Mary J. Ruebush

INDUCTION OF NATURAL KILLER CELLS AND INTERFERON PRODUCTION DURING INFECTION OF MICE WITH BABESIA MICROTI OF HUMAN ORIGIN1

Publisher Summary This chapter examines induction of natural killer (NK) cells and interferon production during infection of mice with Babesia Microti (B. microti) of human origin. To examine the effect of B. microti infection on NK activity, in a study described in the chapter, groups of female +/+, +/bg, and bg/bg mice were infected intravenous with 108 parasites in +/+ blood. Peak induced NK cytotoxicity occurred on day 2 postinfection in each mouse strain, at levels that were comparable to those observed after inoculation of mice with NK-inducing agents such as poly I:C or VSV. Similar results were obtained when the size of the parasite inoculum was reduced. On days 4, 6, 8, and 21 postinfection, spontaneous cytotoxicity in B. microti-infected mice decreased toward or below control values. The level of NK activity of the infected bg/bg mice on days 1, 2, and 4 was approximately equal to the normal level of NK activity observed in wild-type mice. Thus, the relative increases in NK activity because of B. microti infection were similar in beige and wild-type mice, although the absolute levels of NK activity in the two mouse strains were always significantly different.

Cytotoxic T lymphocytes specific for vesicular stomatitis virus recognize the major surface glycoprotein of VSV

Abstract The major surface glycoprotein (G) of vesicular stomatitis virus (VSV) was purified and incorporated into lipid vesicles containing the purified hemagglutinin-neuraminidase (HN) and fusion (F) glycoproteins of Sendai virus. These lipid vesicles were then used to modify and render target cells susceptible to lysis by anti-VSV cytotoxic T lymphocytes (CTLs). This result provides direct evidence that the G protein is a target antigen of anti-VSV CTLs.

Surface analysis of early and late MOPC-315-EL tumor cells

Abstract The surface properties of a tumor line which undergoes a cyclic change in reactivity with cytotoxic T lymphocytes (CTLs) have been analyzed. The findings indicate that MOPC-315-EL when transplanted into the peritoneum of a BALB/c mouse for 4–5 days (early MOPC315-EL) becomes sensitive to lysis by anti-H-2 d CTL. After 9 to 10 days of growth in the peritoneal cavity these tumor cells (late MOPC-315-EL) become unreactive to CTLs. The amount of H-2 antigens on the surface of the cells is the same on the early and late tumor cells. By scanning electron microscopy (SEM) we have shown that the early population is a mixture of two cell types which are characterized by surface villi or surface blebs; the late cells are essentially one population which are characterized by surface villi. The net charge on the surface of the cell was evaluated by two methods: (i) rate of cell migration across an electric potential and (ii) binding by cationic ferritin to the glycocalyx. Both techniques indicated that the early cells have a higher net negative charge. The implication of this work is that surface charge may be involved in T cell-target cell interactions.