Immunological parameters: what do they mean?

Infancy Dietary Patterns, Development, and Health: An Extensive Narrative Review

Correct dietary patterns are important for a child’s health from birth to adulthood. Understanding a child’s health as a state of entire physical, mental, and social well-being is essential. However, reaching adulthood in a complete health proper state is determined by feeding and dietary habits during preconception, pregnancy, or children infancy. Different factors, such as the mother’s lifestyle, culture, or socioeconomic status, are crucial during all these phases. In this review, we aimed to assess the long-term associations between infancy dietary patterns and health and their influence on development and growth. To reach this objective, a consensus critical review was carried out using primary sources such as scientific articles, and secondary bibliographic indexes, databases, and web pages. PubMed, SciELO, and Google Scholar were the tools used to complete this research. We found that high-income countries promote high-calorie foods and, consequently, obesity problems among children are rising. However, undernutrition is a global health issue concerning children in low- and middle-income countries; thus, parental socioeconomic status in early life is essential to children’s health and development, showing that biological, social, and environmental influences are increased risk factors for chronic diseases. This narrative review is aimed to collect evidence for early nutritional intervention and future disease prevention.

Antioxidant and Antimicrobial Activity of Cleome droserifolia (Forssk.) Del. and Its Biological Effects on Redox Status, Immunity, and Gut Microflora

Simple Summary

The antioxidant, antimicrobial, and immunomodulatory activities of the Cleome droserifolia (Forssk.) Del. (Cd) shrub were investigated considering the biological activity of its phytogenic compounds. Cd shrub encompasses several phenolic compounds, mainly phenolic acids, such as benzoic acid. The methanolic extract of Cd exhibited strong in vitro antioxidant and antimicrobial activities. Anin vivo study using rabbits as an animal model confirmed the ability of a powder of Cd aerial parts to improve humoral and innate immunity, as well as gastrointestinal microbiota homeostasis. In conclusion, Cd shrub represents a novel source of secondary active metabolites that can be employed as antibiotic alternative in the livestock production field and/or in human pharmaceutical applications.

Abstract

This study aimed to investigate the antioxidant, antimicrobial, and immunomodulatory activities of a Cleome droserifolia (Forssk.) Del. (Cd) shoot methanolic extracts considering the biological activity of its phytogenic compounds. For this purpose, the Cd phenolic compounds were detected, and an in vitro evaluation of the antioxidant and antimicrobial activities of the Cd extract was performed. For a biological evaluation, 30 v-line rabbits were randomly distributed into three groups with treatments including: a basal diet without Cd shoots powder supplement (C group) or supplemented with 1.25- (Cdl group) or 2.5 (Cdh group)-mg Cd/kg dry matter (DM). The Cd extract showed a linear scavenging activity for 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), with the maximal activity observed at a concentration of 1 mg/mL. A total of 16 phenolic compounds were identified by reverse-phase high-performance liquid chromatography (RP-HPLC) in the Cd methanolic extract, among which benzoic acid, rutin, ellagic acid, naringenin, and o-coumaric acid were the major compounds. The methanolic extract of Cd showed inhibitory actions against microbial pathogen species. The in vivo study showed that the two concentrations of Cd significantly improved the redox status of the blood plasma and lysozyme activity. Treatment with Cdh significantly decreased the levels of interleukin-β1 in the blood plasma compared with the control. Moreover, the two concentrations of Cd significantly increased the counts of intestinal and cecal yeast and Lactobacillus species and decreased the Salmonella and Coliform species compared with the control. The aerial parts of the Cd shrub had strong antioxidant, antimicrobial, and immunomodulatory activities, which can improve the overall health status and seem to be related to its impressive range of biologically active phenolic compounds.

Effects of Citrus Fruit Juices and Their Bioactive Components on Inflammation and Immunity: A Narrative Review

The immune system provides defence to the host against pathogenic organisms. A weak immune system increases susceptibility to infections and allows infections to become more severe. One component of the immune response is inflammation. Where inflammation is excessive or uncontrolled it can damage host tissues and cause pathology. Limitation of oxidative stress is one means of controlling inflammation. Citrus fruit juices are a particularly good source of vitamin C and folate, which both have roles in sustaining the integrity of immunological barriers and in supporting the function of many types of immune cell including phagocytes, natural killer cells, T-cells and B-cells. Vitamin C is an antioxidant and reduces aspects of the inflammatory response. Important bioactive polyphenols in citrus fruit juices include hesperidin, narirutin and naringin. Hesperidin is a glycoside of hesperetin while narirutin and naringin are glycosides of naringenin. Hesperidin, hesperetin, naringenin, naringin and narirutin have all been found to have anti-inflammatory effects in model systems, and human trials of hesperidin report reductions in inflammatory markers. In humans, orange juice was shown to limit the post-prandial inflammation induced by a high fat-high carbohydrate meal. Consuming orange juice daily for a period of weeks has been reported to reduce markers of inflammation, including C-reactive protein, as confirmed through a recent meta-analysis. A newly emerging topic is whether polyphenols from orange juice have direct anti-viral effects. In summary, micronutrients and other bioactives present in citrus fruit juices have established roles in controlling oxidative stress and inflammation and in supporting innate and acquired immune responses. Trials in humans demonstrate that orange juice reduces inflammation; its effects on innate and acquired immunity require further exploration in well-designed trials in appropriate population sub-groups such as older people.

The effect of probiotics on respiratory tract infection with special emphasis on COVID-19: Systemic review 2010-20

To evaluate the effects of probiotics on respiratory tract infection (RTI) a systematic review of randomized controlled trials (RCTs) from January 2010 to January 2020 was conducted. The PubMed, Google Scholar, Embase, Scopus, Clinicaltrials.gov, and International Clinical Trials Registry Platform databases were systematically searched for the following keywords: respiratory tract infection, probiotics, viral infection, COVID-19, and clinical trial. A total of 27 clinical trials conducted on 9433 patients with RTI plus 10 ongoing clinical studies of probiotics intervention in Coronavirus disease 2019 (COVID-19) were reviewed. The review looked at the potency of probiotics for the hindrance and/or treatment of RTI diseases, this may also apply to COVID-19. The review found that probiotics could significantly increase the plasma levels of cytokines, the effect of influenza vaccine and quality of life, as well as reducing the titer of viruses and the incidence and duration of respiratory infections. These antiviral and immune-modulating activities and their ability to stimulate interferon production recommend the use of probiotics as an adjunctive therapy to prevent COVID-19. Based on this extensive review of RCTs we suggest that probiotics are a rational complementary treatment for RTI diseases and a viable option to support faster recovery.

