Outcome of infection with different strains of Trypanosoma cruzi in mice lacking CD4 and/or CD8.
Mice lacking CD4 and/or CD8 gene expression, generated by embryonic stem-cell technology, were used to study the role of CD4+ and CD8+ cells in the resistance to the acute infection with virulent (Tulahuén and RA) or mild (CA-I) strains of Trypanosoma cruzi. The presence of both CD4+ and CD8+ cells contributed to the survival of mice infected with T. cruzi, and each T-cell subtype was able to sustain protective functions in the absence of the other one. However, in certain host-parasite combinations, CD8+ cell-independent mechanisms were able to control the parasite load. Moreover, CD8- mice chronically infected with a low virulent strain of T. cruzi were protected from an otherwise lethal challenge with the parasite. A different organ distribution of parasite nests was observed when mutant (but not wild type) animals infected with different parasite strains were compared. CD4- mice produced high levels of IgG antibodies against peptide antigens or a whole homogenate from the parasite after infection with CA-I strain. A dramatic enhancement of IgG1- and IgG2a-specific antibodies was observed.
Rottenberg
M E
ME
Immunology Laboratory, Karolinska Institute, Stockholm, Sweden.
Riarte
A
A
Sporrong
L
L
Altcheh
J
J
Petray
P
P
Ruiz
A M
AM
Wigzell
H
H
Orn
A
A
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D015704:CD4 Antigens / Q000235:genetics / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens / Q000235:genetics / Q000502:physiology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D014355:Chagas Disease / Q000150:complications / Q000276:immunology*; D006183:H-2 Antigens / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007153:Immunologic Deficiency Syndromes / Q000150:complications / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D014349:Trypanosoma cruzi / Q000276:immunology* / Q000472:pathogenicity; D014774:Virulence
D000953:Antigens, Protozoan; D015704:CD4 Antigens; D016827:CD8 Antigens; D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D007074:Immunoglobulin G