Recognition of Leishmania antigens by T lymphocytes from nonexposed individuals
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Recognition of Leishmania antigens by T lymphocytes from nonexposed individuals. / Kemp, M; Hansen, M B; Theander, T G.
In: Infection and Immunity, Vol. 60, No. 6, 1992, p. 2246-51.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Recognition of Leishmania antigens by T lymphocytes from nonexposed individuals
AU - Kemp, M
AU - Hansen, M B
AU - Theander, T G
N1 - Keywords: Adult; Animals; Antigens, CD; Antigens, CD45; Antigens, Protozoan; DNA; Histocompatibility Antigens; Humans; Interferon Type II; Leishmania; Lymphocyte Activation; Phenotype; T-Lymphocytes
PY - 1992
Y1 - 1992
N2 - Crude antigen preparations of Leishmania promastigote sonicates were found to induce in vitro proliferation and gamma interferon production in peripheral blood mononuclear cells (PBMC) from individuals without known exposure to the parasite. The proliferating cells were mainly CD2-positive T cells. The proliferative response was maximal after more than 6 days of incubation with the antigens in contrast to the proliferation induced by the mitogenic lectin phytohemagglutinin (PHA), which peaked after 3 to 5 days. Judged by limiting dilution analysis, the frequencies of antigen-reactive precursor cells were less than 1:10,000 and varied considerably between individuals. Depletion of CD45R0-positive (memory) cells from the PBMC abolished proliferative responses induced by Leishmania antigen and by tetanus toxoid. In cell populations depleted of CD45RA-positive (naive) cells, only a small reduction in response was observed. Cell populations depleted of either CD45R0-positive cells or CD45RA-positive cells both responded to PHA. We conclude that presumably unexposed individuals have a low number of Leishmania-reactive T cells in their circulatory systems. The Leishmania-reactive T cells in these individuals are most likely memory cells recognizing antigens present both in the Leishmania preparations and in the environment.
AB - Crude antigen preparations of Leishmania promastigote sonicates were found to induce in vitro proliferation and gamma interferon production in peripheral blood mononuclear cells (PBMC) from individuals without known exposure to the parasite. The proliferating cells were mainly CD2-positive T cells. The proliferative response was maximal after more than 6 days of incubation with the antigens in contrast to the proliferation induced by the mitogenic lectin phytohemagglutinin (PHA), which peaked after 3 to 5 days. Judged by limiting dilution analysis, the frequencies of antigen-reactive precursor cells were less than 1:10,000 and varied considerably between individuals. Depletion of CD45R0-positive (memory) cells from the PBMC abolished proliferative responses induced by Leishmania antigen and by tetanus toxoid. In cell populations depleted of CD45RA-positive (naive) cells, only a small reduction in response was observed. Cell populations depleted of either CD45R0-positive cells or CD45RA-positive cells both responded to PHA. We conclude that presumably unexposed individuals have a low number of Leishmania-reactive T cells in their circulatory systems. The Leishmania-reactive T cells in these individuals are most likely memory cells recognizing antigens present both in the Leishmania preparations and in the environment.
M3 - Journal article
C2 - 1534072
VL - 60
SP - 2246
EP - 2251
JO - Infection and Immunity
JF - Infection and Immunity
SN - 0019-9567
IS - 6
ER -
ID: 6766865