Takao Akama

Effects of 12 months of exercise training on salivary secretory IgA levels in elderly subjects

Background: The immune system declines in efficiency with advancing age, making the elderly less resistant to pathogenic microorganisms. Upper respiratory tract infection (URTI) is a common illness. Recent studies have shown that suppression of secretory immunoglobulin A (SIgA) is associated with increased incidence of URTI. Objective: To assess the effect of exercise on salivary SIgA in elderly subjects. Methods: Forty five elderly subjects (18 men, 27 women; mean (SD) age 64.9 (8.4) years) performed both 60 minute resistance and 60 minute moderate endurance training a week for 12 months. Saliva samples were obtained before training, and at four and 12 months during the training period. Salivary SIgA concentrations were measured by enzyme linked immunosorbent assay, and the SIgA secretion rate was calculated. Results: SIgA concentrations before training, and at four and 12 months during training were 24.7 (14.4), 27.2 (14.2), and 33.8 (18.5) μg/ml respectively. SIgA secretion rates were 29.5 (26.0), 33.8 (27.2) and 46.5 (35.1) μg/min respectively. The results indicate that both the concentration and secretion rate of SIgA significantly (p<0.01) increased during 12 months of exercise in these elderly subjects. Conclusion: Regular moderate exercise seems to enhance mucosal immune function in elderly subjects.

A rat model of saliva secretory immunoglobulin: a suppression caused by intense exercise

We aimed to develop a valid model of immunosuppression induced by intense exercise in rats. Rats were divided into three groups. In the rest (Rest) group, saliva was collected from resting rats on 4 consecutive days. In the exercise (Ex) group, rats ran on a treadmill untill exhaustion (exercise time: 60.0 ± 3.7 min), and their saliva was collected before and after exercise; the salivary glands were removed after exercise. In the control (Con) group, saliva collection and gland removal were also performed, but the rats did not exercise. Secretory immunoglobulin A (SIgA) concentrations in saliva and polymeric immunoglobulin receptor (pIgR) mRNA expression in the glands were measured. There was no significant change in SIgA concentration in the Rest group over 4 days. In the Ex group, SIgA concentration decreased significantly after exercise compared with before, whereas there was no significant change in the Con group. The expression of pIgR mRNA was significantly lower in the Ex group post‐exercise than in the Con group. Our procedure for saliva collection appeared suitable, and the exercise‐induced SIgA suppression was probably caused by a decline in pIgR mRNA expression. We propose to use this reproducible and reliable rat model of exercise‐induced SIgA suppression in future studies.

Effect of brief maximal exercise on circulating levels of interleukin-12

Abstract Interleukin-12 (IL-12) is a cytokine that was originally identified as natural killer cell stimulatory factor. It induces the activity of T-helper 1 (Th1) cells and exhibits strong anti-tumor activity. In this study, we studied the effects of brief anaerobic maximal exercise on circulating levels of IL-12. Six healthy males [mean (SD) 25.2 (2.6) years] performed a modified Wingate test exercise (resistance 0.075 kg/kg of body mass). The exercise consisted of five bouts of maximal cycling for 10 s, with rest intervals of 50 s between them. Blood samples were taken before, immediately after, 30 min after, 60 min after and 120 min after the exercise. Plasma concentrations of IL-12 were measured using an enzyme-linked immunosorbent assay. Data were corrected for hemoglobin and hematocrit measurements. Plasma concentrations of IL-12 averaged [mean (SD)] 234.2 (40.9) pg/ml before, 305.2 (62.1) pg/ml immediately after, 202.8 (24.2) pg/ml 30 min after, 239.7 (35.1) pg/ml 60 min after, and 199.6 (49.2) pg/ml 120 min after the exercise. We showed that plasma concentrations of IL-12 increased significantly immediately after brief anaerobic maximal cycle ergometer exercise (P < 0.01).

