This MQP investigated the viral tropism and neutralizing antibody sensitivities of gp120 and gp41 sequences of three parental HIV-1 strains (Q43-378.2, Q43-378.c, and SQ43-380.1) isolated from a single patient, and of various engineered chimeras. The data indicate that gp120 alone is able to confer macrophage tropism, while gp41 has no noticeable effect on tropism. The data further indicate that gp41 has no visible effect on the resistance to a b12 antibody that reacts with the CD4-binding domain on gp-120, and that gp120 sequences are the most likely cause of neutralization resistance
