HIV-1 infection is usually associated with a quantitative deficiency of CD4 helper/inducer T cells. Patients with HIV-1 infection have severely impaired CD4 helper/inducer T cell function. This is manifested by cutaneous anergy, decreased T cell proliferation to antigens and failure of antigen specific antibody production. The CD4 helper cell defect appears to be qualitative in that immunologic unresponsiveness in HIV-1 infected patients can occur despite normal numbers of circulating CD4 T lymphocytes. This is particularly true in children with maternally acquired HIV infection. A detailed understanding of the CD4 helper cell defect is important for devising rational therapies in HIV infection. We propose to study the CD4 helper T cell activation defect in children with maternally acquired HIV infection by examining: (1) T cell activation via the TCR/CD3-CD4 supramolecular complex. We will measure proliferation, IL-2R expression, and IL-2 synthesis in response to heteroconjugates of anti-CD3 and anti-CD4 mAbs. (2) Signalling via CD4. We will measure (a) proliferation, IL-2R expression and IL-2 synthesis in response to a mitogenic anti-CD4 mAb (mAb B66.6), (b) signal transduction following cross linking of surface C-D4 as evidenced by activation of the CD4 associated tyrosine kinase (p56IcK ) and by phosphorylation of CD3 C zeta. (3) Signalling via TCR/CD3. We will measure, (a) proliferation, IL-2R expression, and IL-2 synthesis in response to anti-TCR and anti-CD3 mAb, (b) signal transduction in T cells stimulated with anti-TCR and anti-CD3 mAbs as evidenced by generation of second messengers, Ca++ fluxes, and activation of protein kinase C, (c) the composition of the TCR/CD3 receptor complex. The results of these studies have important implications for the therapy of HIV infection and for understanding CD4 helper cell defects in immunodeficiency, infection and autoimmunity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI029906-05
Application #
2065311
Study Section
Special Emphasis Panel (ARR (V1))
Project Start
1990-07-01
Project End
1995-10-31
Budget Start
1994-05-01
Budget End
1995-10-31
Support Year
5
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Children's Hospital Boston
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02115
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Tsitsikov, E N; Fuleihan, R; McIntosh, K et al. (1995) Cross-linking of Fc gamma receptors activates HIV-1 long terminal repeat-driven transcription in human monocytes. Int Immunol 7:1665-70
Fuleihan, R; Trede, N; Chatila, T et al. (1994) Superantigens activate HIV-1 gene expression in monocytic cells. Clin Immunol Immunopathol 72:357-61