Factors that Influence the Concentration of Immunoglobulin A in Bovine Milk

Additional measures of well-being would be beneficial to the management of a variety of species in human care, including elephants. Immunoglobulin A (IgA) is an immune protein associated with pathogen defense, which has been demonstrated to decrease during times of stress, and increase in response to positive stimuli. This paper describes the development and validation of an enzyme immunoassay (EIA) for the quantification of Asian elephant (Elephas maximus) IgA in feces, saliva, urine, and serum. Samples were collected weekly from four females for 6 months to assess IgA and glucocorticoid (GC) concentrations, establish relationships between these two biomarkers, and determine variability in IgA within and between individuals, and across sample types. IgA was quantified in all four sample types, although urinary concentrations were low and sometimes undetectable in individual samples. Concentrations were highly variable within and between individuals, with fecal, salivary and serum IgA, and fecal, salivary and urinary GCs all differing significantly across individuals. Contrary to previous findings, IgA and GC were generally not correlated. Serum IgA was less variable within individuals, with the exception of one female that experienced a brief illness during the study. However, marked inter-individual differences were still apparent. When data from all individuals were combined, fecal IgA was significantly predicted by salivary and urinary IgA; however, this relationship did not hold when individuals were analyzed separately. Analysis of a fifth female that exhibited a more severe systemic illness demonstrated clear increases in fecal IgA and GC, suggesting these may also be useful health biomarkers. Further investigation is needed to determine what sample type is most reflective of biological state in elephants, and how IgA concentrations are associated with health and positive and negative welfare states. Based on observed variability, a longitudinal approach likely will be necessary to use IgA as a measure of well-being.

Bacterial sinusitis can be a focus for initial lung colonisation and chronic lung infection in patients with cystic fibrosis

Comparison of total immunoglobulin A levels in different samples in Leghorn and broiler chickens

Primary IgA nephropathy (IgAN) is associated with elevated levels of circulating IgA and is characterized by deposition of primarily IgA1 in the renal mesangium. It has not yet been clarified which mechanisms govern the deposition of IgA1 in the mesangium. One of the factors which may play a role in trapping of IgA in the mesangial area is the interaction of IgA with specific IgA receptors (Fc alphaR, CD89) on the mesangial cells. In the present study IgA derived from patients with IgAN and controls was investigated for its interaction with human CD89, expressed on the surface of the murine B cell line IIA1.6. IgA binding to CD89 expressing cells was specific, concentration dependent and binding of dIgA and pIgA occurred in a more efficient fashion than that of mIgA. IgA binding to CD89 directly from serum of patients compared to controls showed no significant difference. However these experiments are affected by differences in IgA concentration and combinations of different sizes of IgA. Using purified fractions of mIgA, dIgA, and pIgA isolated from serum, a significantly reduced binding of mIgA to CD89 from patients compared to controls was observed. Finally, the binding of aIgA2 to CD89 was less inhibited using mIgA from patients with IgAN compared to controls. The reduced binding of mIgA to CD89 seems to contradict a direct role for CD89 in deposition of IgA. However reduced binding of mIgA to CD89 may affect IgA clearance, leading to higher serum IgA. Furthermore, since it has been demonstrated that mIgA can interfere with binding of di- and pIgA, CD89 could still contribute to pIgA deposition in the mesangial area.

To analyze anti-rotavirus antibodies in human milk in order to determine their isotypes and neutralizing activity on rotavirus strains representing different viral serotypes. One hundred seventy-three milk samples (65 colostrum, 55 transitional milk and 53 mature milk) obtained from 65 mothers were analyzed along with 49 serum samples collected just before delivery. Total immunoglobulin A (IgA) and rotavirus-specific IgA and immunoglobulins G (IgG) antibodies were determined in milk and serum by enzyme-linked immunosorbent assay. Neutralizing activity was evaluated by an immunoperoxidase focus reduction assay. Milk IgA was purified by binding to the lectin jacalin, elution and ultrafiltration. Total IgA antibodies were detected in all serum and milk samples analyzed. IgA levels decreased sharply during the replacement of colostrum by transitional milk, and more gradually from transitional to mature milk. These differences in IgA concentration during the 3 periods were statistically significant. Anti-rotavirus antibodies detected in human milk were exclusively of the IgA type, whereas both IgA and IgG anti-rotavirus antibodies were present in serum samples. Both milk and serum samples showed in vitro neutralization of the infectivity of rotavirus strains SA11, Wa and VA70, this activity being stronger toward the human rotavirus strain Wa. No correlation was however found between the inhibitory effect on rotavirus and the concentrations of IgA in human milk and serum samples. Anti-rotavirus antibodies are only partly responsible for the neutralizing activity detected in milk and serum. This result suggests that other components possessing suppressive activity against rotavirus must also be present.

