Pulmonary macrophages suppress the proliferation and cytotoxicity of tumor-infiltrating lymphocytes

Adoptive immunotherapy with interleukin-2 and tumor-infiltrating lymphocytes (TIL) is rarely effective in primary lung cancer. We hypothesize that pulmonary macrophages (PM), which are increased substantially in the lungs of smokers, might suppress TIL function. The addition of PM into the TIL cytotoxicity assay produced a concentration-dependent suppression of TIL cytotoxicity with up to 71% inhibition of autologous tumor killing at the 1:1 PM:TIL ratio. Inhibition was not target-specific, as killing of NK-sensitive (K562), NK-resistant (M14), and autologous tumor targets were equally suppressed. Nor was inhibition specific for lung TIL, as similar inhibition was observed with melanoma and renal TIL. Using a model system, we demonstrated that both CD3+ antigen-specific and CD56+ nonspecific lymphocytes are susceptible to the suppressive effects of the PM. Direct co-incubation of PM and TIL for 4 to 44 h resulted in progressive suppression of TIL proliferation and cytotoxicity. TIL cytotoxicity remained suppressed even if PM were removed from the co-culture after 24 h, but was restored if the separated TIL were re-incubated in interleukin-2. These results suggest that PM may locally regulate the proliferative and cytotoxic function of adoptively transferred TIL.     

A practical approach to crosslinking

The various aspects of chemical crosslinking are addressed. Crosslinker reactivity, specificity, spacer arm length and solubility characteristics are detailed. Considerations for choosing one of these crosslinkers for a particular application are given as well as reaction conditions and practical tips for use of each category of crosslinkers.     

Intrauterine transmission of Borrelia burgdorferi in dogs

To determine whether intrauterine transmission of Borrelia burgdorferi could exist in dogs, 10 female Beagles were inoculated intradermally with approximately 1,000 B burgdorferi on day 1 of proestrus; inoculation was repeated every 2 weeks during the gestation period. Ten female control Beagles were similarly inoculated with phosphate-buffered saline solution. Prior to the start of the study, all females and 3 males used for breeding were seronegative for B burgdorferi on the basis of results of the indirect fluorescent antibody test and immunoblot (western analysis. Similarly, results of culture of blood for B burgdorferi were negative. All 20 of the females were bred naturally. Blood samples were collected weekly for serologic testing and culture. Blood samples were obtained from live pups on day 1 of life, then weekly until pups were 6 weeks old when they were euthanatized. Tissues were obtained for culture and testing by use of polymerase chain reaction (PCR). Of 10 spirochete-inoculated (SI) females, 8 became infected with B burgdorferi as evidenced by spirochete culture results and/or PCR-detected B burgdorferi DNA in the tissues of females or their pups. Of the 10 SI females, 8 delivered litters (3 to 7 pups) that had at least 1 neonatal or 6-week-old pup with B burgdorferi DNA-positive tissues (by PCR), and spirochetes were cultured from tissues from pups of 2 litters.(ABSTRACT TRUNCATED AT 250 WORDS)     

Expression of G protein alpha subunits in normal rat colon and in azoxymethane-induced colonic neoplasms

BACKGROUND & AIMS: Heterotrimeric G proteins are important in growth-regulating signal transduction. The aim of this study was to characterize the relative expression of G protein alpha subunits in rat colonocytes, colonocyte antipodal plasma membranes, and colonic neoplasms. METHODS: Antipodal plasma membranes were prepared from isolated colonocytes. Azoxymethane was administered to rats to induce colonic neoplasms. K-ras mutations in the neoplasms were determined by oligonucleotide hybridization and confirmed by primer mediated-restriction fragment length polymorphism. Colonocyte and tumor homogenates or membranes were probed for Galpha subunits by Western blotting with isoform-specific antibodies. RESULTS: The expressions of Galphai2, alphai3, and alphaq/11 were significantly enriched in the basolateral compared with brush border fraction of colonic antipodal plasma membranes. In neoplasms without K-ras mutations, the expression of Galphai2 increased 4-fold, Galphas(long) increased 2.5-fold, and Galphai3 increased 1.5-2-fold. Expression did not differ among tumor grades. K-ras mutations were associated with lowered expression of G proteins, especially Galphao. CONCLUSIONS: In colonocytes, Galpha subunits are localized primarily in basolateral plasma membranes. The increased expressions of Galphai2 and, to a lesser degree, Galphai3 and Galphas(long) in tumors was independent of tumor grade but was modulated by the presence of K-ras mutations.     

Propylene glycol: the safe diluent that continues to cause harm

Propylene glycol (PG) is present in many pharmaceutical products, lotions, ointments, and cosmetics. Although considered to be a relatively safe substance, overdoses have been associated with serious adverse effects. Propylene glycol intoxication occurred in a child and caused central nervous system depression and a severe metabolic acidosis. Initial assessment revealed an elevated serum anion gap, a slight increase in measured serum osmolality, and a normal osmolal gap. The child's acidosis was due to increased concentrations of lactate and pyruvate. The possibility of serious PG intoxication should be considered in any patient with an unexplained serious metabolic acidosis.