• IMMUNE NETWORK
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• v.16 no.1
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• pp.1-12
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• 2016

Th2 cell immunity is required for host defense against helminths, but it is detrimental in allergic diseases in humans. Unlike Th1 cell and Th17 cell subsets, the mechanism by which dendritic cells modulate Th2 cell responses has been obscure, in part because of the inability of dendritic cells to provide IL-4, which is indispensable for Th2 cell lineage commitment. In this regard, immune cells other than dendritic cells, such as basophils and innate lymphoid cells, have been suggested as Th2 cell inducers. More recently, multiple independent researchers have shown that specialized subsets of dendritic cells mediate Th2 cell responses. This review will discuss the current understanding related to the regulation of Th2 cell responses by dendritic cells and other immune cells.

• Journal of Medicine and Life Science
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• v.16 no.1
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• pp.27-30
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• 2019

We describe a case of a 48-year-old Korean woman who had a subepithelial mass incidentally discovered by endoscopic examination. Endoscopic mucosal resection revealed a well-circumscribed whitish solid mass within the submucosal space. Microscopically, the tumor was comprised of sparse spindle cells in the dense collagenous stroma with several calcifications and lymphoid aggregates. Immunohistochemical analysis showed that the tumor cells are negative for c-kit, smooth muscle actin, desmin, S-100 and CD34. Based on these findings, the tumor was diagnosed with calcifying fibrous tumor.

• Molecules and Cells
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• v.38 no.3
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• pp.195-201
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• 2015

Antibodies are powerful defense tools against pathogens but may cause autoimmune diseases when erroneously directed toward self-antigens. Thus, antibody producing cells are carefully selected, refined, and expanded in a highly regulated microenvironment (germinal center) in the peripheral lymphoid organs. A subset of T cells termed T follicular helper cells (Tfh) play a central role in instructing B cells to form a repertoire of antibody producing cells that provide life-long supply of high affinity, pathogenspecific antibodies. Therefore, understanding how Tfh cells arise and how they facilitate B cell selection and differentiation during germinal center reaction is critical to improve vaccines and better treat autoimmune diseases. In this review, I will summarise recent findings on molecular and cellular mechanisms underlying Tfh generation and function with an emphasis on T cell costimulation.

• IMMUNE NETWORK
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• v.24 no.4
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• pp.31.1-31.16
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• 2024

Urinary tract infections (UTIs) represent one of the most prevalent bacterial infections globally, manifesting in diverse clinical phenotypes with varying degrees of severity and complications. The mechanisms underlying UTIs are gradually being elucidated, leading to an enhanced understanding of the immune responses involved. Innate immune cells play a crucial defensive role against uropathogenic bacteria through various mechanisms. Despite their significant contributions to host defense, these cells often fail to achieve complete clearance of uropathogens, necessitating the frequent prescription of antibiotics for UTI patients. However, the persistence of infections and related pathological symptoms in the absence of innate immune cells in animal models underscore the importance of innate immunity in UTIs. Therefore, the host protective functions of innate immune cells, including neutrophils, macrophages, mast cells, NK cells, innate lymphoid cells, and γδ T cells, are delicately coordinated and timely regulated by a variety of cytokines to ensure successful pathogen clearance.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.3
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• pp.167-174
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• 2012

Natural killer (NK) cells provide one of the initial barriers of cellular host defense against pathogens, in particular intracellular pathogens. Because bone marrow-derived hematopoietic stem cells (HSCs), lymphoid protenitors, can give rise to NK cells, NK ontogeny has been considered to be exclusively lymphoid. Here, we show that porcine c-$kit^+$ bone marrow cells (c-$kit^+$ BM cells) develop into NK cells in vitro in the presence of various cytokines [interleukin (IL)-2, IL-7, IL-15, IL-21, stem cell factor (SCF), and fms-like tyrosine kinase-3 ligand (FLT3L)]. Adding hydrocortisone (HDC) and stromal cells greatly increases the frequency of c-$kit^+$ BM cells that give rise to $CD2^+CD8^+$ NK cells. Also, intracellular levels of perforin, granzyme B, and NKG2D were determined by RT-PCR and western blotting analysis. It was found that of perforin, granzyme B, and NKG2D levels significantly were increased in cytokine-stimulated c-$kit^+$ BM cells than those of controls. And, we compared the ability of the cytotoxicity of $CD2^+CD8^+$ NK cells differentiated by cytokines from c-$kit^+$ BM cells against K562 target cells for 28 days. Cytokines-induced NK cells as effector cells were incubated with K562 cells as target in a ratio of 100 : 1 for 4 h once a week. In results, $CD2^+CD8^+$ NK cells induced by cytokines and stromal cells showed a significantly increased cytotoxicity 21 days later. Whereas, our results indicated that c-$kit^+$ BM cells not pretreated with cytokines have lower levels of cytotoxicity. Taken together, this study suggests that cytokines-induced NK cells from porcine c-$kit^+$ BM cells may be used as adoptive transfer therapy if the known obstacles to xenografting (e.g. immune and non-immune problems) were overcome in the future.

