Role of T-lymphocytes in production of antibody to antigens of Rickettsia tsutsugamushi and other Rickettsia species

Abstract

The requirement of thymus-dependent lymphocytes for antibody production to Rickettsia tsutsugamushi, Rickettsia akari, Rickettsia conorii, and Rickettsia typhi was investigated by comparing antibody production in athymic (nu/nu) or thymus-bearing BALB/c mice. Athymic BALB/c mice produced antibody after infection with R. akari, R. conorii, and R. typhi as measured by indirect fluorescent antibody titration or radioimmunoassay. Antibody production in these mice was as great or greater than in the thymus-bearing mice and demonstrated similar kinetics. In contrast, athymic BALB/c mice infected either intraperitoneal

Structural and functional studies of the early T lymphocyte activation 1 (Eta-1) gene. Definition of a novel T cell-dependent response associated with genetic resistance to bacterial infection.

“…Susceptible mouse strains (Ric') allow local and systemic bacterial growth during the first week of RT infection and die within 10-12 d. By contrast, RICK strains show minimal levels of bacterial infection over the first week and survive infection (37,40). Although Ric affects early resistance to RT infection, mice bearing the RicR genotype are converted to the Ric' phenotype if T cell development is genetically impaired by the nu mutation (39,41). An explanation for these observations is provided by analysis of the Eta-1 gene, which maps to the Ric locus .…”

Immunosuppression associated with the development of chronic infections with Rickettsia tsutsugamushi: adherent suppressor cell activity and macrophage activation

“…This chronic infection is thought to persist for the life of the animal, suggesting that the rickettsiae are able to survive in the face of an immune response which is demonstrable at the same times (16,32,33). The immunity which develops in response to infection consists of a cell-mediated immunity as measured by a delayed-type hypersensitivity (15), antigen-induced lymphocyte proliferation (16), lymphokine production (27,28), and the development of lymphocytes capable of transferring protective immunity to naive animals (33), as well as a T-dependent antibody response (13).…”

Short‐ and Long‐Term Immune Responses of CD‐1 Outbred Mice to the Scrub Typhus DNA Vaccine Candidate: p47Kp

“…The host immune response to Orientia tsutsugamushi, an obligate intracellular bacterium that is the causative agent of scrub typhus, is believed to be mediated by both the humoral and cellular arms of the immune system, with greater importance associated with the latter. 1,2 To develop an effective vaccine to prevent or ameliorate scrub typhus, knowledge of the protective immune response to O. tsutsugamushi needs to be ascertained. Our laboratory has demonstrated that the DNA vaccine vector pVR1012 carrying the O. tsutsugamushi Karp strain 47-kDa protein gene (p47Kp) consistently provides outbred mice protection against homologous challenge (W-M. Ching et al, unpublished data).…”