Normal PHA Research Articles

INTESTINAL LYMPHANGIECTASIA AS A SECONDARY CAUSE OF ABNORMAL TREC SCREEN

<h3>Introduction</h3> Less than 5 percent of abnormal T-Receptor Excision Circles (TREC) results have been associated with gastrointestinal anomalies. This case describes the presentation and work up of a patient with intestinal lymphangiectasia who presented as a TREC referral <h3>Case Description</h3> A 6-week-old male born at 38-weeks of gestation was referred to the Immunology service for low TRECs of 53. Total lymphocyte count was 3.4 k/ul, CD3 count was 1760, CD4 was 636, CD8 was 1000. He had a ratio of 52% RA and 48% RO with a reverse CD4:CD8 ratio (0.58), raising concern for possible infectious etiology and or leaky SCID . His PHA was normal, ruling out SCID. Infectious work up was sent and negative. IgG was 282 mg/dl, IgM 29.7, and IgA 31. Microarray showed a normal XY male with no deletions or duplications. A PID panel was sent and did not identify a diagnosis. At 3 months of life, he was noted to have swelling of the right arm, raising concern for possible lymphatic malformation or lymphangiectasia. Liver ultrasound was performed showing moderate ascites throughout the peritoneum and bowel wall thickening in the right upper quadrant. Albumin was low. EGD and colonoscopy confirmed intestinal lymphangiectasia affecting small bowel and colon. Evaluation was expanded to WES and targeted sequencing of affected gut tissue was unsuccessfully attempted. <h3>Discussion</h3> This case demonstrates how an abnormal TREC screen can pick up secondary causes of T cell lymphopenia. Early clues in this case included subtle asymmetry of his limb, low albumin, normal PHA and low RA.

Immunohistochemical localization of receptor protein tyrosine phosphatase γ in mouse renal proximal tubule, thick ascending limb and distal convoluted tubule

Most normal physiological processes require that both intracellular (i) and extracellular (o) pH be maintained within a tight range. pHo is contingent on arterial (a) pH, which is determined by the ratio of the arterial carbon dioxide to the arterial bicarbonate concentration, [CO2]a/[HCO3−]a. Pulmonary ventilation controls [CO2]a. The kidney controls [HCO3−]a by adjusting HCO3− transport rates (JHCO3) across the basal membranes of particular nephron epithelia into the blood to maintain normal pHa, or compensate for an acid‐base insult. In an effort to identify the sensor proteins for pHa, [CO2]a, or [HCO3−]a, our laboratory previously reported that, in isolated proximal tubules (PTs) from receptor protein tyrosine phosphatase γ (RPTPγ) knockout (KO) mice, JHCO3 is insensitive to changes in the basolateral [CO2] or [HCO3−]. Furthermore, RPTPγ‐KO mice have a deficiency in defending against a whole‐body metabolic acidosis. These data implicate RPTPγ as a major [CO2] or [HCO3−] sensor. RPTPγ possesses an extracellular catalytically inactive carbonic‐anhydrase‐like domain (CALD) and fibronectin type III (FNIII) domain, a single transmembrane helix, and intracellular domains D1 and D2. Dimerization of RPTPγ presumably allows the inhibitory D2 of one monomer to inhibit the otherwise catalytically active D1 of the other monomer. Thus, the dimerization/monomerization state controls downstream signaling. We hypothesize that the binding of CO2 or HCO3− to the CALD alters the CALD conformation, thereby transmitting signals that control the dimerization status of RPTPγ and thereby regulate downstream effects on JHCO3. We hypothesize that RPTPγ is localized in nephron segments important for regulating HCO3− transport/reabsorption, in the basal membranes that face the blood. To determine the location of RPTPγ in wild‐type mouse kidney cryosections, we use a chicken IgY anti‐RPTPγ antibody (Ab) raised against an epitope within the FNIII domain, and co‐stain with rabbit polyclonal Abs against the Na/HCO3 cotransporter (NBCe1‐A) as a PT marker, the Na/K/Cl cotransporter 2 (NKCC2) as a thick ascending limb (TAL) marker, and the Na/Cl cotransporter (NCC) as a distal convoluted tubule (DCT) marker. Imaging sections by confocal microscopy, we observe in 3 WT mice that RPTPγ localizes primarily to the PT basal membrane. However, 54% of PTs (NBCe1‐A positive) also exhibit apical RPTPγ staining of comparable intensity to the RPTPγ staining observed in the basal membrane. We also observe both apical and basal RPTPγ staining in Bowman’s capsules. We stained additional sections from the same animals with a rabbit polyclonal primary Ab that targets the RPTPγ CALD domain. In these sections, co‐stained with the anti‐FNIII Ab, we similarly observe both apical and basal staining in PTs. We observe RPTPγ staining in a minority of TALs, and at much lower intensity than observed in the PT. We observe minimal to no RPTPγ staining in the DCT. We validated the specificity of the RPTPγ Abs on RPTPγ‐KO kidney sections, which exhibit low background levels of fluorescence for both the anti‐FNIII and anti‐CALD Abs. In conclusion, these data confirm RPTPγ expression in PT basal membranes, but also describe the first examples of apical RPTPγ expression in renal epithelia.