• Tuberculosis and Respiratory Diseases
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• v.69 no.3
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• pp.212-216
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• 2010

Nodular lymphoid hyperplasia is a very rare benign disease and usually shows consolidation on chest X-ray with symptoms of pneumonia due to the proliferation of lymphoid cells in the lung parenchyma. It is common for patients to be diagnosed with pneumonia and treated with antibiotics, but patients often enter a cycle of repeated improvement, followed by aggravation of symptoms. At this point, surgical diagnostic tools are considered in order to differentiate between malignant disease and interstitial lung disease. Here, we report 2 cases of patients with nodular lymphoid hyperplasia and review the associated references.

• The Korean Journal of Cytopathology
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• v.17 no.2
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• pp.99-107
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• 2006

In the investigation of superficial lymphadenopathy of unknown cause, fine needle aspiration (FNA) cytology plays an invaluable role. It enables the differentiation of benign lymphadenopathy from lymphoid and non-lymphoid malignancies, obviating the need for open biopsy, and allowing the triage of patients. Cytopathologists should be familiar with the typical FNA patterns of benign lymphadenopathy, and recognize and differentiate among categories. In a minority of cases of benign lymphadenopathy, FNA can render a specific diagnosis. Benign lymphadenopathies are generally categorized into reactive lymphoid hyperplasia (RLH), inflammatory or infectious processes, and benign lymphoproliferative disorders. RLH characteristically presents with a heterogeneous and polymorphous smear composed of normal cellular constituents of lymph nodes, in contrast with the homogeneous or monomorphic smear of most lymphomas. The caveat is that various malignant disorders may also present with polymorphous populations. It is also important to recognize thatbenign lymphoid smears may sometimes contain atypical cells that raise the suspicion of malignancy. Clinical information should always be the integral part of the diagnostic criteria in FNA of lymphadenopathy. If there is any doubt about the benign nature of the smear, it is prudent to suggest biopsy and ancillary studies.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.439-443
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• 2005

Rejection is one of the life-threatening complications after organ transplantation. An eight-month-old, intact male, mixed breed dog was presented with acute rejection after renal allograft. The heterotopic renal transplantation with bilateral nephrectomy was performed in the dog. The triple drug protocol for immunosuppression was applied for prevention of the acute rejection. Postoperative care was done according to the transplantation protocol of VMTH, Kangwon National University. The dog was euthanized when the serum creatinine concentration exceeded 5 mg/dL followed by tile signs of illness. The transplanted kidney was enlarged. The renal cortex lesions were characterized by necrosis of the renal tubules and the glomeruli. Interstitial lesions were characterized by hemorrhage and severe infiltration of lymphoid cells. Intrarenal arteries showed necrosis of the walls and infiltration of perivascular lymphoid cells. In immunohistochemical (IHC) findings, infiltration of the CD4 and the CD8 positive T lymphocytes was examined. In this case, acute rejection was shown by humoral and cellular immunity on the basis of histopathologic and IHC evaluation.

• Parasites, Hosts and Diseases
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• v.49 no.2
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• pp.109-114
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• 2011

Dendritic cells have been known as a member of strong innate immune cells against infectious organelles. In this study, we evaluated the cytokine expression of splenic dendritic cells in chronic mouse toxoplasmosis by tissue cyst-forming Me49 strain and demonstrated the distribution of lymphoid dendritic cells by fluorescence-activated cell sorter (FACS). Pro-inflammatory cytokines, such as IL-$1{\alpha}$, IL-$1{\beta}$, IL-6, and IL-10 increased rapidly at week 1 post-infection (PI) and peaked at week 3 PI. Serum IL-10 level followed the similar patterns. FACS analysis showed that the number of $CD8{\alpha}^+/CD11c^+$ splenic dendritic cells increased at week 1 and peaked at week 3 PI. In conclusion, mouse splenic dendritic cells showed early and rapid cytokine changes and may have important protective roles in early phases of murine toxoplasmosis.

• IMMUNE NETWORK
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• v.23 no.5
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• pp.41.1-41.21
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• 2023

CD4 and CD8 T cells are key players in the immune response against both pathogenic infections and cancer. CD4 T cells provide help to CD8 T cells via multiple mechanisms, including licensing dendritic cells (DCs), co-stimulation, and cytokine production. During acute infection and vaccination, CD4 T cell help is important for the development of CD8 T cell memory. However, during chronic viral infection and cancer, CD4 helper T cells are critical for the sustained effector CD8 T cell response, through a variety of mechanisms. In this review, we focus on T cell responses in conditions of chronic Ag stimulation, such as chronic viral infection and cancer. In particular, we address the significant role of CD4 T cell help in promoting effector CD8 T cell responses, emerging techniques that can be utilized to further our understanding of how these interactions may take place in the context of tertiary lymphoid structures, and how this key information can be harnessed for therapeutic utility against cancer.