferation and suppressive molecules.
Animals ; Antigen-Presenting Cells ; Autoimmune Diseases ; Bone Marrow ; Bone Marrow Cells ; Breast ; Humans ; Mice ; Recurrence ; Spleen ; T-Lymphocytes ; Tumor Microenvironment

OBJECTIVETo explore the effects of blocking TCR-CD3 and B7-CD28 signals on immune function of mice with chronic GVHD by using TJU103 and CTLA4-Ig.

METHODSOn the basis of foregoing murine model of chronic GVHD, according to interference modes after infusion 6×10 spleen cells of donor mice, the recipients were divided into 5 groups: blank control, cGVHD, TJU103 interference, CTLA4-Ig interference and TJU103+CTLA4-Ig interference groups. The score of clinical manifestation and tissue histopathology were used to evaluate the effects of all the interferences on chronic GVHD.

RESULTSTJU103 and CTLA4-Ig could not influence the formation of the mouse chimera. The analysis of Kaplan survival curve of mice with chronic GVHD showed that the CTLA4-Ig and TJU103+CTLA4-Ig reduced the incidence of chronic GVHD, the TJU103 could delay the occurrence of chronic GVHD, but all the interference factors could not change the severity of chronic GVHD.

CONCLUSIONTJU103 can delay the onset time of chronic GVHD, and the CTLA4-Ig can reduce the incidences of cGVHD, the combining use of TJU103 and CTLA4-Ig can significantly reduce the incidence of chronic GVHD, but can not change the severity of chronic GVHD.

Abatacept ; Animals ; Antigen-Presenting Cells ; Antigens, CD ; Antigens, Differentiation ; CTLA-4 Antigen ; Chronic Disease ; Graft vs Host Disease ; prevention & control ; Immunoconjugates ; Mice ; Mice, Inbred C57BL ; T-Lymphocytes

B cells play a role in graft rejection via several mechanisms. Specifically, B cells produce high-affinity antibodies to alloantigens including allogeneic major histocompatibility complex (MHC) with the help of follicular helper T cells. B cells also function as antigen-presenting cells for alloreactive T cells, resulting in the activation of alloreactive T cells. Conversely, the frequency of regulatory B cells increases under inflammatory conditions and suppresses the rejection process. Here, the differential roles of the major B cell subpopulations (B-1, follicular B, marginal zone B, and regulatory B cells) involved in transplantation rejection are discussed together with their interaction with T cells.
Antibodies ; Antibody Diversity ; Antigen-Presenting Cells ; B-Lymphocytes* ; B-Lymphocytes, Regulatory ; Graft Rejection* ; Isoantigens ; Major Histocompatibility Complex ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer

A mysterious puzzle in immunology is how the immune system decides what types of immune response to initiate against various stimuli. Although much is known about control of T helper 1 (Th1) and Th17 responses, the mechanisms that initiate Th2 responses remain obscure. Antigen-presenting cells, particularly dendritic cells (DCs), are mandatory for the induction of a Th cell response. Numerous studies have documented the organizing role of DCs in this process. The present review summarizes the fundamental roles of DCs in inducing Th2 responses.
Allergy and Immunology ; Antigen-Presenting Cells ; Dendritic Cells* ; Immune System

Dendritic cells (DCs) are the most professional antigen presenting cells that play important roles in connection between innate and adaptive immune responses. Numerous studies revealed that the functions of DCs are related with the capture and processing of antigen as well as the migration to lymphoid tissues for the presenting antigens to T cells. These unique features of DCs allow them to be considered as therapeutic vaccines that can induce immune responses and anti-tumor activity. Here, we discuss and understand the immunological basis of DCs and presume the possibilities of DC-based vaccines for the promising cancer therapy.
Antigen-Presenting Cells ; Cancer Vaccines ; Dendritic Cells ; Immunotherapy ; Lymphoid Tissue ; T-Lymphocytes ; Vaccines