Characterizing Pneumocystis jirovecii Pneumonia in patients with Primary Immunodeficiency Disorders, Data from the US Immunodeficiency Network (USIDNET) Registry

Pneumocystis jirovecii pneumonia (PJP) is a life-threatening infection that affects immunocompromised individuals, including those with primary immunodeficiencies (PID). The US Immunodeficiency Network (USIDNET) registry was utilized to perform retrospective analysis of PID patients who developed PJP. The cohort was categorized into those who developed PJP before or at PID diagnosis versus those who developed PJP after PID diagnosis. Frequency of PJP in PID patients within USIDNET was 63/5204 (1.2%). Forty-nine patients developed PJP prior to history of transplantation and were included in final analysis. This cohort was 22% female (11/49), 78% male (38/49). The majority developed PJP before/at PID diagnosis (40/49,82%). Median age at PID diagnosis in the PJP before/ at PID diagnosis group was 0.65 years [IQR 0.40,2.08]. PID diagnoses varied, including Hyper IgM syndromes (17/49,34.7%), Severe Combined Immunodeficiency (SCID) (15/49,30.6%) and Common Variable Immunodeficiency (CVID) (8/49,16.3%), among others. Hyper IgM patients with PJP before/ at diagnosis of PID median first CD4 count was 1233/uL [IQR 929,4100]. All other patients with PJP before/at diagnosis of PID median first CD4 count was 197/uL [IQR 12,560], though for CVID patients, median first CD4 was 580/uL. Of patients with phytohemagglutinin data, 16/27 (59%) had normal PHA response. This characterization of PJP in PID from the USIDNET registry demonstrates the importance of considering the particular PID defect when contemplating PJP prophylaxis. However, PJP often precedes or is part of the initial consideration of a PID diagnosis. T cell lymphopenia and poor mitogen response may not adequately identify PID patients at risk of PJP.

Studies on the mechanisms of nickel induced immunosuppression

Abstract Nickel (Ni) inhibits lymphoproliferative responses. Proliferation was performed on PBMC of 20 controls and 10 patients with Ni allergy. NiSO4 was used at a concentration of 0.1mM. PHA was added at a concentration of 5 μg/ml. Cells were incubated for 5 days and proliferation assessed by CFSE staining. At 0.1mM Ni strongly reduced (&amp;gt;40%) PHA-induced proliferation. The inhibition decreases in a dose-dependent manner and response to PHA is restored at 20 mM Ni. Ni alone induces small (&amp;lt;5%) proliferative response in both allergic and non allergic donors. Nickel inhibition requires the presence of Ni in the supernatant and is abrogated when Ni is incubated with the cells for up to 4 hours and the supernatant is washed. Strong inhibition was also observed in preliminary experiments with tuberculin purified protein derivative (PPD) stimulated PBMC. Staining for CD8 on CFSE cultures showed that PHA response was due to both CD8 and CD4 cells. Ni increased % of CD4 cells and decreased the % of CD8 cells. PPD response was predominantly a CD4 response, with Nickel reducing the % of CD4 cells at higher concentations, while unaffecting the CD8. Ni inhibits IL-6 production essential to normal PHA response. The addition of 10–100 IU of IL-6 and/or IL-2 to the cultures did not affect Ni inhibition of PHA proliferation. Addition of IL-6 increased CD25+ cells. Our data suggest that Ni induced inhibition of PHA response is due to steric interference between PHA and its cellular ligand. Further studies will clarify the precise mechanism of Ni mediated inhibition of immune responses and its the role in the pathogenesis of Ni allergy.

