• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.2
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• pp.137-170
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• 2015

In this paper, we propose and analyze three viral infection models with humoral immunity including an eclipse stage of infected cells. The incidence rate of infection is represented by bilinear incidence and saturated incidence in the first and second models, respectively, while it is given by a more general function in the third one. The neutralization rate of viruses is giv0en by bilinear form in the first two models, while it is given by a general function in the third one. For each model, we have derived two threshold parameters, the basic infection reproduction number which determines whether or not a chronic-infection can be established without humoral immunity and the humoral immune response activation number which determines whether or not a chronic-infection can be established with humoral immunity. By constructing suitable Lyapunov functions we have proven the global asymptotic stability of all equilibria of the models. For the third model, we have established a set of conditions on the threshold parameters and on the general functions which are sufficient for the global stability of the equilibria of the model. We have performed some numerical simulations for the third model with specific forms of the incidence and neutralization rates and have shown that the numerical results are consistent with the theoretical results.

• Molecules and Cells
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• v.44 no.6
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• pp.392-400
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• 2021

It has been more than a year since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first emerged. Many studies have provided insights into the various aspects of the immune response in coronavirus disease 2019 (COVID-19). Especially for antibody treatment and vaccine development, humoral immunity to SARS-CoV-2 has been studied extensively, though there is still much that is unknown and controversial. Here, we introduce key discoveries on the humoral immune responses in COVID-19, including the immune dynamics of antibody responses and correlations with disease severity, neutralizing antibodies and their cross-reactivity, how long the antibody and memory B-cell responses last, aberrant autoreactive antibodies generated in COVID-19 patients, and the efficacy of currently available therapeutic antibodies and vaccines against circulating SARS-CoV-2 variants, and highlight gaps in the current knowledge.

• YAKHAK HOEJI
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• v.29 no.2
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• pp.55-61
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• 1985

The effect of dietary fat on the immunotoxicity of chloramphenicol was investigated in mice, sensitized and challenged with sheep red blood cells. Chloramphenicol suppressed more cell-mediated immunity than humoral immunity. The saturated fat diet elevated humoral and cell-mediated immunotoxicity, whereas the unsaturated fat diet decreased humoral immunotoxicity, but elevated cell-mediated immunotoxicity of chloramphenicol. Especially, the normal diet in saturated and unsaturated fat restored immunosuppressive effect of chloramphenicol compared to the saturated fat diet and the unsaturated fat diet.

• Journal of Nutrition and Health
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• v.27 no.5
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• pp.483-494
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• 1994

The purpose of this study was to investigate the effect of nutritional status on the cell-mediated and humoral immunity in female college students. The nutritional status of twenty subjects was determined by six-days food records, anthropometric measurements, and biochemical assessments of serum nutrients. Cell-mediated and humoral immunity of the subjects was analyzed by in vivo and in vitro assessments. The results were summerized as follows : First, The average daily energy intake was 1437Kcal(CHO : PRO : FAT = 61:13:26), which corresponds to 71.9% of RDA. Anthropometric measurements showed that 50% of the subjects was under-weight(BMI<20), only 5% was over-weight(25

• Proceedings of the Korean Nutrition Society Conference
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• 1994.05a
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• pp.46-46
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• 1994

• YAKHAK HOEJI
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• v.36 no.5
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• pp.412-426
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• 1992

Effects of beta-carotene on the immunobiological responses were studied in ICR mice. ICR male mice were divided into 8 groups (10 mice/group), and beta-carotene at doses of 4, 20 and 100 mg/kg were orally administered to ICR mice once daily for 28 consecutive days. Cyclophosphamide (CY) was injected intraperitoneally (i.p.) to ICR mice with a single dose of 5 mg/kg body weight at 2 days before secondary immunization. Mice were sensitized and challenged with sheep red blood cells (5-RBC). Immune responses were evaluated by humoral immunity, cellular immunity and non-specific immunity. The results of this study were summarized as follows: (1) Beta-carotene significantly increased the weight ratios of liver, spleen and thymus to body weight depending on dose, and significantly increased the increasing rate of body weight and the number of circulating leukocyte. (2) Beta-carotene dose-dependently increased hemagglutination titer, Arthus reaction and hemolytic plaque forming cell related to humoral immunity. (3) Beta-carotene significantly increased delayed-type hypersensitivity reaction and rosette forming cell related to cellular immunity. (4) Beta-carotene dose-dependently increased phagocytic activity, and significantly increased natural killer (NK) cell activity. (5) Beta-carotene dose-dependently inhibited reductions in humoral immunity, cellular immunity, NK cell activity and phagocytic activity by treatment with CY.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2000.11a
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• pp.81-84
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• 2000

