Evaluating immune cells in physiological settings: Studying the neonatal immune landscapes and the effect of fever-range temperatures on T-cell differentiation

Abstract

The immune network is modulated by an n-dimensional matrix of genetic, epigenetic and environmental factors. In neonates, development occurs in an immunologically sterile environment. Their immune landscape is modelled predominantly by genetic and ethno-geographical factors. These inherent variations give rise to populations of immune subsets that are both tightly and loosely regulated. One such human population study, from 6 villages near Pune, showed interesting trends in frequencies of B, T, and innate cell subsets. Moreover, the data also presented correlations between frequencies of immune subsets that developmentally belong to distinct lineages, therefore raising questions about probable “common” interacting pathways. Conversely, post infection in vertebrates, a febrile response is generated on immunological challenge. Previous reports have demonstrated that hyperthermia augments immune responses of the innate and adaptive arms. However, the effect of temperature on T-cell fate determination is not known. The data presented here, suggests that the Th2 response is likely to be affected more significantly than the Th1 response at raised temperatures. Further quantitative studies need to be undertaken to decipher the molecular players that sense temperature fluctuations and activate downstream signaling in this pathway.