A homozygous STIM1 mutation impairs store-operated calcium entry and natural killer cell effector function without clinical immunodeficiency

A homozygous STIM1 mutation impairs store-operated calcium entry and natural killer cell effector function without clinical immunodeficiency

Visualization of the segment IV hepatic artery using 128-section MDCT angiography

To visualize the segment IV hepatic artery and to evaluate the variations in anatomy using multidetector computed tomography (MDCT) angiography. Six hundred and seventeen patients (381 men and 236 women; mean age 62.7 ± 8.1 years; age range 22-92 years) who underwent MDCT angiography performed using a 128-section MDCT system were included in the study. The segment IV hepatic arteries of 453 patients with adequate image quality were displayed using volume rendering (VR), maximum intensity projection (MIP), and multiplanar reconstruction (MPR), and were analysed regarding the origination and variation of the arteries by two radiologists and an anatomist retrospectively. Segment IV arteries were categorized into five different types according to their points of origin: left hepatic artery (LHA, 51.66%), right hepatic artery (RHA, 30.68%), proper hepatic artery (PHA, 5.3%), dual (12.14%), and triple (0.22%). Segment IV arteries arising from normal LHA, RHA, and PHA were found in 73.73% of patients, and those arising from variant LHA or RHA were found in 26.27%. The patterns RN2, LA2, LA3, LA4, PN2, PV1, DA1, DA2, DV3, and DV4 were first reported in the present study. MDCT angiography can evaluate normal as well as anatomical variants of segment IV arteries. Predicting arterial patterns of segment IV of the liver is important in planning and performing all radiological and surgical procedures in the liver, especially in hemi-liver graft procedures.

The Effects of Reduced Air Flow Method on Time to Exhaustion and Oxygen Consumption During Maximal Aerobic Assessment Cycle Ergometer Condition

PURPOSE: The purpose of this study is to examine if exercising aerobically with a snorkel has a possible effect if used as a conditioning tool. The current study examined the impact of using of a snorkel as an intermittent hypoxic training (IHT) device on time to volitional exhaustion (VE) and maximal oxygen consumption (V̇o2max). METHODS: Participants: 6 (3 males, 3 females) participants (Age = 24.0 ± 3 years, Height = 173.6 ± 11.4 cm, Weight = 75.7 ± 18.5 kgs) volunteered from exercise and sports science classes and all were currently engaged in a regular exercise program. Maximal Cycle Ergometer Exercise Test NORMAL/IHT Conditions: Participants performed a maximal graded exercise test (GXT) on an upright cycle ergometer (CE) until volitional exhaustion in a traditional exercise method (NORM). Participants performed the CE GXT at a cadence of 60 rpm with the resistance for the initial stage set at 1 kg and increased .5 kg every 2 minutes until volitional exhaustion. Rate of perceived exertion (RPE), oxygen consumption (V̇o2), and Heart Rate (HR) were recorded at the end of every stage. In contrast to the traditional GXT, the IHT GXT was performed while breathing through a snorkel. Statistical Analysis: Two paired t-tests were used to compare time to VE and V̇o2max between NORM and IHT between NORM and IHT conditions alpha set (≤ 0.05). RESULTS: The IHT condition demonstrated a statistically significant (p ≤ 0.05) reduction in mean relative V̇o2max (39.1 ± 6.8 ml/kg/min) compared to the NORM condition (42.3 ± 6.6 ml/kg/min) (Figure 1). There was no significant difference in time to volitional exhaustion between the NORM and IHT condition. CONCLUSION: Although the time to VE was not significantly different between conditions, relative V̇o2max was statistically lower for the IHT. Based on the data from this study, an athlete's ability to train at a high enough intensity needed to improve physical performance may be impaired by using a snorkel similar in effects as seen when not unlike training at high altitude. A restricted air flow accompanied by an increase in dead space may reduce the diffusion gradient of CO2 in the lungs which could decrease the ability to avoid acidosis at high work rates. Additionally, the increased work of the respiratory muscles during the IHT GXT may require a greater blood flow, taking blood away from active skeletal muscles, and increase the afferent sense of work to the brain. PRACTICAL APPLICATIONS: While training with a snorkel has been used with certain athletic populations, based on these results the use of a snorkel is not recommended for use in aerobic athletes. However, training with a snorkel may provide some currently non-researched benefit anaerobically and further investigation is needed to determine possible adaptations from long-term application. ACKNOWLEDGEMENTS: The authors would like to thank US Divers for their donation of snorkels for this study and the PEAK Academy, University of Utah.

