• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.461-468
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• 2005

The major function of immune system is to protect infections. The immune systems are composed of innate and adaptive immunity. In adaptive immunity, the cellular and humoral components interact each other. Neonates and infants are infected frequently, because immune systems are naive and easy to expose to infectious agents. The complete history and physical examination is essential to evaluate the child with recurrent infections. The environmental risk factors of recurrent infections are day care center, cigarette smoke, and air pollution. The underlying diseases such as immunodeficiency, autoimmune diseases, allergy, and disorders of anatomy or physiology increase the susceptibility to infections. In immunodeficiency, infections are characterized by severe, chronic, recurrent, and unusual microbial agents infection. The defects of antibody production are susceptible to sinopulmonary bacterial infections. T cells defects are vulerable to numerous organisms such as virus, fungi, bacteria and etc. The screening tests for immune functions are the quantitative and qualitative measurements of each immune components. A complete blood count with white blood cell, differential, and platelet provide quantitative informations of immune components. Total complement and immunoglobulin levels represent the humoral component. Antibody levels of previously injected vaccines also provide informations of the antigen specific antibody immune responses. T cell and subsets count is quantitative measurement of cell mediated immunity. Delayed hypersensitivity skin test is a crude measurement of T cell function. The long term outcome of children with recurrent infections is completely dependent on the underlying diseases, the initial time of diagnosis and therapy, continued management, and genetic counscelling.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.83-90
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• 2000

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.1
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• pp.37-43
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• 2006

Enterococcus faecalis was isolated from the body fluid of dead Galleria mellonella larvae. Upon injection of E. faecalis into the hemocoel of G. mellonella, the bacteria destroyed parts of humoral defense systems in the hemolymph. In a test for the proteolytic activity of E. faecalis CS, it was confirmed that the enzyme degraded three well-known a-helical antimicrobial peptides, cecropin A, melittin and halocidin, and abolished their activities. We also determined putative cleavage sites on the primary sequences of three peptides through purification and mass analysis of peptide fragments digested by E. faecalis CS. Furthermore it was found that apolipophorin-III, recently known as a critical recognition protein for invading microbes in the hemolymph of G. mellonella, was also degraded by E. faecalis CS. Taken together, the present work shows that the protease in secretions from E. faecalis destroyed two critical humoral immune factors in the hemolymph of G. mellonella larvae. In addition, this paper demonstrates that the relationship between the host insect and the pathogenic bacteria might provide a valuable model system to study the enterococcal virulence mechanism, which may be relevant to mammalian pathogenesis.

• BMB Reports
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• v.38 no.2
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• pp.128-150
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• 2005

Invertebrate animals, which lack adaptive immune systems, have developed other systems of biological host defense, so called innate immunity, that respond to common antigens on the cell surfaces of potential pathogens. During the past two decades, the molecular structures and functions of various defense components that participated in innate immune systems have been established in Arthropoda, such as, insects, the horseshoe crab, freshwater crayfish, and the protochordata ascidian. These defense molecules include phenoloxidases, clotting factors, complement factors, lectins, protease inhibitors, antimicrobial peptides, Toll receptors, and other humoral factors found mainly in hemolymph plasma and hemocytes. These components, which together compose the innate immune system, defend invertebrate from invading bacterial, fungal, and viral pathogens. This review describes the present status of our knowledge concerning such defensive molecules in invertebrates.

• IMMUNE NETWORK
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• v.12 no.6
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• pp.230-239
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• 2012

Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.

• Journal of Nutrition and Health
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• v.43 no.2
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• pp.152-160
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• 2010

The purpose of this study was to investigate the effects of aging process on the immunity in human subjects. In this investigation, nineteen families of three generations (daughters on college age, their mothers, and grandmothers) participated to avoid genetic variation among individuals. Dietary food records, anthropometric measurements and biochemical assessments of serum nutrients were used to evaluate the nutritional status of subjects. The immune parameters of subjects were assessed by the total and differential WBC count. Total B and T lymphocytes, and T cell subsets were quantified by flowcytometer. Serum immunoglobulin G, A, M concentrations were also measured as an index of humoral immunity. The result of this study can be summarized as follows: 1. Along with the aging process, body fat was found to be increased whereas lean body mass and total body water were diminished. Since there were no significant difference in serum vitamin E levels in all age groups, serum retinal concentrations tended to decrease as one gets old. 2. Although total number of T lymphocytes seemed to be unchanged, B lymphocytes and NK cell numbers were increased by aging. The Percentage of CD8 + lymphocytes was lower in the elderly subjects compared with the younger, resulting in higher ratio of CD4 +/CD8 + lymphocytes in the elderly. Serum Ig G and Ig A levels remained unchanged, but IgM levels were significantly decreased as the age processes continue. Taking all together, it could be suggested that the alteration of immune cell population by aging is selective and possibly nonage factors such as nutrition may be attributable to the change of immunity in the elderly. The nutritional status and aging process may selectively affect both the cell-mediated (CD8 +, CD4 + CD8 + ratio, NK cell) and humoral (B lymphocyte, Immunoglobulin M, G) immune parameters in human subjects.

