An IL-15 dependent CD8 T cell response to selected HIV epitopes is related to viral control in early-treated HIV-infected subjects.
In some early-treated HIV-positive patients, Structured Treatment Interruption (STI) is associated to spontaneous control of viral rebound. Thus, in this clinical setting, we analyzed the immunological parameters associated to viral control. Two groups of early treated patients who underwent STI were retrospectively defined, according to the ability to spontaneously control HIV replication (Controller and Non-controller). Plasma cytokine levels were analyzed by multiplex analysis. CD8 T cell differentiation was determined by polychromatic flow cytometry. Antigen-specific IFN-gamma production was analyzed by ELISpot and intracellular staining after stimulation with HIV-peptides. Long-term Elispot assays were performed in the presence or absence of IL-15. Plasma IL-15 was found decreased over a period of time in Non-Controller patients, whereas a restricted response to Gag (aa.167-202 and 265-279) and Nef (aa.86-100 and 111-138) immunodominant epitopes was more frequently observed in Controller patients. Interestingly, in two Non-Controller patients the CD8-mediated T cells response to immunodominant epitopes could be restored in vitro by IL-15, suggesting a major role of cytokine homeostasis on the generation of protective immunity. In early-treated HIV+ patients undergoing STI, HIV replication control was associated to CD8 T cell maturation and sustained IL-15 levels, leading to HIV-specific CD8 T cell responses against selected Gag and Nef epitopes.
D'Offizi
G
G
National Institute for Infectious Diseases, Lazzaro Spallanzani - I.R.C.C.S., Rome, Italy. gdoffizi@inmi.it
Gioia
C
C
Corpolongo
A
A
Martini
F
F
Paganelli
R
R
Volpi
I
I
Sacchi
A
A
Tozzi
V
V
Narciso
P
P
Poccia
F
F
D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D000939:Epitopes / Q000276:immunology* / Q000494:pharmacology; D015488:HIV Antigens / Q000276:immunology* / Q000494:pharmacology; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D006801:Humans; D007156:Immunologic Memory / Q000187:drug effects; D007371:Interferon-gamma / Q000276:immunology; D019409:Interleukin-15 / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology / Q000494:pharmacology; D011994:Recombinant Proteins / Q000276:immunology / Q000494:pharmacology; D014779:Virus Replication / Q000187:drug effects; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000276:immunology / Q000494:pharmacology; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000276:immunology / Q000494:pharmacology
D019380:Anti-HIV Agents; D000939:Epitopes; D015488:HIV Antigens; D019409:Interleukin-15; D010446:Peptide Fragments; D011994:Recombinant Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; D054311:nef Gene Products, Human Immunodeficiency Virus; D007371:Interferon-gamma