Deficient in vitro anti-mycobacterial immunity despite successful long-term highly active antiretroviral therapy in HIV-infected patients with past history of tuberculosis infection or disease

We evaluated the anti- Mycobacterium tuberculosis (Mtb) immune responses of HIV patients after long-term successful HAART, presenting > 500 TCD4+ cells/μl, undetectable viral load, and past history of tuberculosis infection (HIV + PPD+, n = 14) or disease (HIV + CTB, n = 17). Their lymphoproliferative and IFN-γ responses were compared with those from HIV-uninfected controls either PPD+ (HIV − PPD+, n = 17) or with past history of pulmonary tuberculosis ( n = 15). Most HIV-infected patients presented normal PHA responses while responses to the Mtb recombinant polypeptides ESAT-6 and Ag85B were markedly reduced. Responses to a whole Mtb lysate (S-Mtb) in HIV + PPD+ patients were lower than in HIV − PPD+ controls, while in HIV + CTB patients these responses were similar to that of past-tuberculosis controls. Comparison between the two HIV groups also suggested better S-Mtb responses in those cured from tuberculosis. Thus, while immune responses to single Mtb proteins are depressed even after successful HAART, reactivity to S-Mtb is high, specially in those cured from tuberculosis, possibly as a result of the survival of higher numbers of mycobacteria-specific T cell clones during the immunosuppression phase, which may afford sufficient protection against new Mtb challenges.

The Effects of Campath 1H upon Graft-Versus-Host Disease, Infection, Relapse, and Immune Reconstitution in Recipients of Pediatric Unrelated Transplants

Graft-versus-host disease (GVHD) is a cause of serious morbidity and mortality in >50% of recipients of unrelated hematopoietic stem cell transplantation (HSCT). We performed a trial using Campath 1 H pre- and post-HSCT in an attempt to decrease the incidence of GVHD without increasing the risk of infection or relapse. Patients were retrospectively compared to a population of patients who received antithymocyte globulin (ATG) pre- and post-HSCT. Twenty-seven patients were evaluated for this study. Fourteen patients received Campath 1H and 13 patients received ATG. Demographics of patients who received Campath 1H consisted of 9 males and 5 females, with a median age of 13 years (3-17.8 years). Thirteen patients received unrelated bone marrow and 1 patient received unrelated PBSC. Demographics of patients receiving ATG consisted of 9 males, 4 females with a median age of 7.4 years (21 months-19 years). Twelve patients received unrelated bone marrow and 1 patient received unrelated PBSC. Diagnoses were similar between the 2 groups. Patients who received Campath1H received a total dose of 52 mg/m 2 pre-HSCT and 20 mg/m 2 post-HSCT. Patients who received ATG received a total dose of 60 mg/kg pre-HSCT and 100 mg/kg post-HSCT. GVHD prophylaxis and supportive care measures were similar in both groups, including aggressive antimicrobial therapy. There was a significant difference in the incidence of severe (grade III and grade IV) GVHD between the 2 groups (Campath [0 of 14] versus ATG [6 of 13], P = .006). Among the patients who were transplanted for leukemia, there was no significant difference between the 2 groups in terms of relapse (Campath [2 of 14] versus ATG [4 of 9], P = 0.16). The 100-day survival between the 2 groups was not significantly different. Patients receiving Campath 1H had the presence of CD3 + T cells (>30 cells/mL) in their peripheral blood later than in those who received ATG (64.5 days [Campath 1H] versus 27days [ATG], P = .001). The median time to the development of a normal PHA response occurred later in the Campath 1H arm (283 days[(Campath 1H] versus 88 days [ATG], P = .0001). The median time to an antigen specific response also occurred later in those receiving Campath 1H (365 days [Campath 1H] versus 150 days [ATG], P = .004). There was no significant difference between the 2 groups in terms of fungal or viral infections. Campath 1H is effective in decreasing the incidence of GVHD without increasing the risk of relapse. Although there is a significant delay in immune reconstitution, there was no increase in infectious complications or relapse in recipients of Campath 1H. Further studies are warranted to assess if a lack of difference in infection rates are still demonstrated in larger cohorts.