Jejunal fluid was collected from 40 children aged 1-12.2 years and from 10 adults (age 20-25 years) who were without gastrointestinal disorders. They were intubated pernasally with a special tube system that made it possible to avoid contamination from the upper respiratory tract secretions. Quantitation of immunoglobulin A (IgA), secretory IgA (SIgA), IgM, SIgM, IgD, IgG, and albumin was performed by double sandwich enzyme-linked immunosorbent assay. IgA was the dominating immunoglobulin in jejunal fluid, showing the highest concentrations, followed in order by IgM, IgG, and IgD. The IgD concentrations were about 1,000 times less than in plasma of age-matched children. The immunoglobulin concentrations did not show any age-related differences, except for IgG and for the SIgA/IgA ratio. The former declined with children's age (p less than 0.02), whereas the latter was significantly higher in adults (interquartile range: 97-100%) than in young children aged 1-less than 5.5 years (interquartile range: 55-94%) (p less than 0.001). This indicates an age-related decline in leaking from gut mucosa. The concentrations of SIgA and SIgM showed a positive correlation (p less than 0.001). The majority of IgA and IgM were estimated to be locally produced, whereas IgD and IgG were transudated from plasma.

SummaryJejunal fluid was collected from 40 children aged 1–12.2 years and from 10 adults (age 20–25 years) who were without gastrointestinal disorders. They were intubated pernasally with a special tube system that made it possible to avoid contamination from the upper respiratory tract secretions. Quantitation of immunoglobulin A (IgA), secretory IgA (SIgA), IgM, SIgM, IgD, IgG, and albumin was performed by double sandwich enzyme‐linked immunosorbent assay. IgA was the dominating immunoglobulin in jejunal fluid, showing the highest concentrations, followed in order by IgM, IgG, and IgD. The IgD concentrations were about 1,000 times less than in plasma of age‐matched children. The immunoglobulin concentrations did not show any age‐related differences, except for IgG and for the SIgA/IgA ratio. The former declined with children's age (p < 0.02), whereas the latter was significantly higher in adults (interquartile range: 97–100%) than in young children aged l‐<5.5 years (interquartile range: 55–94%) (p < 0.001). This indicates an age‐related decline in leaking from gut mucosa. The concentrations of SIgA and SIgM showed a positive correlation (p < 0.001). The majority of IgA and IgM were estimated to be locally produced, whereas IgD and IgG were transudated from plasma.

