New insights into the dual recruitment of IgA+ B cells in the developing mammary gland.
Dorothée Bourges, François Meurens, Mustapha Berri, Claire Chevaleyre, Galliano Zanello, Benoît Levast, Sandrine Melo, Volker Gerdts, Henri Salmon
Molecular immunology
45
3354-62
2008
Show Abstract
In monogastric mammals, transfer of passive immunity via milk and colostrum plays an important role in protecting the neonate against mucosal infections. Here we analyzed the hypothesis that during gestation/lactation IgA+ plasmablasts leave the intestinal and respiratory surfaces towards the mammary gland (MG). We compared the recruitment of lymphocytes expressing homing receptors alpha4beta1 and alpha4beta7 to expression of their vascular counter-receptors, VCAM-1 and MAdCAM-1. Furthermore, the expression of the chemokines responsible for the recruitment of IgA+ plasmablasts was analyzed. Data confirmed that expressions of CCL28 and MAdCAM-1 in the MG increased during pregnancy and alpha4beta1+ and alpha4beta7+/IgA+ cell recruitment in lactation correlated with increase of CCL28 expression. Interestingly, VCAM-1 expression was found in small blood vessels of the lactating porcine MG, while in mice VCAM-1 was expressed in large blood vessels within the MG. Thus, our results indicate that the recruitment of IgA+ plasmablasts to MG is mediated by VCAM-1/alpha4beta1 and MAdCAM-1/alpha4beta7 in conjunction with CCL28/CCR10. They support the existence of a functional link between entero- and upper respiratory surfaces and MG, thereby, conferring protection against aero-digestive pathogens in the newborn. | | 18533264
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Brain-derived neurotrophic factor (BDNF) and TrkB in the piglet brainstem after post-natal nicotine and intermittent hypercapnic hypoxia.
Samantha Tang,Rita Machaalani,Karen A Waters
Brain research
1232
2008
Show Abstract
Brain-derived neurotrophic factor (BDNF) and its receptor TrkB play a significant role in the regulation of cell growth, survival and death during central nervous system development. The expression of BDNF and TrkB is affected by noxious insults. Two insults during the early post-natal period that are of interest to our laboratory are exposure to nicotine and to intermittent hypercapnic hypoxia (IHH). Piglet models were used to mimic the conditions associated with the risk factors for the sudden infant death syndrome (SIDS) including post-natal cigarette smoke exposure (nicotine model) and prone sleeping where the infant is subjected to re-breathing of expired gases (IHH model). We aimed to determine the effects of nicotine and IHH, alone or in combination, on pro- and rhBDNF and TrkB expression in the developing piglet brainstem. Four piglet groups were studied, with equal gender ratios in each: control (n=14), nicotine (n=14), IHH (n=10) and nic+IHH (n=14). Applying immunohistochemistry, and studying six nuclei of the caudal medulla, we found that compared to controls, TrkB was the only protein significantly decreased after nicotine and nic+IHH exposure regardless of gender. For pro-BDNF and rhBDNF however, observed changes were more evident in males than females exposed to nicotine and nic+IHH. The implications of these findings are that a prior nicotine exposure makes the developing brainstem susceptible to greater changes in the neurotrophic effects of BDNF and its receptor TrkB in the face of a hypoxic insult, and that the effects are greater in males than females. | Pig | 18674523
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