Inverted CD4+/CD8+ T cell ratio in Boran (Bos indicus) cattle

The CD4⁺/CD8⁺ ratio is used as a marker of the immune regulation of T cell balance. When the ratio in peripheral blood is less than 1, this is considered an indication of immune suppression in an individual. Previous work on bovine Peripheral Blood Mononuclear Cells (PBMC) has consistently reported a ratio ≥1 as seen in other mammalian hosts, i.e. higher circulating CD4⁺ cell numbers than CD8⁺ cell numbers. However, a consistent inverted CD4⁺/CD8⁺ ratio (<1) was observed in Boran cattle, an African Bos indicus breed. The T cell populations were characterized in Boran cattle (n = 52), revealing higher percentages of circulating CD8⁺ cells (31.9 % average) than CD4⁺ cells (19.1 % average), thus resulting in the inversion of the expected T cell homeostasis in these animals. The results show that this inversion is not an effect of age or relatedness of the cattle, rather, it was shared by almost all Boran cattle used in this study. Despite this inversion being a feature shared by both males and females, the female cattle had significantly higher CD4⁺/CD8⁺ ratios than the male Boran. This paper describes the characteristics of the T cell fractions in the study animals and compares the findings to those of other Boran cattle in Kenya, and four other cattle breeds representing African indicine, African taurine, Brazilian indicine and European taurine cattle. We demonstrate that the consistent observation of inverted CD4⁺/CD8⁺ cell ratio was restricted to the Boran.

An Ayurvedic personalized prophylactic protocol in COVID-19

The current COVID-19 pandemic brought about by the SARS-CoV-2, a novel β coronavirus is creating intense health havoc globally. Researchers suspect the situation to stay for long in the community, considering this virus’s pathogenesis, high rate transmission and tendency to provoke uncontrolled immune response activation. Immune mechanisms are highly individualistic. We put forward a hypothetical model of prakruti (Ayurvedic body phenotyping character) based personalized prophylactic-therapeutic strategies aiming at a better immunomodulation and quicker resolution of host immune mechanisms. We propose this model in symptomatic, mild to moderate, COVID-19 diagnosed cases and in cases quarantined for high to low risk primary contact with a positive case. We also suggest a community level personalized Ayurvedic prophylactic-therapeutic strategy based on the DOTS model.

Person-centered body purificatory measures (panchakarma procedures) like therapeutic purgation (virechana) and medicated enema (basti) are suggested in this hypothetical protocol with justification on evidence-based links between immune responses and prakruti along with specific jwara (fevers of varied origin as per Ayurvedic sciences) and COVID-19 symptomatology. The paper also appraises the importance of pitta dosha/ama dosha in the manifestation of inflammation driven destructive phase of immune responses along with its stage-wise intervention. This hypothetical model intends to open up discussions on significance of prakruti assessment as a predictive marker to screen people who are at risk of succumbing into deteriorating states if infected with COVID-19. It also intends to discuss the predictive personalized medicine measures based on prakruti in yielding individual host immune homeostasis which may positively reduce the chances of untoward events of an aggravated immune responsiveness and subsequent inflammation driven tissue destruction – the candidate causes for COVID-19 related casualties. Testing this model may give insight towards emphasizing personalized host immune coping mechanisms that may prove crucial in any infectious outbreaks in near future too.

Evaluation of immuno-modulating effect of recombinant heat shock protein 40 of Brucella abortus in mice

The present study was aimed to evaluate the immuno-modulatory effect of Brucella-specific recombinant HSP40 (rDnaJ) when co-immunized with Brucella rOmp22 in mice. For this, dnaJ of Brucella abortus was cloned, expressed in E. coli, and purified to homogeneity using Ni-NTA agarose columns. Three groups of mice (n = 6 in each group) were used in the study. The control group was immunized with rOmp22 alone, while group 1 mice were injected subcutaneously with rOmp22 along with conventional adjuvants (FCA, FIA), and group 2 mice with rOmp22 mixed with rDnaJ. IgG isotype (IgG1 and IgG2a) response to rOmp22 immunization was evaluated by enzyme-linked immunosorbent assay which was found to be directed towards the cell-mediated arm of immune system (CMI) in group 2 mice in which rOmp22 was co-immunized with rDnaJ. Expression profiling of IL-4 and IL-12 was checked in all the groups by qRT PCR. IL12 mRNA was up-regulated to a greater extent in group2 mice, suggesting that the CMI arm of immune system was stimulated. Hence, it was concluded that CMI response against rOmp22 is stimulated to a greater extent in mice when co-immunized with Brucella rDnaJ.

Dogs with osteosarcoma have altered pro- and anti-inflammatory cytokine profiles

Background

Current advances in immunotherapy are an exciting area of study in canine osteosarcoma (OSA). The objective of this study was to determine the immune response in dogs with osteosarcoma by measuring stimulated leukocyte production of tumor necrosis factor (TNF), interleukin (IL)‐6, IL‐10 and TNF and IL‐6 to IL‐10 ratios.

Methods

Whole blood was collected from dogs with osteosarcoma receiving non‐steroidal anti‐inflammatory drugs (NSAIDs, n = 11), dogs with osteosarcoma not receiving NSAIDs (n = 14) and healthy dogs (n = 5).

Results

No difference in TNF production was found among healthy and OSA dogs regardless of NSAID administration following stimulation with lipopolysaccharide (LPS) (p = .410), lipoteichoic acid (LTA) (p = .693) or PBS (p = .120). Leukocyte IL‐6 production was greater in all dogs with OSA after stimulation with LPS (p = .015), LTA (p = .014) and PBS (p = .034) with no difference between OSA dogs receiving NSAIDs and those not. No differences in IL‐10 were found among healthy controls and dogs with OSA regardless of NSAID use. There was no difference among groups for LPS‐stimulated TNF to IL‐10 ratios (p = .407). For LTA‐stimulated leukocytes, the TNF to IL‐10 ratio was lower in dogs with OSA than in healthy dogs (p = .031) with no difference between OSA NSAID dogs compared to OSA non‐NSAID dogs (p = .059). No differences were found in LPS (p = .310)‐ or LTA (p = .265)‐stimulated leukocyte IL‐6 to IL‐10 production ratios among groups.

Conclusions

Dogs with osteosarcoma have an altered pro‐ and anti‐inflammatory immunologic profile compared to healthy dogs regardless of NSAID use. Further study is indicated to determine the potential prognostic and therapeutic implications of these findings.

