title: Apoptosis and frequency of total and effector CD8+ T lymphocytes from cutaneous leishmaniasis patients during antimonial therapy.
abstract: BACKGROUND
  Leishmaniasis is an important parasitic disease affecting millions worldwide. Human cutaneous leishmaniasis (CL) is endemic in Rio de Janeiro, Brazil, where is caused by Leishmania braziliensis. The adaptive immune response is accountable for the healing of CL and despite of key role of CD8+ T cells in this immune response little is known about the CD8+ T lymphocytes frequencies, apoptosis and antigen-responsive CD8+ T lymphocytes of CL patients during antimonial therapy.
  
  
  METHODS
  Using flow cytometry, we examined total and effector CD8+ T cells from CL patients before (PBT), during (PDT) and after (PAT) treatment for apoptosis and frequencies upon isolation and after in vitro L. braziliensis antigens (LbAg)-stimulation culture. Besides, a correlation study between immunological findings and lesion size was done.
  
  
  RESULTS
  PDT showed lower frequencies of total CD8+ T lymphocytes and higher levels of apoptosis of these cells, which were also observed following LbAg-stimulation culture. Regarding effector CD8+ T cells, high frequencies were observed in PDT, while lower frequencies were observed in PAT. Interestingly, PDT showed higher frequencies of apoptotic-effector CD8+ T lymphocytes. Similar results were seen after in vitro antigenic-stimulation assays. Correlation analysis showed that the greater the size of lesion, the smaller the frequency of effector CD8+ T lymphocytes in PDT and PAT, as well as a positive correlation between apoptotic-effector CD8+ T cells frequency and lesion size of PDT.
  
  
  CONCLUSIONS
  Changes in effector CD8+ T-lymphocyte frequencies, during and after treatment, seem to represent a critical stage to generate an efficient immune response and suggest that these cells would be evolved in the triggering or in the resolution of lesion, under the influence of therapy. This hypothesis opens new perspectives to clarify controversial statements about the protective or deleterious role of CD8+ T cells in the cure or aggravation of CL and the new approach of evaluating patients during treatment proved to be of utmost importance for understanding the immune response in the healing process of human CL.
authors: Raquel
authors: R
authors: Ferraz
authors: Clarissa F
authors: CF
authors: Cunha
authors: Adriano
authors: A
authors: Gomes-Silva
authors: Armando O
authors: AO
authors: Schubach
authors: Maria Inês F
authors: MI
authors: Pimentel
authors: Marcelo Rosandiski
authors: MR
authors: Lyra
authors: Sergio Cf
authors: SC
authors: Mendonça
authors: Cláudia M
authors: CM
authors: Valete-Rosalino
authors: Alda Maria
authors: AM
authors: Da-Cruz
authors: Álvaro Luiz
authors: ÁL
authors: Bertho
mesh_terms: D000328:Adult; D000953:Antigens, Protozoan / Q000276:immunology; D000981:Antiprotozoal Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D001938:Brazil; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007892:Leishmania braziliensis / Q000187:drug effects / Q000276:immunology; D016773:Leishmaniasis, Cutaneous / Q000188:drug therapy* / Q000276:immunology*; D008297:Male; D008536:Meglumine / Q000627:therapeutic use*; D000077485:Meglumine Antimoniate; D008875:Middle Aged; D009942:Organometallic Compounds / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D000953:Antigens, Protozoan; D000981:Antiprotozoal Agents; D009942:Organometallic Compounds; D008536:Meglumine; D000077485:Meglumine Antimoniate