• IMMUNE NETWORK
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• v.14 no.1
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• pp.21-29
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• 2014

Follicular helper T ($T_{FH}$) cells are recently highlighted as their crucial role for humoral immunity to infection as well as their abnormal control to induce autoimmune disease. During an infection, na$\ddot{i}$ve T cells are differentiating into $T_{FH}$ cells which mediate memory B cells and long-lived plasma cells in germinal center (GC). $T_{FH}$ cells are characterized by their expression of master regulator, Bcl-6, and chemokine receptor, CXCR5, which are essential for the migration of T cells into the B cell follicle. Within the follicle, crosstalk occurs between B cells and $T_{FH}$ cells, leading to class switch recombination and affinity maturation. Various signaling molecules, including cytokines, surface molecules, and transcription factors are involved in $T_{FH}$ cell differentiation. IL-6 and IL-21 cytokine-mediated STAT signaling pathways, including STAT1 and STAT3, are crucial for inducing Bcl-6 expression and $T_{FH}$ cell differentiation. $T_{FH}$ cells express important surface molecules such as ICOS, PD-1, IL-21, BTLA, SAP and CD40L for mediating the interaction between T and B cells. Recently, two types of microRNA (miRNA) were found to be involved in the regulation of $T_{FH}$ cells. The miR-17-92 cluster induces Bcl-6 and $T_{FH}$ cell differentiation, whereas miR-10a negatively regulates Bcl-6 expression in T cells. In addition, follicular regulatory T ($T_{FR}$) cells are studied as thymus-derived $CXCR5^+PD-1^+Foxp3^+\;T_{reg}$ cells that play a significant role in limiting the GC response. Regulation of $T_{FH}$ cell differentiation and the GC reaction via miRNA and $T_{FR}$ cells could be important regulatory mechanisms for maintaining immune tolerance and preventing autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Here, we review recent studies on the various factors that affect $T_{FH}$ cell differentiation, and the role of $T_{FH}$ cells in autoimmune diseases.

• Journal of Veterinary Science
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• v.23 no.2
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• pp.20.1-20.8
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• 2022

Background: Emergent and re-emergent canine tick-borne infections are attracting increasing attention worldwide. The rise in pet ownership and the close relationship between dogs and their owners are the most concerning factors because dogs may act as competent reservoirs for human tick-transmitted infectious agents. Objectives: This study contributes to the epidemiological surveillance of canine tick-transmitted infections with zoonotic risk in the Republic of Korea (ROK) by investigating the seroprevalence of the pathogens, Anaplasma spp., Borrelia burgdorferi, and Ehrlichia canis. Methods: Four hundred and thirty whole blood samples from domestic dogs were collected in seven metropolitan cities and nine provinces in the ROK and tested using SensPERT Ab test kits (VetAll Laboratories^®) to detect seroreactive animals. Results: The seroprevalence rates identified were 9.8% (42/430) for Anaplasma spp., 2.8% (12/430) for B. burgdorferi, and 1.4% (6/430) for E. canis. The risk factors evaluated in this study that could be associated with the development of a humoral immune response, such as sex, age, and history of tick exposure, were similar. There was only one exception for dogs seroreactive to Anaplasma spp., where the risk factor "tick exposure" was statistically significant (p = 0.047). Conclusions: This serological survey exhibited the widespread presence of Anaplasma spp., B. burgdorferi, and E. canis throughout the ROK. Hence, dogs may play a key role as the sentinel animals of multiple zoonotic infectious agents in the country.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.467-474
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• 2014