MONOCYTE AND T-CELL RESPONSES TO EXERCISE TRAINING IN ELDERLY SUBJECTS

Shimizu, K, Suzuki, N, Imai, T, Aizawa, K, Nanba, H, Hanaoka, Y, Kuno, S, Mesaki, N, Kono, I, and Akama, T. Monocyte and T-cell responses to exercise training in elderly subjects. J Strength Cond Res 25(9): 2565-2572, 2011—The purpose of this study was to examine the effects of exercise training on age-related impairment of immune parameters related to T-cell activation in elderly individuals. Twenty-four elderly subjects were assigned to an exercise training group (EXC: 3 men, 9 women; age 61-76 years) or a nonexercise control group (CON: 4 men, 8 women; age 62-79 years). Subjects in EXC participated in exercise sessions 2 d·wk−1 for 12 weeks. The training session included stretching and endurance exercise (10 minutes), resistance training comprised leg extension, leg press, hip abduction, and hip adduction using exercise machine and each subjects body weight. Subjects in CON maintained their normal physical activity levels during the study period. Blood samples were collected before and after the training period. Samples were measured for the numbers of leukocytes, lymphocytes, and monocytes, and for CD3+, CD4+, CD8+, CD28+CD4+, CD28+CD8+, TRL-4+CD14+, and CD80+CD14+ cells. The number of leukocytes, lymphocytes, monocytes, CD3+, CD4+, and CD8+ cells did not change after 12 weeks in either EXC or CON. The number of CD28+CD8+ cells increased significantly after training in EXC (p ≤ 0.05), although CON showed no significant change. In the EXC group, CD80+CD14+ cell counts were significantly higher after training (p ≤ 0.05), but the TLR-4+CD14+ cell counts were unchanged. In the CON group, no significant alteration existed in TLR-4+CD14+ and CD80+CD14+ cell numbers. In conclusion, exercise training in elderly people is associated with increased CD28-expressing Tc cells and CD80-expressing monocytes. Therefore, exercise training might upregulate monocyte and T-cell-mediated immunity in elderly people.

Relationship between clinical features and binding domains of anti-prothrombin autoantibodies in patients with systemic lupus erythematosus and antiphospholipid syndrome.

Autoantibodies against prothrombin, including lupus anticoagulant antibodies (LAC), have been identified in patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). To identify the epitopes of LAC in patients with SLE and APS, we analyzed B cell epitopes of anti-prothrombin Abs. Prothrombin was purified from fresh plasma samples from healthy subjects, and fragmented by thrombin. Two fragments (prethrombin-1, 50kDa, and fragment-i, 22 kDa) were separated and used for further experiments. The two fragments were coated on irradiated plate and the binding activities of sera from 13 patients with anti-prothrombin Abs (SLE, 7; APS, 4; SLE + APS, 2) were determined by using ELISA. The assay was conducted under the following conditions: use of irradiated plates, and TBS containing Tween-20. We detected two types of anti-prothrombin Abs. The first was anti-prethrombin-l (n = 5) while the other was Ab against fragment-I (n = 8). There were no patients with Abs that showed binding activities to both fragments. A higher proportion of patients with thrombosis were positive for anti-prethrombin-I Abs (80%) than for anti-fragment-I Abs (25%). Two patients with anti-prethrombin-I Ab were positive for LAC and negative for anti-cardiolipin-f32 glycoprotein I antibody (aCL-I32GPI). Our results strongly support the notion that both prethrombin-I and fragment-1 on prothrombin molecule are B cell epitopes.

Virus Activation and Immune Function During Intense Training in Rugby Football Players

Epidemiological studies suggest that highly trained athletes are more susceptible to upper respiratory tract infections (URTI) compared with the general population. Upper respiratory symptoms (URS) often appear as either primary invasion of pathogenic organisms and/or reactivation of latent viruses such as Epstein-Barr virus (EBV). The purpose of this study was to examine the relationship between EBV reactivation and the appearance of URS during intensive training in collegiate rugby football players. We evaluated EBV-DNA expression in saliva and examined the relationship between onset of URS and daily changes in EBV-DNA as well as secretory immunoglobulin A (SIgA) levels among 32 male collegiate rugby football players during a 1-month training camp. The EBV-DNA expression tended to be higher in subjects who exhibited sore throat (p=0.07) and cough (p=0.18) than that of those who had no symptoms, although their differences were not significant. The SIgA level was significantly lower 1 day before the EBV-DNA expression (p<0.05). The number of URS increased along with the EBV-DNA expression and decrease of SIgA levels. These results suggest that the appearance of URS is associated with reactivation of EBV and reduction of SIgA during training.

Antiprothrombin autoantibodies in severe preeclampsia and abortion

PURPOSE We examined the levels of autoantibodies against prethrombin-1 and fragment-1 in pregnant women to determine the type of autoantibodies that were associated with severe preeclampsia or spontaneous abortion. SUBJECTS AND METHODS We measured autoantibodies bound to prothrombin, prethrombin-1, and fragment-1 by using an enzyme-linked immunosorbent assay (ELISA) in 12 healthy nonpregnant women, 36 women with normal pregnancies, 28 pregnant women with severe preeclampsia, and 19 pregnant women who subsequently had spontaneous abortion. RESULTS Plasma samples in 10 (36%) of the 28 women with severe preeclampsia and 11 (58%) of the 19 women with spontaneous abortion were positive for antiprothrombin antibodies as compared with 3 (9%) of the 36 women with normal pregancies. All 11 of the positive samples from women who had spontaneous abortions were positive for antiprethrombin-1 antibody, but only 1 was positive for antifragment-1 antibody. The mean (+/- SD) titer of antiprethrombin-1 antibodies in patients with spontaneous abortion (36 +/- 9 U) was higher than that in women with normal pregnancies (10 +/- 4 U; P < 0.01). Antiprethrombin-1 antibody was detected in only 2 women with severe preeclampsia, whereas all 10 women with antiprethrombin antibodies were positive for antifragment-1 antibody. The antifragment-1 antibody titer in patients with severe preeclampsia (49 +/- 15 U) was higher than in women with normal pregnancies (13 +/- 6 U, P < 0.01). CONCLUSIONS There is a strong and specific association between various types of antiprothrombin antibodies with severe preeclampsia and spontaneous abortion.

