Peripheral blood lymphocytes from normal donors and patients with chronic lymphocytic leukemia, B-cell type, were purified into T, helper T, and suppressor T lymphocytes by fluorescence-activated cell sorting using OKT3, OKT4, and OKT8 monoclonal antibodies. The maximum response of the purified subpopulations to stimulation by phytohemagglutinin (PHA) was determined by measuring the production ...

Cognitive radio is being intensively investigated by regulatory bodies as the enabling technology for opportunistic access to the TV white spaces. The successful deployment of cognitive radio networks and the realization of their benefits depend on the assignment of essential security challenges to resist misuse of the systems. In this paper, we propose a primary user authentication scheme in t...

The nature of the helper lymphocytes in lymphocytosis-promoting factor (LPF)-induced proliferation was explored. Removal of macrophages from adherent splenocytes by either carbonyl-iron incubation or passage through Sephadex G-10 columns did not affect their synergistic function. Nor did cytolysis with Thy-1.2 antiserum and complement. The helper cells were found to be surface immunoglobulin-po...

Co-infection of neonatal BALB/c mice with Friend virus (FV) complex (containing defective spleen focus-forming virus [SFFV] and endogenous N-tropic leukemia-inducing helper virus [LLV-F]) and B-tropic Tennant leukemia virus (TenLV) resulted in the inhibition of LLV-F by the Fv-1(b) gene and recovery of a TenLV pseudotype of SFFV, abbreviated SFFV(TenLV). The host range of this pseudotype was B-...

The cooperating preference of helper T cells originating from F1 bone marrow, but differentiating in adult thymectomized, lethally irradiated F1 recipients reconstituted with either f1 or homozygous parental thymus grafts was investigated. Cooperating preference was assayed by determining the levels of helper activity provided by antigen-primed T cells derived from such thymic chimeras for hapt...

Investment by helpers in cooperative breeding systems is extremely variable among species, but this variation is currently unexplained. Inclusive fitness theory predicts that, all else being equal, cooperative investment should correlate positively with the relatedness of helpers to the recipients of their care. We test this prediction in a comparative analysis of helper investment in 36 cooper...

Although many subviral RNAs reduce or intensify disease symptoms caused by the helper virus, only recently have clues concerning the mechanism of disease modulation been revealed. New models for DI RNA-mediated reduction in helper virus levels and symptom attenuation include DI RNA enhancement of posttranscriptional gene silencing (PTGS), which is an antiviral defense mechanism in plants. Sympt...

Many popular programs, such as Netscape, use untrusted helper applications to process data from the network. Unfortunately, the unauthenticated network data they interpret could well have been created by an adversary, and the helper applications are usually too complex to be bug-free. This raises signi cant security concerns. Therefore, it is desirable to create a secure environment to contain ...

Experimental leishmaniasis is widely used to study the effector functions of T helper cell subsets in vivo. Healing and nonhealing Leishmania major infections have been correlated with T helper 1 and T helper 2 responses, respectively. In the present study, we determined T cell effector functions ex vivo, without any further restimulation and compared them to those obtained following antigen-sp...

It has long been known that thymus-derived lymphocytes (T cells) can produce cytokines that have powerful effects on hematopoiesis. All major classes of T cells--CD4 T helper cells, CD4 regulatory T cells, CD8 T cells, gammadelta T cells and NKT cells--produce a number of cytokines and chemokines that can modulate hematopoiesis. More recent research has shown that specific T helper cell types, ...