Parathyroid Gland Transplantation without Posttransplantation Immunosuppression

RATIONALE: Determine if combined thymus and parathyroid gland transplantation in a patient with DiGeorge syndrome will result in function of both organs. METHODS: The patient had both athymia with a total T cell count of 29 cells/μL and profound hypoparathyroidism with a parathyroid hormone level below the limit of detection. Allogeneic postnatal cultured thymus and a maternal parathyroid gland were transplanted after conditioning with 3 doses of rabbit antithymocyte globulin. The mother, thymus donor, and patient had partial HLA matching. RESULTS: The parathyroid hormone level was normal when first tested on day +17 and has since remained normal. The patient weaned off all calcium supplementation. On day +139, she developed a bacterial infection of her central line, during which she maintained ionized calcium levels above 1.10 mmol/L without the requirement for calcium supplementation. At day +213, her ionized calcium levels remain within normal limits (1.24 mmol/L). Thymic function has been excellent. A thymus graft biopsy performed on day +80 showed evidence of thymopoiesis. Naïve T cells were detectable in the blood on day +86, with progressively increasing numbers over time (naïve CD4+ 114 cells/μL and naïve CD8+ 42 cells/μL on day +202). The total T cell count increased over time (258 cells/μL on day +202), as well. Normal PHA responses were seen on days +157 and +202. The patient did not require any posttransplantation immunosuppression. CONCLUSIONS: Parathyroid transplantation, when combined with thymus transplantation in this patient with complete DiGeorge syndrome, led to parathyroid function without posttransplantation immunosuppression.

Response to Hepatitis B Vaccination Following Allogeneic Hematopoietic Cell Transplantation (HCT).

Liver disease secondary to Hepatitis B virus (HBV) is a vaccine preventable disease. Currently, the European Group for BMT recommends recombinant HBV vaccination starting 6–12 months post HCT, in the 2000 CDC guidelines, vaccination against HBV is optional. Nevertheless, immunization against HBV is generally mandated prior to school re-entry and in adults with an increased risk for exposure to HepB. In healthy children and adolescents, seroconversion rates of >95% have been reported. In adults, including those >40 years of age, response rates of 85–95% are observed. To determine the ability of allogeneic transplant recipients to respond to recombinant HBV vaccination, the pre and post vaccine titers of 260 patients, including 100 children (< 18 years), vaccinated following an unrelated (n=67), HLA matched (n=173) or HLA mis-matched related (n=20) HCT were analyzed. Thirty-four percent of the vaccinated patients received an unmodified HCT and 76% received total body irradiation in their conditioning regimen. All patients had a normal PHA response at the time of vaccination. In patients less than or greater than 18 years of age, the median time to vaccination was 20.0 and 24.5 months post HCT, respectively. Overall, 181 (69.7%) of the 260 patients responded to HBV vaccination. Seventy-five percent of children and sixty-six percent of adults responded to HepB vaccination (p=0.08). The poorest response (55%) was observed in recipients of an HLA-mismatched related HCT, although the numbers are small. Following an unrelated or HLA-matched related transplant, there were no significant differences in the proportion of responders on the basis of pre-transplant diagnosis, stem cell source, use of T cell depletion, inclusion of total body irradiation in the conditioning regimen, or positive donor serology. Univariate and multivariate analysis in recipients of an unrelated or HLA matched related HCT, demonstrated that younger age at transplantation was associated with significantly higher rates of seroconversion (p<0.05). Prior treatment for chronic GVHD, was associated with a significantly poorer response to HepB vaccination (p<0.01). There were no significant differences in responses among pediatric recipients of a TCD or unmodified unrelated or HLA matched related transplant. Eighty-nine percent of patients <18 years of age who received a TCD unrelated transplant responded to HBV vaccine initiated at a median (range) of 20.6 (5.3–48.7) months post transplant compared to eighty percent of children following an unmodified unrelated transplant. Seroconversion rates in adults ranged from 58–70% following TCD or unmodified unrelated or HLA matched related HCT, with the lowest response rate observed in recipients of an unmodified unrelated transplant despite vaccination later post transplant. Of the seventy-eight patients who failed Hep B vaccination, 22 completed a second series, following which 13 (73%) seroconverted. No patient responded to a single booster vaccination after failing to an initial series. These data demonstrate that although the vast majority of patients respond to recombinant Hep B vaccination, the rate of seroconversion is still lower than that observed in normal controls, emphasizing the need to document pre and post vaccine titers to ensure response, particularly in adult patients.