Use of supplements by young elite Japanese athletes participating in the 2010 youth Olympic games in Singapore.

Objective:To investigate the prevalence of supplement use among young elite Japanese athletes. Design:Survey study. Setting:2010 Youth Olympic Games, Singapore. Participants:Data were collected from individual interviews during medical evaluations of 75 athletes selected for the Japanese national team. Main Outcome Measures:Main outcome measures included the use of supplements, products used, frequency of use, purpose of use, and relationships between supplement use and athlete attitudes toward a balanced diet. Results:All 75 athletes agreed to participate in this study, and individual interviews by pharmacists made it possible to collect complete answers from all athletes. Of these athletes, 47 (62.7%) used 1 or more supplement products (average number of products used, 1.1 ± 1.3). The most popular supplement was amino acids, which were used by 33 athletes (44.0%). Of the supplements used, 28 (32.6%) were taken every day, whereas 28 (32.6%) were used only on special occasions. Moreover, 34 of the supplement products (39.5%) were taken to enhance recovery from fatigue, whereas 19 (22.1%) were used to improve athletic performance. Statistical analysis suggested that there was no significant relationship between supplement use and attitudes toward a balanced diet. Conclusions:The results revealed widespread supplement use among young elite athletes in the Japanese national team for the Singapore Youth Olympic Games in 2010. Moreover, these athletes apparently used supplements without considering the effects of their normal diets.

The effects of Lactobacillus pentosus strain b240 and appropriate physical training on salivary secretory IgA levels in elderly adults with low physical fitness: a randomized, double-blind, placebo-controlled trial

The purpose of the study was to evaluate the effects of Lactobacillus pentosus strain b240 (b240) intake and appropriate physical training on salivary secretory immunoglobulin A secretion in elderly adults with low physical fitness. Elderly adults with low physical fitness (daily step count below 3,500 steps) were divided into 2 groups: a b240 intake + exercise group (b240 group) and a placebo intake + exercise group (placebo group). Each subject continued intake of b240 or placebo and moderate-intensity resistance exercise for 12 weeks. Before and 4, 8, and 12 weeks after the start of intervention, each subject underwent saliva sampling. Before and after intervention, physical fitness tests and step count were measured. Our results showed that secretory immunoglobulin A secretion in 57 subjects during the b240/placebo intake period was significantly greater in the b240 group than in the placebo group (p<0.05). There were no significant changes in physical fitness tests before and after intervention in the 2 groups. The daily amount of walking increased significantly after intervention in both groups (p<0.05). These results suggest that in elderly adults with low physical activity and fitness, intake of b240 with appropriate physical exercise elevate salivary secretory immunoglobulin A secretion.

Mucosal immune function comparison between amenorrheic and eumenorrheic distance runners

Abstract Shimizu, K, Suzuki, N, Nakamura, M, Aizawa, K, Imai, T, Suzuki, S, Eda, N, Hanaoka, Y, Nakao, K, Suzuki, N, Mesaki, N, Kono, I, and Akama, T. Mucosal immune function comparison between amenorrheic and eumenorrheic distance runners. J Strength Cond Res 26(5): 1402–1406, 2012—This study examined the effects of amenorrhea on mucosal immune function and susceptibility to upper respiratory tract infection (URTI) in elite female distance runners. Based on their menstrual cycles during the prior year, 21 elite, collegiate, female distance runners were designated as eumenorrheic runners (ERs; n = 8; 19.9 ± 0.8 years) or amenorrheic runners (ARs; n n = 13; 20.0 ± 0.3 years). Resting saliva and blood samples were collected in the morning. The secretory immunoglobulin A (SIgA) concentration was measured using enzyme-linked immunosorbent assay. The SIgA secretion rate was calculated. Serum 17&bgr;-estradiol concentrations and serum progesterone concentrations were measured using radioimmunoassay. Subjects reported the appearance of URTI symptoms (sore throat, headache, runny nose, coughing, or fever), if any, during the prior month. The serum estradiol concentration and salivary SIgA secretion rate were significantly lower for ARs than for ERs (p < 0.05). Serum progesterone concentration was not significantly different between groups. Higher frequencies of headache, runny nose, coughing, and fever were observed in ARs than in ERs. Results show that athletic amenorrhea with low estrogen might accelerate downregulation of mucosal immune function in athletes and enhance susceptibility to infection.