Objective: To observe the effects of allogeneic and autologous transfusion on cellular immunity, humoral immunity and secretion of serum inflammatory factors and perforin during the perioperative period in patients with malignant tumors. Methods: A total of 80 patients (age: 38-69 years; body weight: 40-78 kg; ASA I - II) receiving radical operation for gastro-intestinal cancer under general anesthesia were selected. All the patients were divided into four groups based on the methods of infusion and blood transfusion: blank control group (Group C), allogeneic transfusion group (group A), hemodiluted autotransfusion Group (Group H) and hemodiluted autotransfusion + allogenic transfusion Group (A+H group). Venous blood was collected when entering into the surgery room ($T_0$), immediately after surgery ($T_1$) and 24h ($T_2$), 3d ($T_3$) and 7d ($T_4$) after surgery, respectively. Moreover, flow cytometry was applied to assess changes of peripheral blood T cell subpopulations and NK cells. Enzyme linked immunosorbent assays were performed to determine levels of IL-2, IL-10, TNF-${\alpha}$ and perforin. Immune turbidimetry was employed to determine the changes in serum immunoglobulin. Results: Both CD3+ and NK cells showed a decrease at $T_1$ and $T_2$ in each group, among which, in group A, CD3+ decreased significantly at $T_2$ (P<0.05) compared with other groups, and CD3+ and NK cell reduced obviously only in group A at $T_3$ and $T_4$ (P<0.05). CD4+ cells and the ratio of D4+/CD8+ were decreased in groups A, C and A+H at $T_1$ and $T_2$ (P<0.05). No significant intra- and inter-group differences were observed in CD8+ of the four groups (P<0.05). IL-2 declined in group C at $T_1$ and $T_2$ (P<0.05) and showed a decrease in group A at each time point (P<0.05). Moreover, IL-2 decreased in group A + H only at $T_1$. No significant difference was found in each group at $T_1$ (P<0.05). More significant decrease in group ?? at $T_2$, $T_3$ and $T_4$ compared with group A (P<0.05), and there were no significant differences among other groups (P>0.05). IL-10 increased at $T_1$ and $T_2$ in each group (P<0.05), in which it had an obvious increase in group A, and increase of IL-10 occurred only in group A at $T_3$ and $T_4$ (P<0.05). TNF-${\alpha}$ level rose at $T_1$ (P<0.05), no inter- and intra-group difference was found in perforin in all groups (P<0.05). Compared with the preoperation, both IgG and IgA level decreased at $T_1$ in each group (P<0.05), and they declined only in Group A at $T_2$ and $T_3$ (P<0.05), and these parameters were back to the preoperative levels in other groups. No significant differences were observed between preoperative and postoperative IgG and IgA levels in each group at $T_4$ (P>0.05). No obvious inter- and intra-group changes were found in IgM in the four groups (P>0.05). Conclusions: Allogeneic transfusion during the perioperative period could obviously decrease the number of T cell subpopulations and NK cells and the secretion of stimulating cytokines and increase the secretion of inhibiting cytokines in patients with malignant tumors, thus causing a Th1/Th2 imbalance and transient decreasing in the content of plasma immune globulin. Autologous transfusion has little impact and may even bring about some improvement oo postoperative immune function in patients with tumors. Therefore, cancer patients should receive active autologous transfusion during the perioperative period in place of allogeneic transfusion.

• Tuberculosis and Respiratory Diseases
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• v.53 no.5
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• pp.497-509
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• 2002

Background : The mechanisms through which cellular activation results in intracellular mycobacterial killing is only partially understood. However, in vitro studies of human immunity to Mycobacterium tuberculosis have been largely modeled on the work reported by Crowle, which is complicated by several factors. The whole blood culture is simple and allows the simultaneous analysis of the relationship between bacterial killing and the effect of effector cells and humoral factors. In this study, we attempted to determine the extent to which M. tuberculosis is killed in a human whole blood culture and to explore the role of the host and microbial factor in this process. Methods : The PPD positive subject were compared to the umbilical cord blood and patients with tuberculosis, diabetes and lung cancer. The culture is performed using heparinized whole blood diluted with a culture medium and infected with a low number of M. avium or M. tuberculosis $H_{37}Ra$ for 4 days by rotating the culture in a $37^{\circ}C$, 5% $CO_2$ incubator. In some experiments, methlprednisolone- or pentoxifyline were used to inhibit the immune response. To assess the role of the T-cell subsets, CD4+, CD8+ T-cells or both were removed from the blood using magnetic beads. The ${\Delta}$ log killing ratio was defined using a CFU assay as the difference in the log number of viable organisms in the completed culture compared to the inoculum. Results : 1. A trend was noted toward the improved killing of mycobacteria in PPD+ subjects comparing to the umbilical cord blood but there was no specific difference in the patients with tuberculosis, diabetes and lung cancer. 2. Methylprednisolone and pentoxifyline adversely affected the killing in the PPD+ subjects umbilical cord blood and patients with tuberculosis. 3. The deletion of CD4+ or CD8+ T-lymphocytes adversely affected the killing of M. avium and M. tuberculosis $H_{37}Ra$ by PPD+ subjects. Deletion of both cell types had an additive effect, particularly in M. tuberculosis $H_{37}Ra$. 4. A significantly improved mycobacterial killing was noted after chemotherapy in patients with tuberculosis and the ${\Delta}$ logKR continuously decreased in a 3 and 4 days of whole blood culture. Conclusion : The in vitro bactericidal assay by human whole blood culture model was settled using a CFU assay. However, the host immunity to M. tuberculosis was not apparent in the human whole blood culture bactericidal assay, and patients with tuberculosis showed markedly improved bacterial killing after anti-tuberculous chemotherapy compared to before. The simplicity of a whole blood culture facilitates its inclusion in a clinical trial and it may have a potential role as a surrogate marker in a TB vaccine trial.