Background and Aim:The dietary probiotics in sows during gestation to lactation period have gained considerable attention with respect to their beneficial effects on sows and their piglets’ performance and health. This study aimed to evaluate the effects of using probiotics in late-pregnant and lactating sows on milk quality, quantity, fecal microflora of sows, and growth performance of their offspring until weaning.Materials and Methods:Thirty-four sows were equally divided into two groups (control and treatment). Only those in the treatment group were fed 5 g of probiotics at 12 weeks of pregnancy, once daily for 7 weeks, until their piglets were weaned. Colostrum samples were collected at 3, 6, 12, and 24 h after farrowing and measured for immunoglobulin concentration. Percentages of fat, protein, and lactose in colostrum, colostrum production, total intake of immunoglobulin A (IgA), immunoglobulin G (IgG), fat, protein, and lactose, the change of fecal microflora of sows, and average daily gain of piglets were measured.Results:The results showed that there were no significant differences in the concentrations of IgA, IgG, and IgM in colostrum and the percentages of fat, protein, lactose, solid-not-fat, and total solid in colostrum between the groups; however, the colostrum production at 24 h in the treatment group (6,075.29 mL) was higher than in the control group (4,809.54 mL). Higher total intakes of IgA and IgG as well as total intake of fat, protein, and lactose, particularly at 3 h after farrowing, were found in the treatment group. Probiotic supplementation remarkably altered the microbiota community at the phylum level. We found that Firmicutes and Bacteroidetes are the dominant phyla, present in the gut of more than 90% of pregnant and lactating sows. Changes in microbial proportions were observed due to the changes of pig production stage. The weaning weight of the treatment group was higher than in the control group (6.34 ± 1.71 vs. 4.84 ± 1.29 kg, respectively).Conclusion:Feeding of multi-species probiotic BACTOSAC-P™ during late pregnancy and lactation in sows positively influenced colostrum production. In this experiment, the use of BACTOSAC-P™ improved the yield of colostrum production. The high immunoglobulin concentration and high yield of the colostrum of sows with a diet supplemented with BACTOSAC-P™ significantly reduced piglet mortality during the suckling period. Furthermore, the probiotic diet induced changes in the fecal microbial population in sows by increasing the number of microorganisms from the Firmicutes phylum, which had positive effects on sow health and their piglets, leading to better piglet growth performance.

There are many factors in mucosal secretions that contribute to innate immunity and the 'first line of defence' at mucosal surfaces. Few studies, however, have investigated the effects of exercise on many of these 'defence' factors. The aim of the present study was to determine the acute effects of prolonged exercise on salivary levels of selected antimicrobial peptides (AMP) that have not yet been studied in response to exercise (HNP1-3 and LL-37) in addition to immunoglobulin A (IgA). A secondary objective was to assess the effects of exercise on saliva antibacterial capacity. Twelve active men exercised on a cycle ergometer for 2.5 h at approximately 60% of maximal oxygen uptake. Unstimulated whole saliva samples were obtained before and after exercise. There was a significant decrease (P < 0.05) in salivary IgA:osmolality ratio, following exercise, but IgA concentration and secretion rate were unaltered. Salivary HNP1-3 and LL-37 concentrations (P < 0.01 and P < 0.05, respectively), concentration:osmolality ratios (P < 0.01) and secretion rates (P < 0.01) all increased following exercise. Salivary antibacterial capacity (against E. coli) did not change. The increased concentration of AMPs in saliva may confer some benefit to the 'first line of defence' and could result from synergistic compensation within the mucosal immune system and/or airway inflammation and epithelial damage. Further study is required to determine the significance of such changes on the overall 'defence' capacity of saliva and how this influences the overall risk for infection.

Immunoglobulin A levels in southern elephant seal ( Mirounga leonina) milk during the suckling period

SARS-CoV-2 continues to infect thousands of people around the world. It has been established that the main transmission mechanism of this virus is via airborne route, which is why it initially infects the respiratory tract. Currently, the effectiveness of medications used against COVID-19 is limited, and although immunization programs have been initiated, there is international inequality in the distribution of vaccines. Accordingly, the search for adjuvant therapies continues to be an alternative for research. Supplementation with vitamin A has been associated to the decrease of mortality from infection; this effect could be mediated by retinoic acid (RA), which is the active metabolite of vitamin A that exerts immunomodulatory functions. According to preclinical studies, RA favors the production of secretory immunoglobulin A (IgA) in the respiratory tract. In addition to this, the retinol-binding protein has been correlated with the concentration of IgA and neutralizing antibodies in patients with influenza. Therefore, this review aims to address the involvement of vitamin A in the production of secretory IgA in the respiratory epithelium in order to highlight its potential protection against SARS-CoV-2 infection.

