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Abstract
DIVERSE NEUTRALIZING ANTIBODY RESPONSE IN HIV-1 INFECTED SIBLINGS WITH DIFFERENT DISEASE PROGRESSION
C. Ripamonti1, F. Sironi2, A. Plebani3, P. Lusso2, G. Scarlatti1
1Viral Evolution and Transmission Unit, 2Human Virology Unit, DIBIT, San Raffaele Scientific Institute, Milan, 3Department of Pediatrics, University of Milan, Milan, Italy
The patterns of disease progression differ among HIV-1 infected children born to seropositive mothers. Besides timing of transmission, viral and immunologic factors were also suggested to play a role in disease progression. Indeed, presence of an X4 virus from early age was shown to be associated with fast progression, whereas little is know about the role of the humoral immune response.
To better outline the role of neutralizing antibody (NAb) we studied two siblings with different disease progression. Sibling A was a delayed progressor who developed only moderate clinical symptoms by 3 years of age and had no signs of immunodeficiency by 5 years of age, whereas sibling B was a fast progressor who developed AIDS-defining symptoms and severe CD4+ T-cell depletion within 2 years of age. Only sibling B was treated with ART from age 6 months.
The study of chemokine receptor usage of viral isolates obtained at yearly intervals showed that both siblings were infected with an R5 virus, which persisted throughout follow-up (for A: 6 years; for B: 3 years). The children sera were tested for NAb against their autologous isolates obtained both simultaneously and during follow-up. Interestingly, the delayed progressor developed during the first months of life a cross-neutralizing response towards both early and late isolates, which persisted during follow-up, whereas the fast progressor developed a NAb response only towards the early isolate. Late but not early sera of both siblings were able to cross-neutralize the other sibling’s viral isolates regardless of the clinical stage. Early and late sera of both siblings were able to bind V3 loop- but not V1/V2 stem- derived synthetic peptides in ELISA. Sequencing of the env V3 region of the viruses showed close but not identical populations in the siblings.
These data indicate that an early and persistent cross-neutralizing response is associated with a better disease outcome in HIV-1 infected children born to seropositive mothers.
The 2nd IAS Conference on HIV Pathogenesis and Treatment
Abstract no.
1078
Suggested Citation
" C. Ripamonti , et al.
DIVERSE NEUTRALIZING ANTIBODY RESPONSE IN HIV-1 INFECTED SIBLINGS WITH DIFFERENT DISEASE PROGRESSION.
Poster:
The 2nd IAS Conference on HIV Pathogenesis and Treatment:
Abstract no.
1078"
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