The leukocytes of dogs with osteosarcoma had altered cytokine production in response to pathogen associated molecular pattern motifs compared to healthy dogs with increased IL‐6 production following LPS and LTA‐stimulation and decreased TNF‐to‐IL‐10 ratios following LTA‐stimulation. Future investigations should monitor leukocyte function through a defined treatment protocol and determine the prognostic significance and potential therapeutic targeting of these changes. These factors, with other immunologic parameters, should also be considered when investigating immunotherapy as potential predictive and prognostic markers.

Regulatory role of vitamin E in the immune system and inflammation

Vitamin E, a potent lipid-soluble antioxidant, found in higher concentration in immune cells compared to other cells in blood, is one of the most effective nutrients known to modulate immune function. Vitamin E deficiency has been demonstrated to impair normal functions of the immune system in animals and humans, which can be corrected by vitamin E repletion. Although deficiency is rare, vitamin E supplementation above current dietary recommendations has been shown to enhance the function of the immune system and reduce risk of infection, particularly in older individuals. The mechanisms responsible for the effect of vitamin E on the immune system and inflammation have been explored in cell-based, pre-clinical and clinical intervention studies. Vitamin E modulates T cell function through directly impacting T cell membrane integrity, signal transduction, and cell division, and also indirectly by affecting inflammatory mediators generated from other immune cells. Modulation of immune function by vitamin E has clinical relevance as it affects host susceptibility to infectious diseases such as respiratory infections, in addition to allergic diseases such as asthma. Studies examining the role of vitamin E in the immune system have typically focused on α-tocopherol; however, emerging evidence suggests that other forms of vitamin E, including other tocopherols as well as tocotrienols, may also have potent immunomodulatory functions. Future research should continue to identify and confirm the optimal doses for individuals at different life stage, health condition, nutritional status, and genetic heterogeneity. Future research should also characterize the effects of non-α-alpha-tocopherol vitamin E on immune cell function as well as their potential clinical application. © 2018 IUBMB Life, 71(4):487-494, 2019.

Tracking antigen specific T-cells: Technological advancement and limitations

Assessing T-cell mediated immune status can help to understand the body's response to disease and also provide essential diagnostic information. However, detection and characterization of immune response are challenging due to the rarity of signature biomolecules in biological fluid and require highly sensitive and specific assay technique for the analysis. Until now, several techniques spanning from flow cytometry to microsensors have been developed or under investigation for T-cell mediated immune response monitoring. Most of the current assays are designed to estimate average immune responses, i.e., total functional protein analysis and detection of total T-cells irrespective of their antigen specificity. Although potential, immune response analysis without detecting and characterizing the rare subset of T-cell population could lead to over or underestimation of patient's immune status. Addressing this limitation, recently a number of technological advancements in biosensing have been developed for this. The potential of simple and precise micro-technologies including microarray and microfluidic platforms for assessing antigen-specific T-cells will be highlighted in this review, together with a discussion on existing challenges and future aspects of immune-sensor development.

Potentiation of the humoral immune response elicited by a commercial vaccine against bovine respiratory disease by Enterococcus faecalis CECT7121

Vaccination against pathogens involved in bovine respiratory disease (BRD) is a useful tool to reduce the risk of this disease however, it has been observed that the commercially available vaccines only partially prevent the infections caused by Pasteurella multocida and Mannheimia haemolytica. Therefore, it is recommended to search for new adjuvant strategies to minimise the economic impact of this respiratory syndrome. A possibility to improve the conventional vaccine response is to modulate the immune system with probiotics, since there is accumulating evidence that certain immunomodulatory strains administered around the time of vaccination can potentiate the immune response. Considering veterinary vaccines are frequently tested in murine models, we have developed an immunisation schedule in BALB/c mice that allows us to study the immune response elicited by BRD vaccine. In order to evaluate a potential strategy to enhance vaccine efficacy, the adjuvant effect of Enterococcus faecalis CECT7121 on the murine specific humoral immune response elicited by a commercial vaccine against BRD was studied. Results indicate that the intragastric administration of E. faecalis CECT7121 was able to induce an increase in the specific antibody titres against the bacterial components of the BRD vaccines (P. multocida and M. haemolytica). The quality of the humoral immune response, in terms of antibody avidity, was also improved. Regarding the cellular immune response, although the BRD vaccination induced a low specific secretion of cytokines in the spleen cell culture supernatants, E. faecalis CECT7121-treated mice showed higher interferon-γ production than immunised control mice. Our results allowed us to conclude that the administration of E. faecalis CECT7121 could be employed as an adjuvant strategy to potentiate humoral immune responses.

Feeding a Mixture of Choline Forms during Lactation Improves Offspring Growth and Maternal Lymphocyte Response to Ex Vivo Immune Challenges

Study objectives were to examine the impact of feeding a mixture of choline forms, or a diet high in glycerophosphocholine (GPC) on maternal immune function and offspring growth during lactation. Lactating Sprague-Dawley rat dams (n = 6/diet) were randomized to one of three diets, providing 1 g/kg total choline: Control (100% free choline (FC)), Mixed Choline (MC; 50% phosphatidylcholine (PC), 25% FC, 25% GPC), or High GPC (HGPC; 75% GPC, 12.5% PC, 12.5% FC). At 3 weeks, cell phenotypes and cytokine production with Concanavalin A (ConA)-or lipopolysaccharide (LPS)-stimulated splenocytes and mesenteric lymphocytes were measured. Feeding MC or HGPC diets improved pups' growth compared to Control (+22% body weight, p < 0.05). In spleen, MC-and HGPC-fed dams had higher proportions of cytotoxic (CD8+) T cells expressing CD27, CD71 and CD127, total B cells (CD45RA+) and dendritic cells (OX6+OX62+), and produced less IL-6 and IFN-γ after ConA than Control-fed dams (p < 0.05). MC and HGPC LPS-stimulated splenocytes produced less IL-1β and IL-6 than Control. ConA-stimulated mesenteric lymphocytes from MC and HGPC dams produced more IL-2 and IFN-γ than Control (p < 0.05). In summary, feeding a mixture of choline forms during lactation improved offspring growth and resulted in a more efficient maternal immune response following mitogenic immune challenge.

