title: Longitudinal analysis of the acute Sendai virus-specific CD4+ T cell response and memory.
abstract: The development and persistence of Sendai virus-specific CD4+ T cell memory has been analyzed following respiratory infection of C57BL/6J mice by determining the prevalence of IL-2-producing Th cell precursors (Thp). Frequencies as high as 1:40 virus-specific CD4+ T cells were found in the regional lymph nodes and spleen during the acute phase of the host response and persisted at levels > or =1:500 for 2 to 3 mo. Thereafter, these CD4+ T cells tended to distribute more to the spleen than to the lymph nodes, a pattern that persisted for the life of the animals. From 3 to 12 mo after infection, virus-specific Thp were always detectable, although the numbers were diminished relative to those measured during the acute phase. Thereafter, however, in both contemporary and cumulative assays, there was a progressive increase in both the frequency and number of Thp. These increases were especially apparent for mice more than 2 years of age. This may reflect enrichment of the CD4+CD44high memory set due to the gradual diminution of the naive CD4+CD62LhighCD44low component. Analysis of DNA staining profiles for the CD4+ T cells showed high levels of cycling for the acute phase of the response, whereas the rate of T cell turnover measured for the CD4+CD44high population by bromodeoxyuridine incorporation indicated a pattern of stable, continuing proliferation throughout life. Virus-specific CD4+ T cell memory resulting from a single exposure to a readily eliminated RNA virus is thus maintained indefinitely in laboratory mice.
authors.affiliation: Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Topham
authors.forename: P C
authors.initials: PC
authors.lastname: Doherty
mesh_terms: D000208:Acute Disease; D000818:Animals; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002453:Cell Cycle; D003289:Convalescence; D005260:Female; D018960:Hyaluronan Receptors / Q000032:analysis; D007156:Immunologic Memory; D007376:Interleukin-2 / Q000096:biosynthesis; D008198:Lymph Nodes / Q000276:immunology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018108:Respirovirus / Q000276:immunology*; D010253:Respirovirus Infections / Q000276:immunology* / Q000473:pathology; D013154:Spleen / Q000276:immunology / Q000473:pathology
chemical_list: D018960:Hyaluronan Receptors; D007376:Interleukin-2