Figure 1.

Route of lymphocytic choriomeningitis virus (LCMV) infection influences the viral titer kinetic and CD8⁺ T number in blood. (A,B) C57BL/6 mice were infected intravenously (i.v.) with 200 plaque-forming units (PFUs) lymphocytic choriomeningitis virus strain WE (LCMV-WE). (A) Conventional immunohistochemistry of LCMV in the spleen and inguinal lymph nodes (iLNs) on day 3 (d3) and day 6 (d6) after infection (n = 3). Scale bars on main images represent 500 µm, and scale bars on inlays represent 100 µm. Histological images were captured at 4× magnification (main images) or 20× magnification (inlays) with a Keyence BZ-9000E microscope. One of the three representative images is shown. (B) Viral titers in the spleen, iLNs, and liver were measured at the indicated time points (n = 7, pooled from two experiments). Black squares = spleen; white squares = iLNs; green squares = liver. (C,D) C57BL/6 mice were infected subcutaneously (s.c.) with 200 PFU LCMV-WE. (C) Conventional histological staining of LCMV in the spleen and iLNs at the indicated time points (d3 and d6). Scale bars on main images represent 500 µm, and scale bars on inlays represent 100 µm (n = 3). Histological images were captured at 4× magnification (main images) or 20× magnification (inlays) with a Keyence BZ-9000E microscope. One of the three representative images is shown. (D) Viral titers in the spleen, iLNs, and liver were measured on d3 and d6 after subcutaneously infection (n = 7; pooled from two experiments). Black squares = spleen; white squares = iLNs; green squares = liver. (E) C57BL/6 mice were intravenously (i.v.) or subcutaneously (s.c.) infected with 200 PFU LCMV-WE. Tetramer (Tet) GP33⁺ CD8⁺ T cells in the blood were counted on d9, d12, and d15 after infection (n = 7; pooled from two experiments). Black squares = LCMV-WE i.v.; white squares = LCMV-WE s.c. Statistical significance was set at the level of P < 0.05 and was determined by two-way analysis of variance (B,D,E). **P < 0.01, ***P < 0.001.