Increased naive CD4+ and B lymphocyte subsets are associated with body mass loss and drive relative lymphocytosis in anorexia nervosa patients

Anorexia nervosa (AN) is an atypical form of malnutrition with peculiar changes in the immune system. We hypothesized that different lymphocyte subsets are differentially affected by malnutrition in AN, and thus, our aim was to investigate the influence of body mass loss on the variability of lymphocyte subsets in AN patients. A group of 66 adolescent female patients, aged 12-17 years, referred for their first episode of either AN or feeding or eating disorders not elsewhere classified were studied upon admission (46 AN-restricting subtype, 11 AN-binge/purging subtype, and 9 feeding or eating disorders not elsewhere classified). Ninety healthy adolescents served as controls. White blood cells and lymphocyte subsets were analyzed by flow cytometry. Relationships with the body mass index (BMI) z score were assessed in linear models adjusted by diagnostic subtype and age. Leukocyte numbers were lower in AN patients than in controls, and relative lymphocytosis was observed in AN-restricting subtype. Lower CD8⁺, NK, and memory CD8⁺ counts were found in eating disorder patients compared with controls. No differences were found for CD4⁺ counts or naive and memory CD4⁺ subsets between the groups. Negative associations between lymphocyte percentage and the BMI z score, as well as between the B cell counts, naive CD4⁺ percentage and counts, and the BMI z score, were found. In conclusion, increased naive CD4⁺ and B lymphocyte subsets associated with body mass loss drive the relative lymphocytosis observed in AN patients, which reflects an adaptive mechanism to preserve the adaptive immune response.

Evaluation of Lactobacillus coryniformis CECT5711 strain as a coadjuvant in a vaccination process: a randomised clinical trial in healthy adults

BACKGROUND

Although the effects of probiotics on the immune system have been extensively evaluated under disease states, their role in healthy situations remains unclear, since changes are hardly expected under immunological homeostasis. EFSA indicates that vaccination protocols could be used to evaluate the potential role of probiotics to improve the immune response against antigen challenges. The aim of the study was to evaluate the effect of Lactobacillus coryniformis CECT5711 (Lc) on the specific immunity of healthy volunteers undergoing vaccination with Hepatitis A virus (HAV).

METHODS

One hundred twenty-three healthy adults were randomised into three groups to follow a 6-week (wk) intervention and all received an intramuscular HAV vaccine 2 weeks after starting the intervention: 1) PRO1 received Lc for 2weeks (1 capsule/day; 3 × 10⁹ CFU/capsule) and placebo capsules after vaccination; 2) PRO2 received a daily capsule of Lc (3 × 10⁹ cfu/day) before and after the challenge; 3) Control group (C) received a daily placebo capsule before and after the vaccine. Blood samples were collected at the beginning (visit 1; V1) and after 2 (V2) and 6 weeks (V3) of the intervention. At each visit, lymphocyte subset counts and cytokine levels were analysed. Specific HAV antibodies were analysed at V1 and V3. To evaluate differences between groups, one-way ANOVA with Bonferroni post-hoc test were used regarding lymphocyte subset counts and specific HAV antibodies production, and Friedman test of related samples and Kendall concordance coefficient for cytokines production. Chi square test was used to analyse seroconversion rates.

RESULTS

Specific HAV antibodies were significantly higher in PRO1 (50.54 ± 29.57) compared to C (36.23 ± 16.45) (P = 0.017) and showed an intermediate value in PRO2 (41.61 ± 15.74). Seroconversion rates were similar in the three groups (97.3, 92.3 and 97.4% in C, PRO1 and PRO2 respectively). Memory T-helper lymphocytes increased in V3 vs. V1 (P = 0.032) in PRO2. No differences were found in cytokine concentrations.

CONCLUSION

Mixed results have been found regarding the usefulness of Lc supplementation to increase the antigen-specific antibody response to an immune challenge. Clinical trial registration number: EudraCT Number 2016-000183-42. Registered 19 January 2016. Retrospectively registered.

Feeding a diet devoid of choline to lactating rodents restricts growth and lymphocyte development in offspring

The nutrient choline is necessary for membrane synthesis and methyl donation, with increased requirements during lactation. The majority of immune development occurs postnatally, but the importance of choline supply for immune development during this critical period is unknown. The objective of this study was to determine the importance of maternal supply of choline during suckling on immune function in their offspring among rodents. At parturition, Sprague-Dawley dams were randomised to either a choline-devoid (ChD; n 7) or choline-sufficient (ChS, 1 g/kg choline; n 10) diet with their offspring euthanised at 3 weeks of age. In a second experiment, offspring were weaned to a ChS diet until 10 weeks of age (ChD-ChS, n 5 and ChS-ChS, n 9). Splenocytes were isolated, and parameters of immune function were measured. The ChD offspring received less choline in breast milk and had lower final body and organ weight compared with ChS offspring (P<0·05), but this effect disappeared by week 10 with choline supplementation from weaning. ChD offspring had a higher proportion of T cells expressing activation markers (CD71 or CD28) and a lower proportion of total B cells (CD45RA+) and responded less to T cell stimulation (lower stimulation index and less IFN-γ production) ex vivo (P<0·05). ChD-ChS offspring had a lower proportion of total and activated CD4+ T cells, and produced less IL-6 after mitogen stimulation compared with cells from ChS-ChS (P<0·05). Our study suggests that choline is required in the suckling diet to facilitate immune development, and choline deprivation during this critical period has lasting effects on T cell function later in life.

The Form of Choline in the Maternal Diet Affects Immune Development in Suckled Rat Offspring

BACKGROUND

Lipid-soluble phosphatidylcholine (PC) and aqueous free choline are absorbed and metabolized differently, but the metabolic effects of feeding these 2 forms of choline have not been thoroughly investigated.

OBJECTIVE

We sought to compare the effects of PC and free choline in the maternal diet on the development of the offspring's immune system.

METHODS

During lactation, Sprague-Dawley dams (n= 10) were randomly assigned to 1 of 2 diet groups containing the same concentration of total choline (1 g/kg diet) as free choline (choline bitartrate) or PC (egg lecithin). The splenocytes of pups aged 21 d were isolated and stimulated ex vivo with concanavalin A (ConA) or lipopolysaccharide (LPS), and the choline concentrations of stomach content, plasma, and the spleen were measured.

RESULTS

Pups from PC-fed dams had a lower proportion of cells involved in antigen presentation but produced 54% more interleukin (IL)-2, 163% more IL-6, and 107% more IFN-γ after ConA stimulation and 110% more IL-6 and 43% more tumor necrosis factor (TNF)-α after LPS stimulation (allP< 0.05). The PC concentrations were significantly higher in the plasma and spleen of pups from PC-fed dams (P< 0.05). Increasing the supply of PC in the form of lysophosphatidylcholine to splenocytes in vitro increased the rate of proliferation and IL-2 production and the surface expression of CD25, CD28, CD71, and CD152 on CD8+ T cells, suggesting 1 possible mechanism.

