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Background: For the relatively nonimmunogenic B16-F10 murine melanoma, it has been found that genetically engineered expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) but not interleukin (IL)-2, IL-4, or interferon-gamma (IFN-gamma) resulted in a vaccine that could induce resistance to rechallenge. Because T cells from lymph nodes draining the sites of some progressive tumors can mediate tumor regression after in vitro activation, it seemed possible that even apparently nonimmunogenic melanoma cells might induce similar preeffector cells in the vaccine-draining lymph nodes (DLNs)., Methods: C57BL/6 mice were vaccinated with B16-F10 cells that were either unmodified or genetically modified to produce IL-2, IL-4, GM-CSF, or IFN-gamma. DLNs were harvested 10 days after vaccination for adoptive immunotherapy (AIT). The DLN cells were activated with bryostatin 1 and ionomycin (B/I), expanded for 10 days in culture, and transferred to mice with 3-day pulmonary metastases. Pulmonary nodules were counted 14 days after AIT., Results: Adoptive transfer of expanded DLN lymphocytes sensitized by inoculation of WT B16-F10, or IL-4, GM-CSF, or IFN-gamma expressing cells significantly reduced pulmonary metastases. Despite the spontaneous regression of IL-2-transduced B16-F10 tumors, DLN from mice inoculated with IL-2 producing B16 cells had little or no antitumor activity., Conclusions: B16-F10 vaccination strategies that apparently do not induce systemic immunity can effectively sensitize DLN preeffector cells.

The polymorphonuclear granulocyte (PMN) kills ingested bacteria by mechanisms that include myeloperoxidase (MPO) and a sudden increase in oxygen consumption (the oxidative burst), both of which are iron dependent. The magnitude of the oxidative burst and activity of MPO were determined in PMNs during the progression of iron deficiency (ID) and following its treatment in rats. As ID developed, the oxidative burst after zymosan activation was less depressed than the activity of MPO. There was no change in the oxidative burst after activation with phorbol myristate acetate (PMA) or in the generation of superoxide (O2-) by NADPH oxidase-containing particles from PMNs. Following iron treatment, impairment of the oxidative burst after zymosan activation was corrected after 1 day. In contrast, the deficit in MPO activity was not corrected until 7 days after initiation of iron treatment. The pattern of recovery in MPO activity after iron treatment corresponded to the prolonged period of maturation of the PMN primary granule since the formation of primary granules, which contain MPO, takes place only in the early, mitotic stages of maturation. The tendency of the PMN to maintain the oxidative burst allows the cell to preserve its capacity for bacterial killing during the progression of iron deficiency.

Unfertilized Strongylocentrotus purpuratus eggs may be treated with ammonia to initiate maternal DNA replication and the maternal cell cycle. When these eggs are polyspermically fertilized 75 min after the beginning of ammonia treatment, the nuclei of the fertilizing spermatozoa undergo premature chromosome condensation (PCC) in an apparent attempt to conform to the advanced maternal cell cycle. PCC is inhibited if maternal DNA replication is blocked by exposing the eggs to aphidicolin but will proceed if this exposure begins after replication is complete. Additionally, PCC will proceed in ammonia-activated, polyspermically fertilized anucleate merogons in the continuous presence of aphidicolin. These results suggest that the direct inhibitory effect of aphidicolin may well be limited to the replication of DNA and that the unreplicated maternal nucleus itself exerts negative control over the development of chromosome-condensing conditions in the maternal cytoplasm.

The motile cells (sporangiospores) of an undescribed member of the Actinoplanaceae are studied by electron microscopy as shadowed, negatively stained, and sectioned preparations. The rod-shaped spores exhibit a typically bacterial internal structure. However, a single tubular structure (rhapidosome) is positioned just inside the site of flagellar attachment of each spore and is oriented perpendicular to the direction of the flagella. Flagella arise from basal dises and pass through the plasma membrane and the two-layered cell wall to become associated with other flagella to function as a posteriorly directed unit. Each flagellum consists of a helical band or ribbon which dissociates into 5 or 6 subfibrils.