HIV type 1 envelope glycoprotein gp120 induces development of a T helper type 2 response to Cryptococcus neoformans.
OBJECTIVE
To analyse the contribution of HIV type 1 envelope glycoprotein gp120 to regulation of a T-cell response to Cryptococcus neoformans.


METHODS
Monocytes treated with recombinant gp120 and exposed to C. neoformans were used as antigen presenting cells (APC) in coculture with autologous T lymphocytes.


METHODS
Costimulatory and major histocompatibility complex class II molecules were evaluated on APC by flow cytometry analysis. T-cell proliferation was determined as 3H thymidine incorporation. Cytokine production was analysed by enzyme-linked immunosorbent assay.


RESULTS
gp120 had multiple effects on APC and the T-cell response including: (i) up-regulation of major histocompatibility complex class II antigens on the APC surface resulting from both redistribution of molecules from the intracellular pool and synthesis of new molecules; (ii) up-regulation of B7-2 molecules on the APC surface; (iii) altered T-cell proliferation; and (iv) promotion of interleukin-4 and inhibition of interferon-gamma synthesis and release.


CONCLUSIONS
These data indicate that gp120 alters the normal T-cell response to C. neoformans, promoting a T-helper type 2 response. The altered T-cell response produced by gp120 may play an important role in the pathogenesis of cryptococcosis in the patient with AIDS.
Pietrella
D
D
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Italy.
Monari
C
C
Retini
C
C
Palazzetti
B
B
Kozel
T R
TR
Vecchiarelli
A
A
D000946:Antigens, Fungal / Q000276:immunology; D018122:B7-1 Antigen / Q000276:immunology; D002455:Cell Division / Q000276:immunology / Q000502:physiology; D002478:Cells, Cultured; D003455:Cryptococcus neoformans / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000502:physiology*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D018418:Th2 Cells / Q000276:immunology* / Q000378:metabolism
D000946:Antigens, Fungal; D018122:B7-1 Antigen; D015699:HIV Envelope Protein gp120; D015847:Interleukin-4; D007371:Interferon-gamma