CONCLUSIONS

The results of this study demonstrate that providing choline to rats in the form of PC (compared to free choline), possibly by increasing the supply of PC to the suckling pups, promotes maturation and improves function of the offspring's immune system.

Initial evidence for the link between activities and health: Associations between a balance of activities, functioning and serum levels of cytokines and C-reactive protein

Growing evidence shows interrelations of psychological factors, neurological and immunological processes. Therefore, constructs like a balance of activities, the so called "occupational balance", could also have biological correlates. The aim of this study was to investigate potential associations between occupational balance, functioning, cytokines and C-reactive protein (CRP) in patients suffering from a chronic inflammatory disease like rheumatoid arthritis (RA) and healthy people. Moreover, we wanted to explore potential differences in gender and employment status. A descriptive study in patients with RA and healthy people was conducted using the Occupational Balance-Questionnaire (OB-Quest) and the Short-Form 36 Health Survey (SF-36). Serum levels of cytokines, such as interleukin 6 (IL-6) and 8 (IL-8), interferon alpha (INFα), tumour necrosis factor alpha (TNFα), rheumatoid factor (RF) and of CRP were measured. Descriptive statistics, as well as Mann-Whitney U tests and Spearmen's rank correlation coefficients (rs) were calculated. One-hundred-thirty-two patients with RA and 76 healthy people participated. Occupational balance was associated with functioning, cytokines and CRP. The strongest associations were identified in the unemployed healthy-people sample with cytokines and CRP being within the normal range. For example, the OB-Quest item challenging activities was associated with IL-8 (rs=-0.63, p=0.04) and the SF-36 sub-scale bodily pain was associated with IFNα (rs=-0.69, p=0.02). The items rest and sleep (rs=-0.71, p=0.01) and variety of different activities (rs=-0.74, p<0.01) correlated with the SF-36 sub-scale social functioning. Employed and unemployed people differed in their age and CRP levels. Additionally, gender differences were found in two OB-Quest items in that fewer women were able to adapt their activities to changing living conditions and fewer men were overstressed. In conclusion, we found preliminary biological evidence for the link between occupation and health in that the concepts encompassed in the construct of occupational balance were associated with functioning, cytokines and CRP.

Effect of Lactobacillus paracasei subsp. paracasei, L. casei 431 on immune response to influenza vaccination and upper respiratory tract infections in healthy adult volunteers: a randomized, double-blind, placebo-controlled, parallel-group study

BACKGROUND

Probiotics can modulate the immune system in healthy individuals and may help reduce symptoms related to respiratory infections.

OBJECTIVE

The objective of the study was to investigate the effect of the probiotic strain Lactobacillus paracasei subsp. paracasei, L. casei 431 (Chr. Hansen A/S) (hereafter, L. casei 431) on immune response to influenza vaccination and respiratory symptoms in healthy adults.

DESIGN

A randomized double-blind, placebo-controlled trial was conducted in 1104 healthy subjects aged 18-60 y at 2 centers in Germany and Denmark. Subjects were randomly assigned to receive an acidified milk drink containing ≥10(9) colony-forming units of L. casei 431 (n = 553) or placebo (n = 551) for 42 d. After 21 d, subjects received the seasonal influenza vaccination. The primary outcome was seroprotection rate (anti-influenza antibody titers by hemagglutination inhibition) 21 d after vaccination. Other outcomes were seroconversion rate and mean titers, influenza A-specific antibodies and incidence, and duration and severity of upper respiratory symptoms. Antibiotic use and use of health care resources were recorded.

RESULTS

There was no effect of L. casei 431 on immune responses to influenza vaccination. Generalized linear mixed modeling showed a shorter duration of upper respiratory symptoms in the probiotic group than in the placebo group (mean ± SD: 6.4 ± 6.1 vs. 7.3 ± 9.7 d, P = 0.0059) in the last 3 wk of the intervention period. No statistically significant differences were found for incidence or severity.

CONCLUSIONS

Daily consumption of L. casei 431 resulted in no observable effect on the components of the immune response to influenza vaccination but reduced the duration of upper respiratory symptoms. The trial was registered at www.isrctn.com as ISRCTN08280229.

Immunophenotyping of normal individuals classified on the basis of human dosha prakriti

Background:

Human variations related to immune response and disease susceptibility is well-documented in Ayurveda. Prakriti (body constitution) is the basic constitution of an individual established at the time of birth and distinguishes variations, into three broad phenotype categories such as vata, pitta and kapha. Variation in immune response is often attributed to and measured from the difference in cluster differentiation (CD) markers expressed in lymphocytes. Currently, there are no reports available on the expression of CD markers related to prakriti.

Objective:

This is a pilot study performed to evaluate a panel of lymphocyte subset CD markers in dominant prakriti individuals.

Materials and Methods:

Immunophenotyping was carried out using whole blood from a total of healthy 222 subjects, who are grouped into kapha (n = 95), pitta (n = 57) and vata (n = 70) prakritis. CD markers such as CD3, CD4, CD8, CD14, CD25, CD56, CD69, CD71 and HLA-DR were analyzed using flow cytometry method. Differences between groups were analyzed using one-way ANOVA or Kruskal-Wallis analysis of variance (ANOVA) and multiple comparisons between groups were performed by Bonferroni or Mann-Whitney U test with corrections for type I error respectively. Significance was evaluated by ANOVA and Pearson's correlation.

Results:

We observed a significant difference (P < 0.05) in the expression of CD markers such as CD14 (monocytes), CD25 (activated B cells) and CD56 (Natural killer cells) between different prakriti groups. CD25 and CD56 expression was significantly higher in kapha prakriti samples than other prakriti groups. Similarly, slightly higher levels of CD14 were observed in pitta prakriti samples.

Conclusion:

Significant difference in the expression of CD14, CD25 and CD56 markers between three different prakriti is demonstrated. The increased level of CD25 and CD56 in kapha prakriti may indicate ability to elicit better immune response, which is in conformity with textual references in Ayurveda.

