In a series of experiments we have demonstrated the progressive enrichment (5- to 40-fold) in lymphokine-activated killer (LAK) precursor activity by adherence depletion, sheep red cell rosetting, and depletion of CD3- and DR-positive lymphocytes. The LAK precursor cell thus appears to fall within the 'null' cell population. CD16 and CD11 are cell surface antigens expressed on the surface of the LAK precursor as demonstrated in sorting experiments. A 6- to 100-fold enrichment compared to unseparated peripheral blood was noted when sorted cells positive for CD16 and CD11 were tested. The LAK effector has been identified as being primarily CD3- and CD2+. Similar sorting equipment demonstrated a 7- to 500-fold difference in lytic activity for fresh tumor when comparing CD2+/CD3- and CD2+/CD3+ cells. The CD16+/CD11+ lymphocyte can proliferate in response to interleukin-2 (IL-2) alone in the absence of accessory cells and can be expanded in IL-2 alone with maintenance of lytic activity.
ABSTRACT The great difficulty in eliciting broadly cross-reactive neutralizing antibodies (NAbs) against human immunodeficiency virus type 1 (HIV-1) isolates has been attributed to several intrinsic properties of their viral envelope glycoprotein, including its complex quaternary structure, extensive glycosylation, and marked genetic variability. Most previously evaluated vaccine candidates have utilized envelope glycoprotein from a single virus isolate. Here we compare the breadth of NAb and protective immune response following vaccination of pigtailed macaques with envelope protein(s) derived from either single or multiple viral isolates. Animals were challenged with Simian/human immunodeficiency virus strain DH12 (SHIV DH12 ) following priming with recombinant vaccinia virus(es) expressing gp160(s) and boosting with gp120 protein(s) from (i) LAI, RF, 89.6, AD8, and Bal (Polyvalent); (ii) LAI, RF, 89.6, AD8, Bal, and DH12 (Polyvalent-DH12); (iii) 89.6 (Monovalent-89.6); and (iv) DH12 (Monovalent-DH12). Animals in the two polyvalent vaccine groups developed NAbs against more HIV-1 isolates than those in the two monovalent vaccine groups ( P = 0.0054). However, the increased breadth of response was directed almost entirely against the vaccine strains. Resistance to SHIV DH12 strongly correlated with the level of NAbs directed against the virus on the day of challenge ( P = 0.0008). Accordingly, the animals in the Monovalent-DH12 and Polyvalent-DH12 vaccine groups were more resistant to the SHIV DH12 challenge than the macaques immunized with preparations lacking a DH12 component (viz. Polyvalent and Monovalent-89.6) ( P = 0.039). Despite the absence of any detectable NAb, animals in the Polyvalent vaccine group, but not those immunized with Monovalent-89.6, exhibited markedly lower levels of plasma virus than those in the control group, suggesting a superior cell-mediated immune response induced by the polyvalent vaccine.
A strain of Eastern equine encephalomyelitis virus was maintained for 11 years by (1) periodic repassage in guinea pig and developing chick embryo between the periods of storage in the dry-ice cabinet and (2) by storage at 4 °C. in the presence of cysteine hydrochloride without repassage. No change in pathogenicity or antigenicity of either clone was noted.
The present communication deals with a survey of neutralizing antibodies to mouse-adapted Lansing strain of poliomyelitis virus in the sera of acute, convalescent, and normal individuals during a 1946 epidemic. Two-phase sera were obtained from residents of Ontario and British Columbia and convalescent and normal sera from Quebec. In the sera of 17 out of 35 Ontario patients neutralizing antibodies were demonstrable during the acute stage. In four of these seropositive individuals, there was an increase in the neutralizing titer during convalescence and in three patients there was a notable drop in the titer. The remaining 18 patients were found to be seronegative during both the acute and convalescent stages. Sera from six out of nine British Columbia patients, likewise contained neutralizing antibodies to the Lansing strain of virus during the acute stage. In four of these the titer remained unchanged during convalescence, in one the titer decreased, and another patient became seronegative. Of the remaining three, two continued to be seronegative and one became seropositive during convalescence. Positive neutralization reactions were obtained with 17 out of 44 convalescent sera from Ontario and 62 out of 146 convalescent sera from Quebec Sera from 51 children without history of poliomyelitis and 100 adult sera taken at random from specimens submitted for Wassermann tests were obtained from Quebec. Of the children's sera 43%, and of the adults’, 48%, contained neutralizing antibodies. The results obtained closely agree with those reported by American workers.