Toxoplasma gondii can infect all the vertebrates including human, and leads to serious toxoplasmosis and considerable veterinary problems. T. gondii heat shock protein 60 (HSP60) is associated with the activation of antigen presenting cells by inducing initial immune responses and releasing inflammatory cytokines. It might be a potential DNA vaccine candidate for this parasite. A pVAX-HSP60 DNA vaccine was constructed and immune responses was evaluated in Kunming mice in this study. Our data indicated that the innate and adaptive immune responses was elicited by successive immunizations with pVAX-HSP60 DNA, showing apparent increases of CD3e+CD4+ and CD3e+CD8a+ T cells in spleen tissues of the HSP60 DNA-immunized mice (24.70±1.23% and 10.90±0.89%, P < 0.05) and higher levels of specific antibodies in sera. Furthermore, the survival period of the immunized mice (10.53±4.78 day) were significantly prolonged during the acute T. gondii infection. Decrease of brain cysts was significant in the experimental group during the chronic infection (P < 0.01). Taken together, TgHSP60 DNA can be as a vaccine candidate to prevent the acute and chronic T. gondii infections.
Animals ; Antibodies ; Antigen-Presenting Cells ; Brain ; Chaperonin 60 ; Cytokines ; DNA ; Humans ; Immunization ; Mice ; Parasites ; Spleen ; T-Lymphocytes ; Toxoplasma ; Toxoplasmosis ; Vertebrates

We investigated whether diclofenac could influence the development of antigen-presenting cells in an oxygenated cholesterol-rich environment by determining its effects on the 27-hydroxycholesterol (27OHChol)-induced differentiation of monocytic cells into mature dendritic cells (mDCs). Treatment of human THP-1 monocytic cells with diclofenac antagonized the effects of 27OHChol by attenuating dendrite formation and cell attachment and promoting endocytic function. Diclofenac inhibited the transcription and surface expression of the mDC markers of CD80, CD83, and CD88, and reduced the 27OHChol-induced elevation of surface levels of MHC class I and II molecules to the basal levels in a dose-dependent manner. It also reduced the expression of CD197, a molecule involved in DC homing and migration. These results indicate that diclofenac inhibits the differentiation of monocytic cells into mDCs, thereby potentially modulating adaptive immune responses in a milieu rich in cholesterol oxidation products.
Antigen-Presenting Cells ; Cholesterol ; Dendrites ; Dendritic Cells* ; Diclofenac* ; Humans ; Oxygen

End-stage renal disease (ESRD) with immune disorder involves complex interactions between the innate and adaptive immune responses. ESRD is associated with various alterations in immune function such as a reduction in polymorphonuclear leukocyte bactericidal activity, a suppression of lymphocyte proliferative response to stimuli, and a malfunction of cell-mediated immunity at the molecular level. ESRD also increases patients' propensity for infections and malignancies as well as causing a diminished response to vaccination. Several factors influence the immunodeficiency in patients with ESRD, including uremic toxins, malnutrition, chronic inflammation, and the therapeutic dialysis modality. The alteration of T-cell function in ESRD has been considered to be a major factor underlying the impaired adaptive cellular immunity in these patients. However, cumulative evidence has suggested that the immune defect in ESRD can be caused by an Ag-presenting dendritic cell (DC) dysfunction in addition to a T-cell defect. It has been reported that ESRD has a deleterious effect on DCs both in terms of their number and function, although the precise mechanism by which DC function becomes altered in these patients is unclear. In this review, we discuss the effects of ESRD on the number and function of DCs and propose a possible molecular mechanism for DC dysfunction. We also address therapeutic approaches to improve immune function by optimally activating DCs in patients with ESRD.
Antigen-Presenting Cells ; Dendritic Cells* ; Dialysis ; Humans ; Immune System Diseases ; Immunity, Cellular ; Inflammation ; Kidney Failure, Chronic* ; Lymphocytes ; Malnutrition ; Neutrophils ; T-Lymphocytes ; Vaccination