Effects of different photoperiod regimens on the cellular and humoral immunity in broiler chickens were studied(Exp 1). Total one hundred ninety two one-day-old commercial broiler chicks(Cobb$\times$Cobb) were raised between constant lighting(CL) and intermittent lighting (1h light: 3h darkness(IL; 1l; 3D) Body weight, feed intake and feed conversion were measured for seven week. Peripheral blood and splenic lymphocyte activities were tested at 3 and 5 wk of age by performing a mitogen cellproliferation assay with a polyclonal T-cell mitogen, concanavalin A (Con A), and B-cell mitogen, lipopolysaccharide (LPS). To investigate the effect of photoperiod on the humoral immunity, chicks were immunized with sheep red blood cell(SRBC) and iinactivated Newcastle disease virus(NDV) vaccine. Total immunoglobulin G(IgG) concentration was also determined. Diurnal change of melatonin was tested in sera. In experiment 2, 0.1ml melatonin were subcutaneously injected from three to five weeks old if immunomodulation effect of lighting regimen was due to the melatonin or not. Injections of melatonin were made at 0700h and the dosage was 10ng (M2), 100ng(M3), 1$\mu\textrm{g}$(M4) per bird daily, respectively. control were quivalent injections of vehicle(M1). Lymphocyte activities were tested and humoral immunities were examined at 5 weeks of age. Blood melatonin concentration was determined at 0h, 1, h, 2h, and 3h posterior to injection at five weeks old. It was higher in CL chicks than IL chickens during the subsequent period of 3 to 5 wk of age. However, weight gain of chicks raised IL were significantly higher at 6 wk of age than CL(P<0.05). Antibody response to NDV was not affected by both photoperiod regimens and melatonin injection, whereas anti-SRMB titer and IgG concentration were enhanced. Lymphocyte activity of chickens raised under IL was sighificantly higher than those of chickens raised under CL. Melatonin injection also increased lymphocyte activity. When peripheral blood lymphocytes were used, proliferation response to LPS and Con A were significantly increased in M2 and respectively. The results of this experiments suggest that IL improved host immune response and melatonin have immunomodulatory roles.

• Environmental Analysis Health and Toxicology
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• v.4 no.1_2
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• pp.1-10
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• 1989

Experiments were performed on mice to investigate the influences of doxycycine and ethanol on the immune responses. Doxycycline was injected intraperitoneally and ethanol was administered in the drinking water. Mice were sensitized and challenged with sheep red blood cells. Immune responses were evaluated by humoral immunity, cellular immunity, peripheral circulating white blood cell and phagocyte activity. Pathotoxicological influences were measured by serum protein and albumin. The weight of spleen, thymus and liver were measured. Doxycline and ethanol combined administration decreased the weight of thymus and spleen. Humoral and cellular immune response were reduced by doxycycline administration. Especially ethanol combined administration significantly reduced humoral and cellular immune response. Phagocyte activity was increased by ethanol combined administration and peripheral circulating white blood cell was significantly increased by ethanol adminstration. Ethanol combined administration decreased serum A/G ratio.

• IMMUNE NETWORK
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• v.3 no.2
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• pp.110-117
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• 2003

Background: The usefulness of DNA vaccine at priming step of heterologous prime-boost vaccination led to DNA vaccine closer to practical reality. DNA vaccine priming followed by recombinant viral vector boosting via systemic route induces optimal systemic immunity but no mucosal immunity. Mucosal vaccination of the reversed protocol (recombinant viral vector priming-DNA vaccine boosting), however, can induce both maximal mucosal and systemic immunity. Here, we tried to address the reason why the mucosal protocol of prime-boost vaccination differs from that of systemic vaccination. Methods: To address the importance of primary immunity induced at priming step, mice were primed with different doses of DNA vaccine or coadministration of DNA vaccine plus mucosal adjuvant, and immunity including serum IgG and mucosal IgA was then determined following boosting with recombinant viral vector. Next, to assess influence of humoral pre-existing immunity on boosting $CD8^+$ T cell-mediated immunity, $CD8^+$ T cell-mediated immunity in B cell-deficient (${\mu}K/O$) mice immunized with prime-boost regimens was evaluated by CTL assay and $IFN-{\gamma}$-producing cells. Results: Immunity primed with recombinant viral vector was effectively boosted with DNA vaccine even 60 days later. In particular, animals primed by increasing doses of DNA vaccine or incorporating an adjuvant at priming step and boosted by recombinant viral vector elicited comparable responses to recombinant viral vector primed-DNA vaccine boosted group. Humoral pre-existing immunity was also unlikely to interfere the boosting effect of $CD8^+$ T cell-mediated immunity by recombinant viral vector. Conclusion: This report provides the important point that optimally primed responses should be considered in mucosal immunization of heterologous prime-boost regimens for inducing the effective boosting at both mucosal and systemic sites.

• Advances in Traditional Medicine
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• v.10 no.3
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• pp.150-154
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• 2010

The immunosuppressive activity of the Methanol extract of bark of Madhuca longifolia (Koenig) consisting of a mixture of saponins, flavonoids, tannins, steroids, phenol and glycosides was studied on the immune responses in mice. Methanol extract of Madhuca longifolia (MLL) was administered orally at doses of 50, 100 and 150 mg/kg/day to healthy mice divided into four groups consisting of six animals each. The assessment of immunomodulatory activity was carried out by testing the humoral (antibody titre) and cellular (foot pad swelling) immune responses to the antigenic challenge by sheep RBCs. Furthermore, the effect on hematological parameters as well as relative organ weight was determined. On oral administration MML showed a significant decrease delayed type hypersensitivity (DTH) response whereas the humoral response to sheep RBCs was unaffected. Thus MLL significantly suppressed the cellular immunity by decreasing the footpad thickness response to sheep RBCs in sensitized mice. With a dose of 100 and 150 mg/kg/day the DTH response was $7.66{\pm}2.75$ and $6.41{\pm}1.21$ respectively in comparison to corresponding value of $14.50{\pm}2.38$ for untreated control group. These differences in DTH response were statistically significant (P < 0.05). The study demonstrates that MLL shows preferential suppression of the components of cell-mediated immunity and shows no effect on the humoral immunity.