Figure 3.

A transient dexamethasone therapy induces CXCR3 mediated CD8⁺ T cells migration to tissue sites. (A) A schematic of the experiments is shown. 10 × 10³ OT1 cells were transferred in C57BL/6 mice. Recipient animals were infected intranasally with MHV68 M2-SIINFEKL virus the following day. Infected animals were then divided into three groups. One group received diluent. The second group received dexamethasone (10 mg/kg B Wt) and the third group received both dexamethasone and anti-CXCR3 antibody at day 6 and 7 post infection. The response of CD8⁺ T cells and viral load were analyzed at 8 dpi. (B,C) The frequencies and phenotype of H-2K^b-SIINFEKL-tetramer^+veCD8⁺ T cells are shown by representative FACS plots (B) and bar diagrams (C) in the peripheral blood of animals in different groups. (D,E) The frequencies of H-2K^b-SIINFEKL-tetramer^+veCD8⁺ T cells are shown by representative FACS plots (D) and bar diagrams (E) in bronchoalveolar tissue lavage samples of animals from different groups. (F,G) The frequencies and phenotype of K^b-SIINFEKL-tetra^+veCD8⁺ T cells are shown by representative FACS plots (F) and bar diagrams (G) in the draining mediastinal LNs of animals in different groups. (H,I) The frequencies and phenotype of H-2K^b-SIINFEKL-tetramer^+veCD8⁺ T cells are shown by representative FACS plots (H) and bar diagrams (I) in the spleens of animals in different groups. (J) Viral load was measured from lung homogenates of different groups of animals by plaque forming assays. The replicating virus load is shown by bar diagrams in different groups. In each experimental group 5 animals were included. ***p < 0.001; **p < 0.005; *p < 0.05, and NS (p > 0.05)- not significant (Unpaired t-test).