designed the animal experiment and led the animal study. and cows milk showed similarity in their inherent immunogenicity, sensitising and eliciting capacity. Results show that there was a lower cross-reactivity between caseins than between whey proteins from camel and cows milk. Conclusions: The study showed that camel and cows milk have a low cross-reactivity, indicating a low protein similarity. Results demonstrate that camel milk could be a promising alternative to cows milk-based hypoallergenic infant formulas. Keywords:food allergy, cows milk, camel milk, infant formula, animal models == 1. Introduction == Cows milk allergy (CMA) is the most prevalent food allergy in infants and small children [1], affecting around 2.5% [2,3], although differences are observed between studies and countries [4]. Although most CMA children outgrow their allergy, some keep it for life [5]. Originally, it was though that most children did outgrow their CMA before the age of three years, but there seems to be a tendency that more and more children outgrow their CMA later in life and for some it Luteoloside may even last for lifetime [6,7]. Breastfeeding is the most suited source of nutrition for a newborn infant [8]. However, in some situations, breastfeeding is impossible or insufficient and a substitute such as an infant formula is needed [9]. Infant formulas are usually based on cows milk, as this is the most easily accessible milk source globally [10]. When an infant suffers from or is at risk of developing CMA, alternatives to conventional infant formulas are recommended such as hypoallergenic infant formulas, based on extensively or partially hydrolysed cows milk proteins [11]. In addition to Luteoloside cows milk-based hypoallergenic infant formulas, additional alternatives to conventional infant formulas are found on the market, such as amino acid-based infant formulas, plant-based infant formulas (e.g., soya-based) and infant formulas based on other mammalian milk (e.g., goat or sheep) [8,12,13]. Extensively and partially hydrolysed infant formulas as well as amino acid-based infant formulas are poor in flavour, and, thus, some newborns may refuse them [5,14]. On the other hand, it has been reported that sheep and goat milk-based infant formulas may only be an alternative for some newborns due to a high cross-reactivity between cows milk proteins and proteins from goat and sheep milk [13,15]. In addition, plant-based infant Luteoloside formulas are seldom recommended due to their low nutritional value [16,17]. For those reasons, new or improved alternatives to conventional infant formulas are still of interest. Due to the large evolutionary distance between Camelus dromedaries (Camelidae family) and the Bovidae family animals, camel milk is quite different in its composition compared to cows milk. Equivalent to human milk, the allergenic milk protein-lactoglobulin (BLG) is also absent in camel milk [18]. Moreover, similar to human milk, camel milk has approximately double the amount of -casein and approximately five times the amount of immunoglobulins in comparison to cows milk [19]. Rastani et al. [13] showed that CMA patients did not recognise camel milk by immunoblotting and concluded that camel milk is a promising alternative to cows milk for infant formula manufacture. Further, based on double-blind, placebo-controlled food challenges, Navarre-Rodriguez et al. [20] concluded that camel milk is a safe and tolerable alternative for CMA patients above the age Luteoloside of one year. Camel milk is already commercially available in the Middle East, Australia, United Kingdom and the Netherlands [21,22,23,24]. In other regions such as in African countries, it is a traditionally consumed product, although without a control on its quality and safety [25]. There are a number of studies showing that camel milk is nutritionally suitable for human consumption [21,26]. For those reasons, camel milk is an exciting and suitable product with the potential to be a future alternative to hypoallergenic cows milk-based infant formulas in prevention, treatment and management of CMA in infants and small children. The purpose of this study was to investigate the immunogenicity and allergenicity of camel and cows milk as well as studying cross-reactivity between proteins from the two sources. To do this, Brown Norway (BN) rats were immunised TMUB2 intraperitoneally (i.p.) with either camel milk, cows milk, cows milk casein fraction or cows milk whey fraction and antibody responses were evaluated for level, specificity, avidity, functionality and cross-reactivity by means of different enzyme-linked immunosorbent assays (ELISAs), immunoblotting and in vivo test. This should allow for an overview of Luteoloside the usability of camel milk as an alternative to hypoallergenic infant formulas. == 2..