Differential effects of synthesized 2′-oxygenated chalcone derivatives: modulation of human cell cycle phase distribution

Ten structurally related 2′-oxygenated chalcone derivatives, bearing either hydroxy and/or methoxy substituents on the A and B rings, were synthesized through Claisen–Schmidt condensation. The synthesis procedure was relatively easy and had an acceptable yield. The in vitro cytotoxicities of these compounds against the human tumor cells such as Jurkat, U937 cells, and normal cells PHA stimulated PBMCs were investigated. Among those, compounds 1 (IC 50=2.5 μM), 2 (1.7 μM), and 8 (3.2 μM) showed potent inhibitory activity toward Jurkat cell line. In parallel, compounds 1 (6.7 μM), 2 (1.5 μM), and 10 (5.3 μM) showed the highest activity against U937 cell line. However, the chalcones also inhibit the PHA stimulated PBMCs cells, but the IC 50 values were relatively high when compared to the tumor cell line values. Studies were also on the effect of synthesized chalcones on the cell cycle phase distribution. In Jurkat cell line, compounds 7 and 9 showed the highest activity and the most striking effect in reduction of the percentage of cells in the S phase, which was associated with an increase of cells in G2/M phase. In U937 cell line, compound 3 increased the proportion of cells in the G0/G1 phase and reduced the proportion in S phase. In contrast, compounds 1, 9, and 10 showed a decrease effect on the percentage of cells in S phase and an increase effect on the percentage of cells in the G2/M phase of the cell cycle. Whereas in the case of PHA stimulated PBMCs, compounds 1, 4, 8, and 10 increased the percentage of cells in G2/M phase, which was associated with a decrease effect in the S phase of the cell cycle.

Targeting of tumor cells for human gammadelta T cells by nonpeptide antigens.

Human Vgamma2/Vdelta2(+) gammadelta T cells respond to low molecular-mass nonpeptide Ags in a gammadelta TCR-dependent manner. Although requirements of Ag presentation have remained controversial, we have indicated that specific responses of the primary gammadelta T cells to pamidronate were dependent on monocytic adherent cells for Ag presentation. Here, we show that human tumor cells can efficiently present aminobisphosphonate and pyrophosphomonoester compounds to gammadelta T cells, inducing specific proliferation and IFN-gamma production. gammadelta TCR dependency of the response to Ag-pulsed tumor cells was confirmed by using a Jurkat line transfected with a Vgamma2/Vdelta2 gammadelta TCR. Furthermore, gammadelta T cells exhibited markedly enhanced cytotoxicity against the Ag-pulsed tumor cells as compared with untreated tumor cells. Survey of a number of human tumor cell lines of different origins revealed that the majority of them became susceptible for gammadelta T cell-mediated cytotoxicity following the Ag pulsing except for breast cancer lines so far examined, while normal PHA blast cells remained resistant. The results not only imply a unique mode of nonpeptide Ag recognition by human gammadelta T cells but also may provide a novel strategic clue for immunotherapy of human malignancy.

Net uptake of lactate by rabbit hindlimb during hypoxia.

Lactate uptake by normoxic tissues is a pH-dependent phenomenon that occurs with increases in arterial lactate concentration. In this study we sought to determine the effect of hypoxia on lactate uptake by the rabbit hindlimb at different arterial blood pH (pHa). Two groups of rabbits were subjected to 20 min of arterial hypoxemia (PaO2 approximately 20 mm Hg). One group was allowed to maintain normal pHa (approximately 7.40 to 7.45; n = 5), whereas the other group was hyperventilated, resulting in hypocarbia and alkalemia (pHa > 7.50; n = 5). Lactate uptake was computed from measurements of femoral blood flow and the arterio-venous lactate difference. We found decreases in hindlimb O2 consumption during hypoxemia from 0.79 +/- 0.08 to 0.33 +/- 0.06 ml/min in the normal pH group (p < 0.01) and from 0.49 +/- 0.06 to 0.24 +/- 0.02 ml/min in the high pH group (p < 0.01). At that time there was net uptake of lactate by the hindlimb of the normal pH group (8.1 +/- 2.0 mumol/min; p < 0.001) and lactate release by the alkalemic group (1.61 +/- 1.0 mumol/min). Furthermore, hindlimb lactate uptake was associated with increased glucose consumption (p < 0.001). We hypothesize that the mechanisms responsible for lactate uptake by resting skeletal muscle during hypoxia may be similar to those that regulate lactate uptake during normoxic exercise.

