INVESTIGATION OF INDUCING EFFECT OF SPECIFIC CYTOTOXICITY OF CTLS BY ANTIGEN PEPTIDES FROM T LYMPHOCYTIC LEUKEMIA CELLS

Objective: To investigate the characteristics of specific antitumor immunity induced by antigen peptides mixture from T lymphocytic leukemia cells. Method: Antigen peptides mixtures were prepared from different leukemia cell lines and then bound with Hsp70 in vitro. Human peripheral blood mononuclear cells (PBMC) were cultured in vitro, and activated with Hsp70-antigen peptides. The activated PBMC was cultured continuously in vitro, and used as effector cells in vitro test of cytotoxicity to different target cells. Results: The antigen peptides from different leukemia cell lines were peptides mixture and could activate PBMC effectively if they were presented by Hsp70. The activated PBMC could proliferate in the presence of IL-2 and Hsp70-antigen peptides. The proliferative PBMC had specific cytotoxicity to leukemia cells corresponding to the antigen peptides. PBMC activated by antigen peptides from T lymphocytic leukemia cell lines could effectively kill T lymphocytic leukemia cells, and the cytotoxicity of these PBMC to T lymphocytic leukemia cells was significantly stronger than that of PBMC activated by antigen peptides from other leukemia cells (P < 0.05). PBMC activated by either Hut78-peptides or Molt 4-peptides could effectively kill Jurkat cells. And the cytotoxicity of PBMC activated by Hut78/Molt-4-peptides to Jurkat cells was significantly stronger than that of PBMC activated by either Hut78-peptides or Molt-4-peptides alone (P<0.05). Conclusion: Antigen peptides mixture from T lymphocytic leukemia cell lines can induce specific cytotoxic effect to T lymphocytic leukemia cells. There exists cross-reactivity among antigen peptides mixture from different T lymphocytic leukemia cell lines. The cross-reactivity could be amplified by blending of different antigen peptides from different T lymphocytic leukemia cell lines, suggesting that it is possible to prepare broad-spectrum antigen peptide vaccine against T lymphocytic leukemia by using multiple leukemia cell lines.

SPECIFIC UPTAKE OF MONOCLONAL ANTIBODY-CONJUGATED METHOTREXATE BY HUMAN LYMPHOCYTIC LEUKEMIC B CELLS

Objective: To analysis the uptake of free MTX and MTX conjugated to tumor specific monoclonal antibody by target and nontarget cells. Methods: The folate antagonist methotrexate (MTX) was conjugated to two monoclonal antibodies (Mab) directed against human chronic lymphocytic leukemia (CLL), Dal B01 and Dal B02, by an active ester method. Both conjugates were more cytotoxic toward the target tumor cell line D101 than to the nontarget cell line MOLT3, and Dal B02MTX conjugate was more inhibitory to D101 cells than free MTX in a 6 h pulse exposure assay. Results: Drug uptake studies revealed that D101 cells took up much more Dal B01 and Dal B02conjugated MTX than free MTX. The amounts of drug taken up by D101 cells incubated with Dal B01 and Dal B02conjugated MTX were always 3 to 5fold higher than that taken up by MOLT3 cells, although the latter took up more drug when incubated with free MTX. Furthermore, tumor cells incubated with Dal B01 or Dal B02conjugated MTX retained much larger amounts of drug for a prolonged period of time than those incubated with free MTX. Conclusion: The enhanced specific cytotoxicity of Dal B01 and Dal B02MTX conjugates toward target tumor cells is therefore likely due to (I) delivery of larger amounts of MTX to target cells when the drug is conjugated to Mab; (ii) longer retention of Mabconjugated MTX by target cells; and (iii) slow, prolonged release of MTX from the surfacebound or endocytosed conjugates, rendering them into a sustained release dosage form.

Effect of Telbivudine tablet combined Jianpi Bushen recipe on HBV specific cytotoxic T lymphocyte and HBe Ag seroconversion in patients with HBe Ag positive chronic hepatitis B

Objective To explore the effect of Telbivudine(LDT)Tablet combined with Jianpi Bushen Recipe(JBR)on serum hepatitis B virus(HBV)specific cytotoxic T lymphocyte(CTL)and HBe Ag seroconversion in chronic hepatitis B(CHB)patients.Methods Totally90 HBe Ag-positive and human leukocyte antigen(HLA)-A2 positive CHB patients were randomly assigned to