Monitoring immune modulation by nutrition in the general population: identifying and substantiating effects on human health

Optimal functioning of the immune system is crucial to human health, and nutrition is one of the major exogenous factors modulating different aspects of immune function. Currently, no single marker is available to predict the effect of a dietary intervention on different aspects of immune function. To provide further guidance on the assessment and interpretation of the modulation of immune functions due to nutrition in the general population, International Life Sciences Institute Europe commissioned a group of experts from academia, government and the food industry to prepare a guidance document. A draft of this paper was refined at a workshop involving additional experts. First, the expert group defined criteria to evaluate the usefulness of immune function markers. Over seventy-five markers were scored within the context of three distinct immune system functions: defence against pathogens; avoidance or mitigation of allergy; control of low-grade (metabolic) inflammation. The most useful markers were subsequently classified depending on whether they by themselves signify clinical relevance and/or involvement of immune function. Next, five theoretical scenarios were drafted describing potential changes in the values of markers compared with a relevant reference range. Finally, all elements were combined, providing a framework to aid the design and interpretation of studies assessing the effects of nutrition on immune function. This stepwise approach offers a clear rationale for selecting markers for future trials and provides a framework for the interpretation of outcomes. A similar stepwise approach may also be useful to rationalise the selection and interpretation of markers for other physiological processes critical to the maintenance of health and well-being.

Effect of fruit and vegetable consumption on immune function in older people: a randomized controlled trial

BACKGROUND

Fruit and vegetable (FV) intake, which is often low in older people, is associated with reduced chronic disease risk.

OBJECTIVE

We determined whether increased FV intake improves measures of immune function.

DESIGN

We conducted a randomized controlled trial (The Ageing and Dietary Intervention Trial) in 83 healthy volunteers aged 65-85 y with low FV intakes (≤2 portions/d); 82 subjects completed the intervention. Participants were assigned to continue their normal diets or to consume ≥5 FV portions/d for 16 wk. At 12 wk, tetanus toxoid (0.5 mL intramuscular) and Pneumovax II vaccine (0.5 mL intramuscular; both vaccines from Sanofi Pasteur) were administered. FV intake was monitored by using diet histories, and biomarkers of nutritional status were assessed. The primary endpoint was the antibody response to vaccination. Specific antibodies binding to tetanus toxoid (total IgG) and pneumococcal capsular polysaccharide (total IgG and IgG2) were assessed at baseline and 16 wk. Participants were recruited between October 2006 and June 2008.

RESULTS

The change in FV consumption differed significantly between groups [mean change in number of portions (95% CI): in the 2-portion/d group, 0.4 portions/d (0.2, 0.7 portions/d); in the 5-portion/d group, 4.6 portions/d (4.1, 5.0 portions/d); P < 0.001)] and also in micronutrient status. Antibody binding to pneumococcal capsular polysaccharide (total IgG) increased more in the 5-portion/d group than in the 2-portion/d group [geometric mean (95% CI) of the week 16:baseline ratio: 3.1 (2.1, 4.4) and 1.7 (1.3, 2.1), respectively; P = 0.005)]. There was no significant difference in the increases in antibody binding to tetanus toxoid.

CONCLUSION

Increased FV intake improves the Pneumovax II vaccination antibody response in older people, which links an achievable dietary goal with improved immune function.

Immunomodulatory effects of heat-killed Enterococcus faecalis TH10 on murine macrophage cells

The objective of this study was to investigate the immunomodulatory effects of heat-killed Enterococcus faecalis TH10 (hk-TH10) and its signal transduction on murine macrophage RAW264 cells. RAW264 cells produced nitric oxide (NO) following hk-TH10 treatment. In order to investigate the mechanisms underlying hk-TH10-stimulated NO production, we further measured NO production in RAW264 cells treated with Toll-like receptor (TLR) 4 inhibitor peptide, NF-κB inhibitor, TLR1-siRNA, TLR2-siRNA, and TLR-6 siRNA. Furthermore, the activation of TLR2-TLR1/6 pathway molecules was analyzed by Western blotting. The result of this study showed that hk-TH10 stimulates NO in RAW264 cells through the activation of the TLR2-TLR1/6 pathway. From our findings, we can conclude that hk-TH10 isolated from a traditional side-dish fermented food (tempeh) may facilitate host immunomodulation.

Early life: gut microbiota and immune development in infancy

The immune system of infants is actively downregulated during pregnancy and therefore the first months of life represent a period of heightened susceptibility to infection. After birth, there is an age-dependent maturation of the immune system. Exposure to environmental microbial components is suggested to play an important role in the maturation process. The gastrointestinal tract is the major site of interaction between the host immune system and microorganisms, both commensal as well as potentially pathogenic. It is well established that the mammalian immune system is designed to help protect the host from invading microorganisms and other danger signals. However, recent research is emerging in the field of host-microbe interactions showing that commensal microorganisms (microbiota) are most likely one of the drivers of immune development and, in turn the immune system shapes the composition of the microbiota. Specific early microbial exposure of the gut is thought to dramatically reduce the incidence of inflammatory, autoimmune and atopic diseases further fuelling the scientific view that microbial colonisation plays an important role in regulating and fine-tuning the immune system throughout life. Therefore, the use of pre-, pro- and synbiotics may result in a beneficial microbiota composition that might have a pivotal role on the prevention of several important diseases that develop in early life such as necrotizing enterocolitis and atopic eczema.

Combined fish oil and astaxanthin supplementation modulates rat lymphocyte function

PURPOSE

Higher intakes of n-3 polyunsaturated fatty acids that are abundant in marine fishes have been long described as a "good nutritional intervention" with increasing clinical benefits to cardiovascular health, inflammation, mental, and neurodegenerative diseases. The present study was designed to investigate the effect of daily fish oil (FO-10 mg EPA/kg body weight (BW) and 7 mg DHA/kg BW) intake by oral gavage associated with the antioxidant astaxanthin (ASTA-1 mg/kg BW) on the redox metabolism and the functional properties of lymphocytes from rat lymph nodes.

METHODS

This study was conducted by measurements of lymphocyte proliferation capacity, ROS production [superoxide (O₂(•-)) and hydrogen peroxide (H₂O₂)], nitric oxide (NO(•)) generation, intracellular calcium release, oxidative damage to lipids and proteins, activities of major antioxidant enzymes, GSH/GSSG content, and cytokines release.

RESULTS

After 45 days of FO + ASTA supplementation, the proliferation capacity of activated T- and B-lymphocytes was significantly diminished followed by lower levels of O₂(•-), H₂O₂ and NO(•) production, and increased activities of total/SOD, GR and GPx, and calcium release in cytosol. ASTA was able to prevent oxidative modification in cell structures through the suppression of the oxidative stress condition imposed by FO. L: -selectin was increased by FO, and IL-1β was decreased only by ASTA supplementation.

CONCLUSION

We can propose that association of ASTA with FO could be a good strategy to prevent oxidative stress induced by polyunsaturated fatty acids and also to potentiate immuno-modulatory effects of FO.