Specific functions of human NK cells

Since natural killer (NK) cells lack both CD3/TCR molecules and surface Ig, it is generally thought that they are unable to recognize antigens. However, CD3-CD16+ cells were found to respond in MLC against irradiated allogeneic mononuclear cells and to lyse normal PHA blasts derived from the stimulating donor, but not autologous cells or cells derived from most allogeneic donors. A similar pattern was obtained with cloned NK cells, thus indicating that the ability to specifically recognize given normal allogeneic cells is a clonally distributed function. Moreover, analysis of NK clones for their ability to lyse either tumor cells or normal PHA blasts (both derived from individual cancer patients) indicated that the two phenomena are distinct. Analysis of a large number of NK clones derived from a given individual for their ability to lyse a panel of allogeneic donors allowed the identification of at least four groups of clones characterized by unique patterns of reactivity ("specificities"). We further studied the mode of inheritance of the various NK-defined specificities: all the characters "susceptibility to lysis" by NK clones (displaying one or another specificity) segregated independently, were inherited in an autosomic recessive manner and were carried by chromosome 6. The finding of clonally distributed specific functions in NK cells suggested the existence of clonally distributed receptor molecules. Along this line mAbs were raised against NK clones, and screened for their ability to trigger the immunizing clones: two mAbs (termed GL183 and EB6) were directed against a novel family of 58-kDa surface molecules.(ABSTRACT TRUNCATED AT 250 WORDS)

EFFECTS OF THYMUS IRRADIATION ON THE IMMUNE COMPETENCE OF T CELLS AFTER TOTAL-LYMPHOID IRRADIATION

Spleen cells from mice receiving TLI, with or without thymus shielding, were investigated for in vitro and in vivo defects. At 4-6 weeks after irradiation spleen cells of both groups showed a normal number of Thy1 (T cells), L3T4 (CD4 positive T cells) cells, and an absence of natural suppressor cells. Splenocytes of the nonthymic shielded TLI group were not able to mount either a normal in vitro response (in MLR or PHA) or an in vivo graft-versus-host-disease reaction when injected into lethally irradiated adult allogeneic recipients or into neonatal F1 hybrids. This was in contrast to the normal immune capacity of spleen cells from the thymus shielded group that gave normal MLR and PHA tests in vitro and provoked GVHD in vivo. Thymuses recovered from mice receiving TLI with or without thymic shielding were however equally efficient in restoring the immune capacity after transplantation into neonatally thymectomized mice as measured by the PHA assay. Thymic irradiation is therefore necessary but not sufficient for creating long-lasting immune defects after TLI.

T cell surface antigen expression on lymphocytes of patients with AIDS during in vitro mitogen stimulation.

