Leptin, but not immune function, is linked to  reproductive responsiveness to photoperiod

Energetic demands are high while energy availability is minimum during winter. To cope with this energetic bottleneck, animals exhibit numerous energy-conserving adaptations during winter, including changes in immune and reproductive functions. A majority of individual rodents within a population inhibits reproductive function (responders) as winter approaches. A substantial proportion of small rodents within a species, however, fails to inhibit reproduction (nonresponders) during winter in the field or in the laboratory when maintained in winter-simulated day lengths. In contrast, immune function is bolstered by short day lengths in some species. The specific mechanisms that link reproductive and immune functions remain unspecified. Leptin is a hormone produced by adipose tissue, and several studies suggest that leptin modulates reproductive and immune functions. The present study sought to determine if photoperiodic alterations in reproductive function and leptin concentrations are linked to photoperiod-modulated changes in immune function. Siberian hamsters ( Phodopus sungorus) were housed in either long (LD 16:8) or short (LD 8:16) day lengths for 9 wk. After 9 wk, blood samples were collected during the middle of the light and dark phase to assess leptin concentrations. One week later, animals were injected with keyhole limpet hemocyanin to evaluate humoral immunity. Body mass, body fat content, and serum leptin concentrations were correlated with reproductive responsiveness to photoperiod; short-day animals with regressed gonads exhibited a reduction in these measures, whereas short-day nonresponders resembled long-day animals. In contrast, immune function was influenced by photoperiod but not reproductive status. Taken together, these data suggest that humoral immune function in Siberian hamsters is independent of photoperiod-mediated changes in leptin concentrations.

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Metabolic stress suppresses humoral immune function in long-day, but not short-day, Siberian hamsters (Phodopus sungorus)

Journal of Comparative Physiology B ◽

10.1007/s00360-006-0133-4 ◽

2006 ◽

Vol 177 (3) ◽

pp. 339-347 ◽

Cited By ~ 28

Author(s):

Devin A. Zysling ◽

Gregory E. Demas

Keyword(s):

Immune Function ◽

Metabolic Stress ◽

Phodopus Sungorus ◽

Humoral Immune ◽

Short Day ◽

Siberian Hamsters ◽

Long Day

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A One-Minute Blood Test Detects Decreased Immune Function and Increased Clinical Risk in COVID-19 Patients

10.21203/rs.3.rs-635353/v1 ◽

2021 ◽

Author(s):

Chirajyoti Deb ◽

Allan Salinas ◽

Tianyu Zheng ◽

Aurea Middleton ◽

Katelyn Kern ◽

...

Keyword(s):

Immune Function ◽

Disease Severity ◽

Humoral Immunity ◽

Blood Test ◽

Immune Status ◽

Clinical Severity ◽

Immune Functions ◽

Humoral Immune ◽

Clinical Risk ◽

Negative Controls

Abstract Upon infection with SARS-CoV-2, the virus that causes COVID-19, most people will develop no or mild symptoms. However, a small percentage of the population will become severely ill, and some will succumb to death. The clinical severity of COVID-19 has a close connection to the dysregulation of the patient’s immune functions. We previously developed a simple, nanoparticle-enabled blood test that can determine the humoral immune status in animals. In this study, we applied this new test to analyze the immune function in relation to disease severity in COVID-19 patients. From the testing of 153 COVID-19 patient samples and 142 negative controls, we detected a drastic decrease of humoral immunity in COVID-19 patients who developed moderate to severe symptoms, but not in patients with no or mild symptoms. The new test may be potentially used to monitor the immunity change and predict the clinical risk of patients with COVID-19.

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Protective Effect of Bergenin against Cyclophosphamide-Induced Immunosuppression by Immunomodulatory Effect and Antioxidation in Balb/c Mice

Molecules ◽

10.3390/molecules23102668 ◽

2018 ◽

Vol 23 (10) ◽

pp. 2668 ◽

Cited By ~ 8

Author(s):

Qiuchen Qi ◽

Zhonghua Dong ◽

Yueyue Sun ◽

Siying Li ◽

Zhongxi Zhao

Keyword(s):

