title: Lower levels of IgG1 in comparison with IgG2a are associated with protective immunity against Leishmania tropica infection in BALB/c mice.
abstract: OBJECTIVE
  Leishmania (L.) tropica is the causative agent of different forms of human leishmaniasis. There is little information about the role of Leishmania-specific antibodies in the immune response against L. tropica infection. The aim of this study is to evaluate the role of Leishmania-specific antibodies and their immunoglobulin G (IgG) isotypes in L. tropica infection.
  
  
  METHODS
  L. tropica at two different doses (high dose, 106parasites/mouse and low dose, 103parasites/mouse) were used for infection of BALB/c mice. BALB/c mice infected with Leishmania major were used for comparison. Anti-Leishmania antibodies of the IgG1 and IgG2a isotypes were assayed by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Our data showed that (1) a higher parasite dose results in higher levels of antibody. (2) L. tropica infection results in a lower IgG1 antibody response, compared with L. major infection. (3) The IgG2a/IgG1 antibody response in L. tropica infection is higher than that in L. major infection.
  
  
  CONCLUSIONS
  A higher IgG2a/IgG1 ratio is associated with protective immune response in L. tropica infection. These data can help to approach the complex profile of immunity against L. tropica infection.
authors.affiliation: Immunology Department, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Mosayeb
authors.initials: M
authors.lastname: Rostamian
authors.affiliation: Department of Microbiology, Qom Branch of Islamic Azad University, Qom, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Sohrabi
authors.affiliation: Department of Microbiology, Kurdistan Science and Research Branch, Islamic Azad University, Sanandaj, Iran.
authors.forename: Hanie
authors.initials: H
authors.lastname: Kavosifard
authors.affiliation: Immunology Department, Pasteur Institute of Iran, Tehran, Iran. Electronic address: mahmoudzadehh@yahoo.com.
authors.forename: Hamid M
authors.initials: HM
authors.lastname: Niknam
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood / Q000276:immunology; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D000949:Histocompatibility Antigens Class II; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D018320:Leishmania major / Q000276:immunology; D007895:Leishmania tropica / Q000276:immunology*; D007896:Leishmaniasis / Q000276:immunology* / Q000469:parasitology*; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D000953:Antigens, Protozoan; D000949:Histocompatibility Antigens Class II; D007074:Immunoglobulin G
keywords: BALB/c mice; Leishmania tropica; immunity; immunoglobulin G