Evaluation of the immune benefits of two probiotic strains Bifidobacterium animalis ssp. lactis, BB-12® and Lactobacillus paracasei ssp. paracasei, L. casei 431® in an influenza vaccination model: a randomised, double-blind, placebo-controlled study

The present study investigated the ability of Bifidobacterium animalis ssp. lactis (BB-12®) and Lactobacillus paracasei ssp. paracasei (L. casei 431®) to modulate the immune system using a vaccination model in healthy subjects. A randomised, double-blind, placebo-controlled, parallel-group study was conducted in 211 subjects (56 % females, mean age 33·2 (sd 13·1) years). Subjects consumed a minimum of 10⁹ colony-forming units of BB-12® (capsule) or L. casei 431® (dairy drink) or a matching placebo once daily for 6 weeks. After 2 weeks, a seasonal influenza vaccination was given. Plasma and saliva samples were collected at baseline and after 6 weeks for the analysis of antibodies, cytokines and innate immune parameters. Changes from baseline in vaccine-specific plasma IgG, IgG1 and IgG3 were significantly greater in both probiotic groups v. the corresponding placebo group (L. casei 431®, P = 0·01 for IgG; P < 0·001 for remaining comparisons). The number of subjects obtaining a substantial increase in specific IgG (defined as ≥ 2-fold above baseline) was significantly greater in both probiotic groups v. placebo (BB-12®, P < 0·001 for IgG, IgG1 and IgG3; L. casei 431®, P < 0·001 for IgG1 and IgG3). Significantly greater mean fold increases for vaccine-specific secretory IgA in saliva were observed in both probiotic groups v. placebo (BB-12®, P = 0·017; L. casei 431®, P = 0·035). Similar results were observed for total antibody concentrations. No differences were found for plasma cytokines or innate immune parameters. Data herein show that supplementation with BB-12® or L. casei 431® may be an effective means to improve immune function by augmenting systemic and mucosal immune responses to challenge.

Immunity traits in pigs: substantial genetic variation and limited covariation

Background

Increasing robustness via improvement of resistance to pathogens is a major selection objective in livestock breeding. As resistance traits are difficult or impossible to measure directly, potential indirect criteria are measures of immune traits (ITs). Our underlying hypothesis is that levels of ITs with no focus on specific pathogens define an individual's immunocompetence and thus predict response to pathogens in general. Since variation in ITs depends on genetic, environmental and probably epigenetic factors, our aim was to estimate the relative importance of genetics. In this report, we present a large genetic survey of innate and adaptive ITs in pig families bred in the same environment.

Methodology/Principal Findings

Fifty four ITs were studied on 443 Large White pigs vaccinated against Mycoplasma hyopneumoniae and analyzed by combining a principal component analysis (PCA) and genetic parameter estimation. ITs include specific and non specific antibodies, seric inflammatory proteins, cell subsets by hemogram and flow cytometry, ex vivo production of cytokines (IFNα, TNFα, IL6, IL8, IL12, IFNγ, IL2, IL4, IL10), phagocytosis and lymphocyte proliferation. While six ITs had heritabilities that were weak or not significantly different from zero, 18 and 30 ITs had moderate (0.1<h2≤0.4) or high (h2>0.4) heritability values, respectively. Phenotypic and genetic correlations between ITs were weak except for a few traits that mostly include cell subsets. PCA revealed no cluster of innate or adaptive ITs.

Conclusions/Significance

Our results demonstrate that variation in many innate and adaptive ITs is genetically controlled in swine, as already reported for a smaller number of traits by other laboratories. A limited redundancy of the traits was also observed confirming the high degree of complementarity between innate and adaptive ITs. Our data provide a genetic framework for choosing ITs to be included as selection criteria in multitrait selection programmes that aim to improve both production and health traits.

Probiotics and prebiotics in pediatrics

This clinical report reviews the currently known health benefits of probiotic and prebiotic products, including those added to commercially available infant formula and other food products for use in children. Probiotics are supplements or foods that contain viable microorganisms that cause alterations of the microflora of the host. Use of probiotics has been shown to be modestly effective in randomized clinical trials (RCTs) in (1) treating acute viral gastroenteritis in healthy children; and (2) preventing antibiotic-associated diarrhea in healthy children. There is some evidence that probiotics prevent necrotizing enterocolitis in very low birth weight infants (birth weight between 1000 and 1500 g), but more studies are needed. The results of RCTs in which probiotics were used to treat childhood Helicobacter pylori gastritis, irritable bowel syndrome, chronic ulcerative colitis, and infantile colic, as well as in preventing childhood atopy, although encouraging, are preliminary and require further confirmation. Probiotics have not been proven to be beneficial in treating or preventing human cancers or in treating children with Crohn disease. There are also safety concerns with the use of probiotics in infants and children who are immunocompromised, chronically debilitated, or seriously ill with indwelling medical devices. Prebiotics are supplements or foods that contain a nondigestible food ingredient that selectively stimulates the favorable growth and/or activity of indigenous probiotic bacteria. Human milk contains substantial quantities of prebiotics. There is a paucity of RCTs examining prebiotics in children, although there may be some long-term benefit of prebiotics for the prevention of atopic eczema and common infections in healthy infants. Confirmatory well-designed clinical research studies are necessary.

Immune response of broiler chickens fed different levels of arginine and vitamin E to a coccidiosis vaccine and Eimeria challenge

One-day-old broiler chicks (n = 300) were orally vaccinated (Coccivac-B) and divided into 6 groups to evaluate Arg at 3 levels of supplementation, 0, 0.3, or 0.6% [normal level (NARG), medium level (MARG), or high level (HARG), respectively], and 2 levels of vitamin E (VE), 40 or 80 IU/kg of feed (VE40 or VE80, respectively), in a factorial experiment. Birds were reared in floor pens with fresh pine shavings and provided a corn-soybean-based diet and water ad libitum. At d 14, all chickens were orally challenged with a mixture of Eimeria field isolates (Eimeria acervulina, Eimeria maxima, and Eimeria tenella). In vitro heterophil and monocyte oxidative burst (HOB and MOB, respectively) was measured at d 21 from cells isolated from peripheral blood. Antibody levels (IgG, IgM, and IgA isotypes, ELISA) and NO were measured at d 14 and 28. The HOB was lower in birds fed the VE40 diets but was increased with the MARG and HARG treatments, whereas birds fed the VE80 diet had a higher HOB irrespective of Arg level. Birds fed the VE80 diet had high levels of MOB, which was not further improved by Arg, whereas birds fed the VE40-MARG diet had the highest MOB response. Plasma NO was not affected by diet at d 14, but at d 28, plasma NO was higher in birds fed the VE80-MARG or the VE40-NARG diet and lower in birds fed the VE80-NARG or the VE40-MARG diet. Birds fed the VE40-HARG or VE80-MARG diet had the highest IgG levels at d 14, but at d 28, birds fed the VE80-MARG diet had the highest IgG levels. The IgM concentration was lower in birds fed NARG levels irrespective of VE levels at d 14, but at d 28, IgM levels were higher in birds fed the VE40-HARG or the VE80-MARG feed. The IgA concentration was not consistently affected at d 14 or 28. These results suggest that Arg and VE fed at levels higher than those recommended by the NRC may play complementary roles on the innate and humoral immune response against an Eimeria challenge, potentially improving vaccine efficacy and response to field infections.