Immune Function ◽

Adverse Reactions ◽

Histological Analysis ◽

Lymphocyte Subsets ◽

Immune Functions ◽

Humoral Immune ◽

Immune Organs ◽

Total Antioxidant ◽

Cellular Immune ◽

Immunosuppressed Mice

In this study, the aim was to investigate the effect of bergenin on immune function and antioxidation in cyclophosphamide (Cy)-induced immunosuppressed mice. Firstly, we estimated its effect on immune organs. Histological analysis and indexes of immune organs showed that cyclophosphamide exhibited spleen and thymus injury compared with the normal control, which was alleviated by bergenin. Secondly, bergenin also enhanced the humoral immune function through increasing the level of IgM and IgG in serum. Thirdly, bergenin also enhanced the cellular immune function. The results indicate that bergenin increased peritoneal macrophage functions, the proliferation of T and B lymphocytes, NK and CTL cell activities, and T (CD4+ and CD8+) lymphocyte subsets. Besides, bergenin also had the ability to modulate the Th1/Th2 balance. Moreover, bergenin prevented the Cy-induced decrease in numbers of peripheral RBC, WBC and platelets, providing supportive evidence for their anti-leukopenia activities. Finally, bergenin also reversed the Cy-induced decrease in the total antioxidant capacity including activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). In conclusion, bergenin protected against Cy-induced adverse reactions by enhancing humoral and cellular immune functions and augmenting antioxidative activity and could be considered as a potential immunomodulatory agent.

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Changes in CD4+CD8–/CD4–CD8+ Ratio and Humoral Immune Functions in Vitamin B12-Deficient Rats

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831.70.4.167 ◽

2000 ◽

Vol 70 (4) ◽

pp. 167-171 ◽

Cited By ~ 8

Author(s):

Ulala Funada ◽

Masahiro Wada ◽

Tetsunori Kawata ◽

Kazumi Mori ◽

Hiroko Tamai ◽

...

Keyword(s):

Vitamin B12 ◽

Immune Function ◽

Control Group ◽

Vitamin B ◽

Immune Functions ◽

Normal Range ◽

Humoral Immune ◽

Deficient Group

To clarify the role of vitamin B12 in the function of cell-mediated and humoral immune functions, the splenocytes expression of CD4, CD8 and serum C3, IgM, IgG concentrations were examined in vitamin B12-deficient rats, and the effect of the administration of methylcobalamin was also studied. The CD4+CD8–/CD4–CD8+ ratio in splenocytes was significantly higher in vitamin B12-deficient rats than in control rats (p < 0.05). The value in the 48 hours after methylcobalamin administration group, was within the normal range (p < 0.05). From these results, the elevation of the CD4+CD8–/CD4–CD8+ ratio by vitamin B12-deficiency was confirmed in rats. The serum C3, IgM and IgG concentrations were lower in the vitamin B12-deficient group than in the control group. These findings suggest that vitamin B12 plays a role in maintaining the immune function in rats.

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A 1-minute blood test detects decreased immune function and increased clinical risk in COVID-19 patients

Scientific Reports ◽

10.1038/s41598-021-02863-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Chirajyoti Deb ◽

Allan N. Salinas ◽

Tianyu Zheng ◽

Aurea Middleton ◽

Katelyn Kern ◽

...

Keyword(s):

Immune Function ◽

Disease Severity ◽

Humoral Immunity ◽

Blood Test ◽

Immune Status ◽

Clinical Severity ◽

Immune Functions ◽

Humoral Immune ◽

Clinical Risk ◽

Negative Controls

AbstractUpon infection with SARS-CoV-2, the virus that causes COVID-19, most people will develop no or mild symptoms. However, a small percentage of the population will become severely ill, and some will succumb to death. The clinical severity of COVID-19 has a close connection to the dysregulation of the patient’s immune functions. We previously developed a simple, nanoparticle-enabled blood test that can determine the humoral immune status in animals. In this study, we applied this new test to analyze the immune function in relation to disease severity in COVID-19 patients. From the testing of 153 COVID-19 patient samples and 142 negative controls, we detected a drastic decrease of humoral immunity in COVID-19 patients who developed moderate to severe symptoms, but not in patients with no or mild symptoms. The new test may be potentially used to monitor the immunity change and predict the clinical risk of patients with COVID-19.

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Effect of Resveratrol Dry Suspension on Immune Function of Piglets

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2018/5952707 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 6

Author(s):

Qiuting Fu ◽

Qiankun Cui ◽

Yi Yang ◽

Xinghong Zhao ◽

Xu Song ◽

...