Surface marker expression on peripheral blood mononuclear cells (PBMC) was evaluated daily in PHA- and PWM-stimulated cultures of eight AIDS patients and eight normals. Before culture, the patients' cells showed the characteristic decrease in OKT 4+ cells (normals 40.4%, patients 22.3%; P less than 0.001), increase in OKT 8+ cells (normals 27.6%, AIDS 38.4%; P = 0.002), increase in OKT 10+ cells (normals 15.5%, AIDS 42.8%; P = 0.002), and increase in HLA-DR+ cells (normals 11.4%, AIDS 28.7%; P = 0.01). The percentage of OKT 11+ cells remained unchanged, while the percentage of OKT 3+ cells dropped over the first 2 days in PHA but not in PWM cultures of both groups (PHA: normals 69.8% to 35.1%; P = 0.001, AIDS 56.5 to 38.5%; P = 0.001, PWM: normals 62.8%-65.9%, AIDS 66.8% to 63.9%), and recovered in both groups by day 5. In PWM cultures OKT 3+ cells increased significantly in normals but not in AIDS (normals 62.6%-77.7%; P = 0.04, AIDS 61.8 to 48.7%). OKT 4 expression decreased in normal PHA cultures after 1 day (38.9% to 29.6%; P = 0.05) and then recovered by day 5. Its expression increased in AIDS PHA cultures by day 5 (18.0%-41.1%; P less than 0.001). The final percentage of OKT 4+ cells in AIDS cultures was within the normal range (35.0%-49.0%). OKT 8 expression increased in both study groups after PHA stimulation (normals 29.5%-50.4%; P = 0.002, AIDS 37.4%-50.7%; P = 0.02) and in normals but not AIDS after PWM stimulation (normals 28.9%-35.5%; P = 0.004, AIDS 38.5%-35.6%). Because of the relative changes in expression of OKT 4 and OKT 8, the 4/8 ratio declined in the normal PHA cultures (1.89 to 1.03; P = 0.1) and increased in the AIDS cultures (0.68-1.18; P = 0.09). Also, the sum of OKT 4+ and OKT 8+ cells in PHA cultures increased from 68% to 94% whilst expression of OKT 11 remained unchanged, indicating co-expression of these antigens on individual cells. Both PHA-and PWM-stimulated normal cells showed an increase in OKT 10 (PHA 16.0%-53.4%; P = 0.01, PWM 16.1%-33.9%; P = 0.03) and HLA-DR (PHA 8.6%-27.3%; P = 0.03, PWM 12.5%-26.6%; P = 0.07). In AIDS PHA cultures this did not change, and in their PWM cultures OKT 10 expression declined (44.8 to 23.0%; P = 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)

Immunosuppression by human skin cancers.

Biopsy samples from normal skin (12 samples) and skin lesions diagnosed as either basal cell (17 cases) or squamous cell carcinoma (5 cases) were frozen, disrupted and extracted with aqueous buffer. The sterilised extract was added to an in vitro system of cultured bovine lymphocytes. The response of the lymphocytes to PHA was measured by tritiated thymidine uptake. Extracts of both basal cell and squamous cell cancers inhibited normal PHA stimulation of lymphocyte mitogenesis. Blastogenesis was reduced by more than 50% by all of the cancer extracts tested. In contrast, similar extracts from normal skin showed less than 40% inhibition.

Cell-Mediated Immunity in Untreated and PUVA Treated Atopic Dermatitis

In 22 adult patients with atopic dermatitis, lymphocyte subpopulation counts, mitogenic responses to several PHA and Con A concentrations, nonspecific mitogen induced, and indomethacin sensitive suppressor cell functions and leukocyte migration inhibitory factor production were investigated. Patients with severe atopic dermatitis had normal PHA and Con A responses, although somewhat lower than matched controls, while mild AD patients equalled controls in this respect. No significant differences between AD patients and controls were detected with respect to lymphocyte subpopulations, suppressor cell function or leukocyte migration inhibitory factor production. Methoxalen plus ultraviolet light (PUVA) therapy induced significant clinical improvement in 9 out of 10 treated patients. A concomitant decrease of the mitogenic responses and increase of the Con A induced nonspecific suppressor cell activity was recorded, while other immunological parameters remained unaffected by the therapy. Thus PUVA therapy induces both local clinical and systemic immunological manifestations. The possibility that the observed immunological changes would be operative in the PUVA induced healing process, however, seems unlikely, as the present study did not disclose any obvious relationship between immune parameters and severity of atopic dermatitis.

Lymphocyte chalone from calf thymus: problems of large scale extraction and assay.

Large scale extraction and assay of the lymphocyte chalone (LC), the natural lymphocyte proliferation inhibitor, require optimized, reproducible and standardizable methods. To this end we compared the effects on LC yield of storing thymus at different temperatures after collection from calves: Both quick freezing on solid CO2 and slow freezing at -50 degrees C led to a 30% loss of LC yield relative to that from unfrozen tissue kept at O degrees C. Moreover we found that the apparent decrease or total loss of LC activity upon storage of a purified LC fraction may result from an occasional lack of LC-responsiveness of human blood lymphocytes depending on the donor's physiological state, in spite of normal PHA reactivity. This suggested the use of LC-responsive, cryopreserved lymphocytes, the advantages of which are documented and discussed in detail.