The protective properties of milk and colostrum in non-human species

Recent Advances in Camel Immunology

Camels are domesticated animals that are highly adapted to the extreme desert ecosystem with relatively higher resistance to a wide range of pathogens compared to many other species from the same geographical region. Recently, there has been increased interest in the field of camel immunology. As the progress in the analysis of camel immunoglobulins has previously been covered in many recent reviews, this review intends to summarize published findings related to camel cellular immunology with a focus on the phenotype and functionality of camel leukocyte subpopulations. The review also describes the impact of different physiological (age and pregnancy) and pathological (e.g. infection) conditions on camel immune cells. Despite the progress achieved in the field of camel immunology, there are gaps in our complete understanding of the camel immune system. Questions remain regarding innate recognition mechanisms, the functional characterization of antigen-presenting cells, and the characterization of camel NK and cytotoxic T cells.

Investigation of total immunoglobulin G concentration, heavy chain antibody levels, and neutrophil to lymphocyte ratio in female camels and their newborn calves

Camels belong to a group of animals, where the structure of placenta does not allow intrauterine transfer of maternal immunoglobulins to the fetus and maternal immunity is exclusively transferred by colostrum to the newborn calf. There are few studies on the passive transfer of maternal immunity in the dromedary camel. This study determined total immunoglobulin G concentration, heavy chain antibody (HCAbs) levels, and neutrophils to lymphocytes ratio (NLR) in female camels and their newborn calves. For this, samples were collected from nine she-camels (blood and colostrum) and their calves (blood). IgG concentration and HCAb level were determined in mother serum and colostrum as well as in calf serum using ELISA. The NLR was calculated after the estimation of relative fractions of neutrophils and lymphocytes in collected blood samples using a blood cell analyzer. Both IgG and HCAbs were higher concentrated in camel colostrum than in mother serum. At parturition and before the first colostrum intake, calf serum did not contain any measurable concentration of IgG and only low levels of HCAbs. After colostrum consumption, a rise in IgG and HCAb levels was observed in calf serum. For total IgG, a minimum was reached on day 30 postnatum. While a significant increase in IgG concentration was seen on day 60 postnatum, no significant rise was measured in HCAbs at that age. Only post-colostrum IgG levels in calf serum correlated positively with IgG levels in mother colostrum. Directly after birth, newborn calves showed significantly higher NLR than their mothers. This indicates a pro-inflammatory nature of the calf immune response. The decrease of the NLR on day 60 postnatum may argue for the maturation of the calf immune response at this age.

Natural and artificial hyperimmune solutions: Impact on health in puppies

Colostrum and milk are complex mammary secretions providing the puppy with many nutritional and immunological factors, which play a crucial role for its correct development and survival. In the case of colostrum and/or milk intake deficiency, puppies are at increased risk of infectious diseases. This work reviews the various nutritional hyperimmune supplementations proposed to provide a passive immune protection and to positively impact puppies' health. Some strategies rely on canine immunoglobulins: canine colostrum banking and canine serum/plasma supplementation. Others involve heterologous sources of antibodies and other immune factors: bovine colostrum or hyperimmune egg powder. Among the different solutions evaluated from birth to weaning, canine plasma and hyperimmune egg powder showed promising beneficial effect on puppies' health. Canine plasma seems to positively impact not only growth (increased growth during the neonatal period), but also digestive health (higher species richness of intestinal microbiota) and the general health (tendency of lower morbidity). Puppies supplemented with hyperimmune egg powder presented increased neonatal growth and decreased risk of canine parvovirus infection. Nevertheless, natural canine maternal colostrum and milk ingestion remains the optimal guarantee for puppies' health and survival, as a source of immunity, energy and growth factors.