UK food standards agency workshop report: diet and immune function

The UK Food Standards Agency convened a workshop on 13 May 2009 to discuss recently completed research on diet and immune function. The objective of the workshop was to review this research and to establish priorities for future research. Several of the trials presented at the workshop showed some effect of nutritional interventions (e.g. vitamin D, Zn, Se) on immune parameters. One trial found that increased fruit and vegetable intake may improve the antibody response to pneumococcal vaccination in older people. The workshop highlighted the need to further clarify the potential public health relevance of observed nutrition-related changes in immune function, e.g. susceptibility to infections and infectious morbidity.

No effect of fish oil supplementation on serum inflammatory markers and their interrelationships: a randomized controlled trial in healthy, middle-aged individuals

BACKGROUND

A high intake of n-3 polyunsaturated fatty acids (PUFAs), mainly present in fish, may be associated with decreased inflammation. Previous intervention studies on fish PUFA and inflammatory markers in healthy individuals did not analyze a broad spectrum of inflammatory cytokines, chemokines and cell adhesion molecules, or their interrelationships. Therefore, we determined the effects of fish oil supplementation on 19 serum inflammatory markers and their interrelationships in healthy, middle-aged individuals.

METHODS

Individuals (n=77) aged 50-70 years completed a randomized, double-blind placebo-controlled intervention study. Participants received 3.5 g/day fish oil (1.5 g/day total n-3 PUFA) (n=39) or placebo (high oleic sunflower oil) (n=38) for 12 weeks. Serum concentrations of 19 inflammatory markers were determined using a multiplex immunoassay before and after intervention. Changes in concentrations were analyzed using analysis of covariance and differences in patterns in inflammatory markers between the fish oil and placebo group were analyzed by principal component analysis.

RESULTS

Fish oil supplementation did not significantly affect serum concentrations of cytokines, chemokines or cell adhesion molecules as compared with placebo. However, there was a trend for all inflammatory markers to increase after fish oil supplementation. PCA did not result in markedly distinctive patterns of inflammatory markers for the fish oil and placebo group.

CONCLUSION

In conclusion, this 12-week randomized, double-blind placebo-controlled intervention trial did not show that 1.5 g/day n-3 PUFA significantly affected the serum inflammatory response in healthy individuals, nor did patterns of inflammatory markers. Thus, a healthy middle-aged population may not benefit from fish oil as an anti-inflammatory agent.

Feeding a formula supplemented with long chain polyunsaturated fatty acids modifies the "ex vivo" cytokine responses to food proteins in infants at low risk for allergy

Long chain polyunsaturates (LCP) status during the early neonatal period is associated with a reduced risk of atopic symptoms and later allergies. In this study, we characterized the immune response of low-risk, term, formula-fed infants randomized at <or=14 d of age to standard term formula (Formula) or formula containing LCP (Formula+LCP) for 4 wks. Infants exclusively fed human milk were included for comparison. Peripheral blood was collected at 14 and 42 d of age, and lymphocyte phenotype, proliferation, and cytokine production (IL-2, IL-4, IL-6, IL-10, IL-12, IFN-gamma, TNF-alpha, TGFbeta) were assessed after incubation with beta-lactoglobulin (BLG) and soy protein (SOY). Lymphocyte proliferation did not differ between groups. Compared with human milk-fed infants at 2 wks, formula-fed infants produced more TNF-alpha and IFN-gamma and had more cells expressing ICAM-1 (CD54) after incubation with BLG and SOY (p < 0.05). At 6 wks of age, infants fed Formula+LCP produced more TNF-alpha with SOY (3.2-fold) and IFN-gamma (3.3-fold) with BLG compared with infants fed Formula (p < 0.05). In conclusion, low-risk term infants fed formula before 14 d of age produced more TNF-alpha and IFN-gamma in response to food proteins. Feeding Formula+LCP for 4 wks maintained the higher TNF-alpha and IFN-gamma response to these food proteins.

Long-chain polyunsaturated fat supplementation in children with low docosahexaenoic acid intakes alters immune phenotypes compared with placebo

OBJECTIVES

The objectives of this study were to assess the effects of long-term supplementation with arachidonic acid (AA; 20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3) on cell phenotypes and cytokine production in children.

PATIENTS AND METHODS

This randomized, double-blind, placebo-controlled trial provided children, (ages 5-7 years; n = 37) who had low intakes of DHA, with a dietary supplement containing AA (20-30 mg daily) and DHA (14-21 mg daily) or a placebo supplement for 7 months. After the supplementation period, a series of stimulants (pokeweed mitogen, phytohemagluttinin, lipopolysaccharide, beta-lactoglobulin, and ibuprofen) was used to stimulate peripheral blood mononuclear cells ex vivo. Antigen expression on T cells (CD25 and CD80), B cells, and macrophages (CD54), as well as cytokine production (interleukin [IL]-4, IL-10, tumor necrosis factor, IL-2, IL-6, and interferon-gamma), were measured using flow cytometry, monoclonal antibodies, and cytometric bead array, respectively.

RESULTS

Mononuclear cells from children provided long-chain polyunsaturated fatty acids (LCPUFAs) had fewer CD8+ cells expressing CD25 and CD80 compared with placebo after exposure to each mitogen. The LCPUFA group also exhibited lower proportions of CD14+ cells after stimulation with beta-lactoglobulin and ibuprofen. The proportion of CD54+ cells was 2-fold higher for the LCPUFA group compared with placebo after exposure to ibuprofen and beta-lactoglobulin (P < 0.05). Each of these immune effects related to the amount of AA and/or DHA in the plasma and erythrocyte phospholipids.

CONCLUSIONS

Alterations in cell phenotypes were evident when children were supplemented with AA and DHA. The results of this study have important implications for immune development and sensitivity to antigens in children.