Table III.

Summary of final alanine-scanning mutants of mCD4 and their effect on T cell functiona

MutantsMutated mCD4 ResiduesResponse to HEL 48–63Response to HEL 48–61
M4_51/53F201A, F182A+++
M4_63/64F201L, F182L+++
M4_53/65F182A, P202A++++/−
M4_53/66F182A, L203A++++/−
M4_53/52F182A, N204A++++/−
M4_53/67F182A, F205A++++/−
M4_53/68F182A, S200A++++
M4_53/80F182A, S109A++++
M4_53/81F182A, L110A+++
M4_53/83F182A, Q112A+++
M4_53/84F182A, Q114A+++
M4_85F182A, L180A++++
M4_51/53/84F201A, F182A, Q114A+++
  • a Residues highlighted in bold were replaced by alanine using site-directed mutagenesis. The effect of these CD4 mutations on T cell function was assessed by their ability to restore responsiveness of the 3A9.CD4− hybridoma to HEL 48–61. Data were evaluated as follows: ++++ = response similar to mCD4.WT transfectant; +++ = 1–2 log10 reduction; ++ = 2–3 log10 reduction; + = 3–4 log10 reduction; +/− = 4–5 log10 reduction; − = no response. Data represent mean results from two to four experiments with each mutant.

  • b M4_51 has the same amino acid mutations as M4_32 in Table II.