Keyword(s):

Immune Responses ◽

Immune Function ◽

Foot And Mouth Disease ◽

Classical Swine Fever ◽

Sod Activity ◽

Humoral And Cellular Immunity ◽

Humoral Immune ◽

Humoral Immune Responses ◽

Mouth Disease Virus ◽

Wide Range

Resveratrol, a polyphenolic plant antitoxin, has a wide range of pharmacological activities. In this study, we systematically evaluated the effects of resveratrol dry suspension (RDS) on immune function in piglets that were treated with different doses of RDS for 2 weeks. The results showed that the RDS has significant effects on the development, maturation, proliferation, and transformation of T lymphocytes. RDS could regulate humoral immune responses by upregulating the release of IFN-γ and downregulating the release of TNF-α. After piglets were vaccinated against classical swine fever virus and foot-and-mouth disease virus, the antibody titers were significantly increased. RDS treatment showed an excellent resistance to enhance T-SOD activity. Values of blood routine and blood biochemistry showed no toxicity. These results suggested that RDS could be considered as an adjuvant to enhance immune responses to vaccines, as well as dietary additives for animals to enhance humoral and cellular immunity.

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Control of torpor and body weight patterns by a seasonal timer in Siberian hamsters

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1989.257.1.r142 ◽

1989 ◽

Vol 257 (1) ◽

pp. R142-R149 ◽

Cited By ~ 8

Author(s):

T. J. Bartness ◽

J. A. Elliott ◽

B. D. Goldman

Keyword(s):

Body Weight ◽

Food Intake ◽

Implant Removal ◽

Daily Torpor ◽

Short Day ◽

Siberian Hamsters ◽

Long Day ◽

Preparatory Phase ◽

Pelage Color ◽

Seasonal Responses

Two experiments were designed to assess whether the short-day-induced patterns of shallow daily torpor, body weight, and other seasonal responses (food intake and pelage pigmentation) exhibited by Siberian hamsters (Phodopus sungorus sungorus) are under the control of a "seasonal timekeeping mechanism" that is independent of reproductive status [testosterone, (T)]. We examined whether the patterning and expression of these seasonal responses were altered by decreases in serum T that accompany gonadal regression during the first 8 wk of short-day exposure (i.e., the "preparatory phase" of the torpor season) or by experimental increases in serum T after this phase. Short-day-housed, castrated hamsters bearing T implants had long-day levels of the hormone and did not exhibit torpor. Appropriate seasonal patterns and levels of torpor, body weight, pelage color stage, and food intake were exhibited after T implant removal although serum T was clamped to long-day levels during the preparatory phase. In animals that were gonad intact during the preparatory phase and were subsequently castrated and given T implants, torpor did not occur as long as the implants were in place. However, the patterns and levels of daily torpor, food intake, and body weight rapidly returned to appropriate seasonal values compared with the castrated, blank-implanted controls on T implant removal; these effects occurred whether the T implants were removed when torpor frequency was increasing, at its peak, or decreasing across the torpor season. T did not affect pelage color stage under any condition.(ABSTRACT TRUNCATED AT 250 WORDS)

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High-Fat Diet and Age-Dependent Effects of IgA-Bearing Cell Populations in the Small Intestinal Lamina Propria in Mice

International Journal of Molecular Sciences ◽

10.3390/ijms22031165 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1165

Author(s):

Yuta Sakamoto ◽

Masatoshi Niwa ◽

Ken Muramatsu ◽

Satoshi Shimo

Keyword(s):

Immune Function ◽

Lamina Propria ◽

High Fat Diet ◽

Immunoglobulin A ◽

Immune Functions ◽

High Fat ◽

Intestinal Villi ◽

Diet Induced Obesity ◽

Obesity And Diabetes

Several studies highlighted that obesity and diabetes reduce immune function. However, changes in the distribution of immunoglobins (Igs), including immunoglobulin-A (IgA), that have an important function in mucosal immunity in the intestinal tract, are unclear. This study aimed to investigate the impaired immune functions in the context of a diet-induced obese murine model via the assessment of the Igs in the intestinal villi. We used mice fed a high-fat diet (HFD) from four to 12 or 20 weeks of age. The distributions of IgA, IgM, and IgG1 were observed by immunohistochemistry. Interestingly, we observed that IgA was immunolocalized in many cells of the lamina propria and that immunopositive cells increased in mice aged 12 to 20 weeks. Notably, mice fed HFD showed a reduced number of IgA-immunopositive cells in the intestinal villi compared to those fed standard chow. Of note, the levels of IgM and IgG1 were also reduced in HFD fed mice. These results provide insights into the impaired mucosal immune function arising from diet-induced obesity and type 2 diabetes.

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