Objective: Nitric oxide (NO) is known as a regulator of inflammation and immunity. The purpose of this study was to investigate the influence of this signal molecule on the rat immunoglobulin A (IgA) system using Nω-nitro-L-arginine-methyl ester (L-NAME), which inhibits the activity of all isoforms of NO synthase. Methods: The experiments were performed on adult female Wistar rats showing diestrus day 1 that were treated with L-NAME (30 or 50 mg/kg, s.c.). Untreated and saline-injected animals were used as controls. The rats were sacrificed 3 h following L-NAME or saline administration. The concentration of IgA in serum and intestinal extracts was determined by a sandwich enzyme-linked immunosorbent assay. The number of IgA-expressing cells per area unit of Peyer’s patches and the intestinal lamina propria was evaluated using stereological analysis. Results: The results showed that L-NAME decreased the level of IgA in serum and elevated its concentration in intestinal extracts. Additionally, the increased number of IgA+ cells was found in the intestinal lamina propria in both experimental groups. Conclusion: Obtained findings imply that endogenous NO may modulate the IgA system in the rat.

Local immune factors may play a role in the protection against oral disease and defences against microflora may be related to immunoglobulin A (IgA) subclass responses. The objectives of this study were to determine the concentrations and ratios of salivary IgA and IgA subclasses in predentate and dentate children and adults and to compare the levels in breastfed and bottle-fed infants. Whole saliva samples were collected from: a) 44 predentate children (mean age 4 months), b) 29 dentate children (1.5 years) and c) 28 adults (29.5 years). Immunoglobulin levels were assayed by enzyne-linked immunosorbent assay using colostral IgA standard. In the predentate children, the mean IgA, IgA1 and IgA2 levels were lower than in the dentate group but the difference reached statistical significance with IgA2 levels only. The comparative concentrations in the adult group were significantly higher than that in both children's groups. The IgA1:IgA2 ratio was similar in all 3 groups, at approximately 58:42. No significant differences were found in the concentration of salivary IgA and IgA subclasses in the breastfed infants compared with the bottle-fed ones. The results of this investigation confirm other studies suggesting that the concentration of salivary IgA subclasses are not significantly different between predentate and dentate children and that they do not reach adult levels until well after 2 years of age.

β-carotene is a robust modulator of mucosal barriers, and it can amplify the immunoglobulin A (IgA) response via the retinoic acid (RA)-mediated pathway. We investigated the influence of β-carotene on intestinal barriers in layer-type cockerels. In this study, β-carotene has a positive influence on growth performance and intestinal morphology. β-carotene remarkably enhanced serum secretory immunoglobulin A (sIgA) levels, jejunal mucosal sIgA, and IgA concentrations. β-Carotene significantly enhanced mRNA expression levels of IgA, CC chemokine receptor-9 (CCR9), polymeric immunoglobulin receptor (pIgR), and retinoic acid receptor α (RARα) in the ileal tissues and pIgR in the jejunal tissues. β-Carotene improves mRNA expression of intestinal barrier-related proteins including: mucin-2 (MUC-2), zonula occludens-2 (ZO-2), occludins (OCLN), and zonula occludens-1 (ZO-1) in the ileal tissues. Moreover, β-carotene decreased the levels of Escherichia coli and elevates the levels of Lactobacillus. The results indicate that β-carotene can promote growth performance and contribute to the gradual development of intestinal barriers in Hyline Brown chicks. This study enriches our knowledge about the effects of β-carotene on intestinal barrier and highlights a theoretical basis of β-carotene application in the poultry industry.

Decreases in function of the immune system with age contribute to the increase the risk of infectious diseases especially the upper respiratory tract. On the other hand, physical activity has been widely recommended for health. However, more studies are needed to support the benefit effect of exercise on immune system in elderly. To evaluate the effect of the hydrogymnastics on the serum level of immunoglobulin A (IgA) in elderly women. Twenty-six participants were randomly assigned to an experimental (n: 16) or a control group (n: 10). IgA concentrations were determined by nephelometry (BN2 Analyzer, Dade Behring). The hydrogymnastics training protocol was performed 5 times a week during 12 weeks. The intensity of the aerobic exercise was 50-60% of the maximum heart rate monitored by telemetry (Polar-FT7). No significant differences (p: 0.797) resulted by ANOVA on serum IgA levels; the percentage of change in experimental group was Δ% = -6.7 mg/dL compared to the control group, Δ%= -7.4 mg/dL. After three months of hydrogymnastics the IgA level did not show significant change on elderly women; However, positive improvement in percentage of change Δ% was found.