Passive transfer of maternal immunity in the dromedary (Camelus dromedarius), involvement of heavy chain antibodies

In many mammalian species, newborns are agammaglobulinemic; thus, colostrum and milk are the main sources of early protective antibodies. These antibodies are produced in the mother's serum and transferred to mammalian glands a few days before parturition. Here, we have studied the transfer of immunity from a she-camel immunized with human serum albumin (HSA) to her calf via colostrum and milk. Our results show that HSA-specific antibodies are produced in the mother's serum and are subsequently transferred to her colostrum. These specific antibodies are then transferred by suckling to the calf. The calf serum did not contain HSA-reactive antibodies at parturition and before the first feed, after suckling, a rise in reactivity was observed peaking at 24 h postpartum. The involvement of heavy chain antibodies (HCAbs) in the process of immunity transfer was also examined, and it was found that they were also transferred from the colostrum to the calf serum like conventional antibodies.

Differential temporal expression of milk miRNA during the lactation cycle of the marsupial tammar wallaby (Macropus eugenii)

BACKGROUND

Lactation is a key aspect of mammalian evolution for adaptation of various reproductive strategies along different mammalian lineages. Marsupials, such as tammar wallaby, adopted a short gestation and a relatively long lactation cycle, the newborn is immature at birth and significant development occurs postnatally during lactation. Continuous changes of tammar milk composition may contribute to development and immune protection of pouch young. Here, in order to address the putative contribution of newly identified secretory milk miRNA in these processes, high throughput sequencing of miRNAs collected from tammar milk at different time points of lactation was conducted. A comparative analysis was performed to find distribution of miRNA in milk and blood serum of lactating wallaby.

RESULTS

Results showed that high levels of miRNA secreted in milk and allowed the identification of differentially expressed milk miRNAs during the lactation cycle as putative markers of mammary gland activity and functional candidate signals to assist growth and timed development of the young. Comparative analysis of miRNA distribution in milk and blood serum suggests that milk miRNAs are primarily expressed from mammary gland rather than transferred from maternal circulating blood, likely through a new putative exosomal secretory pathway. In contrast, highly expressed milk miRNAs could be detected at significantly higher levels in neonate blood serum in comparison to adult blood, suggesting milk miRNAs may be absorbed through the gut of the young.

CONCLUSION

The function of miRNA in mammary gland development and secretory activity has been proposed, but results from the current study also support a differential role of milk miRNA in regulation of development in the pouch young, revealing a new potential molecular communication between mother and young during mammalian lactation.

Preventively enteral application of immunoglobulin enriched colostrums milk can modulate postoperative inflammatory response

Several studies demonstrated acute inflammatory response following traumatic injury. Inflammatory response during surgical interventions was verified by a significant increase of endotoxin plasma levels and a decrease of the endotoxin neutralizing capacity (ENC). However, the incidence of elevated endotoxin levels was significantly higher (89%) than detected bacterial translocation (35%). Thus parts or products of Gram-negative bacteria seem to translocate more easily into the blood circulation than whole bacteria. Along with the bacterial translocation, the inflammatory response correlated directly with the severity of the surgical intervention. In comparison after major and minor surgery Interleukin-6 (IL-6) and C-reactive protein (CRP) was also significantly different. Similar effects in mediator release were shown during endovascular stent graft placement and open surgery in infrarenal aortic aneurysm. Open surgery demonstrated a significant stronger endotoxin translocation and a decrease of ENC. Strategies to prevent translocation seem to be sensible. Colostrum is the first milk produced by the mammary glands within the first days after birth. It contains a complex system of immune factors and has a long history of use in traditional medicine. Placebo-controlled studies verified that prophylactic oral application of immunoglobulin-enriched colostrum milk preparation diminishes perioperative endotoxemia, prevents reduction of ENC and reduces postoperative CRP-levels, suggesting a stabilization of the gut barrier. This effect may be caused by immunoglobulin transportation by the neonatal receptor FcRn of the mucosal epithelium.In conclusion, there is an association of perioperative endotoxemia and the subsequent increase in mediators of the acute phase reaction in surgical patients. A prophylactic oral application of colostrum milk is likely to stabilize the gut barrier i.e. reduces the influx of lipopolysaccharides arising from Gram-negative bacterial pathogens and inhibits enterogenic endotoxemia. This appears to be a major mechanism underlying the therapeutic effect in